Introduction

• Check your system version with the command "sudo cat /etc/os-release", find the following related information related to the two images, and then select one:
  • As the Raspberry Pi OS Bookworm system modifies the camera capture application from "libcamera-*" to "rpicam-*", it is recommended to use rpicam because libcamera may be obsoleted in the future even if it is accessible now.
  • If you use Raspberry Pi OS Bullseye system, you can refer to the following libcamera-* tutorial.

Rpicam

When running the latest version of Raspberry Pi OS, rpicam-apps installed five basic functionalities. In this case, the official Raspberry Pi camera will be detected and auto-on.
You can check whether everything is sound by inputting the following content:

rpicam-hello 

You will see a camera preview window for five seconds.
Note: If running on Raspberry Pi 3 and earlier versions with Bullseye, you need to re-enable Glamor to make the X Windows hardware-accelerated preview window work properly. Enter sudo raspi-config in the terminal window, then select Advanced Options, Glamor, and Yes. Exit and restart your Raspberry Pi. By default, Raspberry Pi 3 and earlier devices running Bullseye may not be using the correct display driver. Refer to the /boot/firmware/config.txt file and ensure dtoverlay=vc4-fkms-v3d or dtoverlay=vc4-kms-v3d is currently active. If you need to change this setting, restart your Raspberry Pi.

rpicam-hello

Equivalent to a camera's "hello world," it starts the camera preview stream and displays it on the screen. You can stop the preview by clicking the window's close button or using Ctrl+C in the terminal.

rpicam-hello -t 0

Tunning File

Raspberry Pi's libcamera has tuning files for each different type of camera module. The parameters in these files are passed to the algorithms and hardware to produce the best quality images. Libcamera can automatically determine the image sensor being used, but it cannot automatically determine the entire module, even though the whole module can affect the "tuning." Therefore, it is sometimes necessary to override the default tuning file for a specific sensor.
For example, the NoIR version of the sensor requires different AWB (auto white balance) settings compared to the standard version. Therefore, the IMX219 NoIR used with Pi 4 or earlier devices should be run as follows:

rpicam-hello --tuning-file /usr/share/libcamera/ipa/rpi/vc4/imx219_noir.json

Raspberry Pi 5 uses different tuning files in different folders, here you can use:

rpicam-hello --tuning-file /usr/share/libcamera/ipa/rpi/pisp/imx219_noir.json

This also means users can copy existing tuning files and make changes according to their preferences, as long as the --tuning-file parameter points to the new version. The --tuning-file parameter, like other command line options, is also applicable to all rpicam-apps.

rpicam-jpeg

rpicam-jpeg is a simple still image capture application.
To capture a full-resolution JPEG image, use the following command. This will display a preview for approximately five seconds and then capture the full-resolution JPEG image to a file named test.jpg:

rpicam-jpeg -o test.jpg

The -t <duration> option can be used to change the length of time the preview is displayed, and the --width and --height options will change the resolution of the captured still image. For example:

 rpicam-jpeg -o test.jpg -t 2000 --width 640 --height 480

Exposure Control

rpicam-apps allows users to operate the camera at a fixed shutter speed and gain. Capture images with an exposure time of 20ms and a gain of 1.5x, where the gain serves as analog gain within the sensor until reaching the maximum analog gain allowed by the sensor driver demo, with the remain gain used as digital gain.

rpicam-jpeg -o test.jpg -t 2000 --shutter 20000 --gain 1.5

Raspberry Pi's AEC/AGC algorithm allows applications to specify exposure compensation, enabling the image to be darkened or brightened by a given number of stops.

rpicam-jpeg --ev -0.5 -o darker.jpg
rpicam-jpeg --ev 0 -o normal.jpg
rpicam-jpeg --ev 0.5 -o brighter.jpg

Digital Gain

Digital gain is applied by ISP rather than the sensor. Its value always keep approximate to 1.0, unless:

• The requested total gain (through the --gain option or via the exposure profile in the camera tuning) exceeds the gain that can be used as analog gain within the sensor. Only the required additional gain will be used as digital gain.
• One of the color gains is less than 1 (note that color gains are also used as digital gains). In this case, the reported digital gain will stabilize at 1/min (red gain, blue gain). This means that one of the color channels (other than the green channel) has unit digital gain applied.
• AEC/AGC is changing. When AEC/AGC adjusts, digital gain usually fluctuates to try to eliminate any instability, but it quickly returns to normal values.

rpicam-still

Simulates many of the original features of the raspistill application.

rpicam-still -o test.jpg

Editor

rpicam-still allows files to be saved in many different formats. It supports png and bmp encoding. It also allows saving files as binary storage of RGB or YUV pixels, with no encoding or file format. In the latter case, the application reading the file must learn its own pixel arrangement.

rpicam-still -e png -o test.png
rpicam-still -e bmp -o test.bmp
rpicam-still -e rgb -o test.data
rpicam-still -e yuv420 -o test.data

Note that the format in which the image is saved depends on the -e (equivalent to --encoding) option and is not automatically selected based on the output filename.

Raw Image Capture

Raw images are directly generated by the image sensor. Before processing with ISP or any CPU kernel, the images generally are in Bayer format for color image sensor. Please note that the raw image is very different from the processed but uncoded RGB or YUV images we have seen before.
Obtain raw image:

rpicam-still --raw --output test.jpg

Here, "-r" (——raw) represents the captured raw image and JPEG. In fact, raw images are the raw images from which JPEGs are generated. Raw images are saved in DNG (Adobe Digital Negative) format and are compatible with many standard applications such as draw or RawTherapee. Raw images are saved to files with the same name but with the extension . ng file, so it is "test.dng".
These DNG files contain metadata related to image capture, including black levels, white balance information, and the color matrix used by the ISP to generate JPEGs. This makes these DNG files more convenient for later "manual" raw conversions using some of the tools mentioned above. Use exiftool to display all metadata encoded into DNG files:

File Name                       : test.dng
Directory                       : .
File Size                       : 24 MB
File Modification Date/Time     : 2021:08:17 16:36:18+01:00
File Access Date/Time           : 2021:08:17 16:36:18+01:00
File Inode Change Date/Time     : 2021:08:17 16:36:18+01:00
File Permissions                : rw-r--r--
File Type                       : DNG
File Type Extension             : dng
MIME Type                       : image/x-adobe-dng
Exif Byte Order                 : Little-endian (Intel, II)
Make                            : Raspberry Pi
Camera Model Name               : /base/soc/i2c0mux/i2c@1/imx477@1a
Orientation                     : Horizontal (normal)
Software                        : rpicam-still
Subfile Type                    : Full-resolution Image
Image Width                     : 4056
Image Height                    : 3040
Bits Per Sample                 : 16
Compression                     : Uncompressed
Photometric Interpretation      : Color Filter Array
Samples Per Pixel               : 1
Planar Configuration            : Chunky
CFA Repeat Pattern Dim          : 2 2
CFA Pattern 2                   : 2 1 1 0
Black Level Repeat Dim          : 2 2
Black Level                     : 256 256 256 256
White Level                     : 4095
DNG Version                     : 1.1.0.0
DNG Backward Version            : 1.0.0.0
Unique Camera Model             : /base/soc/i2c0mux/i2c@1/imx477@1a
Color Matrix 1                  : 0.8545269369 -0.2382823821 -0.09044229197 -0.1890484985 1.063961506 0.1062747385 -0.01334283455 0.1440163847 0.2593136724
As Shot Neutral                 : 0.4754476844 1 0.413686484
Calibration Illuminant 1        : D65
Strip Offsets                   : 0
Strip Byte Counts               : 0
Exposure Time                   : 1/20
ISO                             : 400
CFA Pattern                     : [Blue,Green][Green,Red]
Image Size                      : 4056x3040
Megapixels                      : 12.3
Shutter Speed                   : 1/20

We note that there is only one calibrated source (the one determined by the AWB algorithm, although it is always labeled "D65"), and the ISO number is divided by 100 to give the analog gain being used.

Ultra-long exposure

To capture long exposure images, disable AEC/AGC and AWB as these algorithms will force the user to wait for many frames at convergence.
The way to disable them is to provide explicit values. In addition, the entire preview phase of the capture can be skipped using the --immediate option.
Thus, to perform a 100-second exposure capture, use the ;-immediate option.

rpicam-still -o long_exposure.jpg --shutter 100000000 --gain 1 --awbgains 1,1 --immediate

For reference, the maximum exposure times for the three official Raspberry Pi cameras can be found in this table.

rpicam-vid

rpicam-vid can help us capture video on our Raspberry Pi devices. Rpicam-vid displays a preview window and writes the encoded bitstream to the specified output. This produces an unpacked video bitstream, which is not packaged in any type of container (e.g. mp4 file) format.

• rpicam-vid uses H.264 encode.
  

For example, the following command writes a 10-second video to a file named test.h264:

rpicam-vid -t 10s -o test.h264

You can use VLC and other video players to play the result file.

VLC test.h264

On the Raspberry Pi 5, you can output directly to the MP4 container format by specifying the MP4 file extension of the output file:

rpicam-vid -t 10s -o test.mp4

Encoder

rpicam-vid supports dynamic JPEG and uncompressed and unformatted YUV420:

rpicam-vid -t 10000 --codec mjpeg -o test.mjpeg
rpicam-vid -t 10000 --codec yuv420 -o test.data

The codec option determines the output format, not the extension of the output file.
segment option splits the output file into segment-sized chunks (in milliseconds). By specifying very short (1 millisecond) segments, this makes it easy to break up a motion JPEG stream into individual JPEG files. For example, the following command combines 1 millisecond segments with a counter in the output filename to generate a new filename for each segment:

rpicam-vid -t 10000 --codec mjpeg --segment 1 -o test%05d.jpeg

Capture high-frame video

To minimize frame loss for high frame rate (> 60fps) videos, try the following configuration adjustments:

• Set the H.264 target level to 4.2 with the parameter --level 4.2.
• Disable software color noise reduction processing by setting denoise option to cdn_off.
• Disable nopreview's display window to free up some extra CPU cycles.
• Set force_turbo=1 in /boot/firmware/config.txt to ensure that the CPU clock is not throttled during video capture. For more information, see force_turbo document.
• Adjust the output resolution parameter of ISP as "--width 1280 --height 720" or lower to realize the target frame rate.
• For Raspberry Pi 4, you can add "gpu_freq=550" or higher frame rate at /boot/firmware/config.txt to overclock the GPU for better performance. For more details, please refer to overclock document.

The following commands demonstrate how to realize 1280×720 120fps video:

rpicam-vid --level 4.2 --framerate 120 --width 1280 --height 720 --save-pts timestamp.pts -o video.264 -t 10000 --denoise cdn_off -n

Integrates Libav and picam-vid

Rpicam-vid can encode audio and video streams using ffmpeg/libav codec backends. You can save these streams to a file or stream them over the network.
To enable the libav backend, pass libav to the codec option:

rpicam-vid --codec libav --libav-format avi --libav-audio --output example.avi

UDP

To stream video over UDP using the Raspberry Pi as a server, replace the < IP -addr> placeholder with the IP address of the client or multicast address and the <port> placeholder with the port you want to use for streaming using the following commands.

rpicam-vid -t 0 --inline -o udp://<ip-addr>:<port>

To view a video stream over UDP using a Raspberry Pi as a client, use the following command, replacing the <port> placeholder with the port you want to stream to:

vlc udp://@:<port> :demux=h264

Or stream using ffplay on the client with the following command:

ffplay udp://<ip-addr-of-server>:<port> -fflags nobuffer -flags low_delay -framedrop

TCP

Video can also be transferred over TCP. Using a Raspberry Pi as a server:

rpicam-vid -t 0 --inline --listen -o tcp://0.0.0.0:<port>

To view the video stream over TCP using a Raspberry Pi as a client, use the following command:

vlc tcp/h264://<ip-addr-of-server>:<port>

Alternatively, use ffplay streaming at 30 frames per second on the client with the following command:

ffplay tcp://<ip-addr-of-server>:<port> -vf "setpts=N/30" -fflags nobuffer -flags low_delay -framedrop

RTSP

To transfer video over RTSP using VLC, using a Raspberry Pi as the server, use the following command:

rpicam-vid -t 0 --inline -o - | cvlc stream:///dev/stdin --sout '#rtp{sdp=rtsp://:8554/stream1}' :demux=h264

To view a video stream over RTSP using a Raspberry Pi as a client, use the following command:

ffplay rtsp://<ip-addr-of-server>:8554/stream1 -vf "setpts=N/30" -fflags nobuffer -flags low_delay -framedrop

Or stream using VLC on the client with the following command:

vlc rtsp://<ip-addr-of-server>:8554/stream1

If you need to close the preview window on the server, use the nopreview command.
The use of inline flags forces stream header information into each inner frame, which helps the client understand the stream if it misses the beginning.

rpicam-raw

rpicam-raw records video as raw Bayer frames directly from the sensor. It does not display a preview window. To record two seconds of raw clips to a file named test.raw, execute the following command:

rpicam-raw -t 2000 -o test.raw

Rpicam-raw outputs raw frames without any formatting information. The application prints the pixel format and image dimensions to a terminal window to help the user parse the pixel data.
By default, rpicam-raw outputs raw frames in a single, possibly very large file. Use the segment option to direct each raw frame to a separate file, and use the %05d directive to make each frame filename unique.

rpicam-raw -t 2000 --segment 1 -o test%05d.raw

With a fast storage device, rpicam-raw can write 18MB of 12-megapixel HQ camera frames to disk at 10fps. rpicam-raw is unable to format the output frames as DNG files; to achieve this, use the rpicam-still to avoid dropped frames with a frame rate option of less than 10:

rpicam-raw -t 5000 --width 4056 --height 3040 -o test.raw --framerate 8

For more details about raw format, you can refer to mode.

rpicam-detect

Note: Raspberry Pi operating system does not include rpicam-detect. If you have installed TensorFlow Lite, you can build rpicam-detect. For more information, you can refer to rpicam-apps. Do not forget to pass -DENABLE_TFLITE=1 when running cmake.
rpicam-detect displays a preview window, and use Google MobileNet v1 SSD (Single Shot Detector) neural network to monitor the content. After training the neural network, you can use Coco data set to identify about 80 class objects. Rpicam-detect can recognize human, car, cat and so on.
Whenever rpicam-detect detects a target object, it captures a full resolution JPEG. then returns to monitor preview mode.
For more information about model usage, please refer to TensorFlow Lite object detector. For example, when you hang out, you can monitor your cat:

rpicam-detect -t 0 -o cat%04d.jpg --lores-width 400 --lores-height 300 --post-process-file object_detect_tf.json --object cat

rpicam parameter setting

• --help -h prints all options and briefly introduces each option.

rpicam-hello -h

• --version output the string of libcamera and rpicam-apps.

rpicam-hello --version

Output example:

rpicam-apps build: ca559f46a97a 27-09-2021 (14:10:24)
libcamera build: v0.0.0+3058-c29143f7

• --list-cameras lists the cameras connected to the Raspberry Pi and available sensor modes.

rpicam-hello --list-cameras

Sensor mode identifiers have the following form:

S<Bayer order><Bit-depth>_<Optional packing> : <Resolution list>

Cropping is specified in the native sensor pixel (even in pixel segmentation mode) as (<x>, <y>)/<Width>×<Height>. (x, y) specifies the position of the width × height crop window in the sensor array.
For example, the following output displays the information of the IMX219 sensor with index=0 and the IMX477 with index=1:

Available cameras
-----------------
0 : imx219 [3280x2464] (/base/soc/i2c0mux/i2c@1/imx219@10)
    Modes: 'SRGGB10_CSI2P' : 640x480 [206.65 fps - (1000, 752)/1280x960 crop]
                             1640x1232 [41.85 fps - (0, 0)/3280x2464 crop]
                             1920x1080 [47.57 fps - (680, 692)/1920x1080 crop]
                             3280x2464 [21.19 fps - (0, 0)/3280x2464 crop]
           'SRGGB8' : 640x480 [206.65 fps - (1000, 752)/1280x960 crop]
                      1640x1232 [41.85 fps - (0, 0)/3280x2464 crop]
                      1920x1080 [47.57 fps - (680, 692)/1920x1080 crop]
                      3280x2464 [21.19 fps - (0, 0)/3280x2464 crop]
1 : imx477 [4056x3040] (/base/soc/i2c0mux/i2c@1/imx477@1a)
    Modes: 'SRGGB10_CSI2P' : 1332x990 [120.05 fps - (696, 528)/2664x1980 crop]
           'SRGGB12_CSI2P' : 2028x1080 [50.03 fps - (0, 440)/4056x2160 crop]
                             2028x1520 [40.01 fps - (0, 0)/4056x3040 crop]
                             4056x3040 [10.00 fps - (0, 0)/4056x3040 crop]

• --camera selects the camera to be used. Specify an index from the list of available cameras.

rpicam-hello --list-cameras 0 
rpicam-hello --list-cameras 1 

• --config -c, specify a file, which includes the command parameter option and value. Generally, the file is named as "example_configuration.txt" file, specify options and values as key-value pairs, one option per line:

timeout=99000
verbose=

Note: Omit the prefix -- which is normally used on the command line with arguments. For flags with missing values, such as verbose in the example above, the trailing = must be included.
Then you can run the following command to specify a timeout of 99000 milliseconds and detailed output:

rpicam-hello --config example_configuration.txt 

• --time -t, default delay of 5000 milliseconds.

rpicam-hello -t  

Specifies how long the application will run before closing. This applies to video recording and preview windows. When capturing a still image, the application displays a preview window with a timeout of milliseconds before capturing the output image.

rpicam-hello -t 0

• --preview sets the position (x,y coordinates) and size (w,h dimensions) of the desktop or DRM preview window. Does not affect the resolution or aspect ratio of the image requested from the camera.

Pass the preview window size in the following comma-separated form:x,y,w,h

rpicam-hello --preview 100,100,500,500

• --fullscreen -f, Force the preview window to use the entire screen with no border or title bar. Scales the image to fit the entire screen. Do not accept values.

rpicam-hello -f

• --qt-preview uses the Qt preview window, which consumes more resources than the other options, but supports X-window forwarding. Incompatible with the fullscreen flag. Do not accept values.

rpicam-hello --qt-preview

• --nopreview Causes the application not to display the preview window. Do not accept the value.

rpicam-hello --nopreview

• --info-text

Default value: "#%frame (%fps fps) exp %exp ag %ag dg %dg"
When run in a desktop environment, the supplied string is set to the title of the preview window. The following image metadata replacements are supported:

rpicam-hello --info-test "Focus measure: %focus" 

• --width
• --height

Each accepts a single number to define the size (in pixels) of the captured image.
For rpicam-still, rpicam-jpeg and rpicam-vid, specify the resolution.
For rpicam-raw, specify the resolution of the raw frame. For cameras with 2×2 bin readout mode, specify a resolution equal to or less than the bin mode to capture 2×2 bin raw frames.
It does not work for rpicam-hello.
Record 1080p video:

rpicam-vid -o test.h264 --width 1920 --height 1080

Capture JPEGs at 2028×1520 resolution. if used with an HQ camera, 2×2 bin mode is used, so the raw file (test. ng) contains the original 2028×1520 Bayer image.

rpicam-still -r -o test.jpg --width 2028 --height 1520

• --viewfinder-width
• --viewfinder-height

Each parameter can accept a number that defines the size of the image displayed in the preview window in pixels. It does not affect the size of the preview window, as the image will be resized to fit. It does not affect the captured still images or videos.

rpicam-still --viewfinder-width 1920 --viewfinder-height 1080

• --mode allows the camera mode to be specified in the following colon separated format: <width>:<height>:<bit-depth>:<packing>, If the values provided do not match exactly, the system will select the closest available option for the sensor. Packed(P) or unpacked(U) can be used, affecting the format of the stored video and still images, but not the format of the frames passed to the preview window.

Bit-depth and packing are optional. Bit-depth default is 12, Packing default is P(packed).
See list-cameras for information on the bit depths, resolutions, and packing options available for the sensor.
As shown below:

• • 4056:3040:12:P - 4056×3040 resolution, 12 bits/pixel, packed.
  • 1632:1224:10 - 1632×1224 resolution, 10 bits/pixel.
  • 2592:1944:10:U - 2592×1944 resolution, 10 bits/pixel, unpacked.
  • 3264:2448 - 3264×2448 resolution.
• --viewfinder-mode is same as the mode option, but it applies to the data passed to the preview window. For more information, you can refer to mode document.
• --lores-width and --lores-height

Provides a second stream of low-resolution images from the camera, scaled down to the specified dimensions. Each accepts a number to define the dimension (in pixels) of the low-resolution stream. Can be used in preview and video modes. Does not provide static capture. For rpicam-vid, disable additional color denoising. It is useful for image post-processing nudge analysis.

rpicam-hello --lores-width 224 --lores-height 224

• --hflip flip the image, Flips the image horizontally. Does not accept values.

rpicam-hello --hflip -t 0

• --vflip Flips the image vertically. Does not accept values.

 rpicam-hello --vflip -t 0

• --rotation Rotates the image extracted from the sensor. Only values 0 or 180 are accepted.

rpicam-hello  --rotation 0

• --roi crops the image extracted from the sensor's full domain. Four decimal values ranging from 0 to 1 are accepted in the following format <x>, <y>, <w>, and <h>. Each of these values is expressed as a decimal between 0 and 1 as a percentage of the available width and height.

These values define the following ratios:
<x>: The x-coordinate to skip before extracting the image.
<y>: The y-coordinate to skip before extracting the image.
<w>: The width of the image to be extracted.
<h>: The height of the image to be extracted.
Defaults to 0,0,1,1 (starting at the first X-coordinate and the first Y-coordinate, using 100% of the image width and using 100% of the image height).
For example:
rpicam-hello --roi 0.25,0.25,0.5,0.5 selects half of the total number of pixels cropped from the center of the image (skip the first 25% of the X coordinates, skip the first 25% of the Y coordinates, use 50% of the total width of the image, and use 50% of the total height of the image).
rpicam-hello --roi 0,0,0.25,0.25 selects one-quarter of the total number of pixels cropped from the upper left corner of the image (skips the first 0% of the X coordinate, skips the first 0% of the Y coordinate, uses 25% of the image width, and uses 25% of the image height).

• --hdr default value: turn off, run the camera on HDR mode. If no value is passed, auto is assumed. accepts one of the following values.
  • off -Disable HDR.
  • auto -Enable HDR on supported devices. use the sensor's built-in HDR mode if available. If the sensor does not have a built-in HDR mode, use the onboard HDR mode (if available).
  • single-exp enable HDR on the supported device. If it is available, use the built-in HDR mode of the sensor. If there is no built-in HDR mode on the sensor, use the onboard HDR mode (if it is available).

rpicam-hello --hdr

Use the onboard HDR mode, if available, even if the sensor has a built-in HDR mode. If onboard HDR mode is not available, disable HDR.
Raspberry Pi 5 and later devices have an onboard HDR mode.
To check the build-in HDR mode of the sensor, you need to add this option to the camera list.

Camera Control Option

The following options control the image processing and algorithms that affect the quality of the camera's images.

• sharpness

Sets the image sharpness. Accepts values in the following ranges.

• • 0.0 is No sharpening applied.
  • Values greater than 0.0 but less than 1.0 apply a sharpening amount less than the default value.
  • 1.0 applies the default sharpening amount.
  • Values greater than 1.0 apply additional sharpening.

rpicam-hello --sharpness 0.0

• contrast

Specifies the image contrast. Accepts values in the following ranges.

• • 0.0 applies the minimum contrast.
  • Values greater than 0.0 but less than 1.0 apply contrast less than the default value.
  • 1.0 applies the default contrast.
  • Values greater than 1.0 apply additional contrast.

rpicam-hello --contrast 0.0

• brightness

Specify the image brightness, added as an offset for all pixels in the output image. Accepts values in the following range:

• • -1.0 applies the minimum brightness (black).
  • 0.0 applies the standard brightness.
  • 1.0 applies the maximum brightness (white).

For more usage, it is recommended to refer to ev.

rpicam-hello --brightness 1.0

• saturation

Specifies the image color saturation. Accepts values in the following ranges.

• • 0.0 applies minimum saturation (grayscale).
  • Values greater than 0.0 but less than 1.0 apply less saturation than the default value.
  • 1.0 applies default saturation.
  • Values greater than 1.0 apply additional saturation.

rpicam-hello --saturation  0.6

• ev

Specifies the exposure value (EV) compensation for the image. Accepts a value that controls the target value passed to the automatic exposure/gain control (AEC/AGC) processing algorithm along the following spectrum.

• • -10.0 applies the minimum target value
  • 0.0 applies the standard target value
  • 10.0 applies the maximum target value

rpicam-hello --ev  10.0

• shutter

Specifies the exposure time in microseconds using the shutter. When you use this option, the gain can still vary. If the camera is running a frame rate so fast that it does not allow the specified exposure time (for example, a frame rate of 1fps and an exposure time of 10,000 microseconds), the sensor will use the maximum exposure time allowed by the frame rate.
For a list of official camera minimum and maximum shutter times, please refer to Canera Hardware Specification. Values higher than the maximum value result in undefined behavior.

rpicam-hello --shutter 10000

• gain

The effect of analoggain and gain are the same.
Set the combined analog and digital gain. When the sensor driver can provide the required gain, only the analog gain is used. When the analog gain is maxed out, the ISP applies the digital gain. Accepts the value.
For the list of Analog Gain Limits for Official Cameras, please refer to Camera Hardware Document.
Sometimes the digital gain exceeds 1.0 even when the analog gain limit is not exceeded. This can happen in the following situations.
Any of these color gains are below 1.0, which causes the digital gain to stabilize at 1.0/min (red gain, blue gain). This causes the total digital gain to be applied to any color channel above 1.0 to avoid color shift artifacts.
Slight differences when the automatic exposure/gain control (AEC/AGC) changes.

rpicam-hello --gain 0.8

• metering default value:centre

Sets the metering mode for the automatic exposure/gain control (AEC/AGC) algorithm. The following values are accepted.

• • centre: Center-weighted measures
  • spot: spot metering for light
  • average: average or full-frame metering
  • custom: self-de: custom metering modes defined in the camera adjustment file.

For more information on defining custom metering modes and adjusting area weights in existing metering modes, please refer to Raspberry Pi camera and libcamera tuning guide.

rpicam-hello --metering centre

• exposure

Set the exposure profile. Changing the exposure profile should not affect the image exposure. Instead, different modes adjust the gain settings to achieve the same net result. The following values are accepted:

• • sport: Short exposure, big gains
  • normal: Normal exposure, normal gain
  • long: Long exposure, small gains

You can use the tuning file to edit the exposure config file. For more details, please refer to Raspberry Pi camera and libcamera tuning guide.

rpicam-hello --exposure sport

• awb

Set the exposure config file. Changing the exposure config file should not affect the image exposure. Instead, different modes adjust the gain settings to achieve the same end result. The following values are accepted. Available white balance modes:

These values are only approximations: Values may vary depending on camera adjustments.
There is no mode to completely disable AWB. However, you can use awbgains to correct color gain.
For more information on AWB modes, including how to define custom modes. Please refer to Raspberry Pi camera and libcamera tuning guide.

rpicam-hello --awb auto

• awbgains

Set a fixed red and blue gain value to replace the automatic white balance (AWB) algorithm. Set a non-zero value to disable AWB. Accepts comma-separated numeric input in the following format:<red_gain> and <blue_gain>.

rpicam-jpeg -o test.jpg --awbgains 1.5,2.0

• denoise

Default value: auto
Sets the denoising mode. Accepts the following values:

• • auto: Enable standard spatial noise reduction. Use super-fast color denoising for videos and high-quality color denoising for images. Do not enable additional color noise in the preview window.
    
  • off: Close space and color denoising.
    
  • cdn_off: Disable color noise.
    
  • cdn_fast: Use quick color denoising.
    
  • cdn_hq: Uses high quality color denoising. Not suitable for video/viewfinder due to reduced throughput.
    

Even fast color noise reduction reduces the frame rate. High-quality color noise reduction significantly reduces the frame rate.

rpicam-hello --denoise off

• tuning-file

Specify the camera tuning file. Tuning files allow you to control many aspects of image processing, including automatic exposure/gain control (AEC/AGC), automatic white balance (AWB), color shading correction, color processing, denoising, and more. Accepts the tuning file path as input. For more details about tuning file, please refer to tuning file.

• autofocus-mode

Default value: default Specifies the autofocus mode. The following values are accepted:

• • default: Put the camera in continuous autofocus mode unless the lens position or autofocus capture overrides manual mode
  • manual: Does not move the lens unless the lens position is manually configured.
  • auto: Only move the lens for autofocus scanning when the camera is started or before capturing, if the autofocus capture function is also used.
  • continuous: Automatically adjusts the lens position as the scene changes.

This option is only supported for certain camera modules.

rpicam-hello --autofocus-mode auto

• autofocus-range

Default value: normal
Specifies the autofocus range. The following values are accepted.

• • normal: Focus range is fairly close to infinity.
  • macro: Focus only on close objects, including the closest focal length supported by the camera.
  • full: Focuses the entire range, from the nearest object to infinity.

This option is only supported for certain camera modules.

rpicam-hello autofocus-range normal

• autofocus-speed

Default value: normal
Specifies the autofocus speed. The following values are accepted.

• • normal: Changing the lens position at normal speed.
  • fast: Quick change of lens position.

This option is only supported for certain camera modules.

rpicam-hello --autofocus-speed normal

• autofocus-window

Specifies the autofocus window over the full range of the sensor. Accepts four decimal values ranging from 0 to 1 in the following format: <x>, <y>, <w> and <h>. Each of these values is expressed as a decimal between 0 and 1 as a percentage of the available width and height.
These values define the following ratios:
<x>: The x-coordinate to skip before applying autofocus.
<y>: The y-coordinate to skip before applying autofocus.
<w>: AF area width.
<h>: AF area height.
The default value uses the middle third of the output image (1/9 of the total image area) in both dimensions.
For example:

rpicam-hello—autofocus-window 0.25,0.25,0.5,0.5

Select half of the total number of pixels cropped from the center of the image (skip the first 25% of the X coordinates, skip the first 25% of the Y coordinates, use 50% of the total width of the image, use 50% of the total height of the image).

rpicam-hello—autofocus-window 0,0,0.25,0.25

Select a quarter of the total number of pixels cropped from the upper left corner of the image (skip the first 0% of the X coordinate, skip the first 0% of the Y coordinate, use 25% of the width of the image, use 25% of the height of the image).
This option is only supported for certain camera modules.

• lens-position

Default value: default Moves the lens to a fixed focal length, usually expressed in diopter (in units of 1/meter distance). The following range of values is accepted.

• • 0.0: Move the camera to the "infinity" position.
  • Any other number:Move the lens to the 1 / number position. For example, a value of 2.0 will focus at approximately 0.5m.
  • normal: Move the lens to the default position corresponding to the lens hyperfocal position.

Lens calibration is not perfect, so it may vary from camera module to camera module for the same model.

• verbose

Nickname: -v
Default value: 1 Sets the level of detail. Accepts the following values:

• • 0: no output
  • 1: normal output
  • 2: detailed output

rpicam-hello --verbose 1

For more details, you can refer to here.

libcamera/libcamera Usage

Introduction

After the Bullseye version, the underlying Raspberry Pi driver for the Raspberry Pi image has been switched from Raspicam to libcamera. Libcamera is an open-source software stack (referred to as a driver later for ease of understanding) that is convenient for third-party porting and developing their own camera drivers. As of December 11, 2023, the official pycamera2 library has been provided for libcamera, making it easier for users to call Python demos.

Call Camera

The libcamera software stack provides six commands for users to preview and test the camera interface.

libcamera-hello

This is a simple "hello world" program that previews the camera and displays the camera image on the screen.
Example

libcamera-hello

This command will preview the camera on the screen for about 5 seconds. The user can use the "-t <duration>" parameter to set the preview time, where the unit of <duration> is milliseconds. If it is set to 0, it will keep previewing all the time. For example:

libcamera-hello -t 0

Tuning File
The libcamera driver of the Raspberry Pi will call a tuning file for different camera modules. The tuning file provides various parameters. When calling the camera, libcamera will call the parameters in the tuning file, and process the image in combination with the algorithm. The final output is the preview screen. Since the libcamera driver can only automatically receive the signal of the chip, the final display effect of the camera will also be affected by the entire module. The use of the tuning file is to flexibly handle the cameras of different modules and adjust to improve the image quality.
If the output image of the camera is not ideal after using the default tuning file, the user can adjust the image by calling the custom tuning file. For example, if you are using the official NOIR version of the camera, the NOIR camera may require different white balance parameters compared with the regular Raspberry Pi Camera V2. In this case, you can switch by calling the tuning file.

libcamera-hello --tuning-file /usr/share/libcamera/ipa/raspberrypi/imx219_noir.json

Users can copy the default tuning files and modify them according to their needs.
Note: The use of tuning files applies to other libcamera commands, and will not be introduced in subsequent commands.

Preview Window
Most libcamera commands will display a preview window on the screen. Users can customize the title information of the preview window through the --info-text parameter, and can also call some camera parameters through %directives and display them on the window.
For example, if you use HQ Camera: You can display the focal length of the camera on the window through --info-txe "%focus".

libcamera-hello --info-text "focus %focus".

Note: For more information on parameter settings, please refer to the following chapters.

libcamera-jpeg

libcamera-jpeg is a simple static picture shooting program, different from the complex functions of libcamera-still, libcamera-jpeg code is more concise and has many of the same functions to complete picture shooting.
Take a JPEG image of full pixel

libcamera-jpeg -o test.jpg

This shooting command will display a preview serial port for about 5 seconds, and then shoot a full-pixel JPEG image and save it as test.jpg.
Users can set the preview time through the -t parameter and can set the resolution of the captured image through --width and --height. E.g.:

libcamera-jpeg -o test.jpg -t 2000 --width 640 --height 480

Exposure control
All libcamera commands allow the user to set the shutter time and gain themselves, such as:

libcamera-jpeg -o test.jpg -t 2000 --shutter 20000 --gain 1.5

This command will capture an image with 20ms exposure and camera gain set to 1.5x. The gain parameter set will first set the analog gain parameter inside the photosensitive chip. If the set gain exceeds the maximum built-in analog gain value of the driver, the maximum analog gain of the chip will be set first, and then the remaining gain multiples will be used as digital gains to take effect.
Note: The digital gain is realized by ISP (image signal processing), not directly adjusting the built-in register of the chip. Under normal circumstances, the default digital gain is close to 1.0, unless there are the following three situations.

1. Overall gain parameter requirements, that is, when the analog gain cannot meet the set gain parameter requirements, the digital gain will be needed for compensation.
2. One of the color gains is less than 1 (the color gain is achieved by digital gain), in this case, the final gain is stabilized at 1/min(red_gain, blue_gain), that is, a uniform digital gain is applied, and is the gain value for one of the color channels (not the green channel).
3. AEC/AGC was modified. If there is a change in AEC/AGC, the digital gain will also change to a certain extent to eliminate any fluctuations, this change will be quickly restored to the "normal" value.

The Raspberry Pi's AEC/AGX algorithm allows the program to specify exposure compensation, which is to adjust the brightness of the image by setting the aperture value, for example:

libcamera-jpeg --ev -0.5 -o darker.jpg
libcamera-jpeg --ev 0 -o normal.jpg
libcamera-jpeg --ev 0.5 -o brighter.jpg

libcamera-still

libcamera-still and libcamera-jpeg are very similar, the difference is that libcamera inherits more functions of raspistill. As before, users can take a picture with the following command.
Test Command

libcamera-still -o test.jpg

Encoder
libcamea-still supports image files in different formats, can support png and bmp encoding, and also supports saving binary dumps of RGB or YUV pixels as files without encoding or in any image format. If you save RGB or YUV data directly, the program must understand the pixel arrangement of the file when reading such files.

libcamera-still -e png -o test.png
libcamera-still -e bmp -o test.bmp
libcamera-still -e rgb -o test.data
libcamera-still -e yuv420 -o test.data

Note: The format of image saving is controlled by the -e parameter. If the -e parameter is not called, it will be saved in the format of the output file name by default.
Raw Image Capture
The raw image is the image output by the direct image sensor without any ISP or CPU processing. For color camera sensors, the output format of the raw image is generally Bayer. Note that the raw image is different from the bit-encoded RGB and YUV images we said earlier, and RGB and YUV are also ISP-processed images.
A command to take a raw image:

libcamera-still -r -o test.jpg

The raw image is generally saved in DNG (Adobe Digital Negative) format, which is compatible with most standard programs, such as dcraw or RawTherapee. The raw image will be saved as a file of the same name with the .dng suffix, for example, if you run the above command, it will be saved as a test.dng, and generate a jpeg file at the same time. The DNG file contains metadata related to image acquisition, such as white balance data, ISP color matrix, etc. The following is the metadata encoding information displayed by the exiftool:

File Name                       : test.dng
Directory                       : .
File Size                       : 24 MB
File Modification Date/Time     : 2021:08:17 16:36:18+01:00
File Access Date/Time           : 2021:08:17 16:36:18+01:00
File Inode Change Date/Time     : 2021:08:17 16:36:18+01:00
File Permissions                : rw-r--r--
File Type                       : DNG
File Type Extension             : dng
MIME Type                       : image/x-adobe-dng
Exif Byte Order                 : Little-endian (Intel, II)
Make                            : Raspberry Pi
Camera Model Name               : /base/soc/i2c0mux/i2c@1/imx477@1a
Orientation                     : Horizontal (normal)
Software                        : libcamera-still
Subfile Type                    : Full-resolution Image
Image Width                     : 4056
Image Height                    : 3040
Bits Per Sample                 : 16
Compression                     : Uncompressed
Photometric Interpretation      : Color Filter Array
Samples Per Pixel               : 1
Planar Configuration            : Chunky
CFA Repeat Pattern Dim          : 2 2
CFA Pattern 2                   : 2 1 1 0
Black Level Repeat Dim          : 2 2
Black Level                     : 256 256 256 256
White Level                     : 4095
DNG Version                     : 1.1.0.0
DNG Backward Version            : 1.0.0.0
Unique Camera Model             : /base/soc/i2c0mux/i2c@1/imx477@1a
Color Matrix 1                  : 0.8545269369 -0.2382823821 -0.09044229197 -0.1890484985 1.063961506 0.1062747385 -0.01334283455 0.1440163847 0.2593136724
As Shot Neutral                 : 0.4754476844 1 0.413686484
Calibration Illuminant 1        : D65
Strip Offsets                   : 0
Strip Byte Counts               : 0
Exposure Time                   : 1/20
ISO                             : 400
CFA Pattern                     : [Blue, Green][Green, Red]
Image Size                      : 4056x3040
Megapixels                      : 12.3
Shutter Speed                   : 1/20

Long Exposure
If we want to take a super long exposure picture, we need to disable AEC/AGC and white balance, otherwise, these algorithms will cause the picture to wait for a lot of frame data when it converges. Disabling these algorithms requires another explicit value to be set. Additionally, the user can skip the preview process with the --immediate setting.
Here is the command to take an image with an exposure of 100 seconds:

libcamera-still -o long_exposure.jpg --shutter 100000000 --gain 1 --awbgains 1,1 --immediate

Remarks: Reference table for the longest exposure time of several official cameras.

libcamera-vid

libcamera-vid is a video recording demo that uses the Raspberry Pi hardware H.264 encoder by default. After the program runs, a preview window will be displayed on the screen, and simultaneously the bitstream encoding will be output to the specified file. For example, record a 10s video.

libcamera-vid -t 10000 -o test.h264

If you want to view the video, you can use vlc to play it.

vlc test.h264

Note: The recorded video stream is unpacked. Users can use --save-pts to set the output timestamp to facilitate the subsequent conversion of the bit stream to other video formats.

libcamera-vid -o test.h264 --save-pts timestamps.txt

If you want to output the mkv file, you can use the following command:

mkvmerge -o test.mkv --timecodes 0:timestamps.txt test.h264

Encoder
Raspberry Pi supports JPEG format and YUV420 without compression and format:

libcamera-vid -t 10000 --codec mjpeg -o test.mjpeg
libcamera-vid -t 10000 --codec yuv420 -o test.data

The --codec option sets the output format, not the output file extension.
Use the --segment parameter to split the output file into segments (unit is ms), which is suitable for JPEG files that need to split the JPEG video stream into separate short (about 1ms) JPEG files.

libcamera-vid -t 10000 --codec mjpeg --segment 1 -o test%05d.jpeg

UDP Video Streaming Transmission
UDP can be used for video streaming transmission, and the Raspberry Pi runs (server):

libcamera-vid -t 0 --inline -o udp://<ip-addr>:<port>

Among them, <ip-addr> needs to be replaced with the actual client IP address or multicast address. On the client (client), enter the following commands to obtain and display the video stream (you can use one of the two commands):

vlc udp://@:<port> :demux=h264
vlc udp://@:<port> :demux=h264

Note: The port needs to be the same as the one you set on the Raspberry Pi.
TCP Video Streaming Transmission
You can use TCP for video streaming Transmission, and the Raspberry Pi runs (server):

libcamera-vid -t 0 --inline --listen -o tcp://0.0.0.0:<port>

The client runs:

vlc tcp/h264://<ip-addr-of-server>:<port> #Select one of the two commands
ffplay tcp://<ip-addr-of-server>:<port> -vf "setpts=N/30" -fflags nobuffer -flags low_delay -framedrop

RTSP Video Streaming Transmission
On the Raspberry Pi, vlc is usually used to process the RTSP video stream:

libcamera-vid -t 0 --inline -o - | cvlc stream:///dev/stdin --sout '#rtp{sdp=rtsp://:8554/stream1}' :demux=h264

On the playback side, you can run any of the following commands:

vlc rtsp://<ip-addr-of-server>:8554/stream1
ffplay rtsp://<ip-addr-of-server>:8554/stream1 -vf "setpts=N/30" -fflags nobuffer -flags low_delay -framedrop

In all preview commands, if you want to turn off the preview window on the Raspberry Pi, you can use the parameter -n (--nopreview) to set it. Also, pay attention to the setting of the --inline parameter. Changing the setting will force the header information of the video stream to be included in each I (intra) frame. This setting allows the client to correctly parse the video stream even if the video header is lost.
High Frame Rate Mode
If you use the libcamera-vid command to record high frame rate video (generally higher than 60fps) while reducing frame loss, you need to pay attention to the following points:

1. The target level of H.264 needs to be set to 4.2, which can be set with the --level 4.2 parameter.
2. The color noise reduction function must be turned off, which can be set with the --denoise cdn_off parameter.
3. If the set frame rate is higher than 100fps, close the preview window to release more CPU resources and avoid frame loss, which can be set with the -n parameter.
4. It is recommended to add the setting force_turbo=1 in the /boot/config.txt file to ensure that the CPU clock will not be limited in the video stream.
5. Adjust the ISP output resolution, use -width 1280 --height 720 to set the resolution, or set it to a lower resolution, depending on the camera model.
6. If you are using Pi 4 or higher-performance model, you can add the setting gpu_freq=550 or higher in the /boot/config.txt file to overclock the motherboard GPU to achieve higher performance.

For example, record 1280x720 120fps video.

libcamera-vid --level 4.2 --framerate 120 --width 1280 --height 720 --save-pts timestamp.pts -o video.264 -t 10000 --denoise cdn_off -n

libcamera-raw

Libcamera-raw is similar to a video recording demo. The difference is, libcamera-raw records the Bayer format data output by the direct sensor, that is, the raw image data. Libcamera-raw doesn't show a preview window. For example, record a 2-second piece of raw data.

libcamera-raw -t 2000 -o test.raw

The demo will directly dump the raw frame without format information, the program will directly print the pixel format and image size on the terminal, and the user can view the pixel data according to the output data.
By default, the program will save the raw frame as a file, the file is usually large, and the user can divide the file by the --segement parameter.

libcamera-raw -t 2000 --segment 1 -o test%05d.raw

If the memory is large (such as using SSD), libcamera-raw can write the official HQ Camera data (about 18MB per frame) to the hard disk at a speed of about 10 frames per second. To achieve this speed, the demo writes the unformatted raw frames, there is no way to save them as DNG files like libcamera-still does. If you want to ensure that there are no dropped frames, you can use --framerate to reduce the frame rate.

libcamera-raw -t 5000 --width 4056 --height 3040 -o test.raw --framerate 8

Common Command Setting Options

Common command setting options apply to all libcamera commands:

--help, -h

Print program help information, you can print the available setting options for each program command, and then exit.

--version

Print the software version, print the software version of libcamera and libcamera-app, then exit.

--list-cameras

Display the recognized supported cameras. For example:

Available cameras
-----------------
0 : imx219 [3280x2464] (/base/soc/i2c0mux/i2c@1/imx219@10)
    Modes: 'SRGGB10_CSI2P': 640x480 [206.65 fps - (1000, 752)/1280x960 crop]
                             1640x1232 [41.85 fps - (0, 0)/3280x2464 crop]
                             1920x1080 [47.57 fps - (680, 692)/1920x1080 crop]
                             3280x2464 [21.19 fps - (0, 0)/3280x2464 crop]
           'SRGGB8' : 640x480 [206.65 fps - (1000, 752)/1280x960 crop]
                      1640x1232 [41.85 fps - (0, 0)/3280x2464 crop]
                      1920x1080 [47.57 fps - (680, 692)/1920x1080 crop]
                      3280x2464 [21.19 fps - (0, 0)/3280x2464 crop]
1 : imx477 [4056x3040] (/base/soc/i2c0mux/i2c@1/imx477@1a)
    Modes: 'SRGGB10_CSI2P': 1332x990 [120.05 fps - (696, 528)/2664x1980 crop]
           'SRGGB12_CSI2P': 2028x1080 [50.03 fps - (0, 440)/4056x2160 crop]
                             2028x1520 [40.01 fps - (0, 0)/4056x3040 crop]
                             4056x3040 [10.00 fps - (0, 0)/4056x3040 crop]

According to the printed information, the IMX219 camera has a suffix of 0, and the IM new 477 camera has a suffix of 1. When calling the camera, you can specify the corresponding suffix.

--camera

Specify the camera, and the corresponding suffix can refer to the print information of the command --list-camera.
For example: libcamera-hello -c config.txt
In the setting file, set parameters one line at a time, in the format of key=value:

timeout=99000
verbose=

--config,	-c

Under normal circumstances, we can directly set the camera parameters through commands. Here we use the --config parameter to specify the setting file and directly read the setting parameters in the file to set the camera preview effect.

--timeout, -t

The "-t" option sets the runtime of the libcamera demo. If the video recording command is run, the timeout option sets the recording duration. If the image capture command is run, the timeout sets the preview time before the image is captured and output.
If "timeout" is not set when running the libcamera demo, the default timeout value is 5000 (5 seconds). If the timeout is set to 0, the demo will continue to run.
Example: libcamera-hello -t 0

--preview, -p

"-p" sets the size and position of the preview window (the qualified settings are valid in both X and DRM version windows), and the format is --preview <x. y, w, h> where "x", "y" sets the preview window coordinates, "w" and "h" set the width and length of the preview window.
The settings of the preview serial port will not affect the resolution and aspect ratio of the camera image preview. The demo will scale the preview image to display in the preview window and adapt it according to the original image aspect ratio.
Example: libcamera-hello -p 100,100,500,500

--fullscreen, -f

The "-f" option sets the preview window full screen, the preview window and the border in full-screen mode. Like "-p", it does not affect the resolution and aspect ratio, and will automatically adapt.
Example: libcamera-still -f -o test.jpg

--qt-preview

Using the preview window based on the QT framework, this setting is not recommended under normal circumstances, because the preview demo will not use zero-copy buffer sharing and GPU acceleration, which will occupy more resources. The QT preview window supports X forwarding (the default preview program does not).
The Qt preview serial port does not support the "--fullscreen" setting option. If the user wants to use the Qt preview, it is recommended to keep a small preview window to avoid excessive resource usage and affecting the normal operation of the system.
Example: libcamera-hello --qt-preview

--nopreview, -n

Images are not previewed. This setting will turn off the image preview function.
Example: libcamera-hello -n

--info-text

Set the title and information display of the preview window (only available in the X graphics window) using the format --info-text <string>. When calling this option, multiple parameters can be set, and the parameters are usually called in the % command format. The demo will call the corresponding value in the graphics metadata according to the instructions.
If no window info is specified, the default --info-text is set to "#%frame (%fps fps) exp %exp ag %ag dg %dg" .
Example: libcamera-hello --info-test "Focus measure: %focus
Available parameters:

--width
--height

These two parameters set the width and height of the image respectively. For libcamera-still, libcamera-jpeg, and libcamera-vid commands, these two parameters can set the resolution of the output image/video.
If the libcamera-raw command is used, these two parameters will affect the size of the obtained metadata frame. The camera has a 2 x 2 block reading mode. If the set resolution is smaller than the split mode, the camera will obtain the metadata frame according to the 2 x 2 block size.
libcamera-hello cannot specify the resolution.
Example:
libcamera-vid -o test.h264 --width 1920 --height 1080 Record a 1080p video
libcamera-still -r -o test.jpg --width 2028 --height 1520 Take a 2028 x 1520 JPEG image

--viewfinder-width
--viewfinder-height

This setting option is also used to set the resolution of the image, the difference is only the image size of the preview. It does not affect the final output image or video resolution.The size of the preview image will not affect the size of the preview window and it will be adapted according to the window.
Example: libcamera-hello --viewfinder-width 640 --viewfinder-height 480

--rawfull

This setting forces the sensor chip to activate --width and --height settings to output still images and video in full-resolution reading mode. This setting libcamera-hello is invalid.
With this setting, the framerate will be affected. In full-resolution mode, frame reading will be slower.
Example: libcamera-raw -t 2000 --segment 1 --rawfull -o test%03d.raw
The example command will capture multiple Metadata frames in full-resolution mode. If you are using an HQ camera, the size of each frame is 18MB, and if --rawfull is not set, the HQ camera defaults to 2 x 2 mode, and the data size of each frame is only 4.5MB.

--mode

This parameter is more general than rawfull. It is used to set the camera mode. When using it, you need to specify the width, height, bit depth and packing mode, and separate them with colons. The set value does not have to be completely accurate, the system will automatically match the closest value, and the bit depth and packing mode can be set (the default is 12 and P means packing).

• 4056:3040:12:P - 4056x3040 resolution, 12 bits per pixel, packing. Packing means that the raw image data will be packed in the buffer. In this case, two pixels will only occupy 3 bytes, which can save memory.
• 1632:1224:10 - 1632x1224 resolution, 10 bits per pixel, packing by default. In 10-bit packing mode, 4-pixel data will occupy 5 bytes.
• 2592:1944:10:U - 2592x1944 resolution, 10 bits per pixel, no packing. In the case of unpacking, each pixel will occupy 2 bytes of memory, in this case, the highest 6 bits will be set to 0.
• 3262:2448 - 3264x2448 resolution, 12 bits and packing mode are used by default. However, if the camera model, such as Camera V2 (IMX219), does not support 12-bit mode, the system will automatically select 10-bit mode.

--viewfinder-mode       #Specify sensor mode, given as <width>:<height>:<bit-depth>:<packing>

The --mode parameter is used to set the camera mode when recording video and shooting still images. If you want to set it when previewing, you can use the --viewfinder-mode parameter.

--lores-width
--lores-height

These two options set low-resolution images. The low-resolution data stream compresses the image, causing the aspect ratio of the image to change. When using libcamera-vid to record video, if a low resolution is set, functions such as color image denoising will be disabled.
Example: libcamera-hello --lores-width 224 --lores-height 224
Note that low-resolution settings are often used in conjunction with image postprocessing, otherwise it has little effect.

--hflip #Flip the image horizontally
--vflip #Flip the image vertically
--rotation #Flip the image horizontally or vertically according to the given angle <angle>

These three options are used to flip the image. The parameters of --rotation currently only support 0 and 180, which are equivalent to --hflip and --vflip.
Example: libcamera-hello --vflip --hflip

--roi #Crop image <x, y, w, h>

The --roi parameter allows the user to crop the image area they want according to the coordinates from the complete image provided by the sensor, that is digital scaling, note that the coordinate values should be within the valid range. For example --roi 0, 0, 1, 1 is an invalid instruction.
Example: libcamera-hello --roi 0.25,0.25,0.5,0.5
The example command will crop 1/4 of the image from the center of the image.

--hdr #Run the camera in HDR mode (supported cameras only)

The --hdr parameter is used to set the wide dynamic mode of the camera. This setting will only take effect if the camera supports a wide dynamic range. You can use --list-camera to see if the camera supports hdr mode.

--sharpness #Set the sharpness of the image <number>

Adjust the sharpness of the image by the value of <number>. If set to 0, sharpening will be applied. If you set a value above 1.0, an extra sharpening amount will be used.
Example: libcamera-still -o test.jpg --sharpness 2.0

--contrast #Set image contrast <number>

Example: libcamera-still -o test.jpg --contrast 1.5

--brightness #Set image brightness <number>

The setting range is -1.0 ~ 1.0
Example: libcamera-still -o test.jpg --brightness 0.2

--saturation #Set image color saturation <number>

Example: libcamera-still -o test.jpg --saturation 0.8

--ev #Set EV compensation <number>

Set the EV compensation of the image in units of aperture, the setting range is -10 ~ 10, the default value is 0. The program runs using the AEC/AGC algorithm.
Example: libcamera-still -o test.jpg --ev 0.3

--shutter #Set the exposure time, the unit is ms <number>

Note: If the frame rate of the camera is too fast, it may not work according to the set shutter time. If this happens, you can try to use --framerate to reduce the frame rate.
Example: libcamera-hello --shutter 30000

--gain #Set gain value (combination of numerical gain and analog gain) <number>
--analoggain #--gain synonym

--analoggain is the same as --gain, the use of analoggain is only for compatibility with raspicam programs.

--metering #Set metering mode <string>

Set the metering mode of the AEC/AGC algorithm, the available parameters are:

• centre - Center metering (default)
• spot - spot metering
• average - average or full frame metering
• custom - custom metering mode, can be set via tuning file

Example: libcamera-still -o test.jpg --metering spot

--exposure #Set exposure profile <string>

The exposure mode can be set to normal or sport. The report profile for these two modes does not affect the overall exposure of the image, but in the case of sport mode, the program will shorten the exposure time and increase the gain to achieve the same exposure effect.

• sport: Short exposure, larger gains
• normal: Normal expoeure, normal gains
• long: Long exposure, smaller gains

Example: libcamera-still -o test.jpg --exposure sport

--awb #Set white balance mode <string>

Available white balance modes:

Example: libamera-still -o test.jpg --awb tungsten

--awbgains #Set a fixed color gain <number,number>

Set red and blue gain.
Example: libcamera-still -o test.jpg --awbgains 1.5, 2.0

--denoise #Set denoising mode <string>

Supported denoising modes:

• auto - Default mode, use standard spatial denoising. If it is a video, fast color denoising will be used, and high-quality color denoising will be used when taking still images. Previewing images will not use any color denoising.
• off - Turn off spatial denoising and color denoising.
• cdn_off - Turn off color denoising.
• cdn_fast - Use fast color denoising.
• cdn_hq - Use high-quality color denoising, not suitable for video recording.

Example: libcamera-vid -o test.h264 --denoise cdn_off

--tuning-file #Specify camera tuning file <string>

For more instructions on tuning files, you can refer to official tutorial.
Example: libcamera-hello --tuning-file ~/my~camera-tuning.json

--autofocus-mode #Specify the autofocus mode <string>

Set the autofocus mode.

• default - By default, the camera will use continuous autofocus mode, unless --lens-position or --autofocus-on-capture manual focus is set.
• manual - Manual focus mode, the focus position can be set by --lens-position.
• auto - Focusing will only be done once when the camera is turned on, and will not be adjusted in other cases. (If you use the libcamera-still command, only when --autofocus-on-capture is used, it will focus once before taking a photo).
• continuous - The camera will automatically adjust the focus position according to the scene changes.

--autofocus-range #Specify the autofocus range <string>

Set the autofocus range.

• normal -- The default mode, from nearest to infinity.
• macro - The macro mode, only focus on nearby objects.
• full - The full distance mode, adjusted to infinity for the closest object.

--autofocus-speed #Specify the autofocus speed <string>

Set the focus speed.

• normal - The default item, normal speed.
• fast - The fast focus mode.

--autofocus-window   --autofocus-window

To display the focus window, you need to set x, y, width and height, and the coordinate value setting is based on the ratio of the image. For example --autofocus-window 0.25,0.25,0.5,0.5 would set a window that is half the size of the image and centered.

--lens-position #Set the lens to a given position <string>

Set the focus position.

• 0.0 -- Set the focus position to infinity.
• number -- Set the focus position to 1/number, number is any value you set, for example, if you set 2, it means that it will focus on the position of 0.5m.
• default -- Focus on the default position relative to the hyperfocal distance of the lens.

--output, -o #Output file name <string>

Set the filename of the output image or video. In addition to setting the file name, you can also specify the output udp or tcp server address to output the image to the server. If you are interested, you can check the relevant setting instructions of the subsequent tcp and udp.
Example: libcamera-vid -t 100000 -o test.h264

--wrap #Wrap the output file counter <number>

Example: libcamera-vid -t 0 --codec mjpeg --segment 1 --wrap 100 -o image%d.jpg

--flush #Flush the output file immediately

The --flush parameter will immediately update each frame of the image to the hard disk at the same time as it is written, reducing latency.
Example: libcamera-vid -t 10000 --flush -o test.h264

Still Image Shooting Setting Parameters

--quality, -q            #Set JPEG image quality <0 ~ 100>
--exif, -x               #Add extra EXIF flags
--timelapse              #Time interval of time-lapse photography, the unit is ms
--framestart             #Start value of frame count
--datetime               #Name the output file with date format
--timestamp              #Name the output file with the system timestamp
-- restart               #Set the JPEG restart interval
--keypress, -k           #Set the Enter key photo mode
--signal, -s             #Set the signal to trigger the photo mode
--thumb                  #Set thumbnail parameters <w:h:q>
--ebcoding, -e           #Set the image encoding type: jpg/png/bmp/rgb/yuv420
--raw, -r                #Save raw image
--latest                 #Associate symbols to the latest saved file
--autofocus-on-capture   #Set to do a focus action before taking a photo

Video Recording Image Setting Parameters

--quality, -q   #Set JPEG commands <0 - 100>
--bitrate, -b   #Set H.264 bitrate
--intra, -g     #Set the internal frame period (only supports H.264)
--profile       #Set H.264 configuration
--level         #Set H.264 level
--codec         #Set encoding type h264 / mjpeg / yuv420
--keypress, -k  #Set Enter key to pause and record
--signal, -s    #Set signal pause and record
--initial       #Start the program in the recording or paused state
--split         #Split video and save to another file
--segment       #Split video into multiple video segments
--circular      #Write video to the circular buffer
--inline        #Write header in each I frame (only supports H.264)
--listen        #Wait for a TCP connection
--frames        #Set the number of frames recorded

• For more camera setup instructions, please refer to Official Camera Documentation.

Raspicam User Guide

Introduction

If you are using the Buster version of the image, the Raspicam driver is installed by default in the system, you can directly turn on the camera and use it.
If you are using the latest Bullseye system, you need to install and configure it separately.
Applicable to OV5647, official IMX219, official IMX477.

Install Raspicam (optional)

Open the Raspberry Pi terminal, and enter the following command to install the driver. Note: This driver cannot support a 64-bit Raspberry Pi system temporarily.

sudo apt-get update
cd
sudo apt install cmake
git clone https://github.com/raspberrypi/userland
cd userland
./buildme
cp build/bin/* ~/bin/

Restart the system after installation.

sudo reboot

Call camera

raspistill

The raspistill command is used to take still pictures. Example: raspistill -o cam.jpg

raspivid

The raspivid command is used to record video. Example: raspivid -o vid.h264

raspiyuv

The raspiyuv command has the same function as raspisitll, the difference is that raspiyuv dosen't output jpgs and other standard image files, but generate YUV420 or RGB888 image files from the camera's ISP output.
In most cases, it is better to use raspistill to capture images, but if you want to use uncompressed black and white images, you can choose to use the raspiyuv command. Example: raspiyuv -o cam.jpg

Instruction Setting Options

When the raspicam command is used, the final imaging effect can be adjusted by setting options. The available setting options are listed below for reference.

--preview, -p #Set the preview window <x, y, w, h>

The user can set the position of the preview window by setting the values ​​of x and y, and adjust the resolution of the preview image by setting the values ​​of w and h.

--fullscreen, -f #Fullscreen preview window

Display the preview window in full screen.

--nopreview, -n #Do not display the preview window

Close the preview window and the command will output the image or video directly to a file.

--opacity, -op #Set the transparency of the preview window

Set the transparency of the preview window, 0 is invisible, and 255 is fully transparent.

--sharpness, -sh #Set image sharpness (-100 - 100)

The default sharpening value is 0.

--contrast. -co #Set image contrast (-100 - 100)

The default contrast is 0.

--brightness, -br #Set image contrast (0 - 100)

The default brightness is 50, 0 is fully black, and 100 is full white.

--saturation, -sa #Set image saturation (-100 - 100)

The default saturation is 0.

--ISO #Set shutter sensitivity (100 - 800)

Set sensitivity when taking pictures.

--vstab, -vs #Enable video stabilization

Only the video recording mode is valid, and video stabilization is enabled.

--ev #Set EV compensation

Set the EV compensation value of the image, default 0.

--exposure, -ex #Set exposure mode

Configurable exposure options:

• auto: automatic exposure mode
• night: night shooting mode
• nightpreview
• backlight: backlight mode
• spotlight
• sports: sports mode (the shutter time will be shortened in sports mode)
• snow: snow mode
• beach: beach mode
• verylong: long exposure mode
• fixedfps: fixed fps
• antishake: anti-shake mode
• fireworks: fireworks mode

Note: Depending on the camera model, some modes are not available.

--flicker, -fli #Flicker avoidance

Configurable modes:

• off: turn off anti-flicker mode
• auto: automatic detection of injection frequency
• 50Hz: set the anti-flicker frequency to 50Hz
• 60Hz: set the anti-flicker frequency to 60Hz

--awb, #Set auto white balance mode

• off: disable auto white balance
• auto: auto white balance mode (default)
• sun: sunny mode (5000K ~ 6500K)
• cloud: cloudy mode (6500K ~ 12000K)
• shade: shadow mode
• tungsten: Tungsten mode (2500K ~ 3500K)
• incadescent: Incadescent mode (2500K ~ 4500K)
• flash: flash mode
• horizon: horizon mode
• greyworld: If you are using a camera without an IR filter (eg NoIR), you can fix the white balance misalignment caused by the lack of an IR filter.

Note: Depending on the camera model, some modes are not available.

--imfx, -ifx #Set image filter effect

Configurable image filter effects:

• none: no effect (default)
• negative: color flip
• solarise: sunlight effect
• posterise: poster effect
• whiteboard: whiteboard effect
• backboard: blackboard effect
• sketch: sketch
• denoise: denoise
• emboss: emboss
• oilpaint: oil painting
• hatch: texture
• gpen: pencil sketch
• pastel: colored pencils
• watercolour: watercolor
• film: film
• blur: blur
• saturation: saturation

Note: Depending on the camera model, some modes are not available.

--colfx, -cfx #Set color effect <U:V>

The setting range of the U and V parameters is 0 ~ 255, which are used to adjust the values ​​of the U and Y channels. For example --colfx 128:128 will set the image to monochrome.

--metering, -mm #Set metering mode

Configurable options:

• average: average or full frame metering
• spot: spot metering
• backlit: preset a backlight image
• matrix: matrix metering

--rotation, -rot #Set image rotation (0 - 359)

The image rotation angle can be set by the angle parameter.

--hflip, -hf #Set the image to flip horizontally

Set the image to be flipped horizontally.

--vflip, -vf #Set the image to flip vertically

Flip the image vertically.

--roi, #Crop image <x, y, w, h>

Crop the image according to the parameters, note that the parameters are all planned in (0,0 ~ 1.0), for example, if you want to crop 1/4 of the image, you can use the command - roi 0.5,0.5,0.25,0.25.

--shutter, --ss set shutter speed/time

Set the shutter time (unit: ms). The maximum shutter time that can be set is different depending on the photosensitive chip.

--drc, -drc #Enable/disable dynamic range compression

• off (default)
• low
• med
• high

--stats, -st #Statistics images by static image frames

--awbgains, -awbg

Set blue and green gain, which takes effect if --awb off is set.

--analoggain, -ag

Set the analog gain value

--digitalgain, -dg

Set digital gain value

--mode, -md

Set sensor mode:

• OV5647

• IMX219

• HQ Camera

--camselect, -cs

When multiple cameras are connected to the system, select camera, 0 or 1.

--annotate, -a #enable/set annotations

The parameters are represented by bit masks in the metadata, which can be directly represented by addition. For example, 12 can represent the display time (4) and the display date (8), which is represented by the addition of 4+8 =12.
Configurable options

--annotateex, -ae #Set additional annotation parameters

--stereo, -3d

Set the binocular mode.

• sbs - Side-by-side mode
• tb: - Portrait mode
• off - turn off binocular mode (default)

--decimate, -dec

Halve the width and height of the binocular image.

--setting, -set

Output current camera settings.

raspistill setting parameters

--width, -w         #Set image width
--height, -h        #Set image height
--quality, 0q       #Set JPEG quality <0 ~ 100>
--raw, -r           #Add raw Bayer data to JPEG metadata
--output, -o        #Output file <filename>
--latest, -l        #Associate the last frame image to the file <filename>
--verbose, -v       #Print details
--timeout, -t       #Set the program preview time
--timelapse, -tl    #Set up demo photography
--framestart, -fs   #Save the number of the first frame
--datetime, -dt     #Name the file with DateTime
--timestamp, -ts    #Name files with timestamps
--thumb, -th        #Set thumbnail parameters <x:y:quility>, the default is (64:48:35)
--demo, -d          #Run demo mode <ms>
--encoding, -e      #Encode according to the specified format, jpg, BMP, or png
--restart, -rs      #Set JPEG restart flag
--exif, -x          #Set EXIF ​​flag
--gpsdexif, -gps    #Set real-time Exif time (requires GPS Dongle access)
--fullpreview, -fg  #Fullscreen preview
--keypress, -k      #Keypress camera mode
--signal, -s        #Signal mode
--burst, -bm        #Snapshot mode

raspivid setting parameters

--width, -w         #Set the video width
--height, -h        #Set the video height
--bitrate, -b       #Set bitrate
--output, -o        #Set the output filename <filename>
--listen, -l        #When using a network connection, wait for a network connection
--versbose, -v      #Print details
--timeout, -t       #Set preview time
--demo, -d          #Run demo <ms>
--framerate, -fs    #Set frame rate
--penc, -e          #Display the encoded preview image
--intra, -g         #Set the internal refresh cycle
--qp, -qp           #Set quantization parameters
--profile, -pf      #Specify H264 profile, baseline/main/high
--level, -lev       #Set H264 encoding level
--irefresh, -if     #Set H264 internal refresh type cyclic/adaptive/both/cyclicrows
--inline, -ih       #Insert PPS, SPS header
--spstimings, -stm  #Insert timing information into SPS blocks
--timed, -td        #Timed switch recording and pause function
--keypress, -k      #Keypress to pause recording
--signal, -s        #Switch pause and record state according to SIGUSR1
--split, -sp        #In signal and keypress mode, the file will be recreated every time you re-record
--vectors, -x       #Vector output
--flush, -fl        #Force the output data buffer to be flushed immediately after writing video data, bypassing any OS cache for written data and reducing latency
--save-pts, -pts    #Save timestamp information to the specified file
--codec, -cd        #Specify encoder H264 / MJPEG
--initial, -i       #Set the initial state of startup
--segment, -sg      #Split video stream into multiple files
--wrap, -wr         #Set the maximum value of the split
--start, -sn        #Set the initial split encoding
--raw, -r           #Set metadata file name
--raw-format, -rf   #Specify metadata format yuv/rgb/grey

Call Camera With Demo Code

The official picamera2 library provided by Raspberry Pi is to provide a Python library for libcamera driver.
Note: The Picamera2 only supports the Raspberry Pi OS Bullseye image.

Library Installation

Install picamera2 (Picamera2 is pre-installed in the latest versions of Raspberry Pi OS Bullseye image), and you can update the library on the terminal by the following steps:

sudo apt update
sudo apt upgrade
sudo apt install -y python3-picamera2

CSI Camera Usage

CSI Camera Test

Before using it, you can open the terminal and input the following commands to check whether the camera is normal.

libcamera-hello -t 0 

Preview Window Operation

Parameters

• x - X offset of the Preview Window
• y - Y offset of the Preview Window
• width - Preview window width
• height - Preview window height
• transform - allows the camera image to be flipped horizontally and/or vertically on the monitor.

All parameters are optional, if you want to ignore them, you can select the default value. The following example places a preview window of 800x600 pixels at coordinates (100, 200) on the display screen and horizontally mirrors the camera preview image:

from picamera2 import Picamera2, Preview
from libcamera import Transform
picam2 = Picamera2()
picam2.start_preview(Preview.QTGL, x=100, y=200, width=800, height=600,
transform=Transform(hflip=1))
picam2.start()

Transformation Support

• Transform () - transformation label, default value here.
  
• Transform (hflip=1) - Flip horizontally
  
• Transform (vflip=1) - Flip vertically
  
• Transform (hflip=1, vflip=1) - Horizontal and vertical flip (equivalent to 180-degree rotation)
  

Note: The display transformation here has no impact on the actual image. In the example above, the start_preview() function must be called before picam2.start(). If the camera's image has a different aspect ratio than the preview window, it will be letter-boxed or pillar-boxed to maintain the appropriate aspect ratio.

No Preview Window

Generally, the preview window is to receive and pass camera images for driving libcamera to the applications, and then, recycling them back to libcamera when they are no longer needed by the user. As a result, something needs to be running to receive and return these camera images even if no preview images are displayed. This is exactly what No Preview does. It shows nothing; it simply drives the camera system. No preview means that the camera self-start function (picam2.start()) is not run when the camera system starts, which is why the alternative preview window must be launched earlier. You can explicitly start No Preview like this:

from picamera2 import Picamera2, Preview
picam2 = Picamera2()
picam2.start_preview(Preview.NULL)

Start And Stop Preview

The first parameter of the start_preview function adopts the following value:

• None - No preview of any kind is launched. The application must provide its code to drive the camera system.
• False - NULL preview starts.
• True - One of the other three previews has started.

It is not recommended to start and stop the preview window at the same time. The start function takes a show_preview parameter that can be any one of these same values. It's just a shorthand to reduce code verbosity. Note that stopping the camera (Picamera2.stop) does not stop the preview window, so you must explicitly call stop_preview before that. For example, the following script will start the camera system running, run for a while, and then attempt to automatically detect which preview window to use so that the actual image display begins:

from picamera2 import Picamera2, Preview
import time
picam2 = Picamera2()
config = picam2.create_preview_configuration()
picam2.configure(config)
picam2.start() #Camera starts to capture  
time.sleep(2) #2 seconds delay for waiting for camera initialization to complete
picam2.stop_preview() #Stop the camera preview to prevent it from hogging resources and thus failing to turn on the camera
picam2.start_preview(True) #Start camera preview
time.sleep(2) #Turn off the camera after two seconds.

Advanced API of Picamera2

Picamera2 supports some advanced and convenient functions for capturing images and video recording. It can capture images with just a few lines of code.

from picamera2 import Picamera2
picam2 = Picamera2()
picam2.start_and_capture_file("test.jpg")

Also, you can use the "start_and_capture_files" function to capture multiple images, or record a 5s video:

from picamera2 import Picamera2
picam2 = Picamera2()
picam2.start_and_record_video("test.mp4", duration=5)

If you want to learn the underlying codes, you can refer to the following codes:

from picamera2 import Picamera2, Preview
import time
picam2 = Picamera2() # Create a Picamera2 example
camera_config = picam2.create_preview_configuration() # Create camera preview configuration  
picam2.configure(camera_config) # Configure camera
picam2.start_preview(Preview.QTGL) # Start camera preview (use QTGL preview window manager)
picam2.start() # Start the camera
time.sleep(2) # Wait for 2s to ensure the camera is started  
picam2.capture_file("test.jpg")  # Save the photo as "test.jpg"

Configure Camera

Picamera2 provides multiple configuration generation methods, suitable for providing appropriate configuration, and the common examples are shown below:

• Picamera2. create_preview_configuration generates a configuration suitable for displaying the camera preview image on the monitor or before capturing a still image.
• Picamera2. create_still_configuration generates a configuration suitable for capturing high-resolution still images.
• Picamera2. create_video_configuration generates a configuration suitable for recording video files.

For example, set the camera to transmit the preview image stream that you may be using.

from picamera2 import Picamera2
picam2 = Picamera2()
config = picam2.create_preview_configuration()
picam2.configure(config)
picam2.start()

General Parameter Configuration

• transform - Whether the camera image is horizontally or vertically mirrored, or both (given a 180-degree rotation).

You can use the "transform" key parameters to pass the transformation to all the configuration methods, note that Picamera2 only supports the above transformation. Other transformations (including image transformation) exist but are not supported. If it is unspecified, the transformation is on the units by default. As shown below:

from picamera2 import Picamera2
from libcamera import Transform
picam2 = Picamera2()
preview_config = picam2.create_preview_configuration(transform=Transform(hflip=True))

• colour_space - Output the color space of the image. The mainstream and lores stream should share a common color space. The original stream is always in a camera-specific color space.

The implementation of color spaces in libcamera is very close to the Linux V4L2 API. Specific choices include providing transfer functions, YCbCr encoding matrices and quantization (or range) for each primary color. Additionally, libcamera provides convenient shorthand forms for commonly used color spaces:

>>> from libcamera import ColorSpace
>>> ColorSpace.Sycc()
<libcamera.ColorSpace 'sYCC'>
>>> ColorSpace.Rec709()
<libcamera.ColorSpace 'Rec709'>

These are the only color spaces supported by the Pi camera system. The desired choices can be passed to everyone using the color_space keyword parameter in the configuration generation methods:

from picamera2 import Picamera2
from libcamera import ColorSpace
picam2 = Picamera2()
preview_config = picam2.create_preview_configuration(colour_space=ColorSpace.Sycc())

When omitted, Picamera2 will select the default value based on the use case:

• The create_preview_configuration and create_still_configuration will default to using the sYCC color space with average sRGB primaries, transfer functions and full-range BT.601 YCbCr encoding.
• If the mainstream request for RGB format, create_video_configuration selects sYCC. For YUV format, if the resolution is less than 1280x720, it will select SMPTE 170M, otherwise, it will select Rec.709.

• buffer_count - The number of buffers allocated to the camera system. A set of buffers indicates one buffer for each requested stream.

This defines how many sets of buffers (one for each request stream) are allocated for the camera system's use. Allocating more buffers may result in smoother camera operation, reducing dropped frames. The downside is that, especially at high resolutions, there may not be enough available memory.
• create_preview_configuration requests four buffers.
• create_still_configuration only requests one buffer (Because these are usually large full-resolution buffers).
• create_video_configuration requests six buffers, as the additional workflow involved in encoding and outputting video makes it more susceptible to jitter or latency, which can be alleviated by having a longer buffer queue. The number of buffers can be overridden using the buffer_count keyword in all configuration generation methods:

from picamera2 import Picamera2
picam2 = Picamera2()
preview_config = picam2.create_still_configuration(buffer_count=2)

• queue - Whether the system allows frame queuing for capture requests.

By default, Picamera2 retains the last frame received from the camera, which may be returned to you when you make a capture request. This is useful for burst captures, especially when the application may take slightly longer than a frame cycle for some processing. In these cases, queued frames can be returned immediately rather than idling until the next camera frame arrives.
However, this does mean that the returned frame may be slightly earlier than when the capture request occurred, up to one frame cycle. If this behavior is not needed, set the queue parameter to False. For example:

from picamera2 import Picamera2
picam2 = Picamera2()
preview_config = picam2.create_preview_configuration(queue=False)

Note that when buffer_count is set to 1 (Still the default for capture configurations), there is no frame queuing (because the only buffer will stop the camera channel).

• display - The stream with this name (if any) will be displayed in the preview window. It doesn't affect the camera image in any way but only influences how Picamera2 handles them.

Usually, we display the mainstream on the preview window, in some cases, it is best to display the low-resolution image (from lores stream), and we can use:

from picamera2 import Picamera2
picam2 = Picamera2()
config = picam2.create_still_configuration(lores={"size": (320, 240)}, display="lores")

This will request a full-resolution mainstream but will also display a QVGA image stream subsequently (even if the application hasn't explicitly requested, the mainstream is always defined). The display parameter can take a value of None, which means no image will be rendered in the preview window. This is the default choice for the create_still_configuration method.

• encode - The stream with this name (if any) is the one to be encoded if a video recording begins. This also doesn't affect the camera image in any way but only influences how Picamera2 handles them.

This is similar to the display parameter as it names the stream to be encoded when the video recording begins as either "main" or "lores". By default, encoding is typically done on the mainstream, but a user may have an application where they want to record a lower-resolution video stream:

from picamera2 import Picamera2
picam2 = Picamera2()
config = picam2.create_video_configuration(main={"size": (2048, 1536)}, lores={"size": (320,
240)}, encode="lores")

It will allow recording of QVGA streams while allowing simultaneous capture of 2048 × 1536 still images. The encoding parameter can also take the value None, which is the default method of choice for create_still_configuration.

Auto-focus Function

• Only for cameras with auto-focus function.

Autofocus control, like other controls, follows the same general rules. As long as you are using a version of libcamera (such as libcamera) where these controls work (provided by Raspberry Pi) and correctly implement the autofocus API released by libcamera, and the attached camera module has autofocus (like the Raspberry Pi Camera Module 3), it should work as expected.
Camera modules without auto-focus function (including the earlier version of Raspberry Pi cameras and HQ cameras), these options can not be used (in Picamera2.camera_controls), and it fails when trying to set it. The following is to set the camera in continuous auto-focus mode:

from picamera2 import Picamera2
from libcamera import controls
import time
picam2 = Picamera2()
config = picam2.create_preview_configuration()
picam2.configure(config)
picam2.start(show_preview=True)
picam2.set_controls({"AfMode": controls.AfModeEnum.Continuous})
time.sleep(2)

USB Camera

Picamera2 has limited support for USB cameras (such as webcams). Multiple USB cameras and CSI2 cameras (connected to the dedicated camera port on the Pi) can be connected, and you can create a Picamera2 object in the usual way, but only the mainstream is available. The supported formats will depend on the camera, but Picamera2 can, in principle, handle MJPEG and YUYV cameras. If the camera supports both formats, you can choose by requesting the format 'MJPEG' or 'YUYV'.
USB cameras can only use the software-rendered Qt preview window (preview.Qt). There is no hardware-accelerated rendering support. MJPEG streams can be directly rendered, but YUYV requires the installation of OpenCV to convert the images to a format understandable by Qt. Both cases will use a significant amount of additional CPU.
The capture_buffer method will provide you with the raw camera data for each frame (JPEG bitstream from an MJPEG camera or uncompressed YUYV image from a YUYV camera). For example:

from picamera2 import Picamera2, Preview
picam2 = Picamera2()
config = picam2.create_preview_configuration({"format": "MJPEG"})
picam2.configure(config)
picam2.start_preview(Preview.QT)
picam2.start()
jpeg_buffer = picam2.capture_buffer()

If you have more than one camera and need to discover which camera to turn on, use the Picamera2.global_camera_info method. In general, users should assume that other features such as video recording, and camera control are not available on supported Raspberry Pi cameras, etc. USB cameras are also not hot-swappable and should be completely shut down and restarted when adding or subtracting cameras.

• For more details, you can refer to picamera2 official manual.

Resources

• User manual
• Dimensions

Support