Capturing images using libcamera in Microchip platforms
Last modified by Microchip on 2025/11/24 07:26
Introduction
libcamera is an open-source software library handling image signal processors and embedded cameras that is supported on Linux based distributions. Refer libcamera architecture to know more about the architecture
Here is a block diagram from the official libcamera page
--------------------------< libcamera Public API >---------------------------
^ ^
| |
v v
+-------------+ +---------------------------------------------------+
| Camera | | Camera Device |
| Manager | | +-----------------------------------------------+ |
+-------------+ | | Device-Agnostic | |
^ | | | |
| | | +--------------------------+ |
| | | | ~~~~~~~~~~~~~~~~~~~~~~~ |
| | | | { +-----------------+ } |
| | | | } | //// Image //// | { |
| | | | <-> | / Processing // | } |
| | | | } | / Algorithms // | { |
| | | | { +-----------------+ } |
| | | | ~~~~~~~~~~~~~~~~~~~~~~~ |
| | | | ========================== |
| | | | +-----------------+ |
| | | | | // Pipeline /// | |
| | | | <-> | /// Handler /// | |
| | | | | /////////////// | |
| | +--------------------+ +-----------------+ |
| | Device-Specific |
| +---------------------------------------------------+
| ^ ^
| | |
v v v
+--------------------------------------------------------------------+
| Helpers and Support Classes |
| +-------------+ +-------------+ +-------------+ +-------------+ |
| | MC & V4L2 | | Buffers | | Sandboxing | | Plugins | |
| | Support | | Allocator | | IPC | | Manager | |
| +-------------+ +-------------+ +-------------+ +-------------+ |
| +-------------+ +-------------+ |
| | Pipeline | | ... | |
| | Runner | | | |
| +-------------+ +-------------+ |
+--------------------------------------------------------------------+
/// Device-Specific Components
~~~ Sandboxing
Traditionally the camera interfaces in linux4sam platforms are configured using media-ctl and v4l2-ctl commands. Each entities in the pipeline has to be configured separately. Libcamera provides a higher level, flexible interface to manage this complexity.
It abstracts away the hardware differences and provides a consistent interface making it easier for application developers to support multiple devices. It provides control over camera pipelines, including white balance, gain and sensor tuning which is very critical for high quality image capture.
Microchip specific pipeline handler
In libcamera, a pipeline handler is a core component responsible for interfacing with camera hardware. It manages the media devices, configures the camera pipeline, and handles image capture operations. Each hardware platform typically requires a specific pipeline handler to accommodate its unique architecture and capabilities.The pipeline handler is a component of libcamera that is device specific. It manages the complex pipelines exposed by the kernel drivers through the Media Controller and V4L2 APIs. You can find the supported devices in the libcamera source in the following path src/libcamera/pipeline. The microchip ISC pipeline handler is implemented here
Capturing images using mchpcam-still
mchpcam-still is a comprehensive userspace demo application that can configure the microchip ISC and capture images. The application supports various image processing options and algorithms that are explained below with few examples.
Features in mchpcam-still
root@sama7g5ek-sd:~# mchpcam-still -h Usage: mchpcam-still [options] Camera options: -c, --camera=CAMERA Camera index or name -o, --output=FILE Output file name (default: output.jpg) -f, --format=FORMAT Set pixel format (YUYV, RGB565) --width=WIDTH Set capture width --height=HEIGHT Set capture height Image options: --jpeg-quality=VALUE Set JPEG quality (1-100, default: 95) --png-compression=VALUE Set PNG compression level (0-9, default: 6) --raw Save raw sensor data instead of processed image --image-format=FORMAT Set output image format (jpeg, png, raw) Image control options: --brightness=VALUE Set brightness (-100 to 100) --contrast=VALUE Set contrast (0 to 100) --gamma=VALUE Set gamma (0 to 2) White balance control options: --awb=MODE Set white balance mode (auto, daylight, cloudy, tungsten, fluorescent, shade, manual) --awb-enable Enable auto white balance --red-gain=VALUE Set red component gain (0 to 8191) --blue-gain=VALUE Set blue component gain (0 to 8191) --green-red-gain=VALUE Set green-red component gain (0 to 8191) --green-blue-gain=VALUE Set green-blue component gain (0 to 8191) --red-offset=VALUE Set red component offset (-4095 to 4095) --blue-offset=VALUE Set blue component offset (-4095 to 4095) --green-red-offset=VALUE Set green-red component offset (-4095 to 4095) --green-blue-offset=VALUE Set green-blue component offset (-4095 to 4095) Image processing options: --enable-agc Enable Automatic Gain Control --disable-agc Disable Automatic Gain Control --enable-ccm Enable Color Correction Matrix --disable-ccm Disable Color Correction Matrix --enable-awb Enable Auto White Balance processing --disable-awb Disable Auto White Balance processing --enable-all Enable all IPA algorithms --disable-all Disable all IPA algorithms General options: -h, --help Print this help message root@sama7g5ek-sd:~# mchpcam-still Requested resolution: 1920x1080 [0:01:33.153693200] [256] INFO Camera camera_manager.cpp:313 libcamera v0.0.0+4933-linux4microchip-2025.04-46-gf7268d4e-dirty (2025-11-20T21:41:40UTC) [0:01:33.275917400] [257] WARN CameraSensor camera_sensor.cpp:259 'imx219 1-0010': Recommended V4L2 control 0x009a0922 not supported [0:01:33.276343000] [257] WARN CameraSensor camera_sensor.cpp:331 'imx219 1-0010': The sensor kernel driver needs to be fixed [0:01:33.276561400] [257] WARN CameraSensor camera_sensor.cpp:333 'imx219 1-0010': See Documentation/sensor_driver_requirements.rst in the libcamera sources for more information [0:01:33.283437800] [257] WARN CameraSensor camera_sensor.cpp:479 'imx219 1-0010': Failed to retrieve the camera location [0:01:33.283731200] [257] WARN CameraSensor camera_sensor.cpp:501 'imx219 1-0010': Rotation control not available, default to 0 degrees [0:01:33.292656200] [257] WARN V4L2 v4l2_pixelformat.cpp:344 Unsupported V4L2 pixel format AR12 [0:01:33.293215000] [257] WARN V4L2 v4l2_pixelformat.cpp:344 Unsupported V4L2 pixel format AR15 [0:01:33.295589600] [257] WARN V4L2 v4l2_pixelformat.cpp:344 Unsupported V4L2 pixel format AR12 [0:01:33.296082000] [257] WARN V4L2 v4l2_pixelformat.cpp:344 Unsupported V4L2 pixel format AR15 [0:01:33.298220400] [257] WARN V4L2 v4l2_pixelformat.cpp:344 Unsupported V4L2 pixel format AR12 [0:01:33.298672800] [257] WARN V4L2 v4l2_pixelformat.cpp:344 Unsupported V4L2 pixel format AR15 [0:01:33.301196400] [257] WARN V4L2 v4l2_pixelformat.cpp:344 Unsupported V4L2 pixel format AR12 [0:01:33.301672200] [257] WARN V4L2 v4l2_pixelformat.cpp:344 Unsupported V4L2 pixel format AR15 [0:01:33.303834600] [257] WARN V4L2 v4l2_pixelformat.cpp:344 Unsupported V4L2 pixel format AR12 [0:01:33.304280600] [257] WARN V4L2 v4l2_pixelformat.cpp:344 Unsupported V4L2 pixel format AR15 [0:01:33.306378600] [257] WARN V4L2 v4l2_pixelformat.cpp:344 Unsupported V4L2 pixel format AR12 [0:01:33.306947400] [257] WARN V4L2 v4l2_pixelformat.cpp:344 Unsupported V4L2 pixel format AR15 [0:01:33.309073600] [257] WARN V4L2 v4l2_pixelformat.cpp:344 Unsupported V4L2 pixel format AR12 [0:01:33.309521400] [257] WARN V4L2 v4l2_pixelformat.cpp:344 Unsupported V4L2 pixel format AR15 [0:01:33.311793600] [257] WARN V4L2 v4l2_pixelformat.cpp:344 Unsupported V4L2 pixel format AR12 [0:01:33.312249200] [257] WARN V4L2 v4l2_pixelformat.cpp:344 Unsupported V4L2 pixel format AR15 [0:01:33.314169600] [257] INFO MicrochipISC microchip-isc.cpp:774 Registered camera '/base/soc/flexcom@e2818000/i2c@600/camera@10' [0:01:33.314390000] [257] INFO MicrochipISC microchip-isc.cpp:778 Camera registration complete with HARDWARE HISTOGRAM support [0:01:33.316156200] [256] INFO Camera camera.cpp:1183 configuring streams: (0) 1920x1080-RGB565 [0:01:33.319234800] [257] INFO ISC_IPA microchip_isc_ipa.cpp:77 Configuring IPA for sensor: imx219 (1920x1080) [0:01:33.320535400] [257] INFO MicrochipISC microchip-isc.cpp:896 ✅ IPA configured successfully [0:01:33.320892600] [257] INFO MicrochipISC microchip-isc.cpp:914 Camera configuration complete: /base/soc/flexcom@e2818000/i2c@600/camera@10 Camera configured with format: RGB565 (1920x1080) AUTOMATIC AWB (Advanced IPA) Using advanced IPA AWB algorithms STILL MODE - Immediate classification Configured for capture: 1920x1080 format: RGB565 Enabled IPA Algorithms: AWB, AGC, CCM Capturing image... [0:01:34.500781000] [257] INFO V4L2 v4l2_videodevice.cpp:1846 /dev/video1[14:cap]: Zero sequence expected for first frame (got 7) Sequence: 000007 timestamp: 94530774000 [0:01:34.536466800] [257] WARN ISC_COMMON common.cpp:38 Invalid channel mean R[1]: 67913.5 [0:01:34.537232200] [257] WARN ISC_IPA microchip_isc_ipa.cpp:182 Hardware stats validation failed [0:01:34.538835800] [257] WARN ISC_COMMON common.cpp:38 Invalid channel mean R[1]: 67913.5 [0:01:34.539426800] [257] WARN ISC_AWB awb.cpp:63 Invalid image statistics - skipping AWB [0:01:34.540769400] [257] WARN ISC_COMMON common.cpp:38 Invalid channel mean R[1]: 67913.5 [0:01:34.586363400] [257] INFO ISC_CCM ccm.cpp:436 Selected CCM: Daylight_Vivid (score=3.19623) [0:01:34.599335000] [257] INFO MicrochipISC microchip-isc.cpp:1427 ✅ AWB values written to ISC hardware [0:01:34.603161200] [257] INFO MicrochipISC microchip-isc.cpp:1555 ✅ Sensor hardware controls applied successfully Captured image with resolution: 1920x1080 Format conversion completed successfully Saved JPEG image to output.jpg with quality 95 File saved successfully!
Capture a high-quality image with specific resolution:
root@sama7g5ek-sd:~# mchpcam-still --width=1920 --height=1080 --jpeg-quality=100 -o high_quality.jpg
Capture with specific white balance mode:
root@sama7g5ek-sd:~# mchpcam-still --awb=daylight -o daylight_scene.jpg
Capture with custom white balance settings:
root@sama7g5ek-sd:~# mchpcam-still --awb=manual --red-gain=2000 --blue-gain=3500 -o custom_wb.jpg
Capture at 640x480 resolution with YUV format:
root@sama7g5ek-sd:~# mchpcam-still --width=640 --height=480 --format=YUYV -o small.jpg