CSI-Camera

Simple example of using a MIPI-CSI(2) Camera (like the Raspberry Pi Version 2 camera) with the NVIDIA Jetson Nano Developer Kit. The camera should be installed in the MIPI-CSI Camera Connector on the carrier board. The pins on the camera ribbon should face the Jetson Nano module.

To test the camera:

$ gst-launch-1.0 nvarguscamerasrc ! 'video/x-raw(memory:NVMM),width=3820, height=2464, framerate=21/1, format=NV12' ! nvvidconv flip-method=0 ! 'video/x-raw,width=960, height=616' ! nvvidconv ! nvegltransform ! nveglglessink -e

There are three examples:

simple_camera.py is a Python script which reads from the camera and displays to a window on the screen using OpenCV:

$ python simple_camera.py

face_detect.py is a python script which reads from the camera and uses Haar Cascades to detect faces and eyes:

$ python face_detect.py

Haar Cascades is a machine learning based approach where a cascade function is trained from a lot of positive and negative images. The function is then used to detect objects in other images.

See: https://docs.opencv.org/3.3.1/d7/d8b/tutorial_py_face_detection.html

The third example is a simple C++ prgoram which reads from the camera and displays to a window on the screen using OpenCV:

$ g++ -std=c++11 -Wall -I/usr/lib/opencv simple_camera.cpp -L/usr/lib -lopencv_core -lopencv_highgui -lopencv_videoio -o simple_camera

$ ./simple_camera

Notes

Camera Image Formats

You can use v4l2-ctl to determine the camera capabilities. v4l2-ctl is in the v4l-utils:

$ sudo apt-get install v4l-utils

For the Raspberry Pi V2 camera the output is (assuming the camera is /dev/video0):

$ v4l2-ctl --list-formats-ext
ioctl: VIDIOC_ENUM_FMT
	Index       : 0
	Type        : Video Capture
	Pixel Format: 'RG10'
	Name        : 10-bit Bayer RGRG/GBGB
		Size: Discrete 3280x2464
			Interval: Discrete 0.048s (21.000 fps)
		Size: Discrete 3280x1848
			Interval: Discrete 0.036s (28.000 fps)
		Size: Discrete 1920x1080
			Interval: Discrete 0.033s (30.000 fps)
		Size: Discrete 1280x720
			Interval: Discrete 0.017s (60.000 fps)
		Size: Discrete 1280x720
			Interval: Discrete 0.017s (60.000 fps)

GStreamer Parameter

For the GStreamer pipeline, the nvvidconv flip-method parameter can rotate/flip the image. This is useful when the mounting of the camera is of a different orientation than the default.

flip-method         : video flip methods
                        flags: readable, writable, controllable
                        Enum "GstNvVideoFlipMethod" Default: 0, "none"
                           (0): none             - Identity (no rotation)
                           (1): counterclockwise - Rotate counter-clockwise 90 degrees
                           (2): rotate-180       - Rotate 180 degrees
                           (3): clockwise        - Rotate clockwise 90 degrees
                           (4): horizontal-flip  - Flip horizontally
                           (5): upper-right-diagonal - Flip across upper right/lower left diagonal
                           (6): vertical-flip    - Flip vertically
                           (7): upper-left-diagonal - Flip across upper left/low

Release Notes

Initial Release March, 2019

• L4T 32.1.0 (JetPack 4.2)
• Tested on Jetson Nano