Some utilities for working with RaspberryPi cameras with the picamera2 python library.
The tools all work by creating a processing pipeline using python's generator functions and then iterating over the output to activate the processing. It's a pretty simple way to put things together and I've found it easy to understand and extend.
The tools include:
| Tool | Description |
|---|---|
| cam-info.py | displays some basic information about the camera capabilities |
| cam-preview.py | starts the camera with a preview output |
| cam-capture.py | captures a sequence of images to disk |
| cam-click.py | uses a flirc usb receiver to trigger image captures |
| cam-focus.py | runs an autofocus algorithm from live camera or image files.. a work in progress |
Install the necessary system packages:
sudo apt install python3-pip python3-picamera2 python3-libcamera python3-opencv python3-numpy python3-pil
To use the cam-click.py utility, you will also need the evdev python package:
pip3 install --user evdev
Displays the information about the camera available from the picamera2 library.
./cam-info.py
Simply creates and initialises the camera and starts a preview at HD resolution.
Useful to make sure everything is connected and ready and is a chance to focus the camera.
./cam-preview.py
Capture a sequence of still images from the camera. Options include the delay between successive captures,
the sensor mode to use (see cam-info.py for options), saving raw images as well as jpegs, and the
total number of images to capture.
$ ./cam-capture.py -h
usage: cam-capture.py [-h] [-p] [-m SENSOR_MODE] [-r] [-d DELAY] [-n NUM_IMAGES] outdir
positional arguments:
outdir output directory to save images
optional arguments:
-h, --help show this help message and exit
-p, --preview run the preview
-m SENSOR_MODE, --sensor-mode SENSOR_MODE
the sensor mode for the camera (default: 10)
-r, --capture-raw capture raw images as well as the jpeg
-d DELAY, --delay DELAY
delay in seconds between captures (default: 5)
-n NUM_IMAGES, --num-images NUM_IMAGES
number of images to capture (default: 10)
An example run:
$ ./cam-capture.py -n 6 -r -p images
saved images/1693780889/img-0000-image.jpg
saved images/1693780889/img-0000-raw.dat
saved images/1693780889/img-0001-image.jpg
saved images/1693780889/img-0001-raw.dat
saved images/1693780889/img-0002-image.jpg
saved images/1693780889/img-0002-raw.dat
This uses a flirc usb receiver to trigger captures. I've been using an old AppleTV remote as the controller.
Once you have configured the device to work with your remote control, plug it into the raspberry pi and run the command and it should all work. Use the key you programmed as 'ENTER' to capture an image and the key programmed as 'ESC' to quit the application.
The command takes the following form:
$ ./cam-click.py -h
usage: cam-click.py [-h] [-v] [-p] [-m SENSOR_MODE] [-r] outdir
positional arguments:
outdir output directory to save images
optional arguments:
-h, --help show this help message and exit
-v, --verbose print remote control events
-p, --preview run the preview
-m SENSOR_MODE, --sensor-mode SENSOR_MODE
the sensor mode for the camera (default: 10)
-r, --capture-raw capture raw images as well as the jpeg
An example run:
$ ./cam-click.py -p images
00 saved images/1693781264/img-0000-image.jpg
01 saved images/1693781264/img-0001-image.jpg
02 saved images/1693781264/img-0002-image.jpg
Check the camera focus using a numeric algorithm. Start the application and then manually focus the HQ camera to see the number varying. The higher the number, the sharper (better focussed) the image.
The actual value of the number will depend on the image contents - but the higher the better.
It only considers the region around the centre of the image which is, by default, 25% of the width and height, but can be overridden on the command line.
Usage information is:
$ ./cam-focus.py -h
usage: cam-focus.py [-h] [-r ROI] [-s SMOOTH_ALG] [-f FOCUS_ALG] [imgdir]
positional arguments:
imgdir directory to read images from (default: camera)
optional arguments:
-h, --help show this help message and exit
-r ROI, --roi ROI centre percentage of image to use (default: 25)
-s SMOOTH_ALG, --smooth-alg SMOOTH_ALG
the smoothing algorithm (default: hqlib.bilateral)
-f FOCUS_ALG, --focus-alg FOCUS_ALG
the focus measure algorithm (default: hqlib.var_of_laplacian)
By default, images are read from the camera and smoothed with the smoothing algorithm, and a contrast or focus measure calculated with the focus algorithm. There are a few available in the code - check the module to find them.
If an imgdir is specified, the images are read from disk.