Testing photonvision with a raspberry Pi and a Pi camera v1.3. The image is very washed out. I tried with two different Pi cameras and it looks the same. Has anyone else been able to get a Pi camera to work?
Turn down your exposure and brightness?
It’s still a pretty poor quality image. Maybe that’s all a Pi camera can do…
we use a PS3 cam with a Pi and PhotonVision…it works very well.
The grey in the image is produced by the “brightness” slider - it just multiplies each pixel value by a scalar to make the image appear lighter. This has the side effect of compressing all the pixel data into a smaller range, near white. It should be used sparingly.
Exposure will change the actual duration the camera shutter is open to the outside world, which in turn changes how much light the camera collects. It should increase/decrease the apparent brightness of the image, but without the grey/whiteout effect.
Note that there are some practical limits to this. To maintain a high framerate, you have to keep the exposure duration fairly small, which means the image stays dark. Increasing the resolution can help make a brighter image. One of the open action items for the summer is to develop a framerate-limiting feature at low resolution to allow for more light to come into the camera even at low resolutions.
The reason this isn’t present is historical. Largely, up till 2022, most FRC games relied heavily on retroreflective targets which need low exposure. 2022 was one of the first years tracking a normally-illuminated colored shape was as useful (or possibly more useful) than tracking the retroreflective target.
One final note- most brands of picam’s do allow for manual focus by twisting plastic around the lens. Once you have a solid image showing up, you may need to play with the focus to make things sharp.
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