Amb82 mini: how to set white balance and region of interest?

Technical Discussion
1

Hello, I got a nice amb82 mini module.
My images are way to bright and I need to find a way to set the white balance via arduino ide code.
There should be a way to activate, or tune, the automatic white balance but I cannot find any information on this. Can anybody please tell me how to do it?

I would also like to limit the area of the image, for instance if you only need a part of the image in many other modules you can specify a “roi” or region of interst by specifying x, y, width and lenght of the region and only that will be captured.

Thank you in advance

2

hi @ruspa, you may test on finding the parameters at this 4 files: video_drv.c, video_drv.h, VideoStream.cpp and VideoStream.h in your Arduino environment on your PC. Thank you.

3

thanks, I found white balance and exposure functions in the new libraries package.
I still miss the region of interest, or a digital (=fake) zoom as my amb82 module stays inside front door’s peephole, and the image obviously is all black with a small circle in the center, which is the part that needs to be displayed.
Chances are that by zooming or cropping the auto exposure and auto white balance will behave better.
Is region of interest/zoom available?

4

Hi @ruspa ,

You may find the usages of roi on video_drv.c in line 203 and currently zooming feature is not available. Thank you so much!

5

thank you Kai!

6

I think that these lines in video_drv.c refer to something internal for neural networks object detection, I’m not sure if it can be used in my case.
In my streaming sketch I initialize the camera with this (pseudo) code

#define CHANNEL 0
VideoSetting config(VIDEO_HD, CAM_FPS, VIDEO_JPEG, 1);
Camera.configVideoChannel(CHANNEL, config);
Camera.videoInit();
Camera.channelBegin(CHANNEL);

I found that by adding this lines I can fiddle with the contrast and exposure etc, even if I don’t really notice any change in how the video looks:
CameraSetting configCam;
configCam.setContrast(xyz);
configCam.setExposureTime(xyz);

I think there should be some .setRoi(x,y,w,h) method or someting similar but I can’t really find it. In the libraries there are some sections for setting the region of interest, but these seem unrelated to the classtypes I use in my code.
I wish there was an example available to help us understand how to set this parameter.