my watermeter does not detect numbers corectly

[jtolksdo]

Hi,
I'm trying to set my watermeter for weeks now. Whatever I try, I'm not getting a good result, hence I'm now asking this forum for support. Sometimes my image has a yellow tone I do not know why. But this happens just every 20th image.

My reference image looks like this:

My ROI recognition image:

[SybexX]

1. Should you better set the camera focus

The font should be easy to read

2. After that you have to put your ROIs better

[jtolksdo]

Thanks a million! I was just too scrared optimizing the focus once more, as I destroyed the lens lat time entirely. I changed the housing once more to bring the cam closer to the meter once more. I removed the circular-pol filter though, as the reflections were not really removed with the filter. Worst case, I need to apply external light, which I try to avoid due to yet another soldering effort....

[SybexX]

You could try to increase CamGainceiling and reduce the LED intensity at the same time to minimize the reflections.

[jtolksdo]

I increased gain from x4 to x16 and reduced LED from 100 to 30, but I cannot get rid of the reflection. I tried also to add foam in front of the LED to spread the light, also added a sheet of paper to spread it, but no luck.

Would you say I rather get back to x4 and increase LED to have a better sharpened image?

[SybexX]

I personally would not do it, since the increase in the LED intensity also means an increase in the temperature of the ESP32 at the same time and this can have a negative impact on WiFi, SD cards lifespan..........
Have you ever tried to improve image quality with the other parameters such as Brightness, Contrast and Saturation............?
For the OV2640 camera I always set Camgainceiling on x8 or x16 and even on x128 and higher for the OV5640 camera.

[jtolksdo]

I only have the OV2640 camera. I'll play around a bit with brightnss / contrast etc. Thanks mate for the help!!