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Computing intensities from Pixy2

Hi all,

I’d like to compute intensities from underwater images, like the one below, utilizing the Pixy2 and the provided getRGB function.


An intensity analysis of the underwater image with MATLAB reveals that the group of pixels that embody the beacon have the an average intensity greater that the intensities of all the other pixels in the image. Here’s the resulting plot:


I wrote an algorithm on an Arduino Uno with the getRGB function to search the image for a block of pixels with an intensity greater than or equal to 0.8. However, when I compute intensities utilizing the getRGB function, all the intensities were in the range 0.6 to 0.73. Turning off the “Auto Exposure Correction” didn’t help. I know that the getRGB function averages the groups of 5 by 5 pixels to obtain a representative result. Any suggestions?

You should pass a false into the saturate argument:

Saturate will amplify all pixels so you can extract the hue. Turning it off will return the true RGB values (unsaturated).


Hi Edward,

Thank you! I will pass a false into the saturate argument and observe what results I get this Sunday.