What would be the best way to isolate these squares?

Question

I've been following this tutorial , but the problem is, my squares have illustrations on it, which causes opencv to pick up on those as well. At least, I think that's what the problem is.

Original image:

I am aware this might work better with a black background but this is all I have to work with for now.

This is the result of my attempt:

windows, python2, opencv3.3-dev

Answer 1

Try to process the S channel in HSV space like this.

1. convert to hsv
2. seperate the s-channel
3. threshold the s-channel
4. some other post-process(such as morph-op)