I'm trying to extract signs from images and classify them. Extracting the signs and doing some classifications already works quite good.
Now I struggle with the simple classification if the sign is completely empty or contains some text. I don't need to do OCR on the text or anything related I just need a simple measure to decide between those two classes. One issue is dirt on the signs I have to classify. Simple thresholding and counting black vs. white pixels doesn't work because pixels counts are sometimes very close.
What would be a good approach to start classification in my case?