I'm currently preprocessing a few images before I can use them for edge detection and I need to make the edges more clear so that the edge algorithm (Canny and Hough) can find them more easily without the need to reconfigure the thresholds. The only important part of the photo that I need are the edges from the items on the pile, the rest is irrelevant.
I have the following images:
How would you make the edges between the items on the pile stand out?