Is it possible to compare two images using Robot Framework? I tried one solution using OpenCV that compares two images, but it's getting difficult to write something specific to Robot Framework.
Robot framework itself doesn't have any such feature. However, it's possible to write a custom keyword to do it. I worked on a team a few years ago that built some keywords based on the ImageMagick library. You can either have the keywords import the imagemagick library itself, or use the imagemagick cli.
For more information see “Diff” an image using ImageMagick