Feature request: diffing images

[mateusza]

Description

This is a feature request.

The feature is visual comparison of images.
This feature is available in GitHub and BitBucket:
https://help.github.com/en/articles/rendering-and-diffing-images

Ideally following methods of comparing images should be implemented:

• side by side
• overlay
• blend
• mark changed pixels

[arthur-bauer]

Yes please. This would make a big difference for us here.

[saitho]

Hey there. I submitted a pull request for the "side by side" part.
That part was pretty easy. The others would require more work. ;)

[lunny]

closed by #6784