Earlier quoted context omitted.
Now automate it for 200 screenshots
If this is indeed the underlying algorithm it should not be hard to implement
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Image-diff – Create an image differential between two images
21–27 of 27 posts
Re: Image-diff – Create an image differential between two images
#22Combine this with my webscrot and diff development vs production websites :-)
Re: Image-diff – Create an image differential between two images
#23This is cool, and a good idea. I will try it out, but I can highly recommend the existing pdiff utility for your image regression testing. http://pdiff.sourceforge.net Pdiff allows you to specify perceptual thresholds of visibility, so diffs that are not pixel perfect can still pass if they're 'good enough'. Semi-critical if you render the input images using different browsers or at different resolutions, or if your…
>It doesn't depend on ImageMagick (a bonus in my book) Why is it a bonus besides lowering the number of dependencies?
Re: Image-diff – Create an image differential between two images
#24ImageMagick already ships the `compare` command [0] which does exactly this.
It also accepts a bunch of CLI flags such as -fuzz to consider colors within a certain distance as equal. That flag is very useful when dealing with JPG or similar compression that slightly alters pixels, so you can ignore these barely visible differences and focus on the 'real' differences.
Re: Image-diff – Create an image differential between two images
#25Not sure I follow - especially if it already depends on IM, how is it different from 'convert -compose difference' or a similar operator? http://www.imagemagick.org/Usage/compose/#difference
It looks like it's a thin wrapper around "GraphicsMagick for node". Which itself is a javascript wrapper around GraphicsMagick / ImageMagick.
I'm so glad I didn't go into web development.
Re: Image-diff – Create an image differential between two images
#26The diff utility (for text) can detect displacement of fragments of text. Can this image-diff utility do a similar thing for images?
Re: Image-diff – Create an image differential between two images
#27ImageMagick already ships the `compare` command [0] which does exactly this. It also accepts a bunch of CLI flags such as -fuzz to consider colors within a certain distance as equal. That flag is very useful when dealing with JPG or similar compression that slightly alters pixels, so you can ignore these barely visible differences and focus on the 'real' differences. 0: http://www.imagemagick.org/script/compare.php
This literally just calls ImageMagick.