Legacy ImageMagick Discussions Archive

Hey friends, I previously used "convert -strip" to remove PNG:datemodify metadata, but found this behavior changed in 6.8.9: # 2014-04-22 6.8.9-1 Glenn Randers-Pehrson <glennrp@image...> # * The "-strip" option now only removes profiles and comments from PNG # output. Previously the background ...

Aha! That makes sense, thank you. I've successfully used the "convert -strip" tool to strip out the PNG metadata from diff_image and now the results are deterministic: $ compare base_image other_image diff_image $ md5 diff_image MD5 (diff_image) = ca723dbec4b3dbc11184f0aba416799f $ compare base ...

Understandable confusion—for clarity I'm talking above about ctime (the "changed time" of the file), not any image metadata. Since it's filesystem metadata it is not included in the image bytes and therefore not included in the MD5 hash. Check the base_image.png MD5 above and you'll notice it's the s ...

A weird one for you... It looks like the compare command produces different results if the base file ctime changes between runs (ie. if the file is touched). That is, it produces a file with different bytes, the image signature itself doesn't change. Is there any way to make compare produce ...