I'm trying to create really small PNG thumbnails from JPGs using GraphicsMagick.

gm convert coolphoto.jpg  -resize 16x16 -colors 6 coolphoto_16x16_6color.png

These get down to 342 bytes, but they seem to have a few fields I don't want, I see these strings floating in the files:


I want to get rid of these to make the file even smaller. I can get rid of these using ImageOptim, taking size to 181 byets, but it's sort of built to be a UI-based app.

Is there a commandline tool, something like GraphicsMagick, that can do this?

closed as off-topic by Philip Kendall, Hugo, NickM, MikeW, inkista Aug 17 '15 at 0:11

  • This question does not appear to be about photography within the scope defined in the help center.
If this question can be reworded to fit the rules in the help center, please edit the question.

  • Is it photography related ? – Olivier Aug 16 '15 at 5:37
  • They are photos? Not sure this is the right place but got good help here with image processing before – OneSolitaryNoob Aug 16 '15 at 5:38
  • 4
    I'm voting to close this question as off-topic because it is unrelated to photography. Try SuperUser instead. – Philip Kendall Aug 16 '15 at 6:45
  • 1
    @OneSolitaryNoob we're happy to help with image processing questions when they're related to photography, but general image processing questions are off-topic. – Philip Kendall Aug 16 '15 at 6:47

To remove all the EXIF info from your photos you can use exiftool

The command should looks like:

exiftool -all= coolphoto_16x16_6color.png

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