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?

  • 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
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    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
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    @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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