pngcrush – PNG optimizer utility in openSUSE


  1. It is also possible to reduce size of png images using imagemagick in a lossy way (but often not noticeable) and then running optipng or pngcrush as a last step:

    For example:

    # Reduce depth to 4 bits and strip comments with
    # imagemagick command line, then run optipng
    $ convert -strip -depth 4 foo.png foo.png
    $ optipng -o9 foo.png foo.png

  2. if i have a digikam tag in the image just using “pngcrush image_with_tag.png crushed_image.png” will result in the loss of my digikam tag, which is not so nice. all digikam settings are set to save the addition informaiton in the file. so if I just copy my image the tag shows up nicely in digikam. is there a way to keep the tags with pngcrush?
    best regards robin

  3. > is there a way to keep the tags with pngcrush?

    Can you try with optipng instead of pngcrush?

    optipng does not lose any information as far as I know.
    I’m not sure what “digikam tag” is, but I assume that’s
    a comment in the image (which should not be removed by

  4. Does anybody know a decent tool for reducing .jpg files (preferibly converting them to png). I’ve checked optipng out but its supported external files does not include .jpg. I need a reduction as lossless as possible.

Leave a Reply

Your email address will not be published. Required fields are marked *