Somewhat distressing to see that the following notice first appeared in a December 2021 update note[0] and has been repeated and updated regularly ever since!<p>> GraphicsMagick really does need some additional productive volunteers. For several years now, the burden has entirely been on me. I have been sheparding the project for 19 years already (and contributed to ImageMagick and GraphicsMagick combined for 25 years already). It is not reasonable to expect someone with a full time job (and expecting to retire in a couple of years) to do all of the work.<p>0: <a href="http://www.graphicsmagick.org/NEWS.html" rel="nofollow">http://www.graphicsmagick.org/NEWS.html</a>
It's worth noting that GraphicsMagick is originally derived from ImageMagick 5.5.2 as of November 2002 but has been completely independent of the ImageMagick project since then.
Normalize each color channel individually. You will be astonished how well this works.<p><pre><code> gm convert $1 -channel red -normalize -channel green -normalize -channel blue -normalize normalized/$1</code></pre>
A while back I had some fun creating animated GIFs using GraphicsMagick via the Tcl binding - <a href="http://www.graphicsmagick.org/TclMagick/doc/" rel="nofollow">http://www.graphicsmagick.org/TclMagick/doc/</a> .<p>Here's an example that was topical back then: <a href="https://cmacleod.me.uk/tcl/magick/boris.gif" rel="nofollow">https://cmacleod.me.uk/tcl/magick/boris.gif</a> .
For most things you would use this for, or ImageMagick for that matter, you are almost certainly better of using libvips[0]<p>0. <a href="https://github.com/libvips/libvips">https://github.com/libvips/libvips</a>