WOW!!! I just applied this to the (big) PNG sprite files used in a project I am working on now, and the gains in file size were amazing! And with hardly any difference in quality!<p>Who ever said that reading Hacker News was a productivity drain?
pngquant is great. I make an iPhone app that displays transit maps. Transit maps are ideal candidates for quantization (limited color range, large blocks of color that are perfect for RLE) and I saved a lot of file size by quantizing the map tiles. Thanks pngquant!
I've never quite understood how its possible to create better encoders without needing a new decoder on the other end. Can anyone explain how this works? When you're writing a png decoder, why wouldn't there just be one optimal png encoder to go along with it?
How about Color Quantizer? I use it for years.
<a href="http://www.softpedia.com/get/Multimedia/Graphic/Graphic-Others/Color-quantizer.shtml" rel="nofollow">http://www.softpedia.com/get/Multimedia/Graphic/Graphic-Othe...</a><p>Offical site <a href="http://x128.ho.ua/color-quantizer.html" rel="nofollow">http://x128.ho.ua/color-quantizer.html</a>
This is how I use pngquant in my thumbnailing workflow: <a href="https://gist.github.com/gigablah/3110899" rel="nofollow">https://gist.github.com/gigablah/3110899</a><p>At 100x100 pixels, I find that this produces small (~8kb) PNG thumbnails which are still sharp with no noticeable color loss.<p>(Disclaimer: I'm a beginner at nodejs)
Read more about the details of implementing something like this in C#:<p><a href="http://www.mattwrock.com/post/2011/09/05/Convert-32-bit-PNGs-to-high-quality-8-bit-PNGs-with-C.aspx" rel="nofollow">http://www.mattwrock.com/post/2011/09/05/Convert-32-bit-PNGs...</a>
The ImageOptim/ImageAlpha OS X apps are fantastic for compressing all kinds of images for the web.<p><a href="http://imageoptim.com/" rel="nofollow">http://imageoptim.com/</a>
<a href="http://pngmini.com/" rel="nofollow">http://pngmini.com/</a>
Very timely, I was just working on a page that had to display complex graphs and the regular PNG's were huge. I set the quality to 50% and it reduced the size to about 30% of the original and it still looks good. Thank you!