Reducing the file size of a very large images, without changing the image dimensions

Question

Consider an application handling uploading of potentially very large PNG files.

All uploaded files must be stored to disk for later retrieval. However, the PNG files ca

Answer 1

You can try the pngquant utility. It is very simple to install and to use. And it can compress your PNGs a lot without visible quality loss.

Once you install it try something like this:

pngquant yourfile.png
pngquant --quality=0-70 yourfile.png

For my demo image (generated by imagemagick) the first command reduces 350KB to 110KB, and the second one reduces it to 65KB.