Recursive PNGCrush

December 14th, 2009

Pardon the geeky interruption for a moment folks, I need to talk about pngcrush. I’ll only be a quick second, so just bear with me.

PNGCrush is a lovely little tool that optimizes your PNG files by removing ancillary chunks of data and applying various compression techniques. Your files won’t look any different to the naked eye, but their size shrinks, sometimes dramatically. Smaller size equals faster loading; faster loading equals your site, loaded completely, in front of a set of eyeballs before they grow impatient and move onto something else.

The only problem with PNGCrush is that it has no built-in recursion, so if you want to walk through an entire images folder, you’re up a creek without a paddle.

Here’s a quick workaround for cygwin-less Windows users, it will recurse a folder structure entirely, replacing each image along the way with a compressed copy.

FOR /F %%Z IN ('dir /b /s ..\your\path\*.png') DO pngcrush -brute %%~fZ tmp_img_file.png && MOVE /Y tmp_img_file.png %%~fZ

Hope that helps!