#261 AdvanceCOMP: Please support optimizing grayscale files with advpng

[Rogério Theodoro de Brito]

Hi.

The pdfsizeopt project (which is a lossless optimizer for PDF files in the fashion as advancecomp) is looking for a PDF optimizer and one of the things that I noticed while running advpng with -z3 or -z4 is that it skips optimization of grayscale files with a message like this:

$ advpng -z3 grayscale.png 
        1208        1208 100% grayscale.png (Unsupported bit depth/color type, 8/0)
        1208        1208 100%
$

Would it be possible to support grayscale figures with optipng? That would be superb!

Thanks,

Rogério Brito.