Other Perl modules on CPAN

Image::ExifTool

Image::ExifTool is a pure Perl (doesn't require a C compiler) solution for accessing the text segments of images. It has extensive support for PNG text segments.

Alien::PNG

Alien::PNG claims to be a way of "building, finding and using PNG binaries". It may help in installing libpng. I didn't use it as a dependency for this module because it seems not to work in batch mode, but stop and prompt the user. I'm interested in hearing feedback from users whether this works or not on various platforms.

Image::PNG::Rewriter

Image::PNG::Rewriter is a utility for unpacking and recompressing the IDAT (image data) part of a PNG image. The main purpose seems to be to recompress the image data with the module author's other module Compress::Deflate7. Unfortunately that only works with Perl versions 5.12.

Image::Pngslimmer

Image::Pngslimmer reduces the size of dynamically created PNG images. It's very, very slow at reading PNG data, but seems to work OK.

Image::Info

Image::Info is a module for getting information out of various types of images. It has good support for PNG and is written in pure Perl (doesn't require a C compiler). As well as basics such as height, width, and colour type, it can get text chunks, modification time, palette, gamma (gAMA chunk), resolution (pHYs chunk), and significant bits (sBIT chunk). At the time of writing (version 1.31) it doesn't support other chunks.