=head2 Other Perl modules on CPAN

=head3 Image::ExifTool

L<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.

=head3 Alien::PNG

L<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.

=head3 Image::PNG::Rewriter

L<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
L<Compress::Deflate7>. Unfortunately that only works with Perl
versions 5.12.

=head3 Image::Pngslimmer

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

=head3 Image::Info

L<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.