Transparency 0.1.151

Transparency is a tool for special, typical tasks performed on transparent PNGs, especially in the context of the WWW.
Transparency currently supports some typical, specialised operations you can easily do with The Gimp or similar applications, but which are likely to be needed in scripts, so this is a command line tool.
Ive implemented typical things I often need that ImageMagicks do not provide.
Currently, two major algorithms are available, along with a few minor ones:
Convert White to Transparency
I needed this for scripted generation of transparent images showing rendered text. The rendered text usually comes out black-on-white, which this tool converts to black-on-transparent.
Perfectly Convert PNG to GIF
PNG features a full-fledged alpha channel, making half-transparent images easy to handle. However, only few Web browsers support it completely, so I wanted GIF images on my web site, but PNG images as my working copy.
This application prepares PNGs for conversion to GIF by making all pixels either opaque or fully transparent. When you provide a background colour, the resulting GIF looks just as smoothly embedded as the original PNG. This works particularly well for antialiased pictures or text.
Combination
You will often want to combine the two steps above and might want to additionally scale the image. You can do this in one step with Transparency.
Enhancements:
- gcc 4.0 compilation was still broken for some people; this version should fix that.