Power Thumb: Output thumbnail with zoom link and color filters

This class is meant to generate thumbnails for images that can be processed with optional color filters and be presented in HTML pages with optional full scale zoom links.

Currently the supported color filters are grayscale, red, green, blue, yellow, magenta, cyan and black.

The full scale image link opens in popup window and displays the description of the picture.

The attributes of the thumbnail image tag maybe defined to set attributes like id, class, style and other event attributes (onmouseover, onclick, etc.).