Standalone viewer for CPD, GPD, JPD image formats.
Lossless compression.
CPD (Compression PhotoDefiner) image format, as an alternative to the .PNG format for create a smaller compressed images.
 CPD can recompress also png files.
GPD (Graphic PhotoDefiner) image format, as an alternative to the .PNG and the .GIF formats.
It uses lossless image compression that can greatly reduce the size of graphic files.
Lossy compression.
The JPD (Joint PhotoDefiner) is a compressed raster image format, as an alternative to the .JPG format. 
It uses lossy compression that quantizes the color space before DCT and entropy coding.
LIGHT parameter:
this function has the same proprieties of a camera diaphragm that permits increasing light without fading the colors up to a certain point.
Light operates on image in a global way by recalculating intensity of each pixel
and not by simply increasing or decreasing brightness.
Decode CPD, GPD and JPD also with:
Apple Mac OS: