"The problem is that the alpha-less 24 bit PICTs need different handling than what's in the available code." The general structure for a convertor 1) Convert the source image 24/32 bit image to an internal memory structure. 2) Convert the internal memory structure to a 24/32 bit output image. In my convertor I use as the internal memory structure a 32 bit RGBA image, also use this representation for diplaying the preview image.

Stupidity also evolves!