AMIGASYSTEM
And anyone else interested, I plan to update the JPEG Datatype and it should be available in about a week from this Friday.
In the course of doing some research regarding color quantizing I discovered that JPEG Library does its own internal quantizing.
While I'm working on save 8bit for jpeg datatype I will experiment with a modified test version to use jpeg library to quantize and save 24bit jpeg as 8bit bmp or gif. The small utility called djpeg can successfully do that. If the experiment works then AROS maybe can use jpeg library for quantizing images!
What a crazy idea! But it might work. And image quality is good.