CompuServe Messages

HAM (Hold And Modify) format, without knowing the specific encoding, was a cheat that the Amiga people came up with to allow more color on screen (up to 4096) using as little space as possible on disk at the expense of clarity (If not done *absolutely* right can produce incredible amounts of artifacts.) HAM is good in some aspects and wishy-washy at others. Here is what HAM is in a nutshell: An Amiga standard IFF picture with a 16 color palette. You can achive more colors than the base by changing one color register at a time (going right.) Example: You have a base color light grey background (Red 13, Grn 13, Blu 13) and you want to put down a color (one that isn't on your base palette) lets say it's a lavender (Red 11, Grn12, Blu 14). The computer looks to the left of that color and tries to pic an intermediate by changing one of the color registers. The computer then looks to the left of *that* color and tries to pick another intermediate by changing one register. And so it goes, until there is a band of pixels, different by one register, from the background to the foreground. My above example looks like this left to right: R13 G13 B13 (light grey Background) One of the base colors. R11 G13 B13 R11 G12 B13 R11 G12 B14 (lavender foreground) Not one of the base colors. So, to get the pixel the color that I wanted the computer *had* to put down two other pixels. This loose way of playing with color *can* and does work… if you know what you're doing. But I would not recommend using it for anything but display work because in printed form these "artifacts" can blow the whole shee-bang. I hope this clears things up for you. Keep it cool ~Brian Silva