Graphics
VGA has a palette size of 256 colors, but only 4,096 colors to choose from—4 bits per channel, or 12 bit color. Programs such as Photoshop assume that each color channel has 8 bits, which results in images that have to be further reduced in color fidelity even if they use a 256 color palette.
This can be solved by processing the image according to the following steps:
- Ensure you have your image open and in full color mode (32 bit).
- Use the Posterize filter set to 64. This will properly set all colors in the image to a range of 0-63 per channel.
- Reduce the image to a 256 color palette and save the resulting palette file.
- Undo the color reduction and the Posterize filter.
- Reduce the image to 256 colors using your previously saved palette.
This ensures the best quality for images within the confines of 12 bit colors.
Palette entries 254, 253 and 252 are reserved for the standard text colors. (255 is reserved for black.) Ensure that images don't use those four color table entries, because they will be overwritten.
