Modify Channel Bit Depth DialogUse this dialog to change the bits for each of the RGB color channels and, if enabled, the alpha channel.
You can define, how much bits can be used by each color channel.
Certain hardware types don't support 256 different values for a color channel, for example only 64 values (=6 bits).
To come closer to the resulting color values this hardware can display you may set the supported number of bits. The application will then restrict the color channel values accordingly. If you for example set 6 bits for the red channel, then you only have 64 different red values like
0, 4, 8, 12...252.
Please keep in mind that these restrictions only apply, if you change the colors using the palette or gradient editors. They won't affect colors loaded with images.
Use Always stretch... to stretch the limited number of values to the complete range of 255. If you for example use 3 bits in a channel then the resctricted values would be 0, 32, 64, ..., 192, 224. If you enable the stretching option then the 8 possible values are linearly placed between 0 and 255 and the values would then be 0, 36, 72, ..., 218, 255.
Preview will update the current image with the selected values automatically when they are changed.
Related topicsMenu Colors
Last modified: 27 December 2016