Color Reduction

Reduce color information (quantization) of a 24-bit RGB bitmap down to 8-bit palette-based bitmap.

Compile

make

or

mingw32-make	# for MinGW32/64 users

or

makedos.bat		# MS-DOS target

No external dependencies required. It was tested on macOS Monterey (clang) Windows 10 (LLVM MinGW64) and MS-DOS (DJGPP).

Usage

./unipal input.bmp [dither]

Whereas:

• input.bmp: image to be quantized, must be a 24-bit Windows bitmap.
• dither: enable dithering using 4x4 ordered matrix

Output image will be stored as a 8-bit Windows bitmap under the name output.bmp.

Preview

Left: Original; Middle: 8-bit undithered; Right 8-bit dithered.