A dithered image tends to produce very short runs of pixels so is likely to get poor compression with RLE. Ordered dithering with a compression algorithm that

A dithered image tends to produce very short runs of pixels so is likely to get poor compression with RLE. Ordered dithering with a compression algorithm that can compress "words" (repeated patterns) (like the LZW in GIF) will perform better if the image has large areas of flat colour (not photos).