In the Mac’s early days, bitmap graphics were a big deal. Apple’s Bill Atkinson developed a fantastic dithering filter which converted grayscale images to 1-bit, black-and-white bitmap images that could be displayed on the Mac’s screen. To some observers, the Atkinson filter is thought to be better than the modern Floyd-Steinberg model (also known as the error-diffusion filter) used by Adobe Photoshop today. Read Go old-school bitmap with HyperDither for an OSX solution to getting the grand-ole-dither back.
