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HyperDither is an OS X image processing utility that converts color or grayscale images to 1 bit black & white using a sophisticated dithering routine. Specifically, HyperDither implements the “Atkinson” dithering filter. Years ago, during the development of the first Macintosh, Bill Atkinson (of HyperCard, QuickDraw, MacPaint & now nature photography fame) discovered a very elegant dithering filter to convert greyscale image data for the 1 bit black & white Mac video display. The dithering produced by this routine was much higher quality than the now-a-days ubiquitous Floyd-Steinberg or “Error-diffusion” filter (used by QuickTime, PhotoShop).