HyperDither is an OS X image processing utility that converts color or grayscale images to 1-bit black-and-white using a sophisticated dithering routine. Specifically, HyperDither implements the “Atkinson” dithering matrix.
HistoryYears ago, during the development of the first Macintosh, Bill Atkinson (of HyperCard, QuickDraw, MacPaint, and now nature photography fame) discovered a very elegant dithering filter to convert greyscale image data for the 1-bit black-and-white Mac video display. The dithering produced by this routine was much higher in quality than the now-ubiquitous Floyd-Steinberg or “error-diffusion” filter (used by QuickTime, Photoshop).
The dither routine was implemented as an option in Apple’s long-gone HyperScan software (A HyperCard stack with some XCMDs/XFCNs) that would connect an early Mac to a flatbed scanner. HyperScan, and hence the most-excellent Atkinson dithering routine, has been unavailable for many, many years—but not forgotten! I e-mailed Bill Atkinson in January, 2003, and inquired about the details of the algorithm. He was kind enough to respond with a brief write-up of the routine.
To process an image with HyperDither, just drag and drop or copy and paste the image into HyperDither’s main window. You can then save it to disk or copy it back to the clipboard.
The HyperDither, this beauty filter has the conversion capability that take a greyscale image to change it into a 1-bit black and white Mac video. What the history entails, is that this has been in production since the first Macintosh was being developed. Those high contrast photos now have a place to stand and shine.