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FTA: I have ways liked the look of images processed with Atkinson Dithering, the algorithm used in the original Apple Macintosh. Nitpick: I don’t think that wa

FTA: I have ways liked the look of images processed with Atkinson Dithering, the algorithm used in the original Apple Macintosh. Nitpick: I don’t think that was used in the original Mac and can’t think of what OS call would use it. I also don’t think MacPaint implemented it (some of the pictures it shipped with may have) Other indications it wasn’t used in the original Mac: - “the phone book” (https://www.folklore.org/StoryView.py?project=Macintosh&story=Inside_Macintosh.txt https://www.folklore.org/StoryView.py?project=Macintosh&stor...) doesn’t have an index entry for ‘dithering’) - Andy Hertzfeld says he implemented the algorithm for the ThunderScan software (https://www.folklore.org/StoryView.py?project=Macintosh&story=Thunderscan.txt https://www.folklore.org/StoryView.py?project=Macintosh&stor...)

JKCalhoun 4y ago
I experienced it first when using a flatbed scanner connected to the Macintosh (not the Thunderscan, however — I guess a little later). By the time Hypercard made the scene you started to come across Atkinson Dithered images with regularity (likely much of the clipart that came with Hypercard). I loved the effect as well. I made it use of it at the time but then had a more recent project where I wanted that "vintage look" and so have made use of it recently as well. I think it's the "tube amp" of dithering algorithms. The dithering noise almost often suggests a pattern — not unlike the old metal engravings where the artist cut the lines in not an arbitrary cross-hatch but to follow or suggest contours. I don't know, I can't explain the appeal.
joezydeco 4y ago
I don’t think that was used in the original Mac and can’t think of what OS call would use it. You're spot on. Images on the original Mac were all 1-bit arrays. There was no concept of 'color' or 'grey' or any way to translate that to-and-from the single pixel images. Doing it for the scanner project, which did look at levels of grey, makes more sense. Those scanned images ended up in later Mac projects like Hypercard.
- Someone 4y ago
  > There was no concept of 'color' Utter nitpick: there were a few system calls for future support of color devices. The idea was to support up to 32 bitplanes (https://en.wikipedia.org/wiki/Bit_plane https://en.wikipedia.org/wiki/Bit_plane). Inside Macintosh says: “if you want to set up your application now to produce color output in the future, you can do so by using QuickDraw procedures to set the foreground color and the background color.“ And there was code for it. See for example https://github.com/jrk/QuickDraw/blob/master/Util.a#L407 https://github.com/jrk/QuickDraw/blob/master/Util.a#L407 I don’t think that ever was used, though. When color arrived, they (rightfully; bit planes are slow for about anything but transparent overlays) went for packed pixels (https://en.wikipedia.org/wiki/Packed_pixel https://en.wikipedia.org/wiki/Packed_pixel)
jsrcout 4y ago
I don't recall an obvious way for ordinary users in the original Mac days to dither images. But it was difficult/impossible for ordinary users to capture an image back then, anyway. The ThunderScan is the first consumer device I remember for real-world image input. On the other hand, the Apple II came with a demo disk that had half a dozen or so scanned images and they had that dithered look. So there were at least experimental scanners in existence circa 1981, when we bought our Apple II.
- Someone 4y ago
  The fax machine dates from the mid-19th century (https://en.wikipedia.org/wiki/Fax https://en.wikipedia.org/wiki/Fax) and there was a commercial machine for sending photographs in 1913 (https://en.wikipedia.org/wiki/Wirephoto https://en.wikipedia.org/wiki/Wirephoto), so it wasn’t even experimental, just not commonly available.
SideQuark 4y ago
"Atkinson dithering is a variant of Floyd-Steinberg dithering designed by Bill Atkinson at Apple Computer, and used in the original Macintosh computer." All recent edits :) Truth forming as we type? There are also much older claims like this, [2] [1] https://en.wikipedia.org/wiki/Atkinson_dithering https://en.wikipedia.org/wiki/Atkinson_dithering [2] https://tannerhelland.com/2012/12/28/dithering-eleven-algorithms-source-code.html https://tannerhelland.com/2012/12/28/dithering-eleven-algori...

JKCalhoun 4y ago

I experienced it first when using a flatbed scanner connected to the Macintosh (not the Thunderscan, however — I guess a little later). By the time Hypercard made the scene you started to come across Atkinson Dithered images with regularity (likely much of the clipart that came with Hypercard). I loved the effect as well. I made it use of it at the time but then had a more recent project where I wanted that "vintage look" and so have made use of it recently as well. I think it's the "tube amp" of dithering algorithms. The dithering noise almost often suggests a pattern — not unlike the old metal engravings where the artist cut the lines in not an arbitrary cross-hatch but to follow or suggest contours. I don't know, I can't explain the appeal.

joezydeco 4y ago

I don’t think that was used in the original Mac and can’t think of what OS call would use it. You're spot on. Images on the original Mac were all 1-bit arrays. There was no concept of 'color' or 'grey' or any way to translate that to-and-from the single pixel images. Doing it for the scanner project, which did look at levels of grey, makes more sense. Those scanned images ended up in later Mac projects like Hypercard.

Someone 4y ago
> There was no concept of 'color' Utter nitpick: there were a few system calls for future support of color devices. The idea was to support up to 32 bitplanes (https://en.wikipedia.org/wiki/Bit_plane https://en.wikipedia.org/wiki/Bit_plane). Inside Macintosh says: “if you want to set up your application now to produce color output in the future, you can do so by using QuickDraw procedures to set the foreground color and the background color.“ And there was code for it. See for example https://github.com/jrk/QuickDraw/blob/master/Util.a#L407 https://github.com/jrk/QuickDraw/blob/master/Util.a#L407 I don’t think that ever was used, though. When color arrived, they (rightfully; bit planes are slow for about anything but transparent overlays) went for packed pixels (https://en.wikipedia.org/wiki/Packed_pixel https://en.wikipedia.org/wiki/Packed_pixel)

jsrcout 4y ago

I don't recall an obvious way for ordinary users in the original Mac days to dither images. But it was difficult/impossible for ordinary users to capture an image back then, anyway. The ThunderScan is the first consumer device I remember for real-world image input. On the other hand, the Apple II came with a demo disk that had half a dozen or so scanned images and they had that dithered look. So there were at least experimental scanners in existence circa 1981, when we bought our Apple II.

Someone 4y ago
The fax machine dates from the mid-19th century (https://en.wikipedia.org/wiki/Fax https://en.wikipedia.org/wiki/Fax) and there was a commercial machine for sending photographs in 1913 (https://en.wikipedia.org/wiki/Wirephoto https://en.wikipedia.org/wiki/Wirephoto), so it wasn’t even experimental, just not commonly available.

SideQuark 4y ago

"Atkinson dithering is a variant of Floyd-Steinberg dithering designed by Bill Atkinson at Apple Computer, and used in the original Macintosh computer." All recent edits :) Truth forming as we type? There are also much older claims like this, [2] [1] https://en.wikipedia.org/wiki/Atkinson_dithering https://en.wikipedia.org/wiki/Atkinson_dithering [2] https://tannerhelland.com/2012/12/28/dithering-eleven-algorithms-source-code.html https://tannerhelland.com/2012/12/28/dithering-eleven-algori...