Timeline for What algorithm did Microsoft use to dither colour in early versions of Windows?
Current License: CC BY-SA 3.0
21 events
| when toggle format | what | by | license | comment | |
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| Mar 11, 2021 at 8:49 | comment | added | Alan B | I would change the title to 'early 1990s' - Super VGA was everywhere by the mid 1990s. | |
| Mar 9, 2021 at 14:59 | answer | added | user3840170 | timeline score: 51 | |
| Jun 22, 2020 at 20:32 | comment | added | supercat | @Levi: Is the problem one of display polarity, or simply a consequence of many panels having unbalanced turn-on/turn-off response rates? If half the pixels are on and the other half are off, and one switches all of them to the opposite state simultaneously, then if "turn-off" transitions have a more pronounced immediate effect than "turn-on", the amount by which formerly-lit pixels get dark may exceed the amount by which formerly-dark pixels get light, thus momentarily reducing the overall brightness. | |
| Jun 12, 2018 at 19:16 | comment | added | rackandboneman | This kind of hideous dithering was not uncommonly seen on 256-color displays.... | |
| Dec 13, 2016 at 11:19 | vote | accept | Mike Nielsen | ||
| Dec 12, 2016 at 6:20 | comment | added | Levi | The "flipping out" is because of LCD polarity inversion: every frame the polarity of each pixel is flipped to prevent burn-in damage. The cheaper the LCD circuitry the less likely the + and - voltages will properly match. See techmind.org/lcd for some test image patterns that demonstrate worst-case behaviour (major epilepsy alert). | |
| Dec 10, 2016 at 23:54 | comment | added | HopefullyHelpful | The flipping out is probably because of interlacing. | |
| Dec 10, 2016 at 0:43 | comment | added | Robert Columbia | The graphic made me have a flashback from my youth of messing around with graphics like these. Well done. | |
| Dec 9, 2016 at 21:11 | comment | added | user722 | @Luaan At best you can only emulate the way it would have appeared on one particular CRT display, and you can't really do that since, as you said, the pixel element pattern of the display actually used will be different. However if it were possible it would only be a minor improvement. The dithering will look largely the same because the dithering was readily apparent on VGA monitors. It didn't all blur together like CGA graphics on a NTSC TV. The composite colour artifacts that were exploited in old CGA PC games simply don't work on RGB computer monitors. | |
| Dec 9, 2016 at 20:58 | comment | added | Luaan | @RossRidge You still need to emulate the way it appeared on a real CRT display - the colour distribution of pixels is entirely different from a typical LCD. The same dithering simply doesn't work on a different display, just like sub-pixel rendering (just snap a screenshot of some text and try looking at it on a display with a different pixel geometry). This is further complicated if you want to scale the graphics (a fair assumption if you want it to run on a modern high-resolution display) - again, the dithering will look much worse than on a real CRT. I just used NTSC as a well-known example | |
| Dec 9, 2016 at 19:05 | comment | added | user722 | @Luaan No, the original poster is talking about VGA level graphics, Windows 3.x doesn't support 16-colours on CGA cards.The VGA cards and monitors that were typically used with Windows 3.x didn't blend colours the way you describe. For that matter neither did actual CGA monitors, the ones that used the 9-pin digital CGA video connector. | |
| Dec 9, 2016 at 17:44 | comment | added | Mark K Cowan | @Luaan: Requiring the user to down 3 tins of Carlsberg should suffice to reproduce those effects | |
| Dec 9, 2016 at 14:18 | comment | added | Luaan | Just reproducing the algorithm isn't quite enough - for real effect, you need to emulate the way the colours blended together on a CRT display too. Otherwise it's just ugly. The same is true for most CGA graphics, actually - they're mostly optimised for an NTSC display, exploiting the (many) flaws of the system to give vastly higher picture quality than would otherwise be possible (Yes, the "Never the same colour" display turns into "How did you do that with 4/16 colours?!"). | |
| Dec 9, 2016 at 12:32 | comment | added | cbmeeks | @hBy2Py long live the CRT!!! | |
| Dec 9, 2016 at 10:48 | answer | added | Neil | timeline score: 20 | |
| Dec 9, 2016 at 9:49 | comment | added | Jan 'splite' K. | Just a note: I dont think its a good idea to make game which will flip out gamers monitors (and eyeballs) | |
| Dec 8, 2016 at 22:48 | answer | added | Tim R. | timeline score: 39 | |
| Dec 8, 2016 at 19:52 | comment | added | Thunderforge | @hBy2Py My flat panel monitor flips out even when I'm not scrolling! | |
| Dec 8, 2016 at 18:35 | comment | added | hBy2Py | This graphic makes my flat panel monitor flip out when I scroll. | |
| Dec 8, 2016 at 4:00 | answer | added | phyrfox | timeline score: 170 | |
| Dec 8, 2016 at 0:34 | history | asked | Mike Nielsen | CC BY-SA 3.0 |