This article is within the scope of WikiProject Computer graphics, a collaborative effort to improve the coverage of computer graphics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.Computer graphicsWikipedia:WikiProject Computer graphicsTemplate:WikiProject Computer graphicscomputer graphics articles
This article is within the scope of WikiProject Professional sound production, a collaborative effort to improve the coverage of sound recording and reproduction on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.Professional sound productionWikipedia:WikiProject Professional sound productionTemplate:WikiProject Professional sound productionProfessional sound production articles
Would be interesting to see not dithered and dithered pictures with an unoptimized 16 colour vga standard palette. Sure, the first one will look terrible and the second on not really good, but they'll serve as good comparisons to the other pictures and show what's possible with very few colours.
i have several implementations of several dithering algorithms on my end, i would be happy to do this but can you please show me the "unoptimized 16 colour vga standard palette" ? google isn't being helpful lol
I think the 16-colour VGA palette only makes sense on an old-fashioned colour display that, compared to modern ones, emitted light much more like a lamp, and much less like a piece of paper.
They had the 8 basic colours that may be represented as 000000 (black), 0000FF (blue), 00FF00 (green), FF0000 (red), 00FFFF (cyan), FF00FF (magenta), FFFF00 (yellow) and FFFFFF (white). The other 8 colours were the same with extra highlight.
Now, in modern colour models you cannot add highlight to e.g. FFFFFF (white).
One could instead say that the 8 colour codes I listed are the highlighted ones, and the non-highlighted are the ones where you replace each FF by half (80, say). But that would not be quite right either, as the colours black-without-highlight, black-with-highlight, white-witout-highlight and white-with-highlight in fact formed a sort of greyscale.
The following is something I just made up, but it at least it seems consistent: The non-highlighted colours could be represented as 000000, 0000AA, 00AA00, AA0000, 00AAAA, AA00AA, AAAA00, AAAAAA, and the highlighted as 555555, 5555FF, 55FF55, FF5555, 55FFFF, FF55FF, FFFF55, FFFFFF. (Here, 55 is one third of FF, and AA is two thirds.) Nø (talk) 12:01, 28 June 2024 (UTC)[reply]
No, as shown in my last paragraph I would go with the values 00, 55, AA, FF (hex) equal to 0, 85, 170, 255 (decimal), rather than 0, 127.5 and 255 (decimal) Nø (talk) 08:01, 1 July 2024 (UTC)[reply]
Yes. As you said, there are no sources (or we haven't found them) giving such RGB codes for the standard 16-colour VGA palette, so it is based my recollection (which I am sure is fairly accurate) and then devising a scheme that is consistent with this. The exact values 85 and 170 could be different, and my assumption that highlighting adds a fixed values to each channel (R, G and B), irrespective of which colour we are considerng, could be different too; e.g., one could instead let the highlighted values be double the un-highlighted ones, except that would make "highlighted black" still black, and I am sure that would be incorrect. -- By the way, you may want to check out List of monochrome and RGB color formats, which, however, doesn't mention the 16-colour palette. Nø (talk) 13:16, 1 July 2024 (UTC)[reply]
one thing about dithering on wikipedia is that it's never mentioned how much impact the color difference formula might have on the output image, i would add examples of the differences but i have yet to implement all of them haha Marbelynrye (talk) 17:08, 1 July 2024 (UTC)[reply]
I deleted the sentence about the ear being more sensitive in the frequency domain. I'm an electrical engineer and this statement makes no sense. Frequency and time domain are two ways of representing the SAME signal. — (unsigned comment by 195.243.189.189, 2005-12-21 01:41:21)
The two sample sound files are an excellent addition but need more explanatory text. Has dithering been added to the second sample? If so, what kind of dithering? It would be ideal if there were three samples: 16 bit original, 6 bit without dithering, 6 bit with dithering.
Ross Fraser (talk) 21:32, 21 July 2010 (UTC)[reply]
These sound files are not particularly illustrative. It sounds like the dithered version has more than 1 LSB of noise. It is hard to hear the difference between 16-bit and 6-bit truncated. Perhaps we should redo with 3 or 4 bit truncation and best practice for level and shape for the dithered version. ~Kvng (talk) 19:01, 22 December 2022 (UTC)[reply]
Sorry, but the Audio spectrum is wrong, if the 500 Hz sine would be correctly dithered, no harmonics will be seen. Nothing. Only the added noise will remain. — Preceding unsigned comment added by 91.51.96.47 (talk) 16:51, 21 July 2012 (UTC)[reply]
.png){kind=link}
