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Why do we need dithering?

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Re: Why do we need dithering?

#91

Post by quitit »

cmovq wrote: post #41

Dithering is still very common in rendering pipelines. 8 bits per channel is not enough to capture subtle gradients, and you’ll get tons of banding. Particularly in mostly monochrome gradients produced by light sources. So you render everything to a floating point buffer and apply dithering. Unlike the examples in this post, this dithering is basically invisible at high resolutions, but it’s still very much in use.

Adobe Illustrator 2026 has only -just- added a dithering option to their gradient tool.

Re: Why do we need dithering?

#92

Post by mytailorisrich »

chromehearts wrote: post #63

Can somebody explain to me how dithering is an aesthetic (as mentioned in the article)? I feel I'm too young to understand that

We don't really need dithering anymore because we have high bit-depth colors so its largely just a retro aesthetic now.

I think "retro aesthetic" is quite plain as to what it means. You needed to read on ;)

Re: Why do we need dithering?

#93

Post by smougel »

Just Vibecoded this : https://x.com/smougel/status/1989309185423532120?s=20

Subpixel dithering ! 1 bit per channel which mean that what you see is only 0 or 1 for each channel (R, G, B) By using gaussian blur, the result is perceptually very good ! X compress the image a lot but this truly 1 subpixel ON / OFF

Re: Why do we need dithering?

#94

Post by amiga386 »

raajg wrote: post #11

This was recently shared on HN: https://visualrambling.space/dithering-part-1/ For anyone interested in seeing how dithering can be pushed to the limits, play 'Return of the Obra Dinn'. Dithering will always remind you of this game after that. - https://visualrambling.space/dithering-part-1 - https://store.steampowered.com/app/653530/Return_of_the_Obra...

On Return of the Obra Dinn's dithering specifically, here is the original developer blog on its dithering: https://forums.tigsource.com/index.php?topic=40832.msg136374...

It's intended, aesthetically, to remind you of Atkinson dithering (https://en.wikipedia.org/wiki/Atkinson_dithering), a variant of Floyd-Steinberg dithering often used in graphics for the black-and-white Macintosh.

Re: Why do we need dithering?

#95

Post by Akronymus »

One thing with dithering writeups that always bothered me: There never seems to be coverage of how to calculate colour similarity when there are multiple different colours involved, rather than just black and white gradients.

I am trying to implement it for myself, but really struggling to find any proper literature on that, that I am actually able to understand.

Re: Why do we need dithering?

#96

Post by mark-r »

That was disappointing. I expected from the title that it would cover modern use cases. When's the last time you needed to use a web-safe palette?

It's still useful if you're trying to display a 10-bit-per-channel image on an 8-bit-per-channel display, but the gain isn't nearly as dramatic. And the need doesn't come up very often.

Re: Why do we need dithering?

#97

Post by mark-r »

Akronymus wrote: post #95

One thing with dithering writeups that always bothered me: There never seems to be coverage of how to calculate colour similarity when there are multiple different colours involved, rather than just black and white gradients. I am trying to implement it for myself, but really struggling to find any proper literature on that, that I am actually able to understand.

The first step is to convert from the RGB color space to something more perceptual, like Lab. I'm sure there's a standard for comparing the color similarity of two images but I'm having trouble remembering the name - too early in the morning I guess.

Re: Why do we need dithering?

#98

Post by mark-r »

lelanthran wrote: post #87
tux3 wrote: post #25

Earlier quoted context omitted.

The original Lenna is controversial, but I'm delighted to share the "ethically sourced Lenna": https://mortenhannemose.github.io/lena/

> The original Lenna is controversial, but I'm delighted to share the "ethically sourced Lenna": https://mortenhannemose.github.io/lena/ How is this ethically better than the original Lena - the model in that also one expressly approved the usage of the photo for the purposes it was being used for.

How did she expressly approve the original, when she didn't know for decades that it was so widely used?

Re: Why do we need dithering?

#99

Post by DonHopkins »

kelseyfrog wrote: post #43
tux3 wrote: post #25

Earlier quoted context omitted.

The original Lenna is controversial, but I'm delighted to share the "ethically sourced Lenna": https://mortenhannemose.github.io/lena/

What's the impetus behind replacing the image with something even sexier ?

Cute, but still not as sexy as the original Mandrill test image!

https://www.researchgate.net/figure/Original-standard-test-i...

Re: Why do we need dithering?

#100

Post by DonHopkins »

malfist wrote: post #22
susam wrote: post #15

This is going to be an odd comment, but I immediately recognised the parrot in the test images. It's the scarlet macaw from 2004 which is often used in many Wikipedia articles about colour graphics. I think this is the original, photographed and contributed by Adrian Pingstone: https://commons.wikimedia.org/wiki/File:Parrot.red.macaw.1.a... But this particular derivative is the one that appears most often in the Wiki…

This also used to be a really common test image: https://en.wikipedia.org/wiki/Lenna But its apparently a cropped centerfold from Playboy

https://news.ycombinator.com/item?id=42571652

DonHopkins 10 months ago | parent | context | favorite | on: ASCII porn predates the Internet but it's still ev...

EBCDIC porn really punched my cards. ;)

I had to carefully select just the characters that would punch low resolution monochrome pornographic images into the holes of the punch card.

Just joking, I'm not that old -- I started with ASCII line printer porn, like "MC:HUMOR;VICKI BODY", over the government sponsored ARPANET, at 300 baud, so it was like a nice long strip tease on taxpayer dollars. Vicki took almost 4 and a half minutes to finish at that rate, longer during busy weekday business hours. If I recall, the good stuff was all UPPER CASE, which made it much more intense.

https://web.archive.org/web/20210512025608/http://its.svenss...

Decades later, somebody on HN with a sharper eye than I noticed that Vicki's nipples were clearly labeled "A" and "B". Go figure!

HN: Should computer scientists keep the Lena picture? (lemire.me)

https://news.ycombinator.com/item?id=15671629

DonHopkins on Nov 10, 2017 | parent | context | favorite | on: Should computer scientists keep the Lena picture?

Does "AI:HUMOR;VICKI BODY" get grandfathered in, too?

NSFW: MS C0LLINS - 0UI - FEBRUARY 1973:

https://web.archive.org/web/20210512025608/http://its.svenss...

https://en.wikipedia.org/wiki/Grandfather_clause

mercer on Nov 11, 2017 [–]

Is the nipples being marked 'A' and 'B' part of the joke?

DonHopkins on Nov 11, 2017 | parent [–]

As far as I know, those were not the points of the joke. I noticed them for the first time yesterday too, after not noticing them for decades!

As a teen, I'd printed it out, pinned it up on my wall next to the Cray-1 centerfold, and scribbled a bunch of modem phone numbers, user names and passwords all over it, and never even noticed.

I did a quick search for other A's and B's and found that it used those characters as much as any other character for shading, but that sure seems like something some mischievous student, lab member, turist or sentient TECO script at the MIT-AI Lab might have done.

There was no file security so anyone could have edited them in.

Maybe one of Minsky's grad students was performing some A/B testing or eye tracking experiments.

Somebody should ask RMS if EMACS had some special mode for editing line printer porn.

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