5 ms·

Dithering – Part 2: The Ordered Dithering

256 points by ChrisArchitect 10mo ago

augusteo 10mo ago
Bookmarking this. Clear explanations of graphics algorithms are surprisingly rare.
ChrisArchitect 10mo ago
Related: Dithering - Part 1 https://news.ycombinator.com/item?id=45750954 https://news.ycombinator.com/item?id=45750954
- VinLucero 10mo ago
  Thank you
csressel 10mo ago
first post was great, this should be interesting!
subprotocol 10mo ago
In chrome it says "Loading assets, please wait..." and hangs. but it works for me in firefox
jonahx 10mo ago
This is really nice work, as are the other posts. If the author stops by, I'd be interested to hear about the tech used.
ggambetta 10mo ago
I used ordered dithering in my ZX Spectrum raytracer (https://gabrielgambetta.com/zx-raytracer.html#fourth-iteration-light-just-the-one https://gabrielgambetta.com/zx-raytracer.html#fourth-iterati...). In this case it's applied to a color image, but since every 8x8-pixel block can only have one of two colors (one of these fun limitations of the Spectrum), it's effectively monochrome dithering.
- onion2k 10mo ago
  Spectrum Basic was my first programming language, so that gives me all sorts of nostalgia feels. Your work is awesome.
a_shovel 10mo ago
Bayer dithering in particular is part of the signature look of Flipnote Studio animations, which you may recognize from animators like kekeflipnote (e.g. https://youtu.be/Ut-fJCc0zS4 https://youtu.be/Ut-fJCc0zS4)
- spicyjpeg 10mo ago
  Bayer dithering was also employed heavily on the original PlayStation. The PS1's GPU was capable of Gouraud shading with 24-bit color precision, but the limited capacity (1 MB) and bandwidth of VRAM made it preferable to use 16-bit framebuffers and textures. In an attempt to make the resulting color bands less noticeable, Sony thus added the ability to dither pixels written to the framebuffer on-the-fly using a 4x4 Bayer matrix hardcoded in the GPU [1]. On a period-accurate CRT TV using a cheap composite video cable, the picture would get blurred enough to hide away the dithering artifacts; obviously an emulator or a modern LCD TV will quickly reveal them, resulting in a distinct grainy look that is often replicated in modern "PS1-style" indie games. Interestingly enough, despite the GPU being completely incapable of "true" 24-bit rendering, Sony decided to ship the PS1 with a 24-bit video DAC and the ability to display 24-bit framebuffers regardless. This ended up being used mainly for title screens and video playback, as the PS1's hardware MJPEG decoder retained support for 24-bit output. [1]: https://psx-spx.consoledev.net/graphicsprocessingunitgpu/#24bit-rgb-to-15bit-rgb-dithering-enabled-in-texpage-attribute https://psx-spx.consoledev.net/graphicsprocessingunitgpu/#24...
PMunch 10mo ago
Just did a bit of a deep dive into dithering myself, for my project of creating an epaper laptop. https://peterme.net/building-an-epaper-laptop-dithering.html https://peterme.net/building-an-epaper-laptop-dithering.html it compares both error diffusion algorithms as well as Bayer, blue noise, and some more novel approaches. Just in case anyone wants to read a lot more about dithering!
- quag 10mo ago
  After implementing a number of dithering approaches, including blue noise and the three line approach used in modern games, I’ve found that quasi random sequences give the best results. Have you tried them out? https://extremelearning.com.au/unreasonable-effectiveness-of-quasirandom-sequences/#dither https://extremelearning.com.au/unreasonable-effectiveness-of...
  - leguminous 10mo ago
    What is the advantage over blue noise? I've had very good results with a 64x64 blue noise texture and it's pretty fast on a modern GPU. Are quasirandom sequences faster or better quality? (There's no TAA in my use case, so there's no advantage for interleaved gradient noise there.) EDIT: Actually, I remember trying R2 sequences for dither. I didn't think it looked much better than interleaved gradient noise, but my bigger problem was figuring out how to add a temporal component. I tried generalizing it to 3 dimensions, but the result wasn't great. I also tried shifting it around, but I thought animated interleaved gradient noise still looked better. This was my shadertoy: https://www.shadertoy.com/view/33cXzM https://www.shadertoy.com/view/33cXzM
  - PMunch 10mo ago
    Ooh, I haven't actually! I'll need to implement and test this for sure. Looking at the results though it does remind me of a dither (https://pippin.gimp.org/a_dither/ https://pippin.gimp.org/a_dither/), which I guess makes sense since they are created in a broadly similar way.
  - PMunch 10mo ago
    Just had a look at this and here is the result for the test image: https://uploads.peterme.net/test-image_qr.png https://uploads.peterme.net/test-image_qr.png. Looks pretty good! It looks a bit like a dither, but with fewer artifacts. Definitely a "sharper" look than blue noise, but in places like the transitions between the text boxes you can definitely see a bit more artifacts (almost looks like the boxes have a staggered edge). Thanks for bringing this to my attention!
mblode 10mo ago
I built a blue noise generator and dithering library in Rust and TypeScript. It generates blue noise textures and applies blue noise dithering to images. There’s a small web demo to try it out [1]. The code is open source [2] [3] [1] https://blue-noise.blode.co https://blue-noise.blode.co [2] https://github.com/mblode/blue-noise-rust https://github.com/mblode/blue-noise-rust [3] https://github.com/mblode/blue-noise-typescript https://github.com/mblode/blue-noise-typescript
ivanjermakov 10mo ago
There is something very satisfying in viewing media at 100% resolution of your screen. Every pixel is crisp and plays a role. Joy not available by watching videos or viewing scaled images.
Fraterkes 10mo ago
Half the posts here are people promoting their own projects without even mentioning the (really impressive) OP. Bit weird
- treavorpasan 10mo ago
  When you look at something like Pietà by Michelangelo or Lolita by Vladimir Nabokov, you realise that some humans are given abilities that far exceed your own and that you will never reach their level. When this happens, you need to stop and appreciate the sheer genius of the creator. This is one of those posts.
  - Fraterkes 10mo ago
    I don’t know about all that, I’m just saying I thought people were being a bit rude
- jasonjmcghee 10mo ago
  Is it self-promotion or just "hey cool I care enough about this I built something too" It's ok for people to get excited about shared passions
AndrewStephens 10mo ago
Normally I am not a fan of gimmicky page formats but this series really hits it out of the park with well-considered presentation. I can't wait until the next installment on error diffusion. I still think Atkinson dithering looks great, so much so that I made a web component to dither images.
ginko 10mo ago
I find these sites that try to feed you stuff at a bite-sized pace extremely disrespectful.
- Sunspark 10mo ago
  I agree many meetings could be an email. Look at it this way though, this site is low-key a CV portfolio piece because he isn't just writing about dithering, he's demonstrating that he can research, analyze and then both code and create a site at a level most vibers cannot.
- haritha-j 10mo ago
  No better quantum for education than bite sized i think.
ivanesmantovich 10mo ago
I’ve created a VS Code theme inspired by dithering/halftone techniques, maybe you’ll like it! I’d really appreciate any feedback: https://github.com/ivanesmantovich/halftone-theme-vsc https://github.com/ivanesmantovich/halftone-theme-vsc
kleiba 10mo ago
Another interesting read: how Lucas Pope did dithering for moving game scenes in his indie game "Return of the Obra Dinn": https://forums.tigsource.com/index.php?topic=40832.msg1363742#msg1363742 https://forums.tigsource.com/index.php?topic=40832.msg136374...
austinthetaco 10mo ago
Outside of being informative in a really fun way (I learned far more in a couple minutes than I thought I would), that website is stunning. I've been a web dev for over 10 years and I'm still baffled at how people make sites like this, does anyone have any info or resources on how to go about making these sorts of transitional 3d sites beyond just "learn threejs"?

256 points by ChrisArchitect 10mo ago

augusteo 10mo ago

Bookmarking this. Clear explanations of graphics algorithms are surprisingly rare.

ChrisArchitect 10mo ago

Related: Dithering - Part 1 https://news.ycombinator.com/item?id=45750954 https://news.ycombinator.com/item?id=45750954

VinLucero 10mo ago
Thank you

csressel 10mo ago

first post was great, this should be interesting!

subprotocol 10mo ago

In chrome it says "Loading assets, please wait..." and hangs. but it works for me in firefox

jonahx 10mo ago

This is really nice work, as are the other posts. If the author stops by, I'd be interested to hear about the tech used.

ggambetta 10mo ago

I used ordered dithering in my ZX Spectrum raytracer (https://gabrielgambetta.com/zx-raytracer.html#fourth-iteration-light-just-the-one https://gabrielgambetta.com/zx-raytracer.html#fourth-iterati...). In this case it's applied to a color image, but since every 8x8-pixel block can only have one of two colors (one of these fun limitations of the Spectrum), it's effectively monochrome dithering.

onion2k 10mo ago
Spectrum Basic was my first programming language, so that gives me all sorts of nostalgia feels. Your work is awesome.

a_shovel 10mo ago

Bayer dithering in particular is part of the signature look of Flipnote Studio animations, which you may recognize from animators like kekeflipnote (e.g. https://youtu.be/Ut-fJCc0zS4 https://youtu.be/Ut-fJCc0zS4)

spicyjpeg 10mo ago
Bayer dithering was also employed heavily on the original PlayStation. The PS1's GPU was capable of Gouraud shading with 24-bit color precision, but the limited capacity (1 MB) and bandwidth of VRAM made it preferable to use 16-bit framebuffers and textures. In an attempt to make the resulting color bands less noticeable, Sony thus added the ability to dither pixels written to the framebuffer on-the-fly using a 4x4 Bayer matrix hardcoded in the GPU [1]. On a period-accurate CRT TV using a cheap composite video cable, the picture would get blurred enough to hide away the dithering artifacts; obviously an emulator or a modern LCD TV will quickly reveal them, resulting in a distinct grainy look that is often replicated in modern "PS1-style" indie games. Interestingly enough, despite the GPU being completely incapable of "true" 24-bit rendering, Sony decided to ship the PS1 with a 24-bit video DAC and the ability to display 24-bit framebuffers regardless. This ended up being used mainly for title screens and video playback, as the PS1's hardware MJPEG decoder retained support for 24-bit output. [1]: https://psx-spx.consoledev.net/graphicsprocessingunitgpu/#24bit-rgb-to-15bit-rgb-dithering-enabled-in-texpage-attribute https://psx-spx.consoledev.net/graphicsprocessingunitgpu/#24...

PMunch 10mo ago

Just did a bit of a deep dive into dithering myself, for my project of creating an epaper laptop. https://peterme.net/building-an-epaper-laptop-dithering.html https://peterme.net/building-an-epaper-laptop-dithering.html it compares both error diffusion algorithms as well as Bayer, blue noise, and some more novel approaches. Just in case anyone wants to read a lot more about dithering!

quag 10mo ago
After implementing a number of dithering approaches, including blue noise and the three line approach used in modern games, I’ve found that quasi random sequences give the best results. Have you tried them out? https://extremelearning.com.au/unreasonable-effectiveness-of-quasirandom-sequences/#dither https://extremelearning.com.au/unreasonable-effectiveness-of...
- leguminous 10mo ago
  What is the advantage over blue noise? I've had very good results with a 64x64 blue noise texture and it's pretty fast on a modern GPU. Are quasirandom sequences faster or better quality? (There's no TAA in my use case, so there's no advantage for interleaved gradient noise there.) EDIT: Actually, I remember trying R2 sequences for dither. I didn't think it looked much better than interleaved gradient noise, but my bigger problem was figuring out how to add a temporal component. I tried generalizing it to 3 dimensions, but the result wasn't great. I also tried shifting it around, but I thought animated interleaved gradient noise still looked better. This was my shadertoy: https://www.shadertoy.com/view/33cXzM https://www.shadertoy.com/view/33cXzM
- PMunch 10mo ago
  Ooh, I haven't actually! I'll need to implement and test this for sure. Looking at the results though it does remind me of a dither (https://pippin.gimp.org/a_dither/ https://pippin.gimp.org/a_dither/), which I guess makes sense since they are created in a broadly similar way.
- PMunch 10mo ago
  Just had a look at this and here is the result for the test image: https://uploads.peterme.net/test-image_qr.png https://uploads.peterme.net/test-image_qr.png. Looks pretty good! It looks a bit like a dither, but with fewer artifacts. Definitely a "sharper" look than blue noise, but in places like the transitions between the text boxes you can definitely see a bit more artifacts (almost looks like the boxes have a staggered edge). Thanks for bringing this to my attention!

mblode 10mo ago

I built a blue noise generator and dithering library in Rust and TypeScript. It generates blue noise textures and applies blue noise dithering to images. There’s a small web demo to try it out [1]. The code is open source [2] [3] [1] https://blue-noise.blode.co https://blue-noise.blode.co [2] https://github.com/mblode/blue-noise-rust https://github.com/mblode/blue-noise-rust [3] https://github.com/mblode/blue-noise-typescript https://github.com/mblode/blue-noise-typescript

ivanjermakov 10mo ago

There is something very satisfying in viewing media at 100% resolution of your screen. Every pixel is crisp and plays a role. Joy not available by watching videos or viewing scaled images.

Fraterkes 10mo ago

Half the posts here are people promoting their own projects without even mentioning the (really impressive) OP. Bit weird

treavorpasan 10mo ago
When you look at something like Pietà by Michelangelo or Lolita by Vladimir Nabokov, you realise that some humans are given abilities that far exceed your own and that you will never reach their level. When this happens, you need to stop and appreciate the sheer genius of the creator. This is one of those posts.
- Fraterkes 10mo ago
  I don’t know about all that, I’m just saying I thought people were being a bit rude
jasonjmcghee 10mo ago
Is it self-promotion or just "hey cool I care enough about this I built something too" It's ok for people to get excited about shared passions

AndrewStephens 10mo ago

Normally I am not a fan of gimmicky page formats but this series really hits it out of the park with well-considered presentation. I can't wait until the next installment on error diffusion. I still think Atkinson dithering looks great, so much so that I made a web component to dither images.

ginko 10mo ago

I find these sites that try to feed you stuff at a bite-sized pace extremely disrespectful.

Sunspark 10mo ago
I agree many meetings could be an email. Look at it this way though, this site is low-key a CV portfolio piece because he isn't just writing about dithering, he's demonstrating that he can research, analyze and then both code and create a site at a level most vibers cannot.
haritha-j 10mo ago
No better quantum for education than bite sized i think.

ivanesmantovich 10mo ago

I’ve created a VS Code theme inspired by dithering/halftone techniques, maybe you’ll like it! I’d really appreciate any feedback: https://github.com/ivanesmantovich/halftone-theme-vsc https://github.com/ivanesmantovich/halftone-theme-vsc

kleiba 10mo ago

Another interesting read: how Lucas Pope did dithering for moving game scenes in his indie game "Return of the Obra Dinn": https://forums.tigsource.com/index.php?topic=40832.msg1363742#msg1363742 https://forums.tigsource.com/index.php?topic=40832.msg136374...

austinthetaco 10mo ago

Outside of being informative in a really fun way (I learned far more in a couple minutes than I thought I would), that website is stunning. I've been a web dev for over 10 years and I'm still baffled at how people make sites like this, does anyone have any info or resources on how to go about making these sorts of transitional 3d sites beyond just "learn threejs"?