[HN Gopher] Why do we need dithering?
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       Why do we need dithering?
        
       Author : ibobev
       Score  : 17 points
       Date   : 2025-11-04 19:27 UTC (9 days ago)
        
 (HTM) web link (typefully.com)
 (TXT) w3m dump (typefully.com)
        
       | abstractspoon wrote:
       | They answered the question in the first two sentences: We don't
       | need it, it's just an aesthetic nowadays.
        
         | debugnik wrote:
         | It's not just aesthetic, I keep seeing games with color banding
         | because they don't bother to dither before quantizing.
        
           | amelius wrote:
           | From the article:
           | 
           | > We don't really need dithering anymore because we have high
           | bit-depth colors so its largely just a retro aesthetic now.
           | 
           | By the way, dithering in video creates additional problems
           | because you want some kind of stability between successive
           | frames.
        
             | dTal wrote:
             | Yeah, the article is wrong about that.
        
               | amelius wrote:
               | It would be nice if you had some examples.
        
               | nofriend wrote:
               | see eg
               | https://xcancel.com/theo/status/1978161273214058786?s=46
        
               | slabity wrote:
               | Acerola recently made a video about how Silk Song has
               | banding with dark colors due to poor dithering (and how
               | to fix it): https://www.youtube.com/watch?v=au9pce-xg5s
               | 
               | Highly recommend for any graphics programmer that might
               | think dithering is unnecessary or simply a "aesthetic
               | choice".
        
             | Sesse__ wrote:
             | You can do with a static dither pattern (I've done it, and
             | it works well). It's a bit of a trade-off between banding
             | and noise, but at least static stuff stays static and thus
             | easily compressable.
        
             | TinkersW wrote:
             | The article is simple wrong, dithering is still widely
             | used, and no we do not have enough color depth to avoid it.
             | Go render a blue sky gradient without dithering, you will
             | see obvious bands.
        
         | jchw wrote:
         | Dithering can be for aesthetic reasons, I presume especially
         | old-school dithering that is especially pronounced. However,
         | dithering is actually still useful in all sorts of signal
         | processing, particularly when there are perceptible artifacts
         | of quantization. This occurs all the time: you can trivially
         | observe it by making gradients that go between close looking
         | colors, something you can see on the web right now. There are
         | many techniques to avoid banding like this, but dithering lets
         | you hide banding without needing increased bit depth or
         | choosing strategic stop colors by trading off spatial
         | resolution for (perceived) color resolution, which works
         | excellently for gradients because it's all low frequency.
         | 
         | And frankly, it turns out 256 colors is quite a lot of colors
         | especially for a small image, so with a very good quantization
         | algorithm and a very good dithering algorithm, you can
         | seriously crunch a lot of things down to PNG8 with no obvious
         | loss in quality. I have done this at many of my employers,
         | armed with other tricks, to dramatically reduce page load
         | sizes.
        
       | tinkelenberg wrote:
       | This is the best explanation I've come across. I enjoy dithering
       | as a playful way to compress file size when it makes sense.
        
       | dcrazy wrote:
       | Slightly frustrating the author started out with color images and
       | then switched to grayscale.
        
       | raajg wrote:
       | 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...
        
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