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Image Dithering: Eleven Algorithms and Source Code

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Re: Image Dithering: Eleven Algorithms and Source Code

#61

Post by MartijnBraam »

joosters wrote: post #34

Has anyone tried using the equivalent of animated GIFs to help with dithering? If you have a limited palette of colours, perhaps you could produce two dithered versions, with pixels sometimes having different colours in alternate frames. If the image is refreshed fast enough, two colours could blend into a third. The most extreme example could be 'dithering' a grey square into 1) a black square and 2) a white square,…

You don't even need the animation speed for this. In the GIF format you can have a new color palette for every frame so paint the first 256 colors in the first frame. Add 256 more colors in the right spots in the second frame etc.

See http://notes.tweakblogs.net/blog/8712/high-color-gif-images.... for a nice animation

Re: Image Dithering: Eleven Algorithms and Source Code

#62

Post by mzw_mzw »

rabidsnail wrote: post #49
joshvm wrote: post #33

Earlier quoted context omitted.

Bear in mind that computer vision has used a cropped image of Lena Söderberg (i.e. the infamous Lena image) for decades now. If you believe the anecdote, the image was not chosen as an in-joke or as a way of sexualising women. The researchers needed a high quality image of a human face (hence they cropped out her body) and they were tired of stock images. Someone in the lab had a playboy magazine and history was made…

That's all true, but that doesn't make it less squicky.

That's true, since the use of this cropped image was completely non-squicky to start with. You can hardly get less squicky than zero!

Re: Image Dithering: Eleven Algorithms and Source Code

#63

Post by rabidsnail »

mzw_mzw wrote: post #62
rabidsnail wrote: post #49

Earlier quoted context omitted.

That's all true, but that doesn't make it less squicky.

That's true, since the use of this cropped image was completely non-squicky to start with. You can hardly get less squicky than zero!

There is no such thing as objectively squicky. I find it squicky.

Re: Image Dithering: Eleven Algorithms and Source Code

#64

Post by Mz »

mynegation wrote: post #4

Back when I was at university, we had a computer graphics course. Each week we got new assignment that we needed to program, write to a floppy disk (it was before Internet became widely available) and give it to the prof next week. Dithering was one of the assignments. We were required to implement black-white quantization and then Atkinson and Floyd-Steinberg. We were given the freedom to choose our own images. Duri…

I am curious if you knew about the Lena photo and history. It seems likely this remark by the professor was inappropriate, but given that context, provided by joshvm https://news.ycombinator.com/item?id=11888153, I think that muddies the water.

Re: Image Dithering: Eleven Algorithms and Source Code

#65

Post by Mz »

Mz wrote: post #64
mynegation wrote: post #4

Back when I was at university, we had a computer graphics course. Each week we got new assignment that we needed to program, write to a floppy disk (it was before Internet became widely available) and give it to the prof next week. Dithering was one of the assignments. We were required to implement black-white quantization and then Atkinson and Floyd-Steinberg. We were given the freedom to choose our own images. Duri…

I am curious if you knew about the Lena photo and history. It seems likely this remark by the professor was inappropriate, but given that context, provided by joshvm https://news.ycombinator.com/item?id=11888153 , I think that muddies the water.

Oh, never mind. I see now that you did know. Excuse my derpy question.
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