
Colorization Using Optimization (2004) - Turing_Machine
http://www.cs.huji.ac.il/~yweiss/Colorization/
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ggambetta
Could this be used for image/video compression? Sounds like a greyscale image
+ colorization metadata (the "marks" in the article) should take less space
than a 3-channel image, no matter how you compress a colour channels. I'd
guess the compressor and the decompressor may be slower (because of the need
to find a set of colorization marks that reproduce the original image under
whatever threshold is required) but achieve higher compression rates?

Of course lossy compression uses other tricks like using different color
representations (YUV, YCbCr) where the techniques described in this article
may not work, and downsampling, but at least it could be an improvement over
lossless image compression?

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pornel
This tool in particular is not well-suited for video, since it's too imprecise
and too complex at the same time.

However, the general idea of getting better color from luma channel has been
tried in Daala:
[https://people.xiph.org/~xiphmont/demo/daala/demo4.shtml](https://people.xiph.org/~xiphmont/demo/daala/demo4.shtml)
and a form of that has been added to the AV1 codec.

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soravux
As a complement of information, the question of colorization was recently
revisited using deep learning methods [1]. All very interesting work!

[1] Zhang, Richard, Phillip Isola, and Alexei A. Efros. "Colorful image
colorization." European Conference on Computer Vision (2016)
[http://richzhang.github.io/colorization/](http://richzhang.github.io/colorization/)

~~~
stefanpie
You could always optimize it by combining both methods in the process somehow.

