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Making Foveon-like Images with a Bayer Camera

Started Feb 23, 2022 | Discussions thread
bizi clop
bizi clop Contributing Member • Posts: 640
Re: re:
2

Tom Schum wrote:

bizi clop wrote:

Tom Schum wrote:

Another good algorithm is "Nearest Neighbor" or merely "nearest". But this one works best if you downscale to 1/2 of the linear dimensions, so it combines 4 adjacent pixels into one.

Nearest Neighbor doesn't combine 4 pixels - it just keeps one, and throws out the other 3. The result may be super-sharp, but the downscaled image keeps the per-pixel noise levels, because no averaging/smoothing happens.

Bilinear at 1/n scales should work like binning/averaging of n*n pixels.

I'll have to take your word for the nearest neighbor thing. I still like it though.

Some examples, I hope the links work. Image from Wikipedia. I made a Poisson noisy one from the original, then downscaled them by bicubic, bilinear, and nearest-neighbour:

Original: https://i.ibb.co/QQfWz7P/Toxicodendron-radicans-01.jpg
Noisy: https://i.ibb.co/CzHQR90/Toxicodendron-radicans-01-poissoned.png
Bicubic: https://i.ibb.co/qmWjf5x/Toxicodendron-radicans-01-poissoned-cub4.jpg
Bilinear/binning: https://i.ibb.co/xS0L6y7/Toxicodendron-radicans-01-poissoned-bin4.png
Nearest Neighbour: https://i.ibb.co/p0X4Vk1/Toxicodendron-radicans-01-poissoned-nn4.png

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