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Creating "effects" using image manipulation

Creating "effects" using image manipulation

by Kapil Paranjape -
Number of replies: 1

It is interesting to use various "mathematical" tricks to create effects which are part of "standard" image manipulation packages.

The attached PDF shows how to make a "sketch" out of a colour image. It also teaches a few image manipulation tricks along the way.

Ultimately, an image is "just" a h\times w\times c array where h is the height, w is the width and c is the number of "primary colour planes" (usually 3 which is RGB). All kinds of matrix manipulation is possible!
In reply to Kapil Paranjape

Re: Creating "effects" using image manipulation

by Kapil Paranjape -

Here is another example.

We take a gray image and find out the permutation P that re-orders the pixels in the order of intensity.

We now create a flat gray image contain each gray level with the same frequency (the middle one is a bit larger to round out the division).

We apply the inverse permutation of P and we get back the image!

This shows that all the information in a gray image is captured by the permutation P.