Swapping of neighborhood pixel values of an image

Hello Everyone,

How to swap neighborhood pixel values of a RGB image?

[Sindar]

How do you want to swap them? For example, you could swap rows so you get [2 1 4 3 ...], then swap columns. Or, you could randomly reorder pixels in a patch, moving the patch through the image

[marie lasz]

Thanks for the response. Actually pixel values should swap some portions of image locally. I mean it's all about local exchange of pixel values.

[Rik]

So essentially you want to divide the image into small tiles and randomize the position of the tiles?

[marie lasz]

I don't have idea that is why I asked here , if anyone knows ? Dividing the image and transfer/swap its tiles can also be the way but I don't want to do it randomly.

[Rik]

You don't have any idea what you want? Then we can't help you. If you have a clear description of what you want, we can help you implement it in Matlab.

[marie lasz]

Before implementation I am looking for the main concept and ways to do. And asking for that shouldn't be a problem here. You are also unsure about the question and cross-questioning me , what is that? :-D

[Rik]

What does 'swapping pixel values' mean to you? What is the concept you want to implement? What brought you to this idea? It probably didn't start in a vacuum.

[marie lasz]

It's an attack on an encrypted image,I got as a task. Just to swap or shift pixel values of an image and then to see it's strength against this attack. That is how I got this.

[Rik]

Then I would suggest blockproc to apply a function to each tile of your image. Within a small tile (e.g. 8x8 pixels) you could shuffle the positions with randperm.