I want to process my image as blocks of size 5*5 and want to map each block to a value based on the color of its central pixel. Next I want to perform block matching with blocks of same or similar key. Please help with matlab code.

For the example code, please map the central pixel to black. How can the key values be stored for easily being processed in further steps

Answer 1

[Image Analyst]

See my blockproc demos, attached. They demonstrate a variety of ways to use blockproc. Feel free to adapt.

[Merlyn Tom]

Thankyou for the blockproc demos. Please give an example of how the central pixel of the block can be accessed and processed when using blockproc.

[Image Analyst]

You'd have to use myFilter in blockproc_demo2. Then in there you have the block as array3x3. So to get the middle pixel (its gray level), you'd do:

middlePixel = array3x3(2,2);

I seriously doubt you'd need to do this unless you're doing something highly specialized. You might be able to just modify some kernel if you're doing regular filtering.