Matlab Question(About matrix sampling)

[miyakooo]

Hi, y'all!

I'm trying to figure out how to do this MATLAB project for school.
We're required to read in an image and then sample random regions(square, matrix-shaped) of it.

I read in the image and it is formed by a lot of numbers(pixels?), and I determined how to generate a random integer that will index to a random point of the image. I know I am supposed to generate a matrix with the random point in its center, but I am clueless as to how to generate a e matrix-shaped region of an image with a designated center...any ideas? Help me please!

Thanks:)
Miyakooo

 

[MRFMengineer]

If you have your random index values, say i and j, why don't you use them to subsample your matrix? p = 1/2 subsample region in pixels

submatrix = image((i-p):(i+p), (j-p):(j+p))
This should give a submatrix with center i, j, with size 2p+1 by 2p+1.

 

[oswaler]

Hi Miyakooo,

To generate a matrix-shaped region of an image with a designated center, you can use the "imcrop" function in MATLAB. This function allows you to specify the coordinates of the center point and the dimensions of the region you want to crop. For example, if your image is stored in a variable called "image" and you want to crop a region of size 5x5 with the center at row 10 and column 15, you can use the following code:

cropped_region = imcrop(image, [15-2.5, 10-2.5, 5, 5]);

This will return a 5x5 matrix containing the pixels from the original image centered at row 10 and column 15. You can then repeat this process for multiple random points to sample different regions of the image. I hope this helps with your project! Good luck.