getting all the nearby pixels from a center pixel in image

Hi everyone, I have a quick question like this: there is an image,suppose with size of 320 * 240, and I extract a center pixel position of sub-window with size 31 * 21 from this image. Now, I want to get all the pixels location of this sub-window and rearrange it as a column. Is there some fast way to do this? Thank you very much!

Answer 1

[Uttiya Ghosh]

Hi Uta,

From my understanding, you want to convert a region of an image into a column vector. Refer to the code below:

I=imread("cameraman.tif");
subregionSize=[2 3];
subregionStartIdx=[5 6];
J=I(subregionStartIdx(1):subregionStartIdx(1)+subregionSize(1)-1,...
    subregionStartIdx(2):subregionStartIdx(2)+subregionSize(2)-1);
JCol=reshape(J,prod(subregionSize),1);

You will receive the required Column Vector in JCol. You can change the sizes as per your requirements.

For more information, refer to the links below:

https://www.mathworks.com/help/matlab/ref/imread.html

https://www.mathworks.com/help/matlab/ref/reshape.html