How do I segment an image into 3x3 blocks or 9x9 blocks for further image processing?

I have a GUI, after you segment an image into 3x3 blocks, user can choose which blocks for further image processing. Is that possible to display number in every block? So that user is able to choose which block for further image processing.

Answer 1

[Image Analyst]

Use ginput(1) to let the user select the part of the image to process. After that you can easily get the row and column to process.

[x, y] = ginput(1); % User picks place
row1 = round(y);
row2 = row1 + 2;
col1 = round(x);
col2 = col1 + 2;
subImage = grayImage(row1:row2, col1:col2);

[KHOR WEI KOK]

what is the meaning of grayImage?

[Image Analyst]

That's the name of your image variable. What did you call your image? Hopefully not something bad like "image" or "I" or something. But it has to have a name, so just replace grayImage with the name of the variable you are using to hold your image.