Question

I have an image to which I want to apply segmentation using local thresholding. This requires the following steps:

• first segment the image into many sub-images

• implement local thresholding by computing the average within each sub image

• convert the image matrix to binary, by comparing each pixel value with the value of the sub-image local average:

  • if the pixel value is above or equal to the local average, then pixel value = 1

  • if the pixel value is below the local average, then pixel value = 0

My image is unit 8 with 240*320 pixels. How can I implement local thresholding to it using MATLAB? I want to compute the average over each 31*31 sub-image.

Answer 1

n=31;
im2=(im>conv2(im,1/(n^2)*ones(n),'same'))