unsharp masking
%file = 'corners1.jpg'; %file = 'binary_blobs.jpg'; file='hallway.jpg' rgb = imread(file); rgb2 = imresize(rgb,0.5); g = rgb2gray(rgb2); im = im2double(g); imshow(im); clear rgb rgb2 g
file = hallway.jpg
h = fspecial('disk',15);
zm = imfilter(im,h);
imshow(zm);
diff = im - zm; bipolar_image(diff);
imshow((diff+1)/2);