mmdpotatoes
Grade potato quality by shape and skin spots.

The input image is read.

a = mmreadgray('potatoes.tif');

mmshow(a);

a

Convert to binary objects by thresholding

b = mmthreshad(a,90);

Warning: upcasting image from scalar to uint8

mmshow(b);

b

The binary image is thinned and the result overlayed on the original image

c = mmthin(b);

mmshow(a,c);

a,c

To detect the skin spots, a closing tophat can enhance the dark areas of the image

d = mmcloseth(a,mmsedisk(5));

mmshow(d);

d

The tophat is thresholded and the result is masked with the binary image of the potatoes as we are interested only on the spots inside them

e = mmthreshad(d,20);

Warning: upcasting image from scalar to uint8

f = mmintersec(e,b);

mmshow(f);

f

Show both results: skeleton and skin spots overlayed on the original image

mmshow(a);

mmshow(a,f,c);

a	a,f,c