bwborder - Border detection for binary images

Calling Sequence

B = bwborder(Img)

B = bwborder(Img, 4)

B = bwborder(Img, 8)

Input Parameters

• Img: binary array, 1 for object and 0 for background (double precision)

Output Parameters

• B: binary(0-1) array (double), same size as Img

Description

Extracts contours from binary images, by detecting which pixel valued 1 has at least one neighbor valued 0. The second argument is 4 or 8 depending if the detection is to be made in 4- or 8-neighborhood. The final border will be 8-connected if 4-neighbors are used, and 4-connected if 8-neighbors are used.

bwborder(Img)

equals bwborder(Img, 8).

Examples

   initial_dir = PWD;
   chdir (SIPDIR + 'images');

   Img = imread('bin2.pbm')
   xbasc()
   imshow(Img,2);
   B = bwborder(Img)
   imshow(B,2);

   chdir(initial_dir);
   

Authors

Ricardo Fabbri <ricardofabbri (AT) users DOT sf DOT net>

Availability

http://siptoolbox.sourceforge.net

See Also

edge,  follow,  im2bw,