Image Processing Toolbox

Perimeter Determination

The bwperim function determines the perimeter pixels of the objects in a binary image. You can use either a 4- or 8-connected neighborhood for perimeter determination. A pixel is considered a perimeter pixel if it satisfies both of these criteria:

• It is an on pixel.
• One (or more) of the pixels in its neighborhood is off.

This example finds the perimeter pixels in the circuit image.

BW1 = imread('circbw.tif'); 
BW2 = bwperim(BW1);
imshow(BW1)
figure, imshow(BW2)

Figure 9-6: Circbw.tif Before and After Perimeter Determination

4- and 8-Connected Neighborhoods

Flood Fill