bweuler(BW) ans = -2
| Image Processing Toolbox | Search Help Desk |
| bweuler | Examples See Also |
Compute the Euler number of a binary image
Syntax
eul = bweuler(BW,n)
Description
eul = bweuler(BW,n) returns the Euler number for the binary image BW. eul is a scalar whose value is the total number of objects in the image minus the total number of holes in those objects. n can have a value of either 4 or 8, where 4 specifies 4-connected objects and 8 specifies 8-connected objects; if the argument is omitted, it defaults to 8.
Class Support
BW can be of class uint8 or double. eul is of class double.
Example
BW = imread('circles.tif');
imshow(BW);
bweuler(BW)
ans =
-2
Algorithm
bweuler computes the Euler number by considering patterns of convexity and concavity in local 2-by-2 neighborhoods. See Pratt, p. 633, for a discussion of the algorithm used.
See Also
bwmorph, bwperim
References
Pratt, William K. Digital Image Processing. New York: John Wiley & Sons, Inc., 1991. p. 633. Horn, Berthold P. K., Robot Vision. New York: McGraw-Hill, 1986. pp. 73-77.