| Image Processing Toolbox | |
Compute global image threshold using Otsu's method
Syntax
Description
level = graythresh(I) computes a global threshold (level) that can be used to convert an intensity image to a binary image with im2bw.
level is a normalized intensity value that lies in the range [0, 1].
The graythresh function uses Otsu's method, which chooses the threshold to minimize the intraclass variance of the black and white pixels.
Multidimensional arrays are converted automatically to 2-D arrays using reshape. The graythresh function ignores any nonzero imaginary part of I.
Class Support
The input image, I, can be of class uint8, uint16, or double and it must be nonsparse. The return value, level, is a double scalar.
See Also
Reference
N. Otsu, "A Threshold Selection Method from Gray-Level Histograms," IEEE Transactions on Systems, Man, and Cybernetics, vol. 9, no. 1, pp. 62-66, 1979.
| | grayslice | histeq | |