Convert image to binary, black and white, by threshold.
The input image img can either be a grayscale or RGB image. In the later
case, img is first converted to grayscale with rgb2gray. Input
can also be an indexed image X in which case the colormap cmap
needs to be specified.
The value of threshold should be in the range [0,1] independently of the
class of img. Values from other classes can be converted to the correct
value with im2double:
bw = im2bw (img_of_class_uint8, im2double (thresh_of_uint8_class));
For an automatic threshold value, consider using graythresh.
The argument method is a string that specifies a valid algorithm
available in graythresh. The following are equivalent:
bw = im2bw (img, "moments"); bw = im2bw (img, graythresh (img, "moments"));
See also: graythresh, ind2gray, otsuthresh, rgb2gray.
Package: image