Binarize

Binarize[image] creates a binary image from image by replacing all values above a globally determined threshold with 1 and others with 0.

Binarize[image, t] creates a binary image by replacing all values above t with 1 and others with 0.

Binarize[image, {t1, t2}] creates a binary image by replacing all values in the range t1 through t2 with 1 and others with 0.

Binarize[image, f] creates a binary image by replacing all channel value lists for which f[v] yields True with 1 and others with 0.

Examples

Binarize an image with automatic threshold:

img = ExampleData[{"TestImage", "Lena"}];
Binarize[img]

Binarize with a specific threshold:

Binarize[img, 0.5]

Please visit the official Wolfram Language Reference for more details.