Image Thresholding is used for image segmentation. From a grayscale image, thresholding can be used to create binary images.
In thresholding we pick a threshold T.
Pixels above threshold get new intensity A.
Pixels above threshold get new intensity B.
In Thresholding, pixels that are alike in gray scale(or in some other feature) are grouped together.
A simple digital image processing technique of segmenting images into grayscale and binary images.