I'm trying to implement a modified version of the otsu binarization algorithm. I'm trying to binarize document images. But in the binarization procedure I want the object (in this case the text) to retain its original grayscale value while the background takes the value of 255; that is, white. I'm posting a sample image version that I found in a paper.
This is the original image:
This is the resultant image I want to obtain:
Could someone please tell me how to do it in Matlab?