how to implement d following algorithm?

Step 1: Read the MRI image and store it in a two dimensional matrix. Step 2: Select the peak threshold value for removing white labels Step 3: Set flag value to 255. Step 4: Select pixels whose intensity value is equal to 255. Step 5:If the intensity value is 255 then, the flag value is set to zero and thus the labels are removed from MRI.

[Image Analyst]

First read this. Then read this. Then, is this homework? If so, tag it as such.