sliding window on gradient image objects

Sir, How to Compute Height of the each Gradient text block? Consider width (W) is also same as H, With these H and W, how to get one square block? and how to Move this square as a sliding window? after this for each sliding window, how to plot a histogram to choose highest peak. lastly Display all pixel in the highest peak as white pixels in the separate image. please give me a help in matlab code.....

Why bother with creating one histogram per sliding window? Why not just use max() over the contents of the window?

sir, how to implement the sliding window on gradient image and how to plot histogram for each sliding window? please....

What exactly is to be histogrammed? A histogram is not appropriate for discovering the maximum of a set of values.

for each sliding window how to plot histogram?

You have to name what it is that you want to plot the histogram of