Let us suppose an image containing a quite small square under a large dark square with both having very close gray level values. If an image contains some of this such that the small squares can’t be visualized and some noise blurred enough to reduce its noise content as shown in fig. below, Which of the following method would be preferred for obtaining the small square clear enough? Figure: original image.

• A. Global histogram equalization
• B. Local histogram equalization
• C. All of the mentioned
• D. None of the mentioned