Abstract
This thesis presents a method to enhance the contrast of an image by applying histogram equalization to the sub-image. The histogram of the image was decomposed into parts with respect to the location of its peak. HE was run on the selected part of the image containing the peak intensity level while the other parts remained unchanged. Then, the equalized and unchanged parts of the histogram were combined into a single image.
Having applied histogram equalization on the sub-images with various sizes on different locations, the images with the highest contrast value were chosen. According to the acquired results, histogram equalization was classified into seven groups by the size and location of the equalized part. Applying histogram equalization to the selected part of the image, where the peak is located, generated higher contrast. Qualitative and quantitative experimental results are shown.
Key words: histogram equalization, contrast enhancement, image decomposition, image partition, sub-image.
