A study of changes in image contrast with various algorithms

The contrast enhancement is an important part of the image enhancement process. The visual details become more visible in an image with a high level of contrast. There are more techniques to improve a contrast image. In this paper we analyze the contrast modification by three main methods: the histogram equalization method, local histogram equalization (LHE) method and contrast limited adaptive histogram equalization (CLAHE) method. The degree of contrast enhancement is measured using the root-mean-square (RMS) parameter.