The dynamic range of the image exceeds the capability of the display device. In that some pixel values are so large that the low value pixels get obscured. A simple day –to day example of such a phenomenon is that during the day time we cannot see the stars. The reason is that the intensity of light of the sun is so large that the stars with low intensity cannot be adjusted by the dynamic range of the human eye. In the image processing, a classic example of such large intensities of grey level is the Fourier. In the Fourier spectrum only some of the values are very large while some of the values are too small. The dynamic range of the pixels is the order of 106. Hence, when we plot the Fourier spectrum, we see only small dots, which represents the large values. Something needs to be done to be able to see the small values as well. This technique of the compressing the dynamic range is known as dynamic range compression. We all know that the log operator is an excellent compressing function. Hence the dynamic range compression is achieved by using a log operator. C is the normalized constant.