In this paper, change in the illumination condition of the background due to degraded lightning condition is analyzed and graded based on three methods using Weber’s law. We present a comparison of the background using three methods. The first method consist of block by block approximation of the gray scale image, while the second method morphological transformations like morphological opening and closing are carried out which consist of the morphological erosion and dilation to detect the background in the images characterized by poor lighting. Opening by reconstruction is used to obtain the background. The objective of contrast operators are employed to avoid abrupt changes in the intensity within the image. Finally, the performance of all the three methods is compared on the basis of the histogram and their SNR curves plotted for all the three methods. The paper consists of three equations. The equations are based on the Weber’s law. By applying these equations, the image background is determined and it is enhanced. And the input and the enhanced image are represented in the graphical form also.

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Digital image Image processing Signal to Noise ratio Histogram