The goal of image enhancement is to improve the visual appearance of the image. For this purpose we are using two methods to compute the image background using morphological transformations. Contrast enhancement in grey level images with poor lighting can be achieved by two operators based on Weber’s law. The one operator employs information from block analysis and the other utilizes the opening by reconstruction. The contrast operators can normalize the grey level of the input image to avoid the abrupt changes in intensity among different regions.