ABSTRACT
Digital image processing deals with manipulation and analysis of a digital image by a digital system. The image enhancement process involves different techniques which are used to improve visual quality or appearance of an image. These techniques convert an image into a form which is better suited for specific applications or analysis by human or machine. Contrast stretching Contrast stretching is a linear mapping function used to manipulate the contrast of an image. In this process, the values of the input image are mapped to the values of the output image. Gray-level slicing Gray-level slicing highlights a specific range of gray levels in an image, i.e., displays high value for gray levels in the range of interest and low value for all other gray levels. Gamma correction operation is applied to images before further processing. This is done in the image display devices or sensors to remove the non-linear mapping between input radiance and the quantized pixel values.
