The contrast stretching operation takes a low-contrast image as input and stretches the narrower range of the intensity values to span a desired wider range of values in order to output a high-contrast output image, thereby enhancing the image's contrast. It is just a linear scaling function that is applied to image pixel values, and hence the image enhancement is less drastic (than its more sophisticated counterpart histogram equalization, to be described shortly). The following screenshot shows the point transformation function for contrast stretching:
As can be seen from the previous screenshot, the upper and lower pixel ...
