Image Processing Reference
Fig. 4.9 Four images and their respective histograms
Fig. 4.10 Four images with the exact same histogram
4.3.1 Histogram Stretching
Armed with this new tool we now seek a method to automatically correct the image
so that it is neither too bright nor too dark and does not have too low contrast. In
terms of histograms, this means that the histogram should start at 0 and end at 255.