I am trying to plot a Luminance histogram of an image. X axis will be intensity (0 to 255). Y axis will be number of pixels. The plot is created and working fine. I followed the example provided in Tutorials->Basic Plotting.
I am trying to create 5 different zones on the X axis namely 0-25 Black, 25-80 Shadow, 80-180 midtones, 180-130 highlights and 230-255 white. How do I create this so that it is visible on the plot