Displays an interactive image histogram dialog.

Use the Histogram dialog to view a histogram of the image’s intensity levels. A histogram is a graph of the intensity distribution for red, green, blue and grayscale (Master) values in an image. The horizontal axis represents the intensity values of the image from lowest to highest intensity. The vertical axis indicates the number of occurrences for each intensity value, which is the number of pixels having each value. An intensity range bar, which is aligned under the graph, shows the intensity range. This is designed to help you visually by viewing the intensity value at a certain position.