A histogram is a chart based on the tonal distribution of pixels in a picture.
From the left to the right (horizontally) the brightness is indicated, and from the bottom up (vertically) the amount of the photo area of a particular tonality. It is often said that vertical columns simply show the ratios of the number of pixels of a particular pitch. That is, the diagram shows how much light or dark shades prevail in the picture, how many green or red or other shades of colors in the picture are larger. Histograms are different. In photography, basically, three types are used: Continue reading