The dynamic range of the image represents the number of discrete values (Gray Levels) that make up the numerical scale used for the conversion of the analog signal into its digital form. The gray scale has several predefined ranges (8bit-256 GL, 12bit- 4096 GL, 16bit-65356 GL). The range is also called Bit-depth.

The dynamic range of the image is determined by the physical features of the acquisition device used.