computer-generated imagery (cgi) is using computer graphics, especially in movies. these images are used for special effects, simulation, and commercials, amongst others. sometimes the technology is used to produce a static background, which is then merged into the image; at other times it is used to produce animations in 2d or 3d. in its broadest sense, a computer- generated image (cgi) can be defined as any image that is created with the use of a computer- based processor or program. because computers are widely used, both in image generating and in image processing, these images are pervasive- from billboard advertisements to film productions and photography.