This means that it is being viewed downward at the central point causing distortion near the edge. To reduce the amount of distortion a planemetric perspective will be achieved. It is when a photo appears as though it is being looked at from straight above the earth at every point. A conversion will be made from a central to a plannemetric perspective. This will be achieved by stretching the distortions.
Today there is a different way to remove distortion from photos by digital alterations.
This is done by first scanning in the photographs so it is in a raster format. Pixels can then be removed or moved around until all distortion is gone. This method provides a quicker and easier way to correct photos. This uses different parts of the electromagnetic spectrum to identify and do analysis on various features and images. Since different parts of the electromagnetic spectrum have differing wave lengths that can be absorbed or detected by a variety of film which can then be represented as a number of colors or multiple band images .