ABSTRACT
An image is a projection of a three-dimensional scene in the object space to a two-dimensional plane in the image space. An ideal imaging system should map every point in the object space to a defined point in the image plane, keeping the relative distances between the points in the image plane the same as those in the object space. An extended object can be regarded as an array of point sources. The image so formed should be a faithful reproduction of the features (size, location, orientation, etc.) of the targets in the object space to the image space, except for a reduction in the size; that is, the image should have geometric fidelity. The imaging optics does this transformation from object space to image space.
