Wave Optics Analysisof Camera Image Formationwith Respect to Rectangular Aperture

In general, analysing cameras is a difficult problem and solutions are often found only for geometric approach. In this paper, the image capturing capability of a camera is presented from optical perspective. Since most compact cameras can acquire only visible light, the description and propagation method of the visible part of the electromagnetic spectrum reflected by a scene object is made based on Maxwell’s equations. We then seek to use this understanding in the modelling of the image formation process of the camera. The dependency of camera sensor field distribution on aperture dimension is emphasized. This modelling leads to an important camera and image quality parameter called Modulation Transfer Function. The model presented is based on a wave optics in which the wavefront is modified by the lens after diffraction has taken place at the camera rectangular aperture positioned at the front focal point of the lens. Simulation results are presented to validate the approach.