ABSTRACT
To overcome the problem with image defocusing, standard high-resolution camera systems usually employ various “active” autofocusing (AF) elements, which allow a shifting image focal plane and bring it back to focus on the sensor array surface. The AF systems provide an efficient and natural way of creating a sharp image of the object as perceived by the observer, but they usually create delays in the operation of cameras as well as increases in camera power consumption, camera size, and system cost. On the other hand, several alternative fixed-focus “passive” methods of extending the DOF of the optical system are also implemented with miniature cameras. They do not require AF technology and instead are based on combining apodized camera optics with digital image-processing algorithms. Extended depth of field (EDOF) technology incorporates modified optics and digital processing for the simultaneous in-focus imaging of near and faraway objects.
