| 摘要 |
In camera systems with more than one aperture plane, light from different object points can be shaded by either the lens' pupil, the system's aperture or both. depending on pupil and aperture diameters, separation and camera system field of view. In an aperture shading correction (ASC) algorithm, the shading that results from the convolution of the lens' pupil function and its aperture function is determined over the image plane for any given pupil and aperture diameter and separation. A shading correction function is then calculated, and/or its parameters are determined, that will undo the adverse relative illumination degradations that result from the tandem pupil and aperture. This can be done in separate color planes. This can be done in tandem with standard lens shading correction that must also be corrected for (i.e., the lens shading correction (LSC) can be performed in the sensor for the case of no aperture shading, then the ASC multiples the LSC during aperture shading). Aperture shading will also impact SNR and MTF, and as such the tuning of these parameters will also benefit from ASC knowledge.
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