Patent ID: 7710469

Claim:
An image acquisition apparatus comprising: an optical system having such distortion aberration characteristics as a central region is expanded and a peripheral region is compressed; an imaging element which converts a subject image formed by the optical system into image data; a first memory which stores filter factors which are used to perform filter processing which interrupts a spatial frequency exceeding a Nyquist frequency of the image data; a second memory which stores parameters which define an outer edge of a Nyquist image region which is a region having a spatial frequency exceeding the Nyquist frequency in the image data; a filter factor setting circuit which judges whether each pixel position of the image data is included in the Nyquist image region based on the parameters, and reads the filter factors from the first memory when each pixel position is included; a filter circuit which executes filter processing with respect to the image data in accordance with the read filter factors; and a distortion correcting circuit which corrects the distortion aberration characteristics with respect to the image data from the filter circuit.