A noise elimination method capable of handling even beat noise occurring in an oblique direction is proposed. In an image processing apparatus that is provided with a correcting unit that subtracts cyclic data of beat noise from effective pixel data included in inputted digital image data, the correcting unit comprises: a distributing unit that sequentially and cyclically distributes optical black area pixel data included in the digital image data; an integrating unit to which the optical black area pixel data distributed by the distributing unit is sequentially inputted; a first calculating unit that divides the integration result of the integrating unit by the number of integrations; a minimum value detecting unit that detects a minimum value of the output of the first calculating unit; and a second calculating unit that calculates the minimum value and the division result to obtain the cyclic data of the beat noise.