Patent Document ID: 9153013
Application ID: 13919367
Patent Status: 1

Claim One:
1. An image processing apparatus comprising: a dividing circuit for dividing an input image into a plurality of divided images; a difference image calculation circuit for calculating a difference image between a divided image prior to noise removal and a divided image after noise removal with respect to each of the plurality of divided images; a relative value calculation circuit for calculating a relative value between a pixel intensity in the divided image prior to noise removal and a pixel intensity in the difference image with respect to each of the plurality of divided images; a distribution detection circuit for detecting a frequency distribution of relative values in a background area of the input image, contained in frequency distribution of relative values calculated with respect to the plurality of divided images; and an estimation circuit for estimating an intensity of noise so that the intensity of noise becomes larger, as the relative value a frequency of which is a local maximal value becomes smaller, in the frequency distribution of the relative values in the background area.