Patent ID: 7822242

Claim:
An image processing apparatus for reducing noise from one original image consisting of digital image data, comprising: an information calculator configured to determine changes in pixel values in predetermined areas on said original image, and calculate information that indicates largeness of spatial changes of the values for each of respective pixels; a smoothed image producer configured to calculate a smoothed image by smoothing said original image; a high-frequency component enhancer configured to produce an enhanced image by enhancing a comparatively high-frequency component in said original image; a weighting-factor calculator configured to calculate a respective weighting factor depending on the calculated information for each of said respective pixels; and a weighting adder configured to mutually perform, using the weighting factor, a weighting addition between the enhanced image and the produced smoothed image, where the information calculator comprises: a filtering unit configured to respectively apply two smoothing filters of mutually different filtering factors to said original image respectively, thereby to produce two smoothed output images; and a subtraction unit configured to perform mutual subtraction, pixel by pixel, between the two smoothed output images, thereby to produce a difference image from which the information that indicates said largeness of spatial change is derived.