Patent ID: 8554006
Filing Date: 2013-10-08
Classification: H04N

Abstract:
1. An image processing apparatus comprising: a decoding unit that decodes encoded image data; a quantization error calculating unit that acquires quantization information, which relates to quantization when said decoding unit decodes the image data, and calculates pixel-by-pixel quantization error; an edge map generating unit that generates an edge map, which represents whether or not each pixel is an edge portion, using the decoded image data and the calculated quantization error; a determination unit that determines whether or not noise is included in a pixel of interest that is to be processed, using the generated edge map; and a correction unit that corrects the image data of a pixel of interest which has been determined to include noise by said determination unit; and wherein said edge map generating unit includes: an input unit that inputs the value of the pixel of interest and values of a plurality of peripheral pixels situated in the vicinity of the pixel of interest; a difference calculating unit that calculates difference absolute values between the pixel of interest and each of the peripheral pixels; a threshold value generating unit that generates a threshold value for every peripheral pixel from the quantization error, the threshold value indicating whether or not the pixel is an edge portion; a comparison unit that compares each calculated difference absolute value and each respective generated threshold value; a selecting unit that, if the difference absolute value is greater than the threshold value, selects this difference absolute value as an output value, and that, if the difference absolute value is equal to or less than the threshold value, selects a prescribed value as an output value; and an adding unit that adds the output values, which have been selected for every difference absolute value, as the value of the pixel of interest in the edge map.