Patent ID: 8483502
Filing Date: 2013-07-09
Classification: H04N

Abstract:
1. An image processing apparatus, comprising: an input unit which inputs a pixel value of a multi-level notice pixel on a pixel to pixel basis; a first add unit which adds an error value which is diffused with respect to a notice pixel to the input value of the multi-level notice pixel which is input from the input unit; a second add unit which adds a green noise value to the input value which is input from the first add unit; a threshold processing unit which outputs an binarized output value, the output value being obtained by binarizing the input value of the notice pixel to which the error value and the green noise value are added by using a threshold; a green noise calculation unit which calculates the green noise value to be added to the input value of the notice pixel by using an output value of a treated pixel which is binarized by the threshold processing unit and positioned at a predetermined position around the notice pixel; a subtract unit which calculates an error value due to binarization by subtracting the input value of the notice pixel to which the error value is added from a binarized output value of the notice pixel; an error diffusion unit which diffuses the calculated error value to an untreated pixel which is not yet binarized by the threshold processing unit and positioned at a predetermined position around the notice pixel; and a correction processing unit which, when the error value which is diffused by the error diffusion unit is smaller than a first threshold, adds a positive first offset to the error value to perform a correction and outputs the corrected error value to the first add unit.