Patent ID: 8331731
Filing Date: 2012-12-11
Classification: G06T,H04N

Abstract:
1. An image processing method of converting a multi-level image having a first resolution into a multi-level image having a second resolution lower than the first resolution and then restoring the multi-level image having the first resolution from the multi-level image having the second resolution, said method comprising the steps of: in a resolution conversion from the multi-level image having the first resolution into the multi-level image having the second resolution, referring to an attribute flag indicating an attribute of a pixel before the resolution conversion; determining whether or not the attribute flag is a font flag; performing a filter processing to the pixel and holding a filter processed flag associated with the filter processed pixel if the attribute flag is determined to be the font flag, wherein the filter processed flag indicates that the filter processing has been performed; and holding a half dots flag associated with the filter processed pixel in a case where a pixel value of the filter processed pixel is smaller than a pixel value of the pixel before the filter processing is performed, wherein the half dots flag indicates a halftone; and in a restoration of the multi-level image having the first resolution from the multi-level image having the second resolution, replacing pixel data of the filter processed pixel with pixel data of a plurality of pixels, in correspondence with the filter processed flag and the half dots flag associated with the filter processed pixel and each pixel of pixels around the filter processed pixel.