EDGE DETECTION DEVICE, IMAGE DATA PROCESSING DEVICE, LIQUID DISCHARGE DEVICE WITH THE IMAGE DATA PROCESSING DEVICE, EDGE DETECTION METHOD AND EDGE DETECTION PROGRAM

摘要

PROBLEM TO BE SOLVED: To enable a pixel which should be detected originally as an edge area from an image to be surely detected as the edge area even when density gradation of the image is decreased.;SOLUTION: An ink-jet recording device 1 comprises: mode set means 86 setting a mode selectively to a normal recording mode forming an image relating to image data on paper P or an ink save mode decreasing density of the image relating to the image data and forming the image on the paper P; and edge area determination means 2 calculating a density gradient value of the image in a pixel area including pixels not less than 1 based on a density value in the image data and determining whether a pixel area corresponds to an edge area of the image based on the density gradient value and a threshold of the image. When the ink save mode is set by the mode set means 86, the edge area determination means 2 sets the threshold to a value smaller than the threshold when the normal recording mode is set.;COPYRIGHT: (C)2013,JPO&INPIT