METHOD AND DEVICE FOR REMOVING BACKGROUND OF CHARACTER IN COLOR IMAGE, METHOD FOR ADJUSTING INSTALLATION OF LINE CAMERA, AND CHART FOR ADJUSTING INSTALLATION

摘要

Provided is a method for removing character background in a color image that obtains an image for printing evaluation by removing a background design of a character from the color image of a printed object on which the character has been printed. The method includes separating a color input image into a character part and a background part, calculating a discriminant function for separating pixels of the character part and pixels of the background part based on pixel values, and generating a background-removed image by removing the background part from the input image by using the discriminant function. Moreover, an installation adjustment method of a line camera including adjusting, based on a signal acquired by capturing an installation adjustment chart fixed to the inspection drum, an installation position of the line camera that acquires an image of a large-size printed object arranged on an inspection drum, is executed by using an installation adjustment chart wherein a plurality of patterns formed by white background and black vertical lines are arranged by shifting in a vertical direction so that the vertical lines continue horizontally only in a predetermined rectangular region that is elongated in a scan line direction of the line camera.