To provide an image processing device able to accurately discriminate a specified
image in an input image data, the input image is converted to binary based on black
and red color extraction blocks 6-1 and 6-2 in binary processing
unit 1. These binary data are consolidated by an OR circuit and stored in storage
device 2. Mark location detection unit 3 extracts a square mark from the image
data stored in device 2. Pattern shape extraction unit 4 extracts another mark
which is inside the square mark. Pattern matching unit 5 obtains and outputs the
goodness of fit between the extracted marks and previously established marks.
