| 摘要 |
PURPOSE:To exactly and automatically discriminate whether a picture is a dot or not by setting two kinds of thresholds at least, and referring to picture information having been binarized by two thresholds, different from each other, by means of a circuit to detect a recorded dot and the circuit to detect a non- recorded dot, and discriminating a dot pattern on the basis of the result of both the detection circuits. CONSTITUTION:A black dot detection circuit 160 processes the signal mij of 29 picture elements portion which are outputted from an XY delay circuit 150, and discriminates the presence or absence of the black dot. The signal processed at the XY delay circuit, is the binary signal, which comes to be '1' if the number of the gradations of the picture signal (b) is 32 or more, and comes to be '0' if not. Namely, by referring to the signal that the picture signal (b) is binarized by the threshold 32, the black dot is detected. A white dot detection circuit 220 processes the signal Cij equivalent to 13 picture elements outputted from the XY delay circuit 210 and discrimenates the presence or absence of the black dot. The white dot detection circuit 220 refers to the signal that the picture signal (b) is binarized by the threshold 48, and detects the white dot. |
