| 摘要 |
PURPOSE:To achieve high speed and high accuracy by shifting input images by a specified line number and a specified dot number, sequentially shifting reference images by a plurality of lines and a dot number continuously, and detecting the position deviations of the images based on the output patterns from counters. CONSTITUTION:A reference image memory 1 holds binary coded reference image data comprising pixels. The data are read out with a reading means 2. Input image signals are inputted into one-line delay circuits 4 and 5. The signals are delayed for the scanning time of one line. The signals are delayed by one dot in one-dot delaying circuits 6 and 7. The signals are inputted into exclusive logic circuits EOR 8-1 - 8-5. The reference images are inputted into one-line delaying circuits 10 - 13 and dot delaying circuits 24 - 27 in this order. The delayed signals are inputted into EOR circuits 9-1 - 9-5. When the inputs to the OR circuits 8 and 9 disagree, the outputs are imparted as enable signals for counters 28-1 - 28-5 and 29-1 - 29-5. Thus, the positions of the images can be detected at a high speed highly accurately based on the output patterns from the counters 28 and 29. |
