| 摘要 |
PURPOSE:To obtain a clear converted image without lacking any image information by extracting a prescribed number of current picture elements corresponding to new picture elements, weighting the picture elements depending on their constitution proportions and concentration differences, and calculating the concentration of the new picture elements according to the weighting. CONSTITUTION:In first and second line buffer memories 12, 13, image signal data (k) is taken in the unit of line. A clock generation circuit 11 generates a timing signal and a memory control signal. The positions of four reference picture elements in relation to the new picture elements are detected by a counter 15, and the result is taken in a concentration difference detection circuit 16 and a coefficient selection circuit 17. The circuit 16 calculates the level difference between the picture element concentration which is maximum concentration ratio in four picture elements and that of other three, respectively, and modifies the ratios of weighting of respective picture elements in case the said calculation results in a value above a set value. By applying such a processing as the above-mentioned, the concentration of neighboring picture elements is not excessively smoothed, and as a result, a clear converted image can be obtained. |
