| 摘要 |
PURPOSE:To display a picture in pseudo full colors even with a color map display device by converting R, G and B colors through the XYZ system of a CIE-1931 advice into L*, u* and v*, and adding dither patterns to the L*, u* and v*. CONSTITUTION:A picture memory 1 is scanned by XY coordinates generated by a picture scanning means 2, and the R, G and B values of respective picture element values are outputted to a color converting means 3. The respective colors are inputted to the color converting means 3, and converted into the L*, u* and v*. A dither pattern memory means 4 is the picture in mXn, and scanned by a picture scanning means 2. The dither pattern has a level at mXn, and when the color difference obtained by sampling representative colors in L*, u* and v* spaces is set at (d), one level exists at every color difference of d/(m+n), and it is prepared so that an average may be 0. An adder group 5 adds the picture element values of the dither pattern for the respective L*, u* and v*. A nearest color deciding means 6 selects the nearest colors to L*', u*' and v*' to be the outputs of the adder group 5, and outputs their numbers. |
