| 摘要 |
PURPOSE:To bring a color close to a storage color by keeping the angle of rotation constant regarding a specified hue group to be brought close to the storage color and turning the hue group in a YIQ color space. CONSTITUTION:I and Q signals input are passed through a memory 410, comparators 413 and 414 and an AND gate 415, whether the I and Q signals are kept within a range of separately input angle signals THETA1(acute angleAOB), THETA2(acute angleA'OB'') or not is compared, and the inputs of multiplexers 425 and 426 are changed over by the outputs of the comparison. Values after revolution are obtained on the basis of I1=I0costau-Q0sintau and Q1=I0sintau+Q0costau [where I0 and Q0 represent the arbitrary coordinates of a hue group G1 and I1 and Q1 coordinates in a hue group G1' after revolution and tau=AOA'(=acute angleBOB'') holds] by multipliers 417-420 and adders and subtracters 421-423 at the same time regarding the I and Q signals. Since an angle tau is not changed in a picture, outputs from memories 411, 412 are held constant, and input to the multipliers 417-420 at all times. Accordingly, when an original picture is reproduced, the hue groups are rotated by utilizing a YIQ color space, thus easily bringing a color close to a storage color. |
