The Research Of Equation From L*a*b* To CMY

Not only is the conversion from L*a*b* to CMY the core of the technology of detecting the printed-paper directly, But also it is important for the developing of the digital press. Although the conversion has been developed and gotten some success in other countries, there is no great 'success in our country. So it is something of value in the theory and applied research to solve the problem of conversion from L*a*b* to CMY.The concept of the color management system and the color space were simply presented in this paper, but I have paid more attention on the conversion from L*a*b* to CMY whose exactness was testified by using some data. I haveaccomplished some following tasks:(1) Testifying the plane theory advanced by a Japanese scholar.(2) Modeling the conversion from L*a*b* to CMY by using mathematic theory.(3) Checking up the exactness of the conversion model.The conversion from RGB (scanner) to CMYK (printer) or the conversion from CMYK (one kind of printer)to CMYK (the other kind of printer) is based on the research, the conversion from L*a*b* to CMY. On the other side, the research can be used in the process of directly detecting the printed-paper quality.