Color And Density Measurements In Laser Digital Photofinishing System

In order to control the quality of photograph from the digital laser color system, color density measurement and color measurement is necessary. In generally, color measurement is based on photo integral colorimeter, and densitometer based on color filter. Densitometer is applied in the printing trade, and the color denstiometer still rest on development and research in our country. Color measurement is different from density measurement on color control, it is rare that one instrument can measure both color and density in our country.In this paper, we discussed principal of color measurement and photograph reflective density measurement, and described a measurement method based on spectrum reflectivity which can measure color and density. In this system, we employed a newly developed holographic filed concave grating as splitting beams element, as well as multi-channel photodetector -CCD (charge coupled devices ) as spectrum detection .these all solidified the foundation of measurement; microcomputer control make the system automatic. We also discussed the chip microcomputer control LCD. If so, the system will be portable instrument with RS-232C port. This instrument is multifunctional and intellective, and its structure is simple. In the system , the measurement aims at color photograph , in fact ,it can be applied in other opaque non-fluorescent material , so it will be widely used in the color control field in the future.The equipment of the measuring system includes optics, mechanics ,electronics and computer technology .according to the work I have done, all of them will be studied respectively in the paper and the improvement and analog result. The feasibility and innovation of the system scheme are demonstrated.