Research And Design Of Diamond Color Recognition System

As we all know that diamond is the most valuable jewel in the world and is called the king of jewel because of its outstanding quality. An end product diamond is usually classified by 4C standard (color,carat,clarity,cut). The color of diamond is a important standard and the international jewel trade are very strict to the classifying of diamond's color , for this reason the color is a primary and basic element to diamond's value. Although the international jewel trade have made a consummate standard for the classifying of diamond's color, but the method of the classifying has depended on naked eye for a long time, so it urgently need a scientific and impersonal way . In this paper, we will apply spectral analysis technique to the identifying and classifying of diamond color and design a system to offer scientific and impersonal gist for the classification of diamond color and the appraisement of its quality. We designed a testing system of diamond color with fiber-optic detector to measure the reflection spectrum of the samples and made a data processing system by Visual C++ to calculate the reflectivity, three stimulate value, color coordinate and chromatism.The testing system is composed of light source, collecting-light system, separating-light system and photic-electricity conversion system. The light source adopts the standard A light source illumination. The collecting-light system mainly means to the fiber-optic detector which used to collect and transmit light energy. The using of the fiber-optic detector can decrease the loss of light energy to reduce the unorder light's effect and can make the testing system flexible. In the separating-light system, the concave grating is drove by the step-in electrical machine to separate spectrum signal in the range of visible light. It need not collimation-focusing system by using of holographic concave grating. Photic-electricity conversion system applied the optic electricity multiply, which has high sensation to handle the weak signal.The data processing system is composed of main interface module, data input interface module and reflectivity graph display interface module. The functions of the main interface module are entering data input interface and reflectivity graph display interface by menu, displaying the results of samples' parameters and classifying. We can read, input and keep datum and calculate the reflectivity, three stimulate value, color coordinate and chromatism in data input interface. And we'll compare the chromatism of testing samples and standard samples to identify and classify the samples. The function of reflectivity graph display interface is displaying the reflectivity graphs of testing samples and standard samples to provide gist for identifying and classifying of diamond color.We chose 45 inartificial stones which are similar to diamond in appearance as samples. First we grouped the samples by naked eye , and then tested them by the system which was designed in this paper and compared the results to prove the feasibility of this system. The samples of this experiment have three colors totally, we grouped every color in three groups before test and picked up one sample in each group as standard sample, others as testing sample. When testing the standard sample, we inputted the response of optic electricity multiply into the data processing system, calculated the reflectivity, three stimulate values, color coordinate and kept the results. We used the same way to test the testing samples. After these processes, we calculated the chromatism between testing samples and standard samples, compared the results, found out the standard sample which has the smallest chromatism with this testing sample, classified the testing sample to this standard sample and displayed the name of this standard sample as the result of classifying. At the same time, this system displayed the calculating results of chromatism between this testing sample and other standard samples and the the reflectivity graphs.After tested by this system, there a...