The quality and value of precious stones is determined by a set of indicators such as color, purity, dimension, type and quality of cut. This article is devoted to the problem of assessment of the color of precious stones as one of the crucial quality indicators. To date, the color is usually evaluated by an expert who relies on his/her own color perception and a set of master stones (precious stones color standards). The authors propose an alternative way of determining the color using special hardware and software and standard colorimetric techniques. On the example of green ("emerald") shades the possibility of digital classification of precious stones by color is shown.
Improving the quality of grain products is of great importance, since grains are the basis of the modern man diet. In this regard, one of the most important tasks is to control the grain quality parameters at the stages of its assessment and classification, transportation and storage, processing and use in production. This work is devoted to the study of the influence of the mutual arrangement of grains, their orientation and color on the determination of wheat grains vitreousity using computer vision system. A significant decrease in the calculated value of the vitreousity index at a close arrangement of grains relative to each other was revealed. The color of the grain is also an important indicator. The experimental results showed that the transmittance of red grain is much lower than that of white, due to the presence of pigment cells. This fact makes it impossible to determine the vitreousity of a mixture of different types of wheat without a preliminary color analysis, which greatly complicates the quality analysis process. To overcome the identified limitations, it was proposed to use the IR source as the lower illumination source. The experiment showed that the use of IR illumination allows to completely exclude the influence of the mutual arrangement of grains and their color on the determination of the vitreousity index.
Scientific and technological progress of recent years in the production of the light emitting diodes (LEDs) has led to the expansion of areas of their application from the simplest systems to high precision lighting devices used in various fields of human activity. However, development and production (especially mass production) of LED lighting devices are impossible without a thorough analysis of its parameters and characteristics. There are many ways and devices for analysis the spatial, energy and colorimetric parameters of LEDs. The most methods are intended for definition only one parameter (for example, luminous flux) or one characteristic (for example, the angular distribution of energy or the spectral characteristics). Besides, devices used these methods are intended for measuring parameters in only one point or plane. This problem can be solved by using a dome diagnostics system of optical parameters and characteristics of LEDs, developed by specialists of the department OEDS chair of ITMO University in Russia. The paper presents the theoretical aspects of the analysis of LED’s spatial (angular), energy and color parameters by using mentioned of diagnostics system. The article also presents the results of spatial), energy and color parameters measurements of some LEDs brands.
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