Method for characterizing color of characteristic tobacco by place of origin

Abstract

The invention provides a method for characterizing the color of characteristic tobacco by place of origin. The method is characterized by comprising the following steps: statistically regarding the random distribution of colors on the surface of tobacco as a fractal structure, and acquiring the high-accuracy digital image of the tobacco and carrying out the background removing and segmenting treatment; calculating the fractal dimensions corresponding to different threshold parameters of each color intensity (red, green, blue and luminance) of the tobacco, taking the fractal dimensions as the indexes for describing the distribution of the colors on the surface of tobacco on a quantified basis, and plotting the fractal dimension variation curve of each color intensity, which can reflect the distribution of the colors on the surface of the tobacco on an overall basis; and characterizing the color of characteristic tobacco by place of origin by using the fractal dimension variation curve. The method for establish the characterization of the color of the tobacco can reflect the characteristics of spatial distribution of colors and include the characteristic of accumulation. The fractal dimension variation curve can reflect the distribution of the colors on the surface of the tobacco on an overall basis, thereby reflecting the provincial characteristics in the color expression of the tobacco in different places of origin in China.

Description

technical field [0001] The invention belongs to the technical field of tobacco leaf quality evaluation, and in particular relates to a method for characterizing the appearance color of tobacco leaves with local characteristics. Background technique [0002] The appearance color of tobacco leaves is one of the important indicators that directly reflect the quality of tobacco leaves. In my country, the purchase of tobacco leaves is mainly based on the unified national text standard of "Cured Tobacco" and the regional standards of flue-cured tobacco physical samples. In the national text standard of "Cured Tobacco", the color of tobacco leaves is divided into lemon yellow, orange and red brown, etc., but in the actual production of flue-cured tobacco, there are large differences in the same color of tobacco leaves in different production areas, just like flue-cured tobacco with orange color, Huanghuai area Most of them are light orange, mostly golden in the southwest, and dark...

AI Technical Summary

Problems solved by technology

However, the evaluation of the appearance and color of tobacco leaves is mostly based on the qualitative evaluation of grading experts, and the judgment results are easily affected by the environment, light, and personal subjective differences, so it is difficult to reflect the differences in the color of tobacco leaves in different places

In recent years, some meaningful research has been done on the appearance color of tobacco leaves by using computer image processing technology and chromaticity theory to extract the appearance quality characteristics of tobacco leaves, but there are still the following deficiencies: (1) Color information is generally used in the extraction of tobacco leaf color information. The histogram calculates the cumulative color value, but it lacks consideration of the surface distribution characteristics of the tobacco leaf color; (2) Due to the shrinkage of the tobacco leaf caused by water loss during the curing process, the surface of the tobacco leaf is not smooth even when the tobacco leaf is naturally tiled and stretched , the image of the tobacco leaf taken will appear local dark light in the shrunken place; in addition, the tiny lesion, damage and the color of the main branch of the tobacco leaf on the surface of the tobacco leaf cannot be used as the color of the tobacco leaf

Therefore, in order to obtain the real tobacco leaf color, it is necessary to segment and preprocess the obtained digital tobacco leaf image; (3) The color rendering characteristics of the tobacco leaf surface are mainly composed of plastid pigments, polyphenols and other chromogenic substances on the surface of the tobacco leaf. The composition ratio of the smallest unit (leaf cell) is different, which leads to random and irregular distribution of tobacco leaf color on the surface of tobacco leaves, and the distribution is very complicated. In the existing literature, there is no related report

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