Method for testing and comprehensively evaluating invisible damage to surface of fruit through infrared images

Abstract

The invention discloses a method for testing and comprehensively evaluating invisible damage to a surface of a fruit through infrared images and belongs to a nondestructive testing method for defects on a surface of a fruit. The method comprises steps as follows: an infrared image about the surface of the fruit is shot; the average temperature of all pixel units of a test object, the sum of low-temperature areas of all low-temperature pixel units in the test object, the sum of high-temperature areas of all high-temperature pixel units in the test object and the sum of temperature areas of all the pixel units in the test object are calculated according to the infrared images, and then the proportion of the sum of the low-temperature areas to the sum of the temperature areas is calculated; the proportion is taken as the judgment basis of the damage degree of the surface of the fruit. The method has the characteristics of non-contact, no damage, real time, fastness and accuracy and can be used for nondestructive test or screening and grading for fruits with characteristics of fruit surface damage, defect damage, pathogenic microorganism infection, decay and the like.

Description

technical field [0001] The invention relates to a method for detecting surface defects of fruits, in particular to a method for comprehensively evaluating the invisible damage, damage degree and damage distribution on the fruit surface by using infrared images. Background technique [0002] Slight mechanical damage (mainly bruising or crushing) on ​​the surface of the fruit has the characteristics of slight depression, darker color, and no juice overflow, which is difficult to detect with the naked eye. After the fruit epidermis is damaged, the biological wax secreted by the epidermis is destroyed, making it easier for microorganisms to invade and cause ulceration. In addition, mechanical extrusion changes the internal tissue of the fruit, resulting in changes in the distribution of components in some areas of the pulp, nutritional imbalances and other factors, resulting in local necrosis of the fruit, which is also the cause of ulceration. It is easy to rot during fresh-ke...

AI Technical Summary

Problems solved by technology

After the fruit skin is damaged, the biological wax secreted by the skin is destroyed, making it easier for microorganisms to invade and cause ulceration

In addition, mechanical extrusion changes the internal tissue of the fruit, resulting in changes in the distribution of components in some areas of the pulp, nutritional imbalances and other factors, resulting in local necrosis of the fruit, which is also the cause of ulceration

It is easy to rot during fresh-keeping storage and transportation, and it is highly contagious.

[0003] At present, the commonly used visible light imaging detection technology can only detect serious epidermal defects, and it is difficult to identify inconspicuous near-surface defects such as slight mechanical damage and early pests and diseases.

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