Infrared image enhancement method for electrical equipment based on non-downsampling shear wave transform

Abstract

The invention relates to an infrared image enhancement method for electrical equipment based on non-downsampling shear wave transform. The method comprises the following steps: step S100, establishinga mapping relationship between RGB and gray value of an infrared image; Step S200, performing non-downsampling shear wave transform on the infrared image of the electric equipment obtained in the experiment; S300, calculating the maximum inter-class difference of the infrared low-frequency image of the electrical equipment, obtaining a segmentation threshold between the background and the foreground, and segmenting the low-frequency image into two classes of the environmental background and the electrical equipment; S400, enhancing the low-frequency image, linearly enhancing the low-frequencyforeground electrical equipment, and performing histogram equalization and enhancement on the low-frequency background; Step S500, designing an optimized fuzzy membership function, and carrying out fuzzy enhancement on the high-frequency image of the electrical equipment; Step S600, synthesizing the enhanced low-frequency coefficient and high-frequency coefficient according to the NSST inverse transform into a new electrical equipment infrared image. Compared with the prior art, the invention has the advantages of higher image quality, stronger practicability and the like.

Description

technical field [0001] The invention relates to the field of infrared energy detection of electrical equipment, in particular to an infrared image enhancement method of electrical equipment based on non-subsampling shear wave transform. Background technique [0002] The stability and reliability of electrical equipment is the basic guarantee for the safe operation of the power system. According to statistics, about 90% of the substation operation accidents caused by electrical equipment failures account for about 90% of the total, and most of the failures will show abnormal temperature in the early stage. Voltage effects, current effects, and electromagnetic effects can all cause heating of electrical equipment. Infrared technology uses photoelectric conversion materials to display the invisible infrared rays emitted by the measured object in the form of temperature distribution, which is convenient, real-time, non-contact, and non-destructive, and can obtain its temperature...

AI Technical Summary

Problems solved by technology

[0006] (1) Disadvantages of simple enhancement: subject to the constraints of the infrared focal plane manufacturing process, or when the signal is subject to related interference, the real scene information will be mixed with noise information, and the simple enhancement directly processes the gray level of the image pixel, and the noise signal and electrical equipment in the enhancement process The target information does not make any distinction. The same algorithm can enhance the contrast between low-grayscale pixels and high-grayscale pixels, and correspondingly increase the contrast between noise and effective signals, that is, amplifying noise, which will reduce the visual effect of infrared images of electrical equipment and interfere with faults. judge

[0007] (2) Disadvantages of traditional frequency domain transform: Fourier transform is the earliest frequency domain transform and lacks time information; although wavelet transform contains frequency information and time information, it ignores anisotropic edge information; shearlet transform can Arbitrary direction transformation, and the number of directions for each scale can also be different, which has a good effect on edge detection and enhancement in infrared images, but the downsampling in the process of scale transformation and direction transformation will cause pseudo-Gibbs in the final composite image The generation of effect

[0008] (3) Disadvantages of full image enhancement: the entire image is included in the enhanced area at the same time, and the electrical equipment area of ​​the enhanced result is easily disturbed by the background environment. The enhancement effect in the picture with regular distribution is unstable, and even destroys the key points of the original picture information. It is not adaptive in the field of image enhancement, and is greatly disturbed by the regularity of the image.

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