Abstract: Abnormal heating may exist at the clamp,stress cone and tail of a bushing-type cable terminal in operation.In order to effectively identify the infrared images about the abnormal heating at each part,both the Radon transform and the Fourier-Mellin transform are introduced to conduct a feature extraction.In the proposed method,the original image is processed first through the Radon transform and then through the Fourier-Mellin transform.Moreover,an invariant function is defined,which is irrelevant to the rotation of original images and the variation of scale,and four feature quantities are extracted by using the invariant function.Finally,the extracted feature vectors are input into the BP neural network to perform the image recognition.The results show that the proposed method can effectively reflect the characteristics of infrared images,and it has a better recognition performance with a strong robustness to noise.

Key words: bushing-type cable terminal, infrared image, Radon transform, Fourier-Mellin transform, BP neural network, feature extraction, pattern recognition