关键词: 图像匹配, 变压器套管, 尺度不变特征变换（SIFT）, 工况识别

Abstract: In view of the difficulty in the identification of transformer bushing, a method of identification of transformer bushing condition based on image matching is proposed. Firstly, on the basis of Guided filter Retinex image enhancement algorithm is used to the acquisition of transformer bushing image preprocessing. Then, the improved SIFT feature matching algorithm is used to accurately locate the measured image. Based on the maximum entropy thresholding（OET） method, the edge of casing is extracted. Finally, the recognition device is designed, and the operating condition identification is carried out. Results and analysis are given. And the method is applied to the engineering field, which reflects higher practical value.

Key words: image matching, transformer bushing, Scale-invariant Feature Transform（SIFT）, condition identification