To segment the discharge area of insulator in ultraviolet（UV） image produced by ultraviolet imaging technology automatically and accurately

we proposed an improved method based on an improved Chan-Vese（C-V） model to analyze the discharge area

where the existing C-V model is improved by adding a penalized energy term

displacing the Dirac function with the norm of level set function gradient

and simplifying amount of parameters. Then

the method was used to obtain the discharge spot of the ultraviolet image of the insulator surface

and the UV image segmentation results based on the conventional edge detection algorithm and mathematical morphology were also given. The research results indicate that the proposed method can segment the discharge area faster and more accurately with stronger anti-interference ability. The accuracy of the improved C-V model is 5% higher than that of current methods

and the dependency on key parameters is lower. The proposed C-V model is excellent for segmentation of ultraviolet image parameters. The research results can provide an important reference for the effective detection of the insulation for the transmission line.