Abstract: This article presented two image segmentation methods on carotid ultrasound images of vascular plactues,i. e. , active shape models and active appearance models, and compares their effectiveness in segmenting the internal and external contours of carotid ultrasound images after segmentation of 38 groups of carotid ultrasound images. Based on comprehensive analysis of experimental results and considering the characteristics of carotid ultrasound images,the ASM method was improved by adding the scale invariant. Experimental results showed that in running time, ASM was close to the improved ASM, while AAM was about 16 times longer than ASM and improved ASM. By evaluating their operating efficiency with FOM and RAY methods, it was demonstrated that the improved ASM was much better than ASM and the improved ASM was the most effective algorithm for carotid ultrasound images segmentation.

Key words: Image segmentation,Carotid ultrasound images,Active shape models,Active appearance models