Amr Abdel-Dayem and Mahmoud R. El-Sakka, "Carotid Artery 
                  Contour Extraction from Ultrasound Images Using 
                  Multi-Resolution-Analysis and Watershed Segmentation Scheme",
                  International Journal on Graphics, Vision and Image 
                  Processing, Vol 5, No. 9, pp. 1-10, December 2005.
               
               
               
               Abstract
               
               
               
                  This paper introduces a novel segmentation scheme based on 
                  multi-resolution analysis and watershed segmentation 
                  algorithm. The proposed scheme consists of six major stages. 
                  These stages are 1) pre-processing, 2) wavelet transform, 3) 
                  image denoising, 4) watershed segmentation, 5) segmented image
                  projection and finally 6) boundary extraction. Experimental 
                  results demonstrated the efficiency of the proposed scheme in 
                  segmenting carotid artery ultrasound images, where the 
                  computational cost of the watershed-based segmentation scheme 
                  is reduced, as it is applied to a small low‑resolution image. 
                  At the same time, the segmentation accuracy is increased as 
                  the proposed scheme is more robust to noise and hence, it 
                  prevents over segmentation in final segmented images.