Level set active contour model improving boundary indicator function

Because of the restriction of imaging principle, ultrasound images led toare always with low contrast and weak boundaries, segmentation effect of level set based on edge was not ideal. In order to improve segmentation precision and efficiency of ultrasound images, new a novel level set segmentation algorithm was proposed combining gradient information with regional information was proposed. Firstly, distance regularized level set evolution (DRLSE) model based on boundary was improved, regional information was put into boundary indicator function. And then, the improved boundary indicator function was used instead of DRLSE model's. Finally, a level set evolution model combining gradient information with regional information was obtained. The experimental results show that the model can accurately segment ultrasound images of thyroid tumor and the segmentation efficiency and precision are higher than DRLSE model.