Firstly

an image segmentation method based on level set evolution without re initialization is studied. This method depends on edge indicator function. However

the method is inaccurate in capturing the sharp corners of the object during image segmention. Then

we analyze the method for image segmentation by using the edge indicator function's curvature information to identify the sharp convex corners. However

the model can only capture the sharp convex corners of the object. When the object has sharp concave corners

the model fails to capture the ones accurately. To overcome this difficulty

we employ the image's curvature information to identify the sharp concave corners

and then combine it with the method of identifying the sharp convex corners by using the edge indicator function's curvature information. By further modifying the edge indicator function to make the method capture both the sharp convex corners and the sharp concave corners of the object more accurately. The numerical experiments show the advantage of the improved model.