How can I use Matlab for subpixel edge detection?

I am trying to detect an entire cell's membrane using edge detection. However, with the canney and sobel operators I am not getting enough detail because the cell membrane changes are very small. I was wondering if someone can please help me figure this out. Once I detect the edge, is there a way I can measure the membrane position all around the entire cell (360 degrees with 1 degree increments)? Any help would be greatly appreciated. Thank you very much. I have attached the picture of the cell whose edge I am trying to find.

Answer 1

[Agustin Trujillo-Pino]

You can try Accurate subpixel edge location to obtain a subpixel edge detection in your image.