Currently I am trying to extract the hieroglyphics symbols from images like this one.

What I have done is used hough transform to find lines and split the image in portions to make it easier for me. But I tried a set of algorithms to extract the sunken letters from the image and I hit a dead end..
What I have tried is a mixture of morphological operations and edge detection and contour finding. So are there any algorithms devised to do something like this or any hint will be appreciated.