In this paper, we present an image-based texture mapping algorithm for medical data processing. Different from traditional complex polygon-based texture mapping procedure, this method flattens the 3D surface onto a 2D plane and then uses 2D metamorphosis to find the feature-based positional relationship between the texture image and the flatten image. We use multi-resolution technique to generate the texture image from two orthogonal images without camera calibration. 3D head surface based on medical data is flattened by cylindrical projection onto 2D plane. The internal information of medical data can be preserved and utilized further. Experimental results have shown preliminarily that the method can photo-realistically render 3D face.