A line integration based method for depth recovery from surface normals

A method for constructing a depth map from surface normals is described. In this depth recovery method, an arbitrary depth must first be preset for a point somewhere in the image, and then path-independent line integrals are computed to get the relative depths at every point in the image. The validity of the proposed method is discussed and its efficiency is tested using surface normals obtained by shape from the shading algorithm. A comparison to previous methods is made. Theoretical analysis and experimental results show that the present method is both powerful and easy to implement