With the advent of image based modeling techniques, it becomes easier to apply textures extracted from reality onto virtual worlds. Many repetitive patterns (structural textures) in human constructions can be parametrized with procedural textures. These textures offer a powerful alternative to traditional color textures, but they require the artist to program the desired effects. We present a system to automatically extract from photographs values for parameters of structural textures, giving the user the possibility to guide the algorithms. Two common classes of procedural textures are studied : rectangular tilings and wood. The results demonstrate that synthesizing textures similar to their real counterpart can be very interesting for computer-augmented reality applications. Key words: procedural textures, texture mapping, image based modeling, feature extraction, wood texture, rectangular tiling, brick layout, computer-augmented reality.