A method of determining the 3D positions of points on the surface of an object, the method comprising obtaining an images of an object from a first view point and from a second view point, fixed relative to the viewpoint of the first view point wherein the images comprise a matrix of pixels, each of the pixels having an associated pixel value, processing the images by determining for pixels in a generated image weighted averages of the pixel values of a pixel and adjacent pixels, identifying corresponding portions of an object from a first view point and from a second view point on the basis of the weighted average values of pixels, and determining 3D positions of points corresponding to the corresponding portions of images.
