1. A method of generating a depth map ( 122 ) comprising depth values representing distances to a viewer, for respective pixels of an image ( 100 ), the method comprising: determining a contour ( 106 ) on basis of pixel values of the image ( 100 ), the contour ( 106 ) comprising a collection of adjacent points; computing curvature vectors ( 108 - 114 ) at a number of the points; and assigning a first one of the depth values corresponding to the first one of the pixels on basis of the curvature vectors ( 108 - 114 ).