Projecting an image is described. A test pattern is rendered over each of two dimensions of a projection surface. Upon the rendered test pattern conforming to a perspective related specification for a spatial configuration of data disposed over the two dimensions the data are decoded. An angle of a projection in each of the two dimensions corresponding to the rendering of the test pattern is detected, relative to a line orthogonal to a plane corresponding to a portion of the projection surface. Upon a nonconformity of the rendered test pattern to the specification, a transformation is computed to a spatial configuration of the rendered test pattern. The computed transformation relates to a perspective related characteristic of the spatial configuration corresponding to the angle of the projection. The projector is controlled based on the computed transformation.