Automatically producing an optical blend mask individually adapted to a projector and its position to a projection surface of the projection system

A method for automatically generating an optical blend mask (7), arranged in a beam path (8) of a projector (2) in a projection system (1) comprising at least two projectors (2), comprising the steps of:

• determining an actual state of the projection system (1) by a calibration,
• determining an individual distortion of the projector (2) by using a front or rear projection surface (11) inserted in the beam path (8) between the projector (2) and a projection surface (3) using patterns (13) from which projected points are derived;
• determining orientation and position of the front or rear projection surface (11) within a blend mask plane with respect to a local reference coordinate system,
• calculating ideal blending for a partial image (4) to be projected by the projector (2) in such a way that the ideal blending is positioned and/or transformed on the blend mask plane,
• adapting the ideal blending to compensate for a soft focus in the beam path (8),
• applying the determined, individual distortion of the projector (2) to the ideal blending, and
• determining data for generating an optical blend mask (7),
• wherein the optical blend mask (7) generated according to the determined data is used at a location in the beam path (8) of the projector (2) at which the front or rear projection surface (11) was positioned when determining the individual distortion of the projector (2).