Alignment optimization in image display systems employing multi-camera image acquisition

A method of calibrating an image display system comprising one or more projectors oriented to project an image on a projection screen and a plurality of image sensors or a single, multi-view sensor configured to acquire overlapping portions of an image projected on the projection screen, the method comprising:

• operating the projector to project a calibration image comprising one or more image fiducials on the image projection screen;
• operating the one or more image sensors to acquire first and second portions I1, I2 of the projected calibration image such that the first and second portions I1, I2 overlap each other in the projected calibration image;
• identifying screen position coordinates for image fiducials in the first and second portions I1, I2 of the projected calibration image;
• establishing a first set of distance metrics D1 for the first portion I1 of the projected calibration image by utilizing the identified screen position coordinates to determine respective distances between adjacent points in the first portion I1 of the projected calibration image;
• establishing a second set of distance metrics D2 for the second portion I2 of the projected calibration image by utilizing the identified screen position coordinates to determine respective distances between adjacent points in the second portion I2 of the projected calibration image;
• constructing a global point set from the first and second sets of distance metrics D1, D2 wherein a first subset G1 of the global point set comprises fiducial positions derived from only one of the first and second sets of distance metrics D1, D2 and a second subset G2 of the global point set comprises fiducial positions derived from the other of the first and second sets of distance metrics D1, D2;
• optimizing alignment of the first and second subsets G1, G2 of the global point set by adjusting fiducial positions in the global point set in a manner that at least partially accounts for differences between local positional data derived from the first and second sets of distance metrics D1, D2 and global positional data of the fiducial positions in the global point set;
• utilizing the optimized global point set to operate the projector in a calibrated projection mode.

An image display system comprising one or more projectors oriented to project an image on a projection screen, a plurality of image sensors or a single, multi-view sensor configured to acquire an image projected on the projection screen, and one or more controllers programmed to operate the projectors, wherein:

• the projector projects an image comprising one or more image fiducials on the image projection screen;
• the image sensors acquire first and second portions I1, I2 of the projected image such that the first and second portions I1, I2 overlap each other in the projected image;
• the system identifies screen position coordinates for image fiducials in the first and second portions I1, I2 of the projected image;
• the system establishes a first set of distance metrics D1 for the first portion I1 of the projected image by utilizing the identified screen position coordinates to determine respective distances between adjacent points in the first portion I1 of the projected image;
• the system establishes a second set of distance metrics D2 for the second portion I2 of the projected image by utilizing the identified screen position coordinates to determine respective distances between adjacent points in the second portion I2 of the projected image;
• the system construct a global point set from the first and second sets of distance metrics D1, D2 wherein points within a region where the first and second portions I1, I2 of the projected image overlap are derived from only one of the first and second sets of distance metrics D1, D2 such that a first subset G1 of the global point set comprises fiducial positions derived from only one of the first and second sets of distance metrics D1, D2 and a second subset G2 of the global point set comprises fiducial positions derived from the other of the first and second sets of distance metrics D1, D2;
• the system optimize alignment of the first and second subsets G1, G2 of the global point set by adjusting fiducial positions in the global point set in a manner that at least partially accounts for differences between local positional data derived from the first and second sets of distance metrics D1, D2 and global positional data of the fiducial positions in the global point set;
• and
• the projector operates in a manner that is at least partially dependent on the optimized alignment of the global point set.

A method of operating an image display system comprising one or more projectors oriented to project an image on a projection screen and a plurality of image sensors or a single, multi-view sensor configured to acquire overlapping portions of an image projected on the projection screen, the method comprising:

• operating the projector to project an image comprising one or more image fiducials on the image projection screen;
• operating the one or more image sensors to acquire first and second portions I1, I2 of the projected image such that the first and second portions I1, I2 overlap each other in the projected image;
• identifying screen position coordinates for image fiducials in the first and second portions I1, I2 of the projected image;
• establishing a first set of distance metrics D1 for the first portion I1 of the projected image by utilizing the identified screen position coordinates to determine respective distances between adjacent points in the first portion I1 of the projected image;
• establishing a second set of distance metrics D2 for the second portion I2 of the projected image by utilizing the identified screen position coordinates to determine respective distances between adjacent points in the second portion I2 of the projected image;
• constructing a global point set from the first and second sets of distance metrics D1, D2 wherein points within a region where the first and second portions I1, I2 of the projected image overlap are derived from only one of the first and second sets of distance metrics D1, D2 such that a first subset G1 of the global point set comprises fiducial positions derived from only one of the first and second sets of distance metrics D1, D2 and a second subset G2 of the global point set comprises fiducial positions derived from the other of the first and second sets of distance metrics D1, D2;
• optimizing alignment of the first and second subsets G1, G2 of the global point set by adjusting fiducial positions in the global point set in a manner that uses virtual springs assigned to intervening spaces between points in the global point set and at least partially accounts for differences between local positional data derived from the first and second sets of distance metrics D1, D2 and global positional data of the fiducial positions in the global point set;
• and
• operating the projector in a manner that is at least partially dependent on the optimized alignment of the global point set.