Patent ID: 7079157

Claim:
A graphics system for aligning images generated by two or more projection devices on a display surface, the graphics system comprising: a graphics processor configured to receive graphics data and to compute samples at sample positions in a two-dimensional viewport in response to a received stream of graphics data; a first calculation unit configured to compute first pixel values by filtering a first subset of the samples at a first plurality of first virtual pixel positions in the two-dimensional viewport, and to provide the first pixel values to a first projection device; a second calculation unit configured to compute second pixel values by filtering a second subset of the samples at a second plurality of second virtual pixel positions in the two-dimensional viewport, and to provide the second pixel values to a second projection device; wherein the first calculation unit is further configured to a) adjust the first virtual pixel positions in the two-dimensional viewport in order to approximate a pattern of distortion in the first virtual pixel positions which is geometrically similar to a distortion pattern exhibited by a first array of first physical pixels projected on the display surface by the first projection device, and b) filter the first subset of the samples at the adjusted first virtual pixel positions; wherein the second calculation unit is further configured to a) adjust the second virtual pixel positions in the two-dimensional viewport in order to approximate a pattern of distortion in the second virtual pixel positions which is geometrically similar to a distortion pattern exhibited by a second array of second physical pixels projected on the display surface by the second projection device, and b) filter the second subset of the samples at the adjusted second virtual pixel positions; and a memory for storing pixel values, wherein the pixel values computed by filtering subsets of the samples at the adjusted first and second virtual pixel positions are stored in memory locations corresponding to the non-adjusted first and second virtual pixel positions.