Abstract: Aiming at geometric calibration for multi-projector display system with irregular curved display wall,a nonlinear auto-geometric calibration algorithm based on structured light projection technique is proposed.Firstly,the mapping relation between every projector and the display wall is calculated using structured light projection technique.Secondly,a camera is used to capture longitude and latitude spot-array on the display wall.Thirdly,the longitude and latitude value in global coordinate for each pixel on the projector frame buffer is calculated by extracting the features in images captured by the camera.Finally,the geometric calibration is achieved by changing the longitude and latitude value to texture coordinate.Both computer simulation experiments and real applications in virtual airport system showed that the proposed algorithm provided high calibration accuracy.Furthermore,since the proposed algorithm does not require the calibration of camera and any prior knowledge of the display,it is suitable for any smooth display walls.