A projection device configured to project a correction pattern to a projection screen, the correction pattern comprising first feature points (u,v) in the projection device coordinate system, wherein the projection device comprises: a processor circuit configured to receive an image of the correction pattern projected to the projection screen that is captured by a three-dimensional image capturing device, so as to obtain coordinate positions of second feature points (x o,y o,z o) in a world coordinate system with a coordinate origin at the position of the three-dimensional image capturing device; characterized in that the processor circuit is further configured to: - perform an eigen decomposition on a covariance matrix of the second feature points (x o,y o,z o), so as to obtain three sets of eigenvectors perpendicular to each other, wherein two maximum eigenvalues of the three sets of eigenvectors represent a plane for describing the second feature points (x 0,y 0,z 0) and a minimum eigenvalue of the three sets of eigenvectors represents a normal vector of the plane; - determine an orientation of a virtual camera in the world coordinate system using the plane by assuming that the normal vector is parallel to the virtual camera optical axis, and set the virtual camera at a position at a distance (v) from the plane, said position representing a viewer position; - calculate a plurality of third feature points (x,y) on a virtual plane at the viewer position according to the coordinate positions of the second feature points (x o,y o,z o) and the viewer position by projecting the second feature points (x 0,y 0,z 0) to the virtual camera to obtain the third feature points (x,y); - generate a plurality of warped feature points (s,t) in the projection device coordinate system according to the third feature points (x,y); and - generate an antiwarp mapping table according to the warped feature points (s,t); - generate an antiwarp image according to an input image and the antiwarp mapping table; and wherein the projection device is configured to project the antiwarp image to the projection screen. wherein the projection device comprises: a processor circuit configured to receive an image of the correction pattern projected to the projection screen that is captured by a three-dimensional image capturing device, so as to obtain coordinate positions of second feature points (x o,y o,z o) in a world coordinate system with a coordinate origin at the position of the three-dimensional image capturing device; characterized in that the processor circuit is further configured to: - perform an eigen decomposition on a covariance matrix of the second feature points (x o,y o,z o), so as to obtain three sets of eigenvectors perpendicular to each other, wherein two maximum eigenvalues of the three sets of eigenvectors represent a plane for describing the second feature points (x 0,y 0,z 0) and a minimum eigenvalue of the three sets of eigenvectors represents a normal vector of the plane; - determine an orientation of a virtual camera in the world coordinate system using the plane by assuming that the normal vector is parallel to the virtual camera optical axis, and set the virtual camera at a position at a distance (v) from the plane, said position representing a viewer position; - calculate a plurality of third feature points (x,y) on a virtual plane at the viewer position according to the coordinate positions of the second feature points (x o,y o,z o) and the viewer position by projecting the second feature points (x 0,y 0,z 0) to the virtual camera to obtain the third feature points (x,y); - generate a plurality of warped feature points (s,t) in the projection device coordinate system according to the third feature points (x,y); and - generate an antiwarp mapping table according to the warped feature points (s,t); - generate an antiwarp image according to an input image and the antiwarp mapping table; and wherein the projection device is configured to project the antiwarp image to the projection screen. - perform an eigen decomposition on a covariance matrix of the second feature points (x o,y o,z o), so as to obtain three sets of eigenvectors perpendicular to each other, wherein two maximum eigenvalues of the three sets of eigenvectors represent a plane for describing the second feature points (x 0,y 0,z 0) and a minimum eigenvalue of the three sets of eigenvectors represents a normal vector of the plane; - determine an orientation of a virtual camera in the world coordinate system using the plane by assuming that the normal vector is parallel to the virtual camera optical axis, and set the virtual camera at a position at a distance (v) from the plane, said position representing a viewer position; - calculate a plurality of third feature points (x,y) on a virtual plane at the viewer position according to the coordinate positions of the second feature points (x o,y o,z o) and the viewer position by projecting the second feature points (x 0,y 0,z 0) to the virtual camera to obtain the third feature points (x,y); - generate a plurality of warped feature points (s,t) in the projection device coordinate system according to the third feature points (x,y); and - generate an antiwarp mapping table according to the warped feature points (s,t); - generate an antiwarp image according to an input image and the antiwarp mapping table; and