An apparatus for compensating a projected image employs a projected image compensator, such as a suitably programmed graphics processor or other processing device, and receives projection display compensation parameters to perform electronic projected image correction based on the received projection on display compensation parameters. The projected image compensator obtains stored final image data, such as data finally rendered by a 2D or 3D graphics engine, that has been stored in a frame buffer, and performs scaling of the final image data to produce projection compensated final image data. In one embodiment, the projection compensated final image data is stored back in the frame buffer memory and then output under control of a display controller. In another embodiment, the projection compensated final image data is not returned back to the frame buffer memory.
A projector has an acceleration sensor for detecting a tilt angle of the projector, a manual controller for manually setting a correction amount for a keystone distortion correction, an auto/manual switch, an upper edge basis corrector for determining parameters for an upper edge basis keystone distortion correction, a lower edge basis corrector for determining parameters for a lower edge basis keystone distortion correction, and an image processor for performing a keystone distortion correction on the image on the basis of the upper edge or lower edge in accordance with parameters applied thereto from the upper edge basis corrector or lower edge basis corrector to display the corrected image on a liquid crystal panel or the like. As the auto/manual switch selects an automatic adjustment, the acceleration sensor and upper edge basis corrector are connected to the image processor. As a manual adjustment is selected, the manual controller and lower edge basis corrector are connected to the image processor.
A method of correcting an image with perspective distortion and creating an artificial image with perspective distortion is disclosed. First, image data including a distorted object image are received. Next, the user inputs an operational instruction for setting a plurality of distortion parameters pertaining to the image data, which include a distorted side of the distorted object image, a central line and a distortion ratio. Thus, a plurality of coordinates of corners of the distorted object image are calculated according to these distortion parameters and a transformation matrix is determined according to the calculated coordinates of the corners of the distorted object image. Finally, the distorted object image is transformed to a corrected object image according to the transformation matrix.
In a projection type display device having an electrical trapezoidal distortion correcting function, there are provided detection means for detecting an angle of inclination in the vertical direction of an optical axis of the projection type display device toward a screen surface, and control means for controlling the display position of an on screen display image displayed in a screen on the basis of the angle of inclination detected by the detection means.
A method and apparatus for automatically correcting projection display of a projector. The disposition parameters including disposition distance (or horizontal inclination angle) and vertical inclination angle for the disposing surface are detected first. Whether the disposition distance (or horizontal inclination angle) and the vertical inclination angle are shifted from the predetermined standard values is determined by a control circuit. If the deviation occurs, a correction value according to the deviation is obtained from a look up table, and an input image signal is corrected with the correction value to obtain a corrected image projected on a screen.
A video system includes a video projector located in a housing a display screen disposed adjacent to the housing, wherein the display screen is capable of being tilted to expose the video projector, logic for generating a test image to display on the tilted display screen in order to calibrate the video projector, logic for projecting the test image onto the tilted display screen; and logic for calibrating the video projector using the test image. The test image is altered to fit the tilted display screen.
