Computer graphics processing and selective visual display system – Display peripheral interface input device
Reexamination Certificate
1999-03-31
2001-09-18
Shalwala, Bipin (Department: 2673)
Computer graphics processing and selective visual display system
Display peripheral interface input device
C702S095000
Reexamination Certificate
active
06292171
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related to interactive video display presentation systems and, more particularly, to a method and apparatus for calibrating such a system.
2. Description of the Related Art
In meetings and in classrooms, charts, text, and various graphical images are commonly presented to the audience by means of optical projection onto a projection screen or a wall. An LCD (liquid crystal display) projector is commonly used, where the charts, text, and graphical images are generated by a personal computer (PC), such as a laptop computer. These LCD/PC projection display systems are becoming more popular than the traditional overhead projector and transparencies which they replace. In such display systems, the PC provides video outputs such as standard VGA, Super VGA, or XGA.
The user controls the image being projected onto the projection screen by means of the PC keyboard, or by clicking a mouse in the appropriate area of the computer monitor display screen. Some systems provide limited, remote mouse control by using a line-of-sight infrared signal that is directed at the LCD projector and which controls some predefined functions, such as advancing the presentation to the next frame or drawing a straight line. One such apparatus, comprising radiation sensing means at the projection screen, enables an operator to interact with a computer-controlled image projection system, as disclosed in U.S. Pat. No. 5,235,363 issued to Vogeley et al. However, even with such features, most control operations need to be performed at the PC itself If the speaker is standing at a lectern or moving before the audience, he cannot readily return to the PC to provide control. It becomes necessary to have an assistant seated at the computer to provide the control for certain aspects of the presentation.
In another variation of the display presentation, a laser pointer is used to project a control beam onto the projected image. An imaging device detects the control beam and relays this information to the PC. The user controls the PC by moving and switching the control beam on and off. To provide an accurate reference of the control beam to the displayed image on the PC screen, it is necessary to calibrate, or align, the projected image to the displayed image.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide an method and apparatus for correlating the projection coordinates of the image elements projected onto a surface to the display coordinates of the corresponding image elements as displayed on the computer screen.
It is another object of the present invention to provide such a method which is computationally simple, fast, and reliable.
SUMMARY OF THE INVENTION
An apparatus and method for calibrating the computer-generated projected image, such as found in a projection display system, to the displayed image viewed on the computer screen. Four or more calibration spots, arrayed in a predetermined pattern in both the displayed and the projected images, are optically imaged and electronically discriminated in the projected image, their coordinates ascertained and related to the predetermined pattern. With this relationship determined, there are found transformation coefficients which are subsequently used in the process of converting a location on the projected image to the corresponding location in the displayed image. Other features of the invention will be readily apparent when the following detailed description is read in connection with the drawings.
REFERENCES:
patent: 4280135 (1981-07-01), Schlossberg
patent: 5181015 (1993-01-01), Marshall et al.
patent: 5235363 (1993-08-01), Vogeley et al.
patent: 5329444 (1994-07-01), Takahashi et al.
patent: 5422693 (1995-06-01), Vogeley et al.
patent: 5434595 (1995-07-01), Macaulay
patent: 5489923 (1996-02-01), Marshall et al.
patent: 5502459 (1996-03-01), Marshal et al.
patent: 5504501 (1996-04-01), Hauck et al.
patent: 5511148 (1996-04-01), Wellner
patent: 5515079 (1996-05-01), Hauck
patent: 5528263 (1996-06-01), Platzker et al.
patent: 5584552 (1996-12-01), Nam-Su et al.
patent: 5594468 (1997-01-01), Marshall et al.
patent: 5661667 (1997-08-01), Rueb et al.
patent: 5663795 (1997-09-01), Rueb
patent: 5682181 (1997-10-01), Nguyen et al.
patent: 5712658 (1998-01-01), Arita et al.
patent: 5777898 (1998-07-01), Teterwak
patent: 5796386 (1998-08-01), Lipscomb et al.
patent: 5803570 (1998-09-01), Chen et al.
patent: 5973672 (1999-10-01), Rice et al.
patent: 5982352 (1999-11-01), Pryor
Fu Bin
Lin Shang-Hung
Osorio Ricardo
Seiko Epson Corporation
Shalwala Bipin
Watson Mark P.
LandOfFree
Method and apparatus for calibrating a computer-generated... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for calibrating a computer-generated..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for calibrating a computer-generated... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2500236