Method and apparatus for performing perspective transformation on visible stimuli

• US 5,684,937 A
• Filed: 06/07/1995
• Issued: 11/04/1997
• Est. Priority Date: 12/14/1992
• Status: Expired due to Term

• Current Assignee: Grandeye Limited (Oncam Global Group AG)
• Original Assignee: Ford Oxaal
• Inventors: Oxaal, Ford
• Primary Examiner(s): Herndon, Heather R.
• Assistant Examiner(s): Fetting, Anton W.
• Application Number:
  US08/478,839
• Time in Patent Office: 881 Days
• Field of Search: 345/127, 345/136, 345/927, 345/139, 348/580, 348/36, 434/43, 382/293
• US Class Current: 345/427
• CPC Class Codes: G03B 37/02 with scanning movement of lens or cameras
• CPC Class Codes: G06T 15/20 Perspective computation
• CPC Class Codes: G06T 3/12 Panospheric to cylindrical image transformations
• CPC Class Codes: G06T 3/18 Image warping, e.g. rearranging pixels individually
• CPC Class Codes: H04N 23/698 for achieving an enlarged field of view, e.g. panoramic image capture

Abstract

The principle purpose of the present invention is to provide an image pressing system which uses the two methods to form visible stimuli which depict visual shape. In particular, the present invention either transforms a first visual configuration to a second visible configuration that depicts (in one of the two possible ways given) the visual shapes induced by the first visible configuration, or it determines the visible configuration necessary to depict the desired visual configuration. Using the present invention, it is possible to transform a full 360 degrees of visible space (i.e., front, back, up, down, right and left directional views) onto a single display surface.

Claims

1. In an image processing system, a method of transforming an input visible image, which defines first visual stimuli into an enlarged or reduced output visible image, which defines second visual stimuli, the method comprising the steps of:

(a) differentiating a plurality of rays v_n by identifying a plurality of corresponding points as a set of first points in a visible space, each of said rays being specified with respect to a reference half plane including a viewpoint disposed on one edge of said half plane and with a direction of vision ƒ

of the user coincident with said one edge, by a first angle θ

denoting angular displacement between said half plane and a second half plane coincident with a respective one of ray v_n and by a second angle ψ

denoting angular displacement between said direction of vision ƒ and

said respective one of said rays v_n;

(b) scaling each respective second angle ψ

by a predetermined constant k to produce a respective scaled second angle ψ

'"'"';

(c) generating a set of second points respectively corresponding to each of said first points based on the scaled second angles ψ

'"'"' produced in step (b); and

(d) projecting said second points on a display device to produce said output visible image, said output visible image corresponding to said second visual stimuli and having visual similarity to said first visual stimuli.

2. The method of claim 1, wherein said projecting step (d) comprises the step of projecting said second set of points on a display device with respect to a variation of direction of vision ƒ

and the viewpoint to produce said resultant image.

3. The method of claim 1, wherein said differentiating step (a) comprises the step of differentiating a plurality of rays identifying a plurality of corresponding points in a planar visible space for projection on said display device.

4. The method of claim 1, wherein said differentiating step (a) comprises the step of differentiating a plurality of rays identifying a plurality of corresponding points in a substantially spherical visible space.

5. The method of claim 4, wherein said projecting step (d) comprises the step of projecting said second set of points onto a circular region of a display device to produce said resultant image representing a 360 degree view of the set of first points.

6. The method of claim 1, wherein said scaling factor is any real number excluding 0.0 and 1.0.

7. The method of claim 6, wherein said scaling factor is any real number excluding 2.0.

8. The method of claim 6, wherein said scaling factor is any real number excluding ∞

.

9. An image processing system for use in transforming an input visible image, which defines first visual, into a scaled output visible image defining second visual stimuli, the system comprising:

first means for storing a plurality of first image points defining said input visible image;

second means for selecting a focal point with respect to said input visible image;

third means for determining a focal length defining an offset distance from said focal point of said input visible image and for defining a direction of vision with respect said input visible image;

fourth means for determining a scaling factor;

fifth means for calculating a plurality of second image points corresponding to an output visible image, which represents a scaled version of said input visible image, based on said focal point, said focal length, said direction of vision and said scaling factor; and

sixth means for projecting said second points on a display device to produce said output visible image, said output visible image corresponding to said second visual stimuli and having visual similarity to said first visual stimuli.

10. The image processing system of claim 9, wherein said sixth means is a cathode ray tube.

11. The image processing system of claim 9, wherein said first means is a computer memory storing a digitized image.

12. The image processing system of claim 9, wherein each of said second image points has a respective distinguishing characteristic and wherein said fifth means further comprises means for ascertaining said respective distinguishing characteristic from said first means.

13. The image processing system of claim 12, wherein said respective distinguishing characteristic is a color value.

14. The image processing system of claim 9, wherein said fourth means comprises means for determining said scaling factor, wherein said scaling factor is any real number excluding 0.0, 1.0.

15. The method of claim 14, wherein said scaling factor is any real number excluding 2.0.

16. The method of claim 14, wherein said scaling factor is any real number excluding ∞

.