Method and system for image transformation

• US 4,965,844 A
• Filed: 03/31/1986
• Issued: 10/23/1990
• Est. Priority Date: 04/03/1985
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kurauchi, Yoshitaka, Oka, Masaaki
• Primary Examiner(s): Boudreau, Leo H.
• Application Number:
  US06/845,955
• Time in Patent Office: 1,667 Days
• Field of Search: 382/41, 382/44, 382/45, 382/50, 358/22, 340/729, 340/723
• US Class Current: 345/581
• CPC Class Codes: G06T 1/0007 Image acquisition
• CPC Class Codes: G06T 17/00 Three dimensional [3D] modelling, e.g. data description of 3D objects
• CPC Class Codes: H04N 5/2628 Alteration of picture size, shape, position or orientation, e.g. zooming, rotation, rolling, perspective, translation

Abstract

A method of transforming an input video image data onto a three-dimensional surface is disclosed which comprises the steps of defining the three-dimensional surface, providing mapping data for transforming the input video image data onto the surface, storing the input video image data in a first memory, transforming the input video image data stored in the first memory according to the mapping data so as to provide an output video image data, calculating first vectors representing, respectively, orientations taken by minute areas on the surface, calculating second vectors representing, respectively, directions from the minute areas toward a virtual light source disposed in a position, calculating weighting factors according to the first and second vectors, the weighting factors quantifying shading to be caused on the minutes areas by the virtual light source, and weighting the input video image data or the output video image data according to the weighting factors.

Claims

1. A method of transforming a two-dimensional input video image data onto a three-dimensional surface comprising the steps of:

(A) defining said three-dimensional surface;

(B) providing mapping data for transforming said two-dimensional input video image data onto said surface;

(C) storing said two-dimensional input video image data in a first memory means;

(D) transforming said two-dimensional input video image data stored in said first memory means according to said mapping data so as to provide a two-dimensional output video image data;

(E) calculating first vectors respectively representing normal vectors of minute areas provided on said surface;

(F) calculating second vectors respectively representing directions from said minute areas toward an imaginary light source disposed at an arbitrary position;

(G) calculating values of an inner product of said first and said second vectors;

(H) calculating weighting factors according to said values of said inner products of said first and said second vectors calculated in step (G), said weighting factors respectively respresenting shading on said minute areas caused by said imaginary light source; and

(I) weighting a signal representative of said two-dimensional input video image data according to said weighting factors, whereby both luminescence and hue components of said signal are changed according to said weighting factors.

2. A method of transforming a two-dimensional input video image data onto a three-dimensional surface according to claim 1, further comprising a step of setting the position of said imaginary light source.

3. A method of transforming a two-dimensional input video image data onto a three-dimensional surface according to claim 1, wherein said step (E) comprises the steps of (1) calculating normal vectors of said minute areas provided on said surface, (2) calculating front/back flags of said minute areas provided on said surfaces and (3) multiplying said normal vectors and said front/back flags.

4. A method of transforming a two-dimensional input video image data onto a three-dimensional surface according to claim 1, further comprising a step of storing said weighting factors in a second memory means.

11. A method of transforming a two-dimensional input video image data onto a three-dimensional surface according to claim 1, wherein said weighting factors calculated in the step (H) have a maximum and/or minimum value.

16. The method of transforming a two-dimensional input video image data onto a three-dimensional surface according to claim 1, wherein said signal representative of said two-dimensional input video image data is a digital signal after A/D conversion of said input video image data.

17. The method of transforming a two-dimensional input video image data onto a three-dimensional surface according to claim 1, wherein said signal representative of said two-dimensional input video image data is said two-dimensional video image data.

5. A system for transforming a two-dimensional input video image data onto a three-dimensional surface comprising:

(A) means for defining said three-dimensional surface;

(B) means for providing mapping data for transforming said two-dimensional input video image data onto said surface;

(C) first memory means for storing said two-dimensional input video image data;

(D) means for transforming said two-dimensional input video image data stored in said first memory means according to said mapping data so as to output a two-dimensional video image data;

(E) second memory means for storing weighting factors representing shading on said surface caused by an imaginary light source disposed at an arbitrary position, said weighting factors being provided by calculation according to first vectors respectively representing normal vectors of minute areas provided on said surface and second vectors respectively representing directions from said minute areas toward said imaginary light source and calculating an inner product of said first and second vectors; and

(F) means for weighting a signal representative of said input video image data or said input video image data according to said weighting factors whereby both luminescence and hue components of said signal are changed according to said weighting factors.

12. A system for transforming a two-dimensional input video image data onto a three-dimensional surface according to claim 5, further comprising means for setting the position of said imaginary light source.

13. A system for transforming a two-dimensional input video image data onto a three-dimensional surface according to claim 5, further comprising means for weighting a digital representation of said input video image signal.

14. A system for transforming a two-dimensional input video image data onto a three-dimensional surface according to claim 5, wherein said second memory means comprises:

(a) means for calculating normal vectors of said minute areas provided on said surface;

(b) means for calculating front/back flags of said minute areas; and

(c) means for calculating an inner product of said first and second vectors.

6. A system for transforming a two-dimensional input video image data onto a three-dimensional surface comprising:

(A) means for defining said three-dimensional surface;

(B) means for providing mapping data for transforming said two-dimensional input video image data onto said surface;

(C) first memory means for storing said two-dimensional input video image data;

(D) means for transforming said input video image data stored in said first memory means according to said mapping data so as to provide a two-dimensional output video image data;

(E) means for detecting gap portions on said output video image data according to said mapping data when no properly transformed video image data exists.

7. A system for transforming a two-dimensional input video image data onto a three-dimensional surface according to claim 6, further comprising second memory means for storing gap data according to said mapping data, said detected gap portions being processed in response to said gap data system.

8. A system for transforming a two-dimensional input video image data onto a three-dimensional surface according to claim 7, wherein said second memory means including a first flag memory in which write flag data are stored corresponding to said output video image data, each of said write flag data being representative of existence of each of said output video image data.

9. A system for transforming a two-dimensional input video image data onto a three-dimensional surface according to claim 7, wherein said second memory means including a second flag memory in which front/back flag data are stored corresponding to said output video image data, each of said front/back flag data indicating whether the front side or the back side of the input video image is transformed onto said surface.

10. A system for transforming a two-dimensional input video image data onto a three-dimensional surface according to claim 7 wherein said second memory means including a third flag memory in which address data of said input video image on said first memory means corresponding to said input video image are stored.

15. A system for transforming a two-dimensional input video image data into a three-dimensional surface as set forth in claim 6, further including means for interpolating video image data for said gap portions by calculation of video image data on the circumference of said gap portions.

18. The method of transforming a two-dimensional input video image data onto a three- dimensional surface wherein said two-dimensional input video image data has been transferred onto a three-dimensional surface according to predetermined mapping data so as provide three-dimensional video image data on said three-dimensional surface, comprising the steps of:

(A) calculating first vectors respectively representing normal vectors of minute areas provided on said surface;

(B) calculating second vectors respectively representing directions from said minute areas toward an imaginary light source disposed at an arbitrary position;

(C) calculating values of an inner product of said first and second vectors;

(D) calculating weighting factors according to said values of said inner product of said first and said second vectors calculated in steps (A) and (B), said weighting factors respectively representing said shading on said minute areas caused by said imaginary light source; and

(E) weighting a signal representative of said two-dimensional input video image data according to said weighting factors whereby both luminescence and hue components of said signal are changed according to said weighting factors.