Method for determining a largest inscribed rectangular image within a union of projected quadrilateral images

• US 6,729,733 B1
• Filed: 03/21/2003
• Issued: 05/04/2004
• Est. Priority Date: 03/21/2003
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Inventors: Raskar, Ramesh, van Baar, Jeroen, Willwacher, Thomas H.
• Primary Examiner(s): Adams, Russell
• Assistant Examiner(s): Koval, Melissa J
• Application Number:
  US10/394,684
• Time in Patent Office: 410 Days
• Field of Search: 353/121, 353/122, 353/30, 353/31, 353/69, 348/744
• US Class Current: 353/121
• CPC Class Codes: H04N 5/74 Projection arrangements for image reproduction, e.g. using eidophor
• CPC Class Codes: H04N 9/12 Picture reproducers H04N9/11 takes precedence
• CPC Class Codes: H04N 9/3147 Multi-projection systems displays in general H04N9/12; video walls G06F3/1446, G09G2300/026
• CPC Class Codes: H04N 9/3185 Geometric adjustment, e.g. keystone or convergence optical or mechanical adjustment of convergence H04N9/317; using scanning means H04N3/22; optical or mechanical adjustments of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/14
• CPC Class Codes: H04N 9/3194 including sensor feedback

Abstract

A method determines a largest rectangle on a display surface. A polygon L is drawn on a first depth plane having a depth z=1 in a depth buffer. A rectangle R is drawn with a predetermined aspect ratio on a second depth plane having a depth z=0. A center of projection is determined with a minimum depth z in a range [0,1] that maps the rectangle R into a largest rectangle S in the first depth plane so that the rectangle S remains completely inside the polygon L.

Claims

1. A method for determining a largest rectangle on a display surface, comprising:

drawing a polygon L on a first depth plane having a depth z=1;

drawing a rectangle R with a predetermined aspect ratio on a second depth plane having a depth z=0; and

locating a center of projection with a minimum depth z in a range [0, 1] that maps the rectangle R into a largest rectangle S in the first depth plane so that the rectangle S remains completely inside the polygon L.

2. The method of claim 1 further comprising:

projecting a plurality of output images on the display surface, the plurality of output images overlapping with each other; and

acquiring an input image of the overlapping output images;

forming the polygon L from a union of the output images in the input image.

3. The method of claim 1 further comprising:

projecting the largest rectangular output image on a display surface using the center of projection.

4. The method of claim 1 further comprising:

constructing pyramids connecting edges of the polygon on first depth plane and edges of the rectangle R on the second depth plane, each face of each pyramid being a triangle;

intersecting each triple of triangles; and

retaining a particular triangle with the minimum depth z to locate the center of projection.

5. The method of claim 3 further comprising:

considering only triangles connecting a vertex of the polygon L with an edge of the rectangle R, and triangles connecting an edge of the polygon L with a vertex of the rectangle R.

6. The method of claim 4 wherein the polygon L has n sides, and there are 8n triangles.