Three dimensional vision device and method, and structured light bar-code patterns for use in the same
AssigneeNEC Laboratories America, Inc.
InventorsWarren D. Smith, Sebastien Roy
Life of this patent
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Abstract
The present invention is a system and method for three dimensional machine vision including a projector and camera. The projector casts a structured light Quadratic Residue Bar Code on the surface to be mapped. The camera then images the surface. The projected image is shifted, and the process is repeated a number of times, according to the particular arrangement selected for the structured light Quadratic Residue Bar Code. The image data collected from this series of images is then processed by relatively simple matrix operations to determine the location of each camera pixel in three dimensional space.
Claims19
A system for accurately mapping a three dimensional surface comprising:
- (a) a digital pixel camera;
- (b), means for processing data collected by said digital pixel camera;
- and
- (c) a projection device capable of projecting structured light bar code on the surface being mapped, said structured light bar code comprising:
- (i) a periodic sequence of parallel bars having symmetric width, each of said bars being one of either light and dark;
- and
- (ii) a numerical index associated with each of said bars, wherein said bars whose numerical index is equal to the remainder of a perfect square number divided by the number of said bars in each period are light, and all other said bars are dark.
A method of mapping a three dimensional surface comprising the steps of:
- (a) providing a two dimensional digital pixel camera;
- (b) providing a means for processing data collected by said digital pixel camera;
- (c) providing a projection device capable of projecting a structured light on the surface to be mapped, said structured light comprising:
- (i) a periodic sequence of parallel bars having symmetric width, each of said bars being one of either light and dark;
- and
- (ii) a numerical index associated with each of said bars, wherein said bars whose numerical index is equal to the remainder of a perfect square number divided by the number of said bars in each period are light, and all other said bars are dark;
- (d) projecting said structured light onto the surface to be mapped;
- (e) shifting the position of said structured light over the surface to be mapped in increments equal to the width of each of said parallel lines, a number of times equal to one less than the number of said parallel lines which make up each said period;
- (f) imaging the surface at each said position of said structured light using said camera, whereby data is collected as to the light intensity of each camera pixel;
- and
- (g) processing said collected data into the location of the image within each camera pixel in three dimensional space.
A structured light bar code pattern for accurately mapping a three dimensional surface, said structured light comprising:
- (a) a periodic sequence of parallel bars having symmetric width, each of said bars being one of either light and dark;
- and
- (b) a numerical index associated with each of said bars, wherein said bars whose numerical index is equal to the remainder of a perfect square number divided by the number of said bars in each period are light, and all other said bars are dark.
Dependencies are inferred from the claim text.