INTENSITY-MODULATED LIGHT PATTERN FOR ACTIVE STEREO
The subject disclosure is directed towards projecting light in a pattern in which the pattern contains components (e.g., spots) having different intensities. The pattern may be based upon a grid of initial points associated with first intensities and points between the initial points with second intensities, and so on. The pattern may be rotated relative to cameras that capture the pattern, with captured images used active depth sensing based upon stereo matching of dots in stereo images.
1 . A system comprising, a projector that projects a light pattern towards a scene, the projector including a laser and a diffractive optical component, the diffractive optical component configured to output the light pattern as a plurality of sets of sub-patterns, each set corresponding to a different range of intensities.
2 . The system of claim 1 wherein the sets comprise differently-sized sub-patterns, including large-sized sub-patterns and at least one set comprising smaller-sized sub-patterns.
3 . The system of claim 2 wherein the sets of differently-sized sub-patterns are interleaved via subdivision.
4 . The system of claim 1 wherein at least some of the sub-patterns comprise triangles corresponding to points.
5 . The system of claim 1 wherein one or more of the sub-patterns comprise points corresponding to positions that form an approximate regular polygon, based upon repositioning points of a substantially regular polygon with additional random repositioning of at least some points thereof.
6 . The system of claim 1 wherein at least one of the points that form a sub-pattern is randomly or pseudo-randomly assigned in intensity value within a range of intensities associated with that sub-pattern.
7 . The system of claim 1 further comprising a pair of stereo cameras that capture the projected pattern in stereo images, and further comprising an image processing component configured to process stereo images into depth maps.
8 . The system of claim 7 wherein the light pattern comprises infrared light for sensing by infrared stereo cameras, or visible light for sensing by color stereo cameras.
9 . The system of claim 7 wherein the stereo cameras and the projector are incorporated into a single device.
10 . The system of claim 7 wherein the diffractive optical component is configured to project a rotated pattern relative to an orientation of the stereo cameras.
11 . A method comprising, generating a grid comprising a first set of points, associating each point in the first set with an intensity value that is within a first intensity range, adding a second set of points between subsets of points of the first set of points, associating each point in the second set with an intensity value that is within a second intensity range, and encoding a diffractive optical component based upon the first set of points and the second set of points.
12 . The method of claim 11 further comprising, projecting light through the diffractive optical component to project a pattern comprising a first set of spots each within the first intensity range, and the second set of spots each within the second intensity range.
13 . The method of claim 11 wherein projecting the light comprises projecting the pattern rotated relative to orientation of a camera.
14 . The method of claim 11 further comprising, adding a third set of points between subsets of points of the second set of points, associating each point in the third set with an intensity value that is within a third intensity range, and wherein encoding the diffractive optical component further comprises encoding the diffractive optical based upon the third set of points.
15 . The method of claim 11 wherein the grid is triangular, and wherein generating the gird comprises arranging the first set of points into triangles based upon the grid, and wherein adding the second set of points comprises subdividing at least some of the triangles.
16 . The method of claim 11 wherein associating each point in the first set with an intensity value that is within a first intensity range comprises randomly or pseudo-randomly selecting an intensity value within the first range for at least some of the points in the first set.
17 . The method of claim 11 wherein associating each point in the second set with an intensity value that is within a second intensity range comprises randomly or pseudo-randomly selecting an intensity value within the second range for at least some of the points in the second set.
18 . The method of claim 11 further comprising, randomly or pseudo-randomly positioning at least some of the points in the first set relative to the grid.
19 . The method of claim 11 further comprising, randomly or pseudo-randomly randomly positioning at least some of the points in the second set relative to their positions between subsets of points of the first set of points.
20 . A method comprising, projecting light through a diffractive optical component to project a pattern comprising a first set of spots corresponding to a the first intensity range, and a second set of spots corresponding to a second intensity range, wherein the positions of the spots of the first set are based upon an initial grid layout and the positions of the spots of the second set of spots are based upon the positions of the spots of the first set, sensing the first set of spots and the second set of spots as left and right stereo camera images, and processing the images to correlate spots in the left image with spots in the right image, in which scanlines of the images are not aligned with the initial grid layout.