Non-uniform spatial resource allocation for depth mapping
A method for depth mapping includes providing depth mapping resources, including a radiation source, which projects optical radiation into a volume of interest containing an object, and a sensor, which senses the optical radiation reflected from the object. The volume of interest has a depth that varies with angle relative to the radiation source and the sensor. A depth map of the object is generated using the resources while applying at least one of the resources non-uniformly over the volume of interest, responsively to the varying depth as a function of the angle.
1. A method for depth mapping, comprising:
providing depth mapping resources comprising:
a radiation source, which is configured to project optical radiation into a volume of interest containing an object; and
a sensor, which is configured to sense the optical radiation reflected from the object; and
generating a depth map of the object using the resources while angularly modulating the projected optical radiation non-uniformly over the volume of interest.
2. The method according to claim 1 , wherein angularly modulating the projected optical radiation comprises varying an intensity of the projected optical radiation as a function of the angle.
3. The method according to claim 2 , wherein the volume of interest, including the object, has a depth that varies with angle relative to the radiation source and the sensor, and wherein varying the intensity comprises modulating the intensity responsively to the varying depth.
4. The method according to claim 1 , wherein providing the depth mapping resources comprises focusing the reflected optical radiation onto the sensor while applying an optically distortion in focusing the reflected optical radiation.
5. The method according to claim 1 , wherein the radiation source is configured to project a spatial pattern of the optical radiation onto the object, and wherein generating the depth map comprises deriving depth coordinates of the object based on transverse shifts of the spatial pattern in an image captured by the sensor.
6. The method according to claim 5 , wherein the depth mapping resources comprise a diffractive optical element (DOE), and wherein the radiation source is configured to transilluminate the DOE so as to generate the patterned optical radiation.
7. The method according to claim 1 , wherein the radiation source projects the optical radiation with a given projection distortion, and wherein the depth mapping resources comprise objective optics configured to focus the reflected optical radiation onto the sensor while applying an optical distortion that compensates at least partially for the projection distortion.
8. The method according to claim 7 , wherein the objective optics comprise an F-theta lens.
9. The method according to claim 1 , wherein the projected optical radiation is angularly modulated so as to optimize a 3D resolution of the depth map.
10. The method according to claim 1 , wherein generating the depth map comprises measuring a time of flight of the optical radiation reflected from the object.
11. Apparatus for depth mapping, comprising:
depth mapping resources comprising:
a radiation source, which is configured to project optical radiation into a volume of interest containing an object while angularly modulating the projected optical radiation non-uniformly over the volume of interest; and
a sensor, which is configured to output a signal in response to the optical radiation reflected from the object; and
a processor, which is configured to process the signal in order to generate a depth map of the object.
12. The apparatus according to claim 11 , wherein angularly modulating the projected optical radiation comprises varying an intensity of the projected optical radiation as a function of the angle.
13. The apparatus according to claim 12 , wherein the volume of interest, including the object, has a depth that varies with angle relative to the radiation source and the sensor, and wherein varying the intensity comprises modulating the intensity responsively to the varying depth.
14. The apparatus according to claim 11 , wherein the depth mapping resources comprise optics configured to focus the reflected optical radiation onto the sensor while applying an optical distortion in focusing the reflected optical radiation.
15. The apparatus according to claim 11 , wherein the radiation source is configured to project a spatial pattern of the optical radiation onto the object, and wherein the processor is configured to derive depth coordinates of the object based on transverse shifts of the spatial pattern in an image captured by the sensor.
16. The apparatus according to claim 15 , wherein the depth mapping resources comprise a diffractive optical element (DOE), and wherein the radiation source is configured to transilluminate the DOE so as to generate the patterned optical radiation.
17. The apparatus according to claim 11 , wherein the radiation source projects the optical radiation with a given projection distortion, and wherein the depth mapping resources comprise objective optics configured to focus the reflected optical radiation onto the sensor while applying an optical distortion to an image captured by the sensor that compensates at least partially for the projection distortion.
18. The apparatus according to claim 17 , wherein the objective optics comprise an F-theta lens.
19. The apparatus according to claim 11 , wherein the projected optical radiation is angularly modulated so as to optimize a 3D resolution of the depth map.
20. The apparatus according to claim 11 , wherein the processor is configured to process the signal so as to measure a time of flight of the optical radiation reflected from the object.