Gated imaging apparatus, system and method

1. A method for imaging objects in a depth-of-field (DOF) of a scene by an apparatus of a moving or movable platform, the method comprising:

a. actively illuminating the scene:

with pulsed light comprising a first train of light pulses according to a first illumination function, and

with second pulsed light comprising a second train of light pulses according to a second illumination function;

wherein the actively illuminating includes:

controlling temporal width of at least one light pulse of the first train of light pulses, or controlling at least one light pulse of the second train of light pulses, or both;

b. receiving, responsive to illuminating the scene with the train of first light pulses and with the train of second light pulses, respectively, a plurality of first reflections and a plurality of second reflections on at least one image sensor comprising at least one pixel element;

selectively controlling the at least one pixel element; for imaging a first DOF by integrating first pixel values relating to the plurality of first reflections according to a first sensor function to obtain first integrated pixel values relating to a first DOF having a first gating profile;

for imaging a second DOF by integrating first pixel values relating to the plurality of second reflections according to a second sensor function to obtain first integrated pixel values relating to a first DOF having a second gating profile;

wherein the first gating profile is different from the second gating profile;

wherein the first and the second gating profiles are spatially overlapping; wherein the first gating profile expresses convolution between the first illumination function and the first sensor function; and

wherein the second gating profile expresses convolution between the second illumination function and the second sensor function.

2. The method of claim 1 , wherein a first DOF range and a second DOF range of the plurality of DOF ranges are at least partially overlapping; and

determining, based on at least one first pixel value of the first DOF range in the overlapping DOF region, and further based on at least one second pixel value of the second DOF range in the overlapping DOF region, depth information of an object located in an overlapping DOF region of the scene.

3. The method according of claim 1 comprising:

reading out pixel data that is associated with at least two pixel subsets to obtain one or more image frames that are descriptive of at least two DOF ranges and their overlapping DOF range.

4. The method according to claim 3 ,

wherein gating the at least two pixel subsets is performed a plurality of times to obtain at least two different overlapping DOF regions in which the object is located; and

depth mapping the pixel data descriptive of the object based on values relating to the at least two different overlapping DOF regions.

5. The method according claim 3 , wherein the at least two pixel subsets are associated with respective Regions-of-Interest (ROIs) of the scene being illuminated during an illumination period.

6. The method of claim 1 , wherein, a plurality of pixel subsets are read out for a same frame.

7. A gated imaging apparatus that is employable by a moving or movable platform for imaging a scene of a geographic area in which the platform is located, the gated imaging apparatus comprising:

at least one pulsed light illuminator configured to:

actively illuminate, in accordance with a first illumination function, the scene with first pulsed light comprising a first train of light pulses;

actively illuminate, in accordance with a second illumination function, the scene with second pulsed light comprising a second train of light pulses;

wherein the imaging apparatus is configured to control:

temporal width of at least one light pulse of the first train of light pulses, or

temporal width of at least one light pulse of the second train of light pulses; or both;

receiving, responsive to illuminating the scene with the train of first light pulses and with the train of second light pulses, respectively, a plurality of first reflections and a plurality of second reflections on at least one image sensor comprising at least one pixel element;

at least one image sensor that comprises a plurality of pixel elements for receiving reflections responsive to illuminating the scene with the pulsed light;

a controller configured to control the plurality of pixel elements for:

imaging, by at least one first pixel, a first DOF by integrating first pixel values relating to the plurality of first reflections according to a first sensor function to obtain first integrated pixel values relating to a first DOF having a first gating profile;

imaging, by at least one second pixel, a second DOF by integrating second pixel values relating to the plurality of second reflections according to a second sensor function to obtain second integrated pixel values relating to a second DOF having a second gating profile;

wherein the first gating profile is different from the second gating profile;

wherein the first and the second gating profiles are spatially overlapping;

wherein the first gating profile expresses convolution between the first illumination function and the first sensor function; and

wherein the second gating profile expresses convolution between the second illumination function and the second sensor function.

8. The gated imaging apparatus according to claim 7 , wherein the controller is operative to selectively gate at least two pixel subsets of the plurality of pixels according to respective subset gating parameter values for imaging by at least two pixel subsets, respectively, at least two DOF ranges of the scene.

9. The gated imaging apparatus according to claim 8 , wherein the gating parameters of one pixel subset are different from the gating parameters of another pixel subset.

10. The gated imaging apparatus of claim 8 , wherein the at least two pixel subsets are associated with respective Regions-of-Interest (ROIs) of the scene being illuminated during an illumination period.

11. The gated imaging apparatus according to claim 8 , wherein at least two of the plurality of DOF ranges are at least partially overlapping.

12. The gated imaging apparatus according to claim 11 , wherein the controller is operative to gate the at least two pixel subsets a plurality of times to obtain at least two different overlapping DOF regions comprising the object;

wherein the controller is further operative to perform depth mapping of pixel data descriptive of an object based on values relating to the at least two different overlapping DOF regions.

13. The gated imaging apparatus of claim 11 , wherein the controller is further configured to determine, based on at least one first pixel value of a first DOF in an overlapping DOF region and further based on at least one second pixel value of a second DOF in the overlapping DOF region, depth information of one or more objects located in the overlapping DOF region of the scene.

14. The gated imaging apparatus of claim 11 , wherein a plurality of pixel subsets are read out for a same frame.

15. A computer program embodied in an information carrier comprising a tangible non-transitory computer-readable storage device to control the operation of and/or for executing the following steps:

a. actively illuminating the scene:

with first pulsed light comprising a first train of light pulses according to a first illumination function, and

with second pulsed light comprising a second train of light pulses according to a second illumination function;

wherein the actively illuminating includes:

controlling temporal width of at least one light pulse of the first train of light pulses, or controlling at least one light pulse of the second train of light pulses, or both;

b. receiving, responsive to illuminating the scene with the train of first light pulses and with the train of second light pulses, respectively, a plurality of first reflections and a plurality of second reflections on at least one image sensor comprising at least one pixel element;

c. selectively controlling the at least one pixel element:

for imaging a first DOF by integrating first pixel values relating to the plurality of first reflections according to a first sensor function to obtain first integrated pixel values relating to a first DOF having a first gating profile;

for imaging a second DOF by integrating first pixel values relating to the plurality of second reflections according to a second sensor function to obtain first integrated pixel values relating to a first DOF having a second gating profile;

wherein the second gating profile is different from the first gating profile; and

wherein the first and the second gating profiles are spatially overlapping;

wherein the first gating profile expresses convolution between the first illumination function and the first sensor function; and

wherein the second gating profile expresses convolution between the second illumination function and the second sensor function.

16. The computer program of claim 15 , wherein gating parameters of one pixel subset are different from the gating parameters of another pixel subset.

17. The computer program of claim 15 , wherein the gating is performed to image at least two at least partially overlapping DOF ranges.

18. The computer program of claim 15 , controlling the operation and/or executing the step of:

depth mapping pixel data descriptive of the object based on values relating to at least two different at least partially overlapping DOF regions.

19. The computer program of claim 15 , controlling the operation and/or executing the step of actively illuminating the scene and gating a plurality of pixels by illumination sources and sensors of a plurality of gated imaging apparatuses respective of a plurality of moving platforms in coordination with each other or randomly, so that depth mapping by the corresponding gated imaging apparatuses can be performed simultaneously without mutual interference between the plurality of gated imaging apparatuses.