Method and devices for enhanced imaging
View Patent ↗A method includes emitting a pattern of transmitted light into a three-dimensional environment from an optical transmitter and receiving reflected light from the pattern of transmitted light at an optical receiver. The method includes identifying light-sensitive pixels of that are stimulated by from the pattern of reflected light and generating an up-sampled matrix with subsections that correspond to light-sensitive pixels. The method includes sparsely populating subsections of the up-sampled matrix with a pattern of non-zero entries and imaging the three-dimensional environment.
1. A method comprising:
emitting a pattern of transmitted light into a three-dimensional environment from an optical transmitter;
receiving a pattern of reflected light originating from the pattern of transmitted light at an optical receiver comprising a plurality of light-sensitive pixels;
identifying a plurality of stimulated light-sensitive pixels of the plurality of light-sensitive pixels, the plurality of stimulated light-sensitive pixels comprising each light sensitive pixel stimulated by light from the pattern of reflected light;
generating an up-sampled matrix comprising a plurality of subsections that correspond to the plurality of stimulated light-sensitive pixels;
sparsely populating the plurality of subsections of the up-sampled matrix with a pattern of non-zero entries before the three dimensional environment has been imaged; and
imaging the three-dimensional environment using the up-sampled matrix.
2. The method of claim 1 , wherein the pattern of non-zero entries is generated by a pseudo-random process.
3. The method of claim 2 , wherein the pattern of transmitted light is generated by a pseudo random process.
4. The method of claim 1 , further comprising pre-computing the pattern of non-zero entries and the pattern of transmitted light.
5. The method of claim 4 , further comprising storing the pattern of non-zero entries and the pattern of transmitted light in a lookup table.
6. The method of claim 1 , wherein imaging the three-dimensional environment using the up-sampled matrix comprises imaging a three-dimensional depth profile of the three-dimensional environment using a compressive sensing process.
7. The method of claim 1 , wherein emitting a pattern of transmitted light comprises selecting a group of light sources from a plurality of light sources of the optical transmitter to generate the pattern of transmitted light.
8. The method of claim 1 , wherein a first stimulated light-sensitive pixel of the plurality of stimulated light-sensitive pixels comprises a light-detecting sensor comprising a number of single-photon avalanche diodes.
9. The method of claim 8 , wherein the number of single-photon avalanche diodes of the first stimulated light-sensitive pixel corresponds to a number of elements of a first subsection of the plurality of subsections.
10. The method of claim 9 , wherein the number of single-photon avalanche diodes is greater than one.
11. The method of claim 1 , further comprising enabling a pattern of light-sensitive pixels of the plurality of light-sensitive pixels to receive the pattern of reflected light, the pattern of light-sensitive pixels corresponding to the pattern of transmitted light.
12. The method of claim 1 , further comprising:
emitting a second pattern of transmitted light into the three-dimensional environment from the optical transmitter;
receiving a second pattern of reflected light originating from the second pattern of transmitted light at the optical receiver;
identifying a second plurality of stimulated light-sensitive pixels of the plurality of light-sensitive pixels that are stimulated by light from the second pattern of reflected light;
generating a second area of the up-sampled matrix comprising a second plurality of subsections that correspond to the second plurality of stimulated light-sensitive pixels; and
sparsely populating the second plurality of subsections of the up-sampled matrix with a second pattern of non-zero entries.
13. The method of claim 1 , wherein the up-sampled matrix further comprises an additional plurality of subsections that correspond to an unstimulated plurality of light-sensitive pixels of the plurality of light-sensitive pixels and wherein a resolution of the imaging of the three-dimensional environment corresponds to a number of elements of the up-sampled matrix.
14. The method of claim 13 , further comprising populating the additional plurality of subsections with zeroes.
15. The method of claim 1 , further comprising measuring a time of flight of the pattern of reflected light for imaging the three-dimensional environment.
16. A system comprising:
an optical transmitter comprising a plurality of light sources;
an optical-source driver configured to drive the plurality of light sources of the optical transmitter to project a pattern of emitted light into a three-dimensional environment;
an optical receiver comprising a plurality of light-sensitive pixels;
a processor in communication with the optical receiver and in communication with a memory comprising an instruction set to be executed in the processor, the processor when executing the instruction set being configured to generate an up-sampled matrix comprising a plurality of subsections corresponding to a plurality of stimulated light-sensitive pixels of the plurality of light-sensitive pixels, the plurality of stimulated light-sensitive pixels comprising each light sensitive pixel stimulated by a pattern of reflected light originating from the pattern of emitted light and received by the optical receiver; and
wherein the processor is configured to sparsely populates the plurality of subsections of the up-sampled matrix with a pattern of non-zero entries before the three-dimensional environment is imaged and the processor being further configured to generate a three-dimensional image of the three-dimensional environment from the up-sampled matrix.
17. The system of claim 16 , further comprising one or more time to digital converters in communication with the optical transmitter, the optical receiver, and the processor to determine a time of flight of the pattern of reflected light at each stimulated light-sensitive pixel of the plurality of stimulated light-sensitive pixels to generate the three-dimensional image of the three-dimensional environment.
18. The system of claim 16 , wherein the processor uses a compressive-sensing process to generate the three-dimensional image of the three-dimensional environment.
19. The system of claim 16 , wherein each of the plurality of light-sensitive pixels comprises a number of light-detecting sensors and each subsection of the plurality of subsections of the up-sampling matrix comprises a number of entries, the number of entries being equal to the number of light-detecting sensors, wherein the number of light-detecting sensors is greater than one.
20. The system of claim 19 , wherein each light-detecting sensor comprise a single-photon avalanche diode.
21. The system of claim 16 , further comprising a memory in communication with the processor comprising a lookup table, wherein the processor retrieves the pattern of non-zero entries from the lookup table.
22. The system of claim 21 , wherein the lookup table stores instructions for the optical-source driver to activate to a subset of the plurality of light sources to project the pattern of emitted light into the three-dimensional environment.
23. The system of claim 16 , wherein the pattern of non-zero entries is determined by a pseudo-random process.
24. The system of claim 16 , wherein the pattern of emitted light is determined by a pseudo-random process.
25. A method comprising:
sampling a three-dimensional environment for a set of time of flight measurements and associated photon count measurements, each measurement of the set of time of flight measurements and associated photon count measurements being taken from a stimulated light-sensitive pixel of a plurality of light sensitive pixels of an optical receiver;
generating an up-sampled matrix comprising a subsection for each light-sensitive pixel and sparsely populating a group of selected subsections with a pattern of non-zero entries before the three-dimensional environment is imaged, the group of selected subsections comprising a selected subsection for each stimulated light sensitive pixel; and
constructing a high-resolution three-dimensional image from the up-sampled matrix.
26. The method of claim 25 , wherein the high-resolution three-dimensional image is constructed by a compressed sensing process.
27. The method of claim 25 , wherein the pattern of non-zero entries is generated by a pseudo-random process.
28. The method of claim 25 , wherein each light-sensitive pixel of the plurality of light-sensitive pixels comprises a number of single-photon avalanche diodes.
29. The method of claim 25 , wherein the selected subsections of the group of selected subsections corresponds to the set of time of flight measurements and associated photon count measurements.