Radiance sensor and radiance reconstruction method
A radiance sensor includes a memory and a microprocessor. The memory stores non-transitory computer-readable instructions and adapted to store a plurality of electrical signals output from a photodetector array in response to electromagnetic radiation transmitted through a lenslet array and incident on the photodetector array. The microprocessor is adapted to execute the instructions to (i) determine irradiance of the electromagnetic radiation in a detector plane from the plurality of electrical signals, each electrical signal having generated by a respective one of a plurality of photodetectors of the photodetector array, and (ii) reconstruct, from the determined irradiance, the 4D-radiance in an input plane, the lenslet array being between the input plane and the detector plane.
1. A radiance sensor comprising:
a lenslet array;
a photodetector array located in a detector plane, and including a plurality of photodetectors configured to generate a respective one of a plurality of electrical signals output in response to electromagnetic radiation transmitted by the lenslet array and incident on the photodetector array;
memory configured to store non-transitory computer-readable instructions and the plurality of electrical signals;
a microprocessor configured to execute the instructions to:
determine irradiance of the electromagnetic radiation in the detector plane from the plurality of electrical signals; and
reconstruct, from the determined irradiance, a radiance field in an input plane, the lenslet array being between the input plane and the detector plane.
2. The radiance sensor of claim 1 , the lenslet array having a plurality of lenslets of focal length f, the photodetector array being located a distance d≥f behind the lenslet array.
3. The radiance sensor of claim 1 , the microprocessor being further configured to, when executing the instructions to reconstruct, apply a pseudoinverse operator to data corresponding to the determined irradiance.
4. A radiance sensor comprising:
memory storing non-transitory computer-readable instructions and adapted to store a plurality of electrical signals output from a photodetector array in response to electromagnetic radiation transmitted through a lenslet array and incident on the photodetector array;
a microprocessor configured to execute the instructions to:
determine irradiance of the electromagnetic radiation in a detector plane from the plurality of electrical signals, each electrical signal having generated by a respective one of a plurality of photodetectors of the photodetector array; and
reconstruct, from the determined irradiance, the 4D-radiance in an input plane, the lenslet array being between the input plane and the detector plane.
5. The radiance sensor of claim 4 , further comprising the lenslet array, the photodetector array located behind the lenslet array in a plane substantially parallel to a plane of the lenslet array.
6. The radiance sensor of claim 4 , the lenslet array having a plurality of lenslets of focal length f, the photodetector array being located a distance q≥f behind the lenslet array.
7. The radiance sensor of claim 4 , a microprocessor being further configured to, when executing the instructions to reconstruct, apply a pseudoinverse operator to data corresponding to the determined irradiance.
8. A method for reconstructing 4D-radiance of electromagnetic radiation transmitted through a lenslet array and detected by a photodetector array in a detector plane, comprising:
determining irradiance of the electromagnetic radiation in the detector plane from a plurality of electrical signals, each of the plurality of electrical signals having been generated by a respective one of a plurality of photodetectors of the photodetector array in response to a respective one of a plurality of spatial regions of the electromagnetic radiation; and
reconstructing, from the determined irradiance, the 4D-radiance in an input plane, the lenslet array being between the input plane and the detector plane.
9. The method of claim 8 , further comprising generating each of the plurality of electrical signals by detecting the electromagnetic radiation with the photodetector array.
10. The method of claim 8 , the lenslet array having a plurality of lenslets of focal length f, the photodetector array being located a distance q≥f behind the lenslet array.
11. The method of claim 8 , the step of reconstructing comprising applying a pseudoinverse operator to data corresponding to the determined irradiance.