# US 11,443,448 B2 · Incoherent digital holography based depth camera > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,443,448 B2 - Document ID: US11443448B2 - Status: Granted - Kind: B2 - Application number: 16/983,995 - Filed: 2020-08-03 - Published: 2021-06-03 - Granted: 2022-09-13 - Earliest claimed: 2019-12-03 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Company, Ltd. - Inventors: Changgeng Liu; Ernest Rehmatulla Post - Web page: https://patentgrep.com/patent/US11443448B2 ## CPC - G06T 7/557: from light fields, e.g. from plenoptic cameras - G06F 16/9017: {using directory or table look-up (use of a directory or look-up table in file systems G06F16/13)} - G06T 7/571: from focus - G06T 7/586: from multiple light sources, e.g. photometric stereo - G06T 2207/20021: Dividing image into blocks, subimages or windows - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract A method includes capturing light reflected off one or more objects and splitting the captured light into a plurality of light fields with a plurality of phase curvatures. The method further includes generating, for the one or more objects, a plurality of holograms based on the plurality of light fields and determining, for each of the plurality of holograms, an intensity and a phase-shift of the hologram. The method thus includes generating a depth map comprising depth information for the one or more objects based at least in part on a function determined by the respective phase-shifts of the plurality of holograms. ## Claims ### Claim 1 A method comprising, by an electronic device: capturing ambient light reflected off one or more objects, wherein the ambient light comprises non-laser light; splitting the captured ambient light reflected off the one or more objects into a plurality of light fields with a plurality of phase curvatures; generating, for the one or more objects, a plurality of holograms based on the plurality of light fields; determining, for each of the plurality of holograms, an intensity and a phase-shift of the hologram; and generating, for the one or more objects, a depth map comprising depth information for the one or more objects based on a reconstruction of the plurality of holograms, wherein the plurality of holograms are reconstructed based at least in part on a function determined by the respective intensities and phase-shifts of the plurality of holograms. ### Claim 2 (depends on 1) The method of claim 1, wherein splitting the captured ambient light into the plurality of light fields comprises splitting, by a spatial light modulator (SLM) of the electronic device, the captured light into a planar light wave and a spherical light wave. ### Claim 3 (depends on 1) The method of claim 1, wherein the plurality of holograms comprises, for each object of the one or more objects, a plurality of phase-shifted holograms corresponding to the respective object. ### Claim 4 (depends on 3) The method of claim 3, wherein the function determined by the respective phase-shifts of the plurality of holograms comprises a complex function corresponding to the plurality of phase-shifted holograms. ### Claim 5 (depends on 4) The method of claim 4, further comprising, for each object of the one or more objects: determining a first reconstruction distance based at least in part on a position of the object or the complex function; determining a range between the first reconstruction distance and the position; numerically refocusing a set of image frames of the object at a plurality of different reconstruction distances within the range; and generating a look-up table based on the position and the plurality of different reconstruction distances. ### Claim 6 (depends on 5) The method of claim 5, further comprising, for each object of the one or more objects: dividing each of the set of image frames into a plurality of image patches; and determining a particular reconstruction distance of the plurality of different reconstruction distances, wherein the particular reconstruction distance corresponds to a maximizing of a focus evaluation function corresponding to one or more of the plurality of image patches. ### Claim 7 (depends on 6) The method of claim 6, further comprising, for each object of the one or more objects: determining a depth value associated with the object based at least in part on the look-up table, wherein the depth value corresponds to the particular reconstruction distance; and assigning the depth value to the one or more of the plurality of image patches to generate the depth map. ### Claim 8 An electronic device comprising: one or more cameras; one or more non-transitory computer-readable storage media including instructions; and one or more processors coupled to the storage media and the one or more cameras, the one or more processors configured to execute the instructions to: capture ambient light reflected off one or more objects, wherein the ambient light comprises non-laser light; split the captured ambient light reflected off the one or more objects into a plurality of light fields with a plurality of phase curvatures; generate, for the one or more objects, a plurality of holograms based on the plurality of light fields; determine, for each of the plurality of holograms, an intensity and a phase-shift of the hologram; and generate, for the one or more objects, a depth map comprising depth information for the one or more objects based on a reconstruction of the plurality of holograms, wherein the plurality of holograms are reconstructed based at least in part on a function determined by the respective intensities and phase-shifts of the plurality of holograms. ### Claim 9 (depends on 8) The electronic device of claim 8, wherein the electronic device further comprises a spatial light modulator (SLM), and wherein the instructions to split the captured ambient light into the plurality of light fields comprise instructions to split, by the SLM, the captured light into a planar light wave and a spherical light wave. ### Claim 10 (depends on 8) The electronic device of claim 8, wherein the electronic device further comprises a piezoelectric transducer (PZT), and wherein the PZT comprises a planar mirror configured to generate a planar light wave and a concave spherical mirror configured to generate a spherical light wave. ### Claim 11 (depends on 8) The electronic device of claim 8, wherein the plurality of holograms comprises, for each object of the one or more objects, a plurality of phase-shifted holograms corresponding to the respective object. ### Claim 12 (depends on 11) The electronic device of claim 11, wherein the function determined by the respective phase-shifts of the plurality of holograms comprises a complex function corresponding to the plurality of phase-shifted holograms. ### Claim 13 (depends on 12) The electronic device of claim 12, wherein, for each object of the one or more objects, the instructions further comprise instructions to: determine a first reconstruction distance based at least in part on a position of each of the one or more objects or the complex function; determine a range between the first reconstruction distance and the position; numerically refocus a set of image frames of the one or more objects at a plurality of different reconstruction distances within the range; and generate a look-up table based on the position and the plurality of different reconstruction distances. ### Claim 14 (depends on 13) The electronic device of claim 13, wherein, for each object of the one or more objects, the instructions further comprise instructions to: divide each of the set of image frames into a plurality of image patches; and determine a particular reconstruction distance of the plurality of different reconstruction distances, wherein the particular reconstruction distance corresponds to a maximizing of a focus evaluation function corresponding to one or more of the plurality of image patches. ### Claim 15 (depends on 14) The electronic device of claim 14, wherein, for each object of the one or more objects, the instructions further comprise instructions to: determine a depth value associated with the one or more objects based at least in part on the look-up table, wherein the depth value corresponds to the particular reconstruction distance; and assign the depth value to the one or more of the plurality of image patches to generate the depth map. ### Claim 16 A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors of an electronic device, cause the one or more processors to: capture ambient light reflected off one or more objects, wherein the ambient light comprises non-laser light; split the captured ambient light reflected off the one or more objects into a plurality of light fields with a plurality of phase curvatures; generate, for the one or more objects, a plurality of holograms based on the plurality of light fields; determine, for each of the plurality of holograms, an intensity and a phase-shift of the hologram; and generate, for the one or more objects, a depth map comprising depth information for the one or more objects based on a reconstruction of the plurality of holograms, wherein the plurality of holograms are reconstructed based at least in part on a function determined by the respective intensities and phase-shifts of the plurality of holograms. ### Claim 17 (depends on 16) The non-transitory computer-readable medium of claim 16, wherein the instructions to split the captured ambient light into the plurality of light fields comprise instructions to split, by a spatial light modulator (SLM) of the electronic device, the captured light into a planar light wave and a spherical light wave.