Method and apparatus for generating depth value corresponding to subject using depth camera

Patent metadata

Field	Value
Publication number	US-9945947-B2
Application number	US-201514728439-A
Country	US
Kind code	B2
Filing date	Jun 2, 2015
Priority date	Jun 2, 2014
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

A method and apparatus for generating a depth value corresponding to a subject by using a depth camera includes dividing a predetermined time section into n sub-time sections in order to measure the depth value, acquiring a voltage value corresponding to the amount of light reflected from the subject in each sub-time section, by using at least one photodiode included in the depth camera, quantizing the voltage value to any one level among predetermined levels, on the basis of the acquired n voltage values, and outputting the quantized value.

First claim

What is claimed is:

1. A method of generating a depth value corresponding to a subject by using a depth camera, the method comprising:
irradiating the subject with light;
dividing a desired time section into n sub-time sections to measure the depth value;
acquiring a voltage value corresponding to an amount of the light reflected from the subject in each sub-time section, by using at least one photodiode included in the depth camera;
quantizing the voltage value to any one level among a plurality of desired levels based on the acquired voltage values; and
outputting the quantized value; wherein
the voltage value comprises at least one of a first voltage value and a second voltage value which correspond to two respective terminals of the photodiode, and
the acquiring of the voltage value comprises acquiring at least one of the first voltage value and the second voltage value in each of the sub-time sections.

2. The method of claim 1 , further comprising:
determining whether the photodiode is saturated in each of the sub-time sections, according to whether the acquired voltage value exceeds a desired voltage value.

3. The method of claim 2 , further comprising:
initializing the voltage value of the photodiode on the basis of a result of the determination.

4. The method of claim 2 , further comprising:
storing the voltage values of the photodiode which are acquired in the respective sub-time sections.

5. The method of claim 4 , further comprising:
generating a representative voltage which is a voltage value corresponding to a highest level among the desired levels, by using the stored voltage values,
wherein the quantizing of the voltage value comprises quantizing the acquired voltage value to the desired level, by using the generated representative voltage.

6. The method of claim 4 , wherein the storing of the voltage values comprises storing a difference value between the acquired voltage value and an initialized voltage value of the photodiode.

7. The method of claim 1 , wherein the acquiring of the voltage value comprises acquiring the first voltage value and the second voltage value in each sub-time section with a phase difference of 180 degrees between each sub-time section.

8. An apparatus for generating a depth value corresponding to a subject by using a depth camera, the apparatus comprising:
a light source configured to irradiate the subject with light;
a division calculator configured to divide a desired time section into n sub-time sections to measure the depth value;
a voltage acquirer configured to obtain a voltage value corresponding to an amount of the light reflected from the subject in each sub-time section, by using at least one photodiode included in the depth camera;
a quantizer configured to quantize the voltage value to any one level among desired levels, based on the obtained voltage values, and
an output device configured to output the quantized value, wherein
the voltage value obtained by the voltage acquirer comprises at least one of a first voltage value and a second voltage value which correspond to two respective terminals of the photodiode, and
the voltage acquirer is further configured to acquire at least one of the first voltage value and the second voltage value in each of the sub-time sections.

9. The apparatus of claim 8 , further comprising a comparator configured to determine whether the photodiode is saturated in each of the sub-time sections, according to whether the acquired voltage value exceeds a desired voltage value.

10. The apparatus of claim 9 , wherein the comparator is further configured to initialize the voltage value of the photodiode on the basis of a result of the determination.

11. The apparatus of claim 9 , further comprising:
a storage configured to store the voltage values of the photodiode which are acquired in the respective sub-time sections.

12. The apparatus of claim 11 , further comprising:
a representative voltage generator configured to generate a representative voltage which is a voltage value corresponding to a highest level among the desired levels, by using the stored voltage values,
wherein the quanitzer is configured to quantize the acquired voltage value to the desired level, by using the generated representative voltage.

13. The apparatus of claim 11 , wherein the storage is configured to store a difference value between the acquired voltage value and an initialized voltage value of the photodiode.

14. The apparatus of claim 8 , wherein the voltage acquirer is configured to acquire the first voltage value and the second voltage value in each sub-time section with a phase difference of 180 degrees between each sub-time section.

15. The apparatus of claim 8 , wherein the photodiode comprises a pinned-photodiode (PPD).

16. A non-transitory computer readable recording medium having embodied thereon computer readable instructions, which when executed by at least one processor, executes the method of claim 1 .

Assignees

• Samsung Electronics Co Ltd
• Univ Michigan Regents

Inventors

• Shin Jungsoon
• Lee Keechang
• Yoon Euisik
• Cho Jihyun

Classifications

• G01S17/36 Primary

  with phase comparison between the received signal and the contemporaneously transmitted signal · CPC title

• G01S17/894

  Three-dimensional [3D] imaging with simultaneous measurement of time-of-flight at a two-dimensional [2D] array of receiver pixels, e.g. time-of-flight cameras or flash lidar · CPC title

• H04N13/254

  in combination with electromagnetic radiation sources for illuminating objects · CPC title

• G01S7/4914

  of detector arrays, e.g. charge-transfer gates · CPC title

• H04N13/271 Primary

  wherein the generated image signals comprise depth maps or disparity maps · CPC title