Method and system for multi-wavelength depth encoding for three-dimensional range geometry compression

Patent metadata

Field	Value
Publication number	US-11050995-B2
Application number	US-202016826573-A
Country	US
Kind code	B2
Filing date	Mar 23, 2020
Priority date	Dec 2, 2015
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

A method for generating encoded depth data includes receiving digital fringe projection (DFP) data corresponding to a three-dimensional structure of a physical object, and generating first and second fringe encodings for a first predetermined wavelength based on the DFP data at a first coordinate. The method further includes generating third and fourth fringe encodings for a second predetermined wavelength based on the DFP data at the first coordinate, the second wavelength being longer than the first wavelength, and generating a combined fringe encoding based on the third fringe encoding and the fourth fringe encoding. The method further includes storing the first, second, and combined fringe encoding data in a pixel of two-dimensional image data at a pixel coordinate in the two-dimensional image data corresponding to the first coordinate.

First claim

What is claimed is:

1. A non-transient computer readable medium containing computer executable instructions which are configured to, when executed by a processor:
receive digital fringe projection (DFP) data corresponding to a three-dimensional structure of a physical object;
generate a first fringe encoding and a second fringe encoding for a first predetermined wavelength based on the DFP data at a first coordinate;
generate a third fringe encoding and a fourth fringe encoding for a second wavelength based on the DFP data at the first coordinate, the second wavelength being longer than the first wavelength;
generate a combined fringe encoding based on the third fringe encoding and the fourth fringe encoding; and
store the first fringe encoding data, the second fringe encoding data, and the combined fringe encoding data in a pixel of two-dimensional image data at a pixel coordinate in the two-dimensional image data corresponding to the first coordinate, the two-dimensional image data being stored in a memory.

2. The computer readable medium of claim 1 , wherein the computer executable instructions are further configured to, when executed by the processor:
store the first fringe encoding data in a first color channel of the pixel, the second fringe encoding data in a second color channel of the pixel, and the combined fringe encoding data in a third color channel of the pixel.

3. The computer readable medium of claim 1 , wherein the computer executable instructions are further configured to, when executed by the processor:
compress the two-dimensional image data prior to storing the two-dimensional image data in the memory.

4. The computer readable medium of claim 3 , wherein the computer executable instructions are further configured to, when executed by the processor:
compress the two-dimensional image data using a lossy compression format.

5. The computer readable medium of claim 3 , wherein the computer executable instructions are further configured to, when executed by the processor:
compress the two-dimensional image data using a lossless compression format.

6. The computer readable medium of claim 1 , wherein the computer executable instructions are further configured to, when executed by the processor:
generate the first fringe encoding based, at least in part, on a sine function value of a proportion of the second wavelength divided by the first predetermined wavelength; and
generate the second fringe encoding based, at least in part, on a cosine function value of the proportion of the second wavelength divided by the first predetermined wavelength.

7. The computer readable medium of claim 1 , wherein the computer executable instructions are further configured to, when executed by the processor:
generate the third fringe encoding based, at least in part, on a sine function value of a proportion of the second wavelength divided by a maximum range of wavelengths present in the DFP data; and
generate the fourth fringe encoding based, at least in part, on a cosine function value of the proportion of the second wavelength divided by a maximum range of wavelengths present in the DFP data.

8. The computer readable medium of claim 7 , wherein the computer executable instructions are further configured to, when executed by the processor:
generate, with the processor, the combined fringe encoding based, at least in part, on an arctangent of a proportion of the third fringe encoding divided by the fourth fringe encoding.

9. A non-transient computer readable medium containing computer executable instructions which, when executed by a processor, decode encoded digital fringe projection (DFP) data corresponding to a physical object by:
retrieving a first pixel of two-dimensional image data from a memory;
decoding a plurality of phase data stored in a plurality of color channels of the first pixel;
generating a stair image including a second pixel corresponding to the first pixel of the two-dimensional image data based on the plurality of phase data; and
generating a depth map including a third pixel corresponding to the second pixel of the stair image, the third pixel storing data corresponding to a depth of a location of the physical object.

10. The computer readable medium of claim 9 , wherein the computer executable instructions are further configured to, when executed by the processor, decode the encoded DFP data corresponding to a physical object wherein the plurality of phase data comprises dense phase data and wrapped phase data.

11. The computer readable medium of claim 10 , wherein the computer executable instructions are further configured to, when executed by the processor,
decode the dense phase data based, at least in part, on an arctangent of a proportion of a first fringe encoding stored in a first color channel of the first pixel divided by a second fringe encoding stored in a second color channel of the first pixel.

12. The computer readable medium of claim 10 , wherein the computer executable instructions are further configured to, when executed by the processor,
retrieve the wrapped phase data from a third color channel of the first pixel; and
scale the wrapped phase data from a first numeric scale to a second numeric scale with a range of values from [−π, π).

13. The computer readable medium of claim 10 , wherein the computer executable instructions are further configured to, when executed by the processor,
generate the second pixel corresponding to the first pixel of the two-dimensional image data based, at least in part, on the wrapped phase data subtracted from a product of the dense phase data multiplied by a proportion of a maximum range of wavelengths present in the encoded DFP data divided by a predetermined wavelength that was used to generate the encoded dense phase data stored in the pixel, the predetermined wavelength being smaller than the maximum range of wavelengths.

14. The computer readable medium of claim 13 , wherein the computer executable instructions are further configured to, when executed by the processor,
generate the third pixel corresponding to the second pixel based, at least in part, on a sum of the dense phase data added to the second pixel of the stair image function multiplied by the predetermined wavelength.

15. A method for generating encoded depth data comprising:
receiving, with a processor, digital fringe projection (DFP) data corresponding to a three-dimensional structure of a physical object;
generating, with the processor, a plurality of fringe encoding values based on the DFP data at a first coordinate;
storing, with the processor, the plurality of fringe encoding values in a plurality of color channels of a pixel of two-dimensional image data at a pixel coordinate in the two-dimensional image data corresponding to the first coordinate, the two-dimensional image data being stored in a memory.

16. The method of claim 15 , wherein generating the plurality of fringe encoding values further comprises:
generating a first fringe encoding and a second fringe encoding for a first predetermined wavelength based on the DFP data at the first coordinate; and
generating a third fringe encoding and a fourth fringe encoding for a second wavelength based on the DFP data at the first coordinate, the second wavelength being longer than the first wavelength.

17. The method of claim 16 , wherein generating the plurality of fringe encoding values further comprises:
generating a combined fringe encoding based on the third fringe encoding and the fourth fringe encoding.

18. The method

Assignees

• Purdue Research Foundation

Inventors

• Zhang Song
• Bell Tyler

Classifications

• H04N19/625

  using discrete cosine transform [DCT] · CPC title

• H04N13/139

  Format conversion, e.g. of frame-rate or size · CPC title

• H04N13/15

  for colour aspects of image signals · CPC title

• G01B11/2513

  with several lines being projected in more than one direction, e.g. grids, patterns · CPC title

• H04N13/161 Primary

  Encoding, multiplexing or demultiplexing different image signal components (for multi-view video sequence encoding H04N19/597) · CPC title