Image based multiview multilayer holographic rendering algorithm

Patent metadata

Field	Value
Publication number	US-9465361-B2
Application number	US-201414525345-A
Country	US
Kind code	B2
Filing date	Oct 28, 2014
Priority date	Mar 31, 2014
Publication date	Oct 11, 2016
Grant date	Oct 11, 2016

Abstract

Algorithms for improved and more efficient rendering of three-dimensional images for use with holographic display systems. These algorithms include creating layers orthogonal to a viewing direction, the separate layers representing different depths in the image. The layers are created based on knowing the color and depth of each point in the image. Each layer then goes through an FFT process until the information for each layer is represented as a diffraction pattern. A holographic lens is then applied to the diffraction pattern of each layer. This lens will cause that layer to appear, in a hologram based thereon, at a different depth than the other layers. The layers, each with their separate lenses, are then coherently summed up and when applied to a suitable portion of a holographic display system (e.g., an SLM), a hologram can be created for that view. A tiled array of such holograms can be combined together by the holographic display system.

First claim

We claim:

1. A computer-implemented method for computing an array of two-dimensional holographic diffraction patterns each representative of an image of a particular scene, comprising:
for the first of the holographic diffraction patterns of the array:
obtaining a two-dimensional color image of one view of the scene from a first viewing angle;
obtaining corresponding depth information about the scene;
creating two-dimensional image layers from the color image and the depth information;
encoding spatial information in each of the two-dimensional image layers into a two-dimensional diffraction pattern for that layer by applying a Fourier-Fresnel Transform to each two-dimensional image layer; and
combining together the two-dimensional diffraction pattern information for each of the two-dimensional image layers to compute the two-dimensional holographic diffraction pattern representative of that view;

repeating the above operations for a plurality of other views of the scene, wherein each different view is taken from a different viewing angle; and
combining together each of the two-dimensional holographic diffraction patterns into an array of two-dimensional holographic diffraction patterns where each two-dimensional holographic diffraction pattern is representative of a different view of the scene and where each diffraction pattern in the array is angularly-tiled with respect to each adjacent diffraction pattern so each diffraction pattern in the array represents a distinct and different view of the scene.

2. A computer-implemented method as defined in claim 1 , further including for each layer adding a holographic lens to the two-dimensional diffraction pattern information for that layer.

3. A computer-implemented method as defined in claim 1 , wherein the two-dimensional color image and the corresponding depth information come from computer graphics rendering.

4. A computer-implemented method as defined in claim 1 , wherein the two-dimensional color image and the corresponding depth information come from a camera.

5. A computer-implemented method as defined in claim 1 , further including displaying images based on the array of two-dimensional holographic diffraction patterns with an angularly-tiled holographic display system.

6. A computer-implemented method as defined in claim 1 , wherein the operation of creating two-dimensional image layers includes thresholding based on the depth information.

7. A computer-implemented method as defined in claim 1 , wherein the operation of creating two-dimensional image layers includes depth blending based on the depth information.

8. A computer-implemented method as defined in claim 1 , further including storing the array of two-dimensional holographic diffraction patterns.

9. A computer-implemented method as defined in claim 8 , further including displaying holographic images based on the stored array of two-dimensional holographic diffraction patterns.

10. A computer-implemented method as defined in claim 1 , further including displaying holographic images based on the stored array of two-dimensional holographic diffraction patterns.

11. A method for computing and displaying an array of holographic images each representative of a different image of a particular scene, comprising:
for the first of the holographic images of the array:
obtaining a color image of one view of the scene;
obtaining corresponding depth information about the scene;
creating image layers from the color image, the depth information, and depth blending;
encoding spatial and depth information in each of the image layers into diffraction patterns for that layer; and
combining together the diffraction patterns for each of the image layers to compute the holographic diffraction pattern representative of that view;

repeating the above operations for each of the other holographic diffraction patterns of the array where each holographic diffraction pattern is representative of a different view of the scene; and
displaying each of the array of a holographic images on an angularly-tiled holographic display system, where each image of the array of holographic images represents a distinct and different view of the scene.

12. A method as defined in claim 11 , wherein the angularly-tiled holographic display system includes one or more spatial light modulators.

13. A method as defined in claim 11 , further including for each layer adding a holographic lens to the diffraction pattern information for that layer.

14. A method as defined in claim 11 , wherein the color image and the corresponding depth information come from a camera.

15. A method as defined in claim 11 , wherein the operation of creating image layers includes thresholding based on the depth information.

16. A computer-implemented method for computing an array of holographic diffraction patterns each representative of an image of a particular scene, comprising:
for the first of the holographic diffraction patterns of the array:
creating image layers that include color image, depth information, and depth blending about one view of a scene;
encoding spatial information in each of the image layers into a diffraction pattern for that layer, where each diffraction pattern includes all of a plurality of points of the image of the scene at a particular depth; and
combining together the diffraction pattern for each of the image layers to compute the holographic diffraction pattern representative of that view; and

repeating the above operations for each of the other holographic diffraction patterns of the array where each holographic diffraction pattern is representative of a different view of the scene;
wherein the method is free of use of the Ping-Pong method of image-based wavefront propagation.

17. A computer-implemented method as defined in claim 16 , further including for each layer adding a holographic lens to the diffraction pattern information for that layer.

18. A computer-implemented method as defined in claim 16 , wherein the color image and the corresponding depth information come from a camera.

19. A computer-implemented method as defined in claim 16 , wherein the operation of creating image layers includes thresholding based on the depth information.

Assignees

• Disney Entpr Inc
• Cambridge Entpr Ltd

Inventors

• Smithwick Quinn Y
• Chen Jhen-Si
• Chu Daping

Classifications

• G03H2210/454

  into planes · CPC title

• G03H1/0808 Primary

  Methods of numerical synthesis, e.g. coherent ray tracing [CRT], diffraction specific · CPC title

• G03H1/2205

  using downstream optical component · CPC title

• G03H1/30

  discrete holograms only · CPC title

• G03H2001/221

  Element having optical power, e.g. field lens · CPC title