Systems and methods for encoding light field image files having depth and confidence maps

• US 9,031,335 B2
• Filed: 09/09/2014
• Issued: 05/12/2015
• Est. Priority Date: 09/28/2011
• Status: Active Grant

• Current Assignee: FotoNation Limited (Adeia Inc.)
• Original Assignee: Pelican Imaging Corporation
• Inventors: Venkataraman, Kartik, Nisenzon, Semyon, Lelescu, Dan
• Primary Examiner(s): Alavi, Amir
• Application Number:
  US14/481,241
• Publication Number:
  US 20140376825A1
• Time in Patent Office: 245 Days
• Field of Search: 382/154, 382/232, 382/233, 382244-246, 382275-276, 382/284, 382/300, 348 42- 60, 348/262, 348349-350, 348/E13.075, 345/158, 345/173, 345/419, 345/427
• US Class Current: 382/232
• CPC Class Codes: G06T 15/08 Volume rendering
• CPC Class Codes: G06T 2207/10052 Images from lightfield camera
• CPC Class Codes: G06T 3/4007 based on interpolation, e.g. bilinear interpolation image demosaicing G06T3/4015; edge-driven or edge-based scaling G06T3/403
• CPC Class Codes: G06T 3/4053 based on super-resolution, i.e. the output image resolution being higher than the sensor resolution
• CPC Class Codes: G06T 7/50 Depth or shape recovery
• CPC Class Codes: G06T 7/596 from three or more stereo images
• CPC Class Codes: G06T 9/00 Image coding bandwidth or redundancy reduction for static pictures H04N1/41; coding or decoding of static colour picture signals H04N1/64; methods or arrangements for coding, decoding, compressing or decompressing digital video signals H04N19/00
• CPC Class Codes: G06T 9/20 Contour coding, e.g. using detection of edges
• CPC Class Codes: H04N 13/128 Adjusting depth or disparity
• CPC Class Codes: H04N 13/139 Format conversion, e.g. of frame-rate or size
• CPC Class Codes: H04N 13/161 Encoding, multiplexing or demultiplexing different image signal components for multi-view video sequence encoding H04N19/597
• CPC Class Codes: H04N 13/178 Metadata, e.g. disparity information
• CPC Class Codes: H04N 13/243 using three or more 2D image sensors
• CPC Class Codes: H04N 13/271 wherein the generated image signals comprise depth maps or disparity maps
• CPC Class Codes: H04N 19/136 Incoming video signal characteristics or properties
• CPC Class Codes: H04N 19/593 involving spatial prediction techniques
• CPC Class Codes: H04N 19/597 specially adapted for multi-view video sequence encoding
• CPC Class Codes: H04N 19/625 using discrete cosine transform [DCT]
• CPC Class Codes: H04N 19/70 characterised by syntax aspects related to video coding, e.g. related to compression standards
• CPC Class Codes: H04N 19/85 using pre-processing or post-processing specially adapted for video compression
• CPC Class Codes: H04N 2013/0081 : Depth or disparity estimation from stereoscopic image signals

Abstract

Systems and methods configured to store images synthesized from light field image data and metadata describing the images in electronic files and render images using the stored image and the metadata in accordance with embodiments of the invention are disclosed. One embodiment includes a processor and memory containing an encoding application and light field image data, where the light field image data comprises a plurality of low resolution images of a scene captured from different viewpoints. In addition, the encoding application configures the processor to: synthesize a higher resolution image of the scene from a reference viewpoint using the low resolution images, where synthesizing the higher resolution image involves creating a depth map that specifies depths from the reference viewpoint for pixels in the higher resolution image; encode the higher resolution image; and create a light field image file including the encoded image and metadata including the depth map.

Claims

1. A system for encoding light field image data as a light field image file, comprising:

a processor; and

memory containing an encoding application and light field image data, where the light field image data comprises a plurality of images of a scene captured from different viewpoints;

wherein the encoding application directs the processor to;

create a depth map that specifies depths for pixels in a reference image in the plurality of images;

create a confidence map for the depth map, where the confidence map indicates the reliability of the depth value for a pixel in the depth map; and

encode the reference image; and

create a light field image file including the encoded image and metadata describing the encoded image, where the metadata includes the depth map and the confidence map.

2. The system of claim 1, wherein the light field image file is structured using the Exchangable image file (Exif) format.

3. The system of claim 2, wherein the light field image file conforms to the JFIF standard.

4. The system of claim 2, wherein the metadata is located within an application marker segment within the light field image file.

5. The system of claim 4, wherein the application marker segment is identified using the APP9 marker.

6. The system of claim 2, wherein the application marker segment is identified using an APP1 marker that is used to identify the Exif data.

7. The system of claim 1, wherein the encoded image is encoded in accordance with the JPEG standard.

8. The system of claim 1, wherein the encoding application directs the processor to encode the depth map and the depth map included in the metadata describing the encoded image is the encoded depth map.

9. The system of claim 8, wherein the depth map is losslessly encoded.

10. The system of claim 9, wherein the rendering application directs the processor to decode the depth map using a JPEG decoder.

11. The system of claim 8, wherein the depth map is encoded using lossy compression.

12. The system of claim 1, wherein the encoding application directs the processor to encode the confidence map and the confidence map included in the metadata describing the encoded image is the encoded confidence map.

13. The system of claim 1, wherein:

encoding the reference image involves identifying pixels in the plurality images of the scene that are occluded in a reference viewpoint; and

the metadata describing the encoded image in the light field image file includes descriptions of the occluded pixels.

14. The system of claim 13, wherein the descriptions of the occluded pixels includes data selected from the group consisting of colors, locations, and depths of the occluded pixels.

15. The system of claim 1, wherein:

the encoding application directs the processor to generate an edge map that indicates pixels in the reference image that lie on a discontinuity; and

the metadata describing the encoded image in the light field image file includes the edge map.

16. The system of claim 15, wherein the edge map identifies whether a pixel lies on a discontinuity selected from the group consisting of an intensity and depth discontinuity.

17. The system of claim 1, wherein:

the encoding application directs the processor to generate a missing pixel map that indicates pixels in the reference image that do not correspond to a pixel from the plurality images of the scene and that are generated by interpolating pixel values from adjacent pixels in the reference image; and

the metadata describing the encoded image in the light field image file includes the missing pixels map.

18. The system of claim 1, wherein the metadata also includes a focal plane.

19. The system of claim 1, wherein the encoding application directs the processor to:

select a second reference image from the plurality of images, where the second reference image is distinct from the reference image and the reference image and the second reference image comprise a stereo pair of images;

encode the second reference image; and

include the second reference image in the encoded light field image file.

20. A method for encoding light field image data as a light field image file, comprising:

obtaining a set of light field image data comprising a plurality of images of a scene captured from different viewpoints using an encoding system;

creating a depth map that specifies depths for pixels in a reference image in the plurality of images using the encoding device;

encoding the reference image using the encoding device; and

creating a light field image file including the encoded image and metadata describing the encoded image using the encoding device, wherein;

the light field image file is structured using the Exchangable image file (Exif) format; and

the metadata includes the depth map.

21. A non-transitory machine readable medium containing processor instructions, where execution of the instructions by a processor causes the processor to perform a process comprising:

obtaining a set of light field image data comprising a plurality of images of a scene captured from different viewpoints;

creating a depth map that specifies depths for pixels in a reference image in the plurality of images;

encoding the reference image; and

creating a light field image file including the encoded image and metadata describing the encoded image, wherein;

the light field image file is structured using the Exchangable image file (Exif) format; and

the metadata includes the depth map.