BINOCULAR VISUAL EXPERIENCE ENRICHMENT SYSTEM

• US 20140055447A1
• Filed: 07/30/2013
• Published: 02/27/2014
• Est. Priority Date: 08/02/2012
• Status: Active Grant

• Current Assignee: Chinese University of Hong Kong
• Original Assignee: Chinese University of Hong Kong
• Inventors: WONG, Tien-Tsin, HENG, Pheng-Ann, YANG, Xuan, ZHANG, Linling
• Granted Patent: US 9,406,105 B2
• Time in Patent Office: Days
• US Class Current: 345/419
• CPC Class Codes: G06T 15/00 3D [Three Dimensional] image rendering
• CPC Class Codes: G06T 5/00 Image enhancement or restoration
• CPC Class Codes: G06T 5/009 Global, i.e. based on properties of the image as a whole applied in cameras using an electronic image sensor H04N23/80, H04N23/70
• CPC Class Codes: G06T 5/92 based on global image properties
• CPC Class Codes: H04N 1/00127 Connection or combination of a still picture apparatus with another apparatus, e.g. for storage, processing or transmission of still picture signals or of information associated with a still picture
• CPC Class Codes: H04N 1/00169 Digital image input
• CPC Class Codes: H04N 1/23 Reproducing arrangements
• CPC Class Codes: H04N 13/106 Processing image signals for multi-view video sequence encoding H04N19/597
• CPC Class Codes: H04N 13/144 for flicker reduction
• CPC Class Codes: H04N 2213/006 Pseudo-stereoscopic systems, i.e. systems wherein a stereoscopic effect is obtained without sending different images to the viewer's eyes

Abstract

In a computer-based graphics imaging system, binocular tone mapping is employed with an optimization-based framework to generate a binocular single vision image with more visual richness than a single tone-mapped image, the binocular tone mapping being guided by a binocular viewing comfort predictor (BVCP) metric in order to assure stable formation of binocularly tone-mapped image pairs, so that visual information content of the image pair can be maximized without triggering visual discomfort.

Claims

1. A system for generating an image for display comprising:

a computer processor with associated digital memory and output element, said processor being operative to employ an optimization-based binocular tone mapping framework;

said computer processor and associated memory being configured to;

receive in digital representation as a source a high-dynamic range image of a source high dynamic range image;

produce a first low-dynamic range image directly from said high-dynamic range image;

synthesize a corresponding second low-dynamic range image from said high-dynamic range image, wherein extra image space is used to enhance image content while preserving visual information, and

produce an output representation of at least a binocular single vision image,

said tone mapping framework being guided by a metric of a binocular viewing comfort predictor (BVCP) in order to assure stable formation of binocular single vision and avoid viewing discomfort.

2. The system of claim 1 wherein said computer processor is configured to provide a first image path for said first image and a second image path for said second image, said first path and said second path being parallel.

3. The system of claim 2 wherein said second image path provides:

an optimization processor element including a visual difference predictor and a binocular viewing comfort predictor, the binocular viewing comfort predictor being configured to establish a metric to minimize risk of said visual discomfort and the visual difference predictor being configured to maximize visual difference between said first image and said second image, subject to constraints of said binocular viewing comfort predictor.

4. The system of claim 3 wherein said first image path includes:

a direct tone mapper configured to produce said first image from the high-definition range image.

5. The system of claim 3 wherein said optimization processor element is configured for iterative feedback to follow a gradient ascent direction based on visual difference prediction of a current low-density range image pair comprising current first image and current second image, wherein step size of said gradient ascent is reduced if the current low-density image pair cannot pass a metric test of said binocular viewing comfort predictor.

6. The system of claim 5 wherein the binocular viewing comfort predictor is configured to measure differences in terms of contour density, contrast, luminance and color.

7. The system of claim 6 wherein contour density criteria are relaxed upon failure of rivalry where contrast is small, in order to allow more visual information to be represented.

8. The system of claim 6 wherein contrast threshold is formulated as a function of luminance and spatial frequency.

9. The system of claim 1 wherein the tone mapping operator is selected from the group consisting of:

bilateral filtering, gradient domain high-density range compression, adaptive logarithmic mapping, and perceptual-based contrast processing.

10. The system of claim 1 wherein the processor is configured to produce stereo image output from two single image inputs.

11. A method for generating an image for display comprising:

receiving, in a digital memory under control of a computer processor in digital representation as a source, a high-dynamic range image of a source high dynamic range image;

producing via said computer processor a first low-dynamic range image directly from said high-dynamic range image;

synthesizing via said computer processor a corresponding second low-dynamic range image from said high-dynamic range image, wherein extra image space is used to enhance image content while preserving visual information; and

producing via said computer processor an output representation of at least a binocular single vision image;

wherein a tone mapping operation is guided by a metric of a binocular viewing comfort predictor (BVCP) in order to assure stable formation of binocular single vision and avoid viewing discomfort.

12. The method of claim 11 wherein said computer processor provides a first image path for said first image and a second image path for said second image, said first path and said second path being parallel.

13. The method of claim 12 wherein said second image path provides:

establishing a metric of a binocular viewing comfort predictor in said second image path to minimize risk of said visual discomfort; and

maximizing visual difference between said first image and said second image, subject to constraints of said metric.

14. The method of claim 13 comprising:

producing said first image from the high-definition range image by a direct tone mapping.

15. The method of claim 14 comprising:

synthesizing said second image by iterative feedback in a gradient ascent direction based on visual difference prediction of a current low-density range image pair comprising current first image and current second image, wherein step size of said gradient ascent is reduced if the current low-density image pair cannot pass a metric test of said binocular viewing comfort predictor.

16. The method of claim 15 wherein the metric is based on measured differences in terms of contour density, contrast, luminance and color.

17. The method of claim 15 wherein contour density criteria are relaxed upon failure of rivalry where contrast is small, in order to allow more visual information to be represented.

18. The method of claim 16 wherein contrast threshold is formulated as a function of luminance and spatial frequency.

19. The method of claim 11 wherein the tone mapping operation is selected from the group consisting of:

bilateral filtering, gradient domain high-density range compression, adaptive logarithmic mapping, and perceptual-based contrast processing.

20. The method of claim 11 wherein the processor is configured to produce stereo image output from two single image inputs.