Probabilistic Gaze Model for 3D Video Compression

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Solution Overview

Problem

Current virtual reality systems face bandwidth constraints and lag due to generating high-quality content for a 360° environment, as most pixels are not viewed by the user, leading to inefficient data transmission and lower quality when predicting user gaze incorrectly.

Innovation Solution

A method using probabilistic models, such as heat maps, to determine optimal segment parameters for three-dimensional video, blurring regions based on user gaze probability, allowing for re-encoding and transmission with lower bitrate, and displaying regions of interest at higher resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If high-quality content is generated for every pixel in the 360° sphere, then visual quality is improved, but bandwidth consumption increases significantly

Engineering Contradiction:
Improvevisual qualityVSAvoidbandwidth consumption
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The patent applies local quality by differentiating the rendering quality across different regions of the 360° video sphere. Regions where users are likely to look (front hemisphere, areas near the gaze direction) are rendered at high quality, while regions where users are unlikely to look (back hemisphere, peripheral areas) are rendered at lower quality or blurred. This resolves the contradiction by maintaining high visual quality only where needed, thereby reducing overall bandwidth consumption while preserving user experience.

Inventive Principle:
Principle #3Local quality

2Loss of information

If content is transmitted for all directions in the 360° environment, then completeness of content is improved, but transmission efficiency deteriorates

Engineering Contradiction:
Improvecompleteness of contentVSAvoidtransmission efficiency
Core Design Contradiction:
Loss of informationVSProductivity

Solution Approach 1:

The patent extracts and transmits only the essential portions of the 360° video content that are likely to be viewed by the user. By using gaze estimation and probability maps, the system identifies and extracts the front hemisphere and regions of interest for transmission, while omitting or heavily compressing the back hemisphere and low-probability regions. This resolves the contradiction by maintaining content completeness for viewed areas while improving transmission efficiency through selective extraction.

Inventive Principle:
Principle #2Taking out (Extraction)

3Adaptability or versatility

If the system updates virtual reality content for different user gaze directions, then responsiveness to user movement is improved, but lag increases due to processing time

Engineering Contradiction:
Improveresponsiveness to user movementVSAvoidlag
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent implements preliminary action by pre-rendering and pre-transmitting the front hemisphere and high-probability regions of the 360° video before the user actually looks in those directions. By anticipating likely gaze directions and preparing content in advance, the system reduces the processing time required when the user moves their gaze, thereby improving responsiveness while minimizing lag. The blurred back hemisphere serves as a placeholder that can be quickly replaced if needed.

Inventive Principle:
Principle #10Preliminary action

4Quantity of substance

If prediction of user gaze direction is used to reduce bandwidth, then bandwidth consumption is reduced, but content quality and stability deteriorate when prediction is wrong

Engineering Contradiction:
Improvebandwidth consumptionVSAvoidcontent quality and stability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent uses parameter changes by dynamically adjusting the quality parameter based on the predicted gaze direction and probability. When gaze prediction confidence is high, the system transmits high-quality content for the predicted region. When confidence is low or the prediction is likely wrong, the system transitions to transmitting a blurred version of the back hemisphere or uses probability maps to adjust quality distribution. This resolves the contradiction by adaptively changing quality parameters to maintain reliability while reducing bandwidth consumption.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS11025959B2Probabilistic model to compress images for three-dimensional video
Publication Date: 2021.06.01 VERIZON PATENT & LICENSING INC
  • US11025959B2 patent drawing
  • US11025959B2 patent drawing
  • US11025959B2 patent drawing

AI summary

A method includes receiving head-tracking data that describe one or more positions of people while the people are viewing a three-dimensional video. The method further includes generating a probabilistic model of the one or more positions of the people based on the head-tracking data, wherein the probabilistic model identifies a probability of a viewer looking in a particular direction as a function of time. The method further includes generating video segments from the three-dimensional video. The method further includes, for each of the video segments: determining a directional encoding format that projects latitudes and longitudes of locations of a surface of a sphere onto locations on a plane, determining a cost function that identifies a region of interest on the plane based on the probabilistic model, and generating optimal segment parameters that minimize a sum-over position for the region of interest.