Depth-Adjusted Time-Warping for VR Latency Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In virtual reality (VR) systems, performing video rendering consumes significant time and computing resources, and existing time-warping techniques face challenges due to inaccurate head pose information and memory bandwidth constraints, leading to latency and oversimplification of depth representation.
Innovation Solution
The method involves determining depth values for each pixel of a frame, down-sampling these values to obtain a subset of down-sampled depth values, and using these to perform depth-adjusted time-warping, which adjusts the position of vertices based on head pose changes, thereby reducing latency and improving computational efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If depth values for all pixels are processed for time-warping, then depth representation accuracy is improved, but computational load and processing time increase significantly
Solution Approach 1:
The patent divides the frame into multiple tiles and processes depth values at different resolution levels. Instead of processing all pixels uniformly, the system segments the image into tiles and applies adaptive processing based on depth information, reducing computational complexity while maintaining accuracy for critical regions.
Solution Approach 2:
The patent applies partial processing by selecting a subset of depth values for time-warping computation. Rather than processing all pixel depth values, the system identifies and processes only the necessary portion (e.g., depth values at specific intervals or in specific regions), achieving sufficient accuracy without the full computational burden.
2Loss of time
If time-warping is performed with current head pose data, then latency is reduced, but head pose information becomes inaccurate during rendering
Solution Approach 1:
The patent performs time-warping computation in advance using depth values captured before the actual display. By preparing the warped frame beforehand based on preliminary depth data, the system can compensate for head movement that occurs during the rendering process, reducing perceived latency while maintaining pose accuracy through the use of depth information from the correct time point.
Solution Approach 2:
The patent introduces depth values as an intermediary element that bridges the timing discrepancy between head pose capture and frame rendering. Instead of directly using potentially inaccurate contemporary head pose data, the system uses depth information as a mediator to perform time-warping, which then compensates for head movement, effectively decoupling the timing issues.
3Measurement precision
If full-resolution depth processing is performed, then depth accuracy is maintained, but memory bandwidth requirements increase
Solution Approach 1:
The patent segments the depth data into tiles and processes them at different resolutions. By dividing the full-resolution depth map into smaller tile-based units, the system maintains depth accuracy for each region while reducing the total memory bandwidth required to transfer and process the entire depth information set.
Solution Approach 2:
The patent applies partial processing to memory bandwidth by selecting and processing only the necessary portion of depth values. Instead of transferring and processing all depth values at full resolution, the system processes a strategically selected subset that provides sufficient depth information for accurate time-warping while consuming less memory bandwidth.
Data Source
AI summary
A technique includes determining a depth value for each of a plurality of pixels of a frame, down-sampling the depth values of a tile of the frame to obtain a plurality of down-sampled depth values, the frame including one or more tiles, determining a change in a head pose, determining, from the plurality of down-sampled depth values, a down-sampled depth value for a vertex, determining an adjusted position for the vertex based on the change in head pose and the down-sampled depth value for the vertex, performing, based on at least the adjusted position for the vertex, a depth-adjusted time-warping of the frame to obtain a depth-adjusted time-warped frame, and triggering display of the depth-adjusted time-warped frame.