Spatiotemporal Depth Extraction Using Forward and Backward Prediction

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Solution Overview

Problem

Conventional depth map extraction techniques for stereoscopic images result in temporal jittering artifacts in 3D playback due to instability of depth maps over time, especially in frames with significant texture changes.

Innovation Solution

A spatiotemporal depth extraction method incorporating forward and backward depth prediction, where the depth map of a current frame is generated based on both a previous and subsequent frame, using a combination of pixel matching, smoothness, and temporal cost functions to improve the smoothness and accuracy of depth maps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a static depth extraction algorithm is applied to each frame pair, then the depth map extraction process is simple and fast, but temporal jittering artifacts occur due to instability of depth maps over time

Engineering Contradiction:
Improvedepth extraction speedVSAvoiddepth map stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by using forward depth prediction from the previous frame and backward depth prediction from the subsequent frame before finalizing the current frame's depth map. This pre-computation of predictive depth maps from temporal neighbors stabilizes the extraction process and reduces jittering artifacts while maintaining efficiency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by incorporating backward depth prediction that uses the subsequent frame's depth map to refine the current frame's depth extraction. This feedback mechanism from future temporal information corrects instability and temporal jittering, improving depth map reliability without significantly increasing processing complexity.

Inventive Principle:
Principle #23Feedback

2Reliability

If forward and backward depth prediction are used, then temporal jittering artifacts are reduced and depth map stability is improved, but the processing complexity increases

Engineering Contradiction:
Improvedepth map stabilityVSAvoidprocessing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges forward depth prediction and backward depth prediction into a unified spatiotemporal extraction process. By combining these two predictive approaches with the current frame's static extraction, the system achieves improved stability through integrated temporal information while managing processing complexity through a cohesive algorithmic framework.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from static spatial depth extraction to spatiotemporal extraction by adding the time dimension. Forward and backward predictions leverage temporal dimensions (previous and subsequent frames) to stabilize current frame extraction, reducing jittering artifacts while the integrated approach manages the increased computational complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS9659382B2System and method for depth extraction of images with forward and backward depth prediction
Publication Date: 2017.05.23 INTERDIGITAL MADISON PATENT HLDG
  • US9659382B2 patent drawing
  • US9659382B2 patent drawing
  • US9659382B2 patent drawing

AI summary

A system and method for spatiotemporal depth extraction of images with forward and backward depth prediction are provided. The system and method of the present disclosure provide for acquiring a plurality of frames, generating a first depth map of a current frame in the plurality of frames based on a depth map of a previous frame in the plurality of frames, generating a second depth map of the current frame in the plurality of frames based on a depth map of a subsequent frame in the plurality of frames, and processing the first depth map and the second depth map to produce a third depth map for the current frame.