Video Frame Pulldown Using Motion Analysis to Reduce Stutter

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Solution Overview

Problem

Conventional video frame pulldown methods often result in undesirable effects like judder and stutter, especially when converting 24 frames per second to 30 frames per second, which affects the viewing experience, particularly in high dynamic range images and during fast motion scenes.

Innovation Solution

A frame analysis and scoring system is employed to determine the least differing frame for insertion, using Peak Signal to Noise Ratio (PSNR) and Mean Square Error (MSE) metrics to select either a repeated or newly created frame, thereby minimizing stutter and blending issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If conventional frame pulldown methods (2:3 or 3:2 pulldown) are used to convert 24 fps to 30 fps, then the frame rate is increased to match video standards, but visible artifacts such as judder, stutter, and double images appear

Engineering Contradiction:
Improveframe rateVSAvoidjudder and stutter artifacts
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary analysis of frame pairs before pulldown conversion, evaluating motion characteristics and selecting optimal candidate frames in advance. This pre-planning allows the system to choose the best frame for repetition or interpolation before the conversion occurs, preventing artifacts rather than correcting them afterward.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adapts the pulldown strategy based on scene characteristics. By analyzing motion vectors and frame differences in real-time, it adjusts whether to repeat a frame, interpolate a new frame, or use field-based pulldown, making the conversion process flexible rather than rigid to minimize visible artifacts.

Inventive Principle:
Principle #15Dynamics

2Speed

If frame repetition is used in pulldown conversion, then the frame rate is increased, but double images and jaggedness appear in the output video

Engineering Contradiction:
Improveframe rateVSAvoidimage quality
Core Design Contradiction:
SpeedVSManufacturing precision

Solution Approach 1:

The system applies different quality treatments to different regions of the video based on local motion characteristics. In areas with low motion, it may safely repeat frames, while in high-motion areas, it uses frame interpolation or field-based approaches to maintain image quality. This localized adaptation prevents double images and jaggedness in critical regions.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system introduces an intermediary frame selection and evaluation process between the source 24 fps frames and the target 30 fps output. By evaluating multiple candidate frames and selecting the best match based on motion analysis, it acts as a mediator that smooths the transition and prevents direct frame repetition artifacts.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Speed

If 30 fps frame rate is used for fast motion video streaming, then motion rendering is improved, but pulldown conversion from 24 fps introduces stutter and viewing issues

Engineering Contradiction:
Improvemotion rendering qualityVSAvoidstutter during fast motion
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary motion analysis on fast-motion sequences to identify high-velocity areas before pulldown conversion. This allows it to pre-select appropriate candidate frames and determine the best conversion strategy for each region, ensuring smooth motion rendering even during rapid movement without introducing stutter.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS11711490B2Video frame pulldown based on frame analysis
Publication Date: 2023.07.25 HOME BOX OFFICE INC
  • US11711490B2 patent drawing
  • US11711490B2 patent drawing
  • US11711490B2 patent drawing

AI summary

The described technology is directed towards generating a new video image sequence (e.g., for playback at 30 frames per second) based on an existing video image sequence (e.g., originated for playback at 24 frames per second). The technology is based on processing frames, e.g., adjacent pairs of frames in a four-frame sequence, to obtain candidate frames for selecting a similar candidate frame to insert into the original sequence to create the new sequence (e.g., a five-frame sequence). Aspects include selecting a repeated frame to insert or creating a new frame from existing frames to insert, to generate the new sequence based on a difference/scoring comparison.