Dynamic Frame Rate Synchronization for Image Stabilization

Solution Overview

Problem

Action cameras experience unstabilized video or image sequences due to high amplitude motion during activities like running, biking, or flying, as the camera moves up and down, leading to undesirable vertical motion and oscillations.

Innovation Solution

The camera dynamically synchronizes its frame rate with the detected cadence by converting motion data from the time domain to the frequency domain and adjusting the frame rate to match the dominant frequency, ensuring frames are captured at consistent vertical positions, thereby stabilizing the image sequence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the camera captures video or images at a fixed frame rate during high amplitude motion activities, then the recording captures the full range of motion, but the image sequence becomes unstabilized with undesirable vertical motion and oscillations

Engineering Contradiction:

Improveimage stabilityVSAvoidrecording operation

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent applies dynamics by making the frame rate adjustable and adaptive rather than fixed. The system dynamically changes the frame rate based on detected motion cadence, allowing the camera to adapt to varying motion conditions during activities like running or biking, thereby stabilizing the image sequence while maintaining reliable operation

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent implements feedback by using motion sensors to detect cadence and vertical oscillations, then using this information to adjust the frame rate. This closed-loop feedback system continuously monitors motion characteristics and modifies capture parameters to eliminate undesirable vertical motion and stabilize the image sequence

Inventive Principle:

Principle #23Feedback

2Reliability

If the frame rate is adjusted to match the dominant frequency of motion, then vertical oscillations are reduced and image stability improves, but the system complexity increases due to frequency domain conversion and cadence detection

Engineering Contradiction:

Improveimage stabilityVSAvoidsignal processing system

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical stabilization systems with a computational approach using frequency domain conversion. Instead of using physical gimbals or mechanical dampers, the system uses signal processing to detect cadence and adjust frame rate, achieving stabilization through software-based frequency analysis rather than mechanical means

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent applies parameter changes by converting the frame rate parameter based on detected motion characteristics. The system changes the temporal parameter (frame rate) to match the dominant frequency of motion, transforming the capture parameters dynamically to achieve stabilization without requiring complex hardware modifications

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If a fixed frame rate is used during activities with varying speed, then the recording process is simple, but the image sequence fails to maintain stability when the user's or object's speed changes

Engineering Contradiction:

Improvespeed adaptationVSAvoidframe rate control system

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the frame rate adjustable and adaptive rather than fixed. The system dynamically changes the frame rate based on detected motion cadence, allowing the camera to adapt to varying motion conditions during activities like running or biking, thereby stabilizing the image sequence while maintaining reliable operation

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent implements feedback by using motion sensors to detect cadence and vertical oscillations, then using this information to adjust the frame rate. This closed-loop feedback system continuously monitors motion characteristics and modifies capture parameters to eliminate undesirable vertical motion and stabilize the image sequence

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS10638047B2Dynamic synchronization of frame rate to a detected cadence in a time lapse image sequence

Publication Date: 2020.04.28 GOPRO INC

AI summary

A frame rate is synchronized to a detected cadence in order to generate an output image sequence that is substantially stabilized. In an in-camera process, a camera receives motion data of the camera while the camera captures the sequence of image frames. A dominant frequency of motion is determined and the capture frame rate is dynamically adjusted to match the frequency of detected motion so that each image frame is captured when the camera is at approximately the same position along the axis of motion. Alternatively, in a post-processing process, frames of a captured image sequence are selectively sampled at a sampling rate corresponding to the dominant frequency of motion so that each sampled frame corresponds to an image capture that occurred when the camera is at approximately the same position along the axis of motion.