Video Camera Image Stabilization Using Filtered Motor and Gyro Signals
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Solution Overview
Problem
Existing image stabilization technologies, such as Electronic Image Stabilization (EIS), typically switch off during pan/tilt movements of a video camera, leading to blurry video streams due to vibration and shaking, which are not effectively addressed.
Innovation Solution
A method involving the generation of motor position and gyro signals, combined using low pass and high pass filters to create a stabilized signal, allowing for image stabilization during pan/tilt movements by comparing this combined signal to a reference signal based on a predetermined movement curve, thereby reducing noise and stabilizing the video stream.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If EIS is used to stabilize video frames during panning and/or tilting, then image stability is improved, but noise in the video stream increases
Solution Approach 1:
The signal from the gyroscopic sensor is segmented into two distinct components: a low-frequency component representing intentional pan/tilt movements (processed through low-pass filter F1) and a high-frequency component representing vibration and shaking (processed through high-pass filter F2). This segmentation allows differential processing where only the harmful high-frequency vibrations are compensated while preserving the intentional movement signal, thereby stabilizing images without introducing noise from motor recoil effects.
Solution Approach 2:
A reference signal generated from a predetermined movement curve serves as an intermediary between the raw gyro signal and the image stabilization process. This reference signal represents the ideal pan/tilt trajectory without vibrations. By comparing the actual gyro signal against this reference and processing only the deviations (through filtering), the system compensates for vibrations while ignoring the intentional movement path, thus achieving stabilization without noise introduction from motor operations.
2Manufacturing precision
If image stabilization is applied during pan/tilt movements, then video clarity is improved, but device complexity increases
Solution Approach 1:
The system changes the parameter domain of signal processing by applying frequency-based filtering (low-pass filter F1 and high-pass filter F2) to separate different movement components. This parameter transformation simplifies the stabilization problem by converting a complex multi-component signal into two manageable frequency bands, where only the high-frequency band requires stabilization processing. This approach improves video clarity while keeping the processing complexity manageable through standard filtering techniques.
3Measurement precision
If gyroscopic sensor signal is used directly for stabilization, then vibration detection is improved, but motor recoil effects are not compensated
Solution Approach 1:
The system performs preliminary processing of the gyroscopic signal by passing it through low-pass filter F1 and high-pass filter F2 before using it for stabilization. The low-pass filter component is used to generate a reference signal that predicts the ideal movement trajectory in advance. By having this reference prepared beforehand, the system can compare actual movements against the predetermined path and compensate only for deviations (vibrations and recoil), rather than trying to process the entire complex signal raw.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively stabilizes video frames during panning and tilting by filtering out noise from both motor position and gyro signals, ensuring a clear and precise video stream, even with recoil effects from the camera's motor movements.
Implementation Method 1
F1 is a low pass filter
Implementation Method 2
F2 is a high pass filter
Implementation Method 3
one or more gyroscopic sensors of the camera continuously detect the camera's movement and vibration
Data Source
AI summary
A method for image stabilization of a video stream captured by a panable and/or tiltable video camera the method comprising: generating a motor position signal, Y1, of a pan/tilt motor of the video camera; generating a gyro signal, Y2, of a gyroscopic sensor of the video camera; generating a reference signal from a predetermined movement curve of the pan/tilt motor of the video camera, the reference signal is a reference on how a pan/tilt operation of the video camera is made without shaking of the video camera; from the motor position signal, Y1, and the gyro signal, Y2, generating a combined signal, Y, according to: Y=F1*Y1+F2*Y2, wherein F1 is a low pass filter and F2 is a high pass filter; and performing image stabilization on the video stream based on a difference between the combined signal, Y, and the reference signal.