Digital Image Stabilization Using Preview Signal Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Digital image stabilization techniques for hand-held devices, such as mobile phones and PDAs, face challenges due to limited hardware resources, including increased manufacturing costs and quality deterioration, as they require angular velocity sensors or prisms to correct camera movement caused by shaky hands.
Innovation Solution
A method and apparatus for digital image stabilization that adapts exposure value conditions using an image signal processing module and an applied image processing module, which determines a second exposure value condition based on a first exposure value condition to correct image signals, eliminating the need for separate hardware like angular velocity sensors or prisms, and maintains image quality by interpolating or replacing pixel data to adjust for camera movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If DIS technique is used to detect and compensate for camera movement using image signals, then image stabilization is achieved, but image quality deteriorates due to digital zoom expansion
Solution Approach 1:
The patent applies preliminary action by capturing a preview image before the actual photograph is taken. This preview image is used to calculate movement vectors and determine compensation parameters in advance, allowing the main image capture to benefit from pre-computed stabilization data without requiring post-processing expansion that would degrade quality.
Solution Approach 2:
The patent uses a copy of the image signal (the preview image) to perform stabilization calculations and movement detection. Instead of processing the main image directly for stabilization which would require expansion, the preview image serves as a reference copy that enables computation of compensation parameters while preserving the original image quality.
2Manufacturing precision
If EIS technique is used to detect and compensate for camera movement using angular velocity sensor and high pixel image pickup device, then image quality is maintained, but manufacturing cost increases
Solution Approach 1:
The patent applies self-service by using the image sensor itself to capture both the preview image and the main image, eliminating the need for separate high pixel image pickup devices. The same sensor that captures the main photograph also captures the preview image used for stabilization calculations, making the system self-sufficient and reducing hardware costs.
Solution Approach 2:
The patent makes the image sensor universal by having it perform multiple functions: capturing the main photograph and capturing the preview image for stabilization processing. This multi-functionality replaces the need for separate dedicated components like high pixel image pickup devices and angular velocity sensors, thereby reducing manufacturing costs.
3Manufacturing precision
If OIS technique is used to detect and compensate for camera movement using angular velocity sensor and prism, then image quality is maintained, but device volume and manufacturing cost increase
Solution Approach 1:
The patent replaces the mechanical OIS system (using prisms and angular velocity sensors) with a digital image processing system. Instead of using physical components to optically compensate for camera movement, the system uses software algorithms that process image signals to achieve stabilization, thereby reducing device volume and eliminating complex mechanical structures.
Solution Approach 2:
The patent uses a copy of the image signal (preview image) to perform stabilization calculations digitally, replacing the need for physical optical compensation components. This digital approach using image copying and processing achieves the same stabilization effect without requiring prisms or angular velocity sensors, reducing device volume.
4Illumination intensity
If EV is increased in dark places to improve exposure, then exposure quality improves, but image blurring occurs due to increased exposure time
Solution Approach 1:
The patent applies preliminary action by capturing a preview image with longer exposure time in advance, then using this preview image to calculate movement vectors and compensation parameters. When the main photograph is taken with shorter exposure time, the movement compensation is already computed, allowing the system to achieve both good exposure quality and sharpness by using the pre-computed stabilization data.
Data Source
AI summary
An apparatus for digital image stabilization according to the present invention comprises an image signal processing module for receiving image signals generated under first and second exposure value conditions (first exposure value condition>second exposure value condition) from an image sensor, and outputting digital image signals of a first size and a second size (first size<second size) corresponding to the first exposure value condition and the second exposure value condition, respectively; and an applied image processing module for determining adaptively the second exposure value condition from the first exposure value condition, changing an exposure attribute of the image sensor from the first exposure value condition to the second exposure value condition, receiving the image signals of the first size and the second size, and correcting a property of the image signal of the second size based on the image signal of the first size.