Auto-focus Method Using Single Image Diffusion Analysis
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Solution Overview
Problem
Current auto-focus methods in digital cameras are time-consuming and power-intensive, requiring multiple images to determine the focal point, which increases power consumption and does not align with consumer preferences for faster and more sustainable battery use.
Innovation Solution
An auto-focus method that sets parameters p and q using a single image, allowing for the computation of object distance and regulation of focal position, eliminating the need for a reflector and reducing hardware costs and power consumption by utilizing an optical focusing device, image capture unit, and digital signal processor to capture and process a single image.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple images are captured to determine the focal point, then the focusing accuracy is improved, but the focusing time and power consumption increase
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing the relationship between object distance and diffusion parameters in a lookup table during camera initialization. When focusing, the system directly queries this pre-prepared data structure using the captured image's diffusion parameter, eliminating the need for multiple image captures and iterative focus adjustment. This resolves the contradiction by preparing the focusing solution in advance, achieving both speed and accuracy.
2Measurement precision
If multiple images are captured to determine the focal point, then the focusing accuracy is improved, but the power consumption increases
Solution Approach 1:
The patent pre-computes the diffusion parameter characteristics and stores them in a lookup table during camera setup, so that during actual operation, only a single image needs to be captured and its diffusion parameter matched against the pre-stored data. This eliminates the need for repeated image capture and processing that would consume additional power, while still achieving accurate focusing through the pre-prepared reference data.
3Reliability
If a reflector is used to conduct the focusing function, then the focusing capability is improved, but the hardware cost and camera volume increase
Solution Approach 1:
The patent extracts the focusing capability from the traditional reflector-based optical system and implements it through a computational approach using image diffusion analysis. By removing the reflector hardware and replacing it with software-based focus determination using the diffusion parameter lookup table, the system achieves the same focusing function with simpler, smaller, and less expensive hardware components.
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 method significantly reduces focusing time, enhances image quality, and lowers power consumption by allowing the digital camera to focus quickly and efficiently using a single image, without the need for a reflector, thus improving battery sustainability and reducing camera volume.
Implementation Method 1
capturing an only image
Implementation Method 2
an identical light source is photographed
Implementation Method 3
an optical focusing device... adapted for regulating a focal position of the digital camera
Implementation Method 4
respective diffusion parameters σi are computed by a Gaussian distribution and according to the images Fi
Data Source
AI summary
An auto-focus method for camera is provided. First, a digital signal processor sets a first parameter p and a second parameter q. An image capture unit captures an only image. Then, the digital signal processor utilizes the only image, the first parameter p and the second parameter q to compute an object distance. Then, an optical focusing device utilizes the object distance to regulate a focal position. Therefore, the present invention substantially shortens the time for regulating the focal position.