Mobile Device Document Image Focus Adjustment for Oblique Distortion
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Solution Overview
Problem
Existing mobile devices struggle with correcting oblique distortion in document images taken at large inclination angles, resulting in low definition and fuzziness of far-end content, especially when using existing document correction functions.
Innovation Solution
A processing method for mobile devices that involves determining the included angle of a document image, resetting the focus location towards the far-end content, and applying geometric correction to improve image quality, including taking multiple pictures and performing image segmentation and splicing to enhance far-end definition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If geometric correction is applied to document images taken at large inclination angles using existing document correction functions, then oblique distortion is corrected, but far-end content definition deteriorates and becomes fuzzy
Solution Approach 1:
The patent applies preliminary action by resetting the focus location towards the far-end content before capturing the image. This advance adjustment ensures that when geometric correction is subsequently applied, the far-end content maintains high definition rather than becoming fuzzy, directly resolving the contradiction between correction quality and far-end content definition
Solution Approach 2:
The patent changes the focus parameter of the camera system. By dynamically adjusting the focus location to the far-end content based on detected document orientation, the system optimizes image quality at the far end before geometric correction is applied, thereby maintaining definition while enabling effective distortion correction
2Area of stationary object
If the camera captures images at large inclination angles to document the entire document, then complete document coverage is achieved, but image distortion increases
Solution Approach 1:
The patent implements feedback by detecting the four sides of the document image and calculating the included angle to determine the inclination degree. Based on this feedback information, the system automatically resets the focus location towards the far-end content, creating a closed-loop control system that adapts to different photographing conditions and minimizes distortion while maintaining complete document coverage
Solution Approach 2:
The patent applies dynamics by making the focus location adjustable and adaptive rather than fixed. The focus point dynamically shifts towards the far-end content based on the detected document orientation and inclination angle, allowing the system to optimize image quality for each specific photographing scenario
Data Source
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AI summary
This specification discloses a processing method and a mobile device. The method includes: receiving a photographing instruction, where the photographing instruction is used to trigger a camera to photograph a target document; identifying, through edge detection, four sides of a document image corresponding to the target document; determining, based on the four sides, a first included angle corresponding to the document image, where the first included angle is used to represent an inclination degree of the document image relative to the target document; if the first included angle is greater than a preset threshold, triggering the camera to reset a focus location in a direction close to far-end content in the document image, and take n pictures, where n is a positive integer; applying geometric correction by using the picture obtained through photographing; and using, as output in response to the photographing instruction, one of the at least one picture to which geometric correction has been applied. The foregoing solution can significantly increase definition of the far-end content in the document image, and improve correction quality of the document image.