Book Image Distortion Correction via Vanishing Point Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image processing methods for correcting geometrical distortions in book images due to bending are either inconvenient for users or limited in scope, as they require grid paper or assume the presence of long text lines, which may not be applicable to all book images.
Innovation Solution
A content-independent image processing method that identifies vanishing points and extracts straight lines between top and bottom contour lines to remove perspective distortion, transforming the curved surface into a flat surface by calculating true widths and depth increments, allowing for the correction of distorted book pages without requiring specific content features.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a content-independent correction method using grid paper is used, then the correction can be applied to any book image, but the user convenience deteriorates due to the need to lay grid paper on pages
Solution Approach 1:
The system automatically detects contour lines and vanishing points from the book image itself, eliminating the need for user intervention to place grid paper. The correction process serves itself by using inherent image features rather than requiring external aids or manual setup.
Solution Approach 2:
The method extracts key geometric features (contour lines and vanishing points) directly from the book image to establish the correction model. By taking out these essential elements, the system achieves both automatic operation and broad applicability without requiring grid paper placement.
2Ease of operation
If content-dependent correction methods assuming long text lines are used, then the correction process is simplified, but the applicability deteriorates for books with pictures or short text
Solution Approach 1:
The contour line-based method serves multiple functions: it works for text-heavy pages, picture-based pages, and mixed-content pages. By using contour lines as the basis for correction rather than text-specific features, the system achieves universal applicability across different book content types while maintaining operational simplicity.
Solution Approach 2:
The invention changes the fundamental parameter used for correction from text-line-based features to contour-line-based features. This parameter change enables the system to handle diverse content types (text, pictures, layouts) uniformly, achieving both simplicity and versatility simultaneously.
3Manufacturing precision
If traditional grid paper method is used, then the correction accuracy is maintained, but the time consumption increases due to manual grid paper placement and removal
Solution Approach 1:
The system performs preliminary automatic detection of contour lines and vanishing points from the captured image, establishing the correction model before actual correction is needed. This preliminary action eliminates the time-consuming manual steps of placing and removing grid paper while maintaining correction accuracy through precise geometric feature detection.
Solution Approach 2:
The invention replaces the mechanical process of physically placing and removing grid paper with an automated image processing system that detects geometric features and calculates correction transformations. This substitution eliminates manual intervention time while preserving the geometric accuracy of the correction process.
Data Source
AI summary
An image processing method generally includes: obtaining a vanishing point on a curved surface in a two-dimension image; extracting all the straight line segments between a top contour line and a bottom contour line of the curved surface by the vanishing point; removing a perspective distortion to get parallel straight line segments; obtaining the lengths of the straight line segments, obtaining the true width of each of the straight line segments in a three-dimension space and the depth increment of the straight line segments according to the lengths; obtaining the expanded width of each straight line segment according to the true width and the depth increment; obtaining the total expanded width of the curved surface to transform it into a flat surface; transforming image contents on the curved surface onto the flat surface.