Imaging Scanner Automatic Form Skew Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing imaging-based barcode scanners require users to input parameters for form documents, which can be tedious and error-prone, and are limited in capturing documents without a uniform background or with imperfections like skew and uneven illumination.
Innovation Solution
An imaging scanner system that automatically corrects skew and uneven illumination, and identifies a reference box to transform the captured image into a rectangle for barcode decoding without pre-setting parameters, allowing capture of various form types with or without a uniform background.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If parameters are preset for form documents in imaging scanners, then document capture can be performed with specific form formats, but the operation becomes tedious and error-prone when parameters are wrong or forms vary
Solution Approach 1:
The imaging scanner automatically detects form parameters (boundaries, skew, perspective) and performs self-calibration without requiring manual parameter input from the user. The system identifies the form document in the captured image, determines its geometric parameters, and adjusts capture settings automatically, making the device serve itself rather than requiring user configuration
Solution Approach 2:
The system dynamically changes capture parameters based on automatic detection of form characteristics. It identifies form boundaries, skew angles, and perspective distortions in real-time, then adjusts imaging parameters accordingly to optimize capture quality for each specific form format without manual intervention
2Measurement precision
If imaging scanners use fixed parameters for document capture, then one specific form format can be captured, but the scanner cannot decode forms with different formats
Solution Approach 1:
The imaging scanner transitions from static fixed parameters to dynamic adaptive parameters. It continuously detects form characteristics in captured images and adjusts capture parameters in real-time based on the detected form geometry, skew, and perspective, enabling the system to adapt to various form formats automatically
Solution Approach 2:
The system implements a universal document capture capability that works across multiple form formats without requiring format-specific configuration. By automatically detecting form boundaries and geometric parameters, the scanner provides multi-functional document capture that handles different form types through a single unified process
3Ease of operation
If document edges are found through color contrast with uniform background, then document capture can be performed, but it fails when no uniform and continuous background is available
Solution Approach 1:
The system replaces the mechanical/optical approach of relying on color contrast with uniform backgrounds with an image processing-based approach. It uses digital image analysis to detect form boundaries, skew, and perspective directly from the captured image content, substituting physical background requirements with computational edge detection and geometric analysis
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method of decoding the barcode in a form with a barcode reading arrangement. The barcode reading arrangement comprises a solid-state imager. The method includes capturing an image of a form having a barcode with a barcode reading arrangement, storing the image of the form captured by the solid-state imager to a memory, and finding a reference box in the image of the form by traversing one of connected lines and connected edges in the image of the form. The method also includes processing the image of the form to improve the image of the form by transforming the reference box to a rectangle, and processing an image of the barcode in the rectangle for decoding the barcode.