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Robust detection of skew in document images.
1Dept. of Electr. Eng., Indian Inst. of Technol., Bombay.
Summary
This study introduces a fast and robust algorithm for detecting skew in document images. The method uses random region analysis and cross-correlation, improving accuracy for various document types.
Area of Science:
- Computer Vision
- Image Processing
- Document Analysis
Background:
- Document skew is a common issue in scanned images.
- Accurate skew detection is crucial for subsequent document processing tasks.
- Existing methods may be slow or require pre-segmentation.
Purpose of the Study:
- To develop a fast and robust algorithm for skew detection in binary document images.
- To improve the efficiency and applicability of skew detection methods.
- To present experimental validation on diverse document types.
Main Methods:
- The algorithm employs interline cross-correlation analysis.
- Correlation is calculated over randomly selected small regions, avoiding full image processing.
- A Monte Carlo sampling technique determines the optimal number of regions for analysis.
- Maximum median of cross-correlation is used as the skew detection criterion.
Main Results:
- The proposed algorithm demonstrates robustness across various document types.
- It effectively detects skew in documents with different linguistic scripts.
- The method achieves high accuracy without prior text/graphics segmentation.
- Experimental results confirm the algorithm's speed and reliability.
Conclusions:
- The developed algorithm offers an efficient and accurate solution for document image skew detection.
- It eliminates the need for complex pre-processing steps like segmentation.
- The method is suitable for a wide range of document images, enhancing automated document analysis workflows.
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