Character Keypoint-based Homography Estimation in Scanned Documents for Efficient Information Extraction
Precise homography estimation between multiple images is a pre-requisite for many computer vision applications. One application that is particularly relevant in today's digital era is the alignment of scanned or camera-captured document images such as insurance claim forms for information extraction. Traditional learning based approaches perform poorly due to the absence of an appropriate gradient. Feature based keypoint extraction techniques for homography estimation in real scene images either detect an extremely large number of inconsistent keypoints due to sharp textual edges, or produce inaccurate keypoint correspondences due to variations in illumination and viewpoint differences between document images. In this paper, we propose a novel algorithm for aligning scanned or camera-captured document images using character based keypoints and a reference template. The algorithm is both fast and accurate and utilizes a standard Optical character recognition (OCR) engine such as Tesseract to find character based unambiguous keypoints, which are utilized to identify precise keypoint correspondences between two images. Finally, the keypoints are used to compute the homography mapping between a test document and a template. We evaluated the proposed approach for information extraction on two real world anonymized datasets comprised of health insurance claim forms and the results support the viability of the proposed technique.
Code (0)
등록된 구현이 없습니다.
Tasks
Homography EstimationOptical Character RecognitionOptical Character Recognition (OCR)Methods 이 논문이 사용한 방법론
Similar Papers 제목 키워드 기반
Good Keypoints for the Two-View Geometry Estimation Problem
Local features are essential to many modern downstream applications. Therefore, it is of interest to determine the properties of local features that contribute to the downstream performance for a better design of feature…
Homography EstimationVideo-based Sequential Bayesian Homography Estimation for Soccer Field Registration
A novel Bayesian framework is proposed, which explicitly relates the homography of one video frame to the next through an affine transformation while explicitly modelling keypoint uncertainty. The literature has previous…
Homography EstimationKeypoint DetectionWords as Geometric Features: Estimating Homography using Optical Character Recognition as Compressed Image Representation
Document alignment and registration play a crucial role in numerous real-world applications, such as automated form processing, anomaly detection, and workflow automation. Traditional methods for document alignment rely …
Anomaly DetectionHomography EstimationOptical Character RecognitionOptical Character Recognition (OCR)Pentagon-Match (PMatch): Identification of View-Invariant Planar Feature for Local Feature Matching-Based Homography Estimation
In computer vision, finding correct point correspondence among images plays an important role in many applications, such as image stitching, image retrieval, visual localization, etc. Most of the research works focus on …
Homography EstimationImage RetrievalImage StitchingRetrieval+1Document Enhancement System Using Auto-encoders
The conversion of scanned documents to digital forms is performed using an Optical Character Recognition (OCR) software. This work focuses on improving the quality of scanned documents in order to improve the OCR output.…
DenoisingDocument EnhancementOptical Character RecognitionOptical Character Recognition (OCR)