• Title/Summary/Keyword: Handwritten Character Recognition

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Preprocessing Techniques for On-Line Handwritten Character Recognition based on Table-Top Display (테이블-탑 디스플레이 기반의 온라인 필기 문자인식을 위한 전처리 기법)

  • Kim, Ji-Woong;Kim, Eui-Chul;Kim, Soo-Hyung
    • Proceedings of the Korea Information Processing Society Conference
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    • 2007.11a
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    • pp.171-174
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    • 2007
  • 최근에 인간과 컴퓨터의 상호작용을 위한 입력장치 중 테이블-탑 디스플레이라는 멀티터치 입력장치가 활발히 연구되고 있다. 본 논문에서는 테이블-탑 디스플레이라는 환경에서 인간에게 가장 직관적인 도구인 손을 사용하여 입력된 온라인 필기 숫자를 전처리하는 방법을 제안한다. 테이블-탑 디스플레이 환경에 적합한 전처리 기법으로 대표점 추출을 위한 거리 필터링과 획 구분 및 잡음제거 등을 사용하였고, 데이터를 16방향 체인코드로 변환하였다. 이는 실제 필기운동 시의 궤적을 크게 왜곡 시키지 않으면서 테이블-탑 디스플레이가 갖는 환경에 기인한 잡음을 없애고, 데이터양을 줄일 수 있는 장점이 있다. 총450개의 필기 숫자 데이터를 사용하여 실험한 결과, 잡음이 제거되고 데이터양이 줄어들었으며 인식에 용이한 체인코드를 형성해 내었다.

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Pattern Recognition using Robust Feedforward Neural Networks (로버스트 다층전방향 신경망을 이용한 패턴인식)

  • Hwang, Chang-Ha;Kim, Sang-Min
    • Journal of the Korean Data and Information Science Society
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    • v.9 no.2
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    • pp.345-355
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    • 1998
  • The back propagation(BP) algorithm allows multilayer feedforward neural networks to learn input-output mappings from training samples. It iteratively adjusts the network parameters(weights) to minimize the sum of squared approximation errors using a gradient descent technique. However, the mapping acquired through the BP algorithm may be corrupt when errorneous training data are employed. In this paper two types of robust backpropagation algorithms are discussed both from a theoretical point of view and in the case studies of nonlinear regression function estimation and handwritten Korean character recognition. For future research we suggest Bayesian learning approach to neural networks and compare it with two robust backpropagation algorithms.

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The Recognition of Grapheme 'ㅁ', 'ㅇ' Using Neighbor Angle Histogram and Modified Hausdorff Distance (이웃 각도 히스토그램 및 변형된 하우스도르프 거리를 이용한 'ㅁ', 'ㅇ' 자소 인식)

  • Chang Won-Du;Kim Ha-Young;Cha Eui-Young;Kim Do-Hyeon
    • Journal of Korea Multimedia Society
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    • v.8 no.2
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    • pp.181-191
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    • 2005
  • The classification error of 'ㅁ', 'ㅇ' is one of the main causes of incorrect recognition in Korean characters, but there haven't been enough researches to solve this problem. In this paper, a new feature extraction method from Korean grapheme is proposed to recognize 'ㅁ', 'ㅇ'effectively. First, we defined an optimal neighbor-distance selection measure using modified Hausdorff distance, which we determined the optimal neighbor-distance by. And we extracted neighbor-angle feature which was used as the effective feature to classify the two graphemes 'ㅁ', 'ㅇ'. Experimental results show that the proposed feature extraction method worked efficiently with the small number of features and could recognize the untrained patterns better than the conventional methods. It proves that the proposed method has a generality and stability for pattern recognition.

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Comparison of Feature Performance in Off-line Hanwritten Korean Alphabet Recognition (오프라인 필기체 한글 자소 인식에 있어서 특징성능의 비교)

  • Ko, Tae-Seog;Kim, Jong-Ryeol;Chung, Kyu-Sik
    • Korean Journal of Cognitive Science
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    • v.7 no.1
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    • pp.57-74
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    • 1996
  • This paper presents a comparison of recognition performance of the features used inthe recent handwritten korean character recognition.This research aims at providing the basis for feature selecion in order to improve not only the recognition rate but also the efficiency of recognition system.For the comparison of feature performace,we analyzed the characteristics of theose features and then,classified them into three rypes:global feature(image transformation)type,statistical feature type,and local/ topological feature type.For each type,we selected four or five features which seem more suitable to represent the characteristics of korean alphabet,and performed recongition experiments for the first consonant,horizontal vowel,and vertical vowel of a korean character, respectively.The classifier used in our experiments is a multi-layered perceptron with one hidden layer which is trained with backpropagation algorithm.The training and test data in the experiment are taken from 30sets of PE92. Experimental results show that 1)local/topological features outperform the other two type features in terms of recognition rates 2)mesh and projection features in statical feature type,walsh and DCT features in global feature type,and gradient and concavity features in local/topological feature type outperform the others in each type, respectively.

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A Hangul Script Matching Algorithm for PDA (PDA상에서의 한글 필기체 매칭 알고리즘)

  • Cho, Mi-Gyung;Cho, Hwan-Gue
    • Journal of KIISE:Software and Applications
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    • v.29 no.10
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    • pp.684-693
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    • 2002
  • Electronic Ink is a stored data in the form of the handwritten text or the script without converting it into ASCII by handwritten recognition on the pen-based computers and Personal Digital Assistants(PDAs) for supporting natural and convenient data input. One of the most Important issue is to search the electronic ink in order to use it. We proposed and implemented a script matching algorithm for the electronic ink. Proposed matching algorithm separated the input stroke into a set of primitive stroke using the curvature of the stroke curve. After determining the type of separated strokes, it produced a stroke feature vector. And then it calculated the distance between the stroke feature vector of input strokes and one of strokes in the database using the dynamic programming technique. We did various experiments and our algorithm showed high matching rate over 97.7% for only the Korean script and 94% for the data mixed Korean with the Chinese character.

Study on the Neural Network for Handwritten Hangul Syllabic Character Recognition (수정된 Neocognitron을 사용한 필기체 한글인식)

  • 김은진;백종현
    • Korean Journal of Cognitive Science
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    • v.3 no.1
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    • pp.61-78
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    • 1991
  • This paper descibes the study of application of a modified Neocognitron model with backward path for the recognition of Hangul(Korean) syllabic characters. In this original report, Fukushima demonstrated that Neocognitron can recognize hand written numerical characters of $19{\times}19$ size. This version accepts $61{\times}61$ images of handwritten Hangul syllabic characters or a part thereof with a mouse or with a scanner. It consists of an input layer and 3 pairs of Uc layers. The last Uc layer of this version, recognition layer, consists of 24 planes of $5{\times}5$ cells which tell us the identity of a grapheme receiving attention at one time and its relative position in the input layer respectively. It has been trained 10 simple vowel graphemes and 14 simple consonant graphemes and their spatial features. Some patterns which are not easily trained have been trained more extrensively. The trained nerwork which can classify indivisual graphemes with possible deformation, noise, size variance, transformation or retation wre then used to recongnize Korean syllabic characters using its selective attention mechanism for image segmentation task within a syllabic characters. On initial sample tests on input characters our model could recognize correctly up to 79%of the various test patterns of handwritten Korean syllabic charactes. The results of this study indeed show Neocognitron as a powerful model to reconginze deformed handwritten charavters with big size characters set via segmenting its input images as recognizable parts. The same approach may be applied to the recogition of chinese characters, which are much complex both in its structures and its graphemes. But processing time appears to be the bottleneck before it can be implemented. Special hardware such as neural chip appear to be an essestial prerquisite for the practical use of the model. Further work is required before enabling the model to recognize Korean syllabic characters consisting of complex vowels and complex consonants. Correct recognition of the neighboring area between two simple graphemes would become more critical for this task.

Development of a Ship's Logbook Data Extraction Model Using OCR Program (OCR 프로그램을 활용한 선박 항해일지 데이터 추출 모델 개발)

  • Dain Lee;Sung-Cheol Kim;Ik-Hyun Youn
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.30 no.1
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    • pp.97-107
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    • 2024
  • Despite the rapid advancement in image recognition technology, achieving perfect digitization of tabular documents and handwritten documents still challenges. The purpose of this study is to improve the accuracy of digitizing the logbook by correcting errors by utilizing associated rules considered during logbook entries. Through this, it is expected to enhance the accuracy and reliability of data extracted from logbook through OCR programs. This model is to improve the accuracy of digitizing the logbook of the training ship "Saenuri" at the Mokpo Maritime University by correcting errors identified after Optical Character Recognition (OCR) program recognition. The model identified and corrected errors by utilizing associated rules considered during logbook entries. To evaluate the effect of model, the data before and after correction were divided by features, and comparisons were made between the same sailing number and the same feature. Using this model, approximately 10.6% of errors out of the total estimated error rate of about 11.8% were identified, and 56 out of 123 errors were corrected. A limitation of this study is that it only focuses on information from Dist.Run to Stand Course sections of the logbook, which contain navigational information. Future research will aim to correct more information from the logbook, including weather information, to overcome this limitation.

Character Recognition for Fast Handwritten Korean Address Reading (고속 필기 한글 주소 인식을 위한 낱자 인식)

  • Jeong, Seon-Hwa;Lim, Kil-Taek;Song, Jae-Gwan;Nam, Yun-Seok
    • Proceedings of the Korea Information Processing Society Conference
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    • 2001.10a
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    • pp.589-592
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    • 2001
  • 본 논문에서는 고속 필기 한글 주소 인식을 위한 낱자 인식기를 제안한다. 인식 대상은 우편번호 여섯 자리에 할당된 주소에 출현 빈도가 높은 필기 한글 469 자이다. 제안된 방법은 낱자 인식 기법을 채택하고 있으며, 인식률과 처리속도를 향상시키기 위하여 2 단계 인식 전략을 채택하였다. 인식기로는 다층퍼셉트론, 최소거리분류기, Subspace 방법을 고려한다. 다층퍼셉트론은 비교적 높은 인식률과 처리속도를 보유하지만 출력값이 확률이 아님으로써 후처리를 필요로 하는 시스템에서 사용하기 어렵다. 최소거리분류기는 간단한 알고리즘으로 처리속도가 높고 확률을 출력하는 장점을 갖지만 인식률이 낮아 활용되기 어렵다. 또한 Subspace 방법은 인식률이 높고 확률을 출력하지만 처리속도가 매우 느리다는 단점이 있다. 따라서 제안방법에서는 처리속도가 높은 인식기 - 다층퍼셉트론, 최소거리분류기 - 를 사용하여 선인식을 수행한 후, 이 결과를 활용하여 인식 대상을 제한한 후 Subspace 방법을 사용하여 정확하게 인식하는 전략을 도입함으로써, 높은 인식결과를 유지하면서 처리속도를 높이고 후처리에 적합하도록 하였다. PE92 데이터베이스를 사용하여 실험한 결과 제안방법이 한글 469 자에 대하여 비교적 높은 인식률과 처리속도를 갖음을 알 수 있었다.

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A Study on Improvement of Korean OCR Accuracy Using Deep Learning (딥러닝을 이용한 한글 OCR 정확도 향상에 대한 연구)

  • Kang, Ga-Hyeon;Ko, Ji-Hyun;Kwon, Yong-Jun;Kwon, Na-Young;Koh, Seok-Ju
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.05a
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    • pp.693-695
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    • 2018
  • In this paper, we propose the improvement of Hangul OCR accuracy through deep learning. OCR is a program that senses printed and handwritten characters in an optical way and encodes them digitally. In the case of the most commonly used Tesseract OCR, the accuracy of English recognition is high. However, Hangul has lower accuracy because it has less learning data for a complex structure. Therefore, in this study, we propose a method to improve the accuracy of Hangul OCR by extracting the character region from the desired image through image processing and using deep learning using it as learning data. It is expected that OCR, which has been developed only by existing alphanumeric and several languages, can be applied to various languages.

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A Developing a Machine Leaning-Based Defect Data Management System For Multi-Family Housing Unit (기계학습 알고리즘 기반 하자 정보 관리 시스템 개발 - 공동주택 전용부분을 중심으로 -)

  • Park, Da-seul;Cha, Hee-sung
    • Korean Journal of Construction Engineering and Management
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    • v.24 no.5
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    • pp.35-43
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    • 2023
  • Along with the increase in Multi-unit housing defect disputes, the importance of defect management is also increased. However, previous studies have mostly focused on the Multi-unit housing's 'common part'. In addition, there is a lack of research on the system for the 'management office', which is a part of the subject of defect management. These resulted in the lack of defect management capability of the management office and the deterioration of management quality. Therefore, this paper proposes a machine learning-based defect data management system for management offices. The goal is to solve the inconvenience of management by using Optical Character Recognition (OCR) and Natural Language Processing (NLP) modules. This system converts handwritten defect information into online text via OCR. By using the language model, the defect information is regenerated along with the form specified by the user. Eventually, the generated text is stored in a database and statistical analysis is performed. Through this chain of system, management office is expected to improve its defect management capabilities and support decision-making.