28 research outputs found
An On-line Handwritten Text Search Method based on Directional Feature Matching
Abstract-In this paper, we describe a method of retrieving online handwritten text based on directional feature matching. Although text search into the character recognition candidate lattice has been elaborated, the character recognition based approach does not support languages which are not assumed. The proposed method is liberated from this constraint. It first hypothetically segments on-line handwritten text into character pattern blocks and prepares the object text patterns by combining the character pattern blocks. On the other hand, it employs handwritten text as a query pattern or prepares a query pattern by combining character ink patterns from query character codes. Then, it extracts directional features from the object text patterns and the query pattern, and the dimensionalities of those features are further reduced by Fisher linear discriminate analysis (FDA). Finally, the similarity is measured between the object text patterns and the query pattern by block-shift matching. This paper discusses the retrieval performance in comparison with our previous character recognition based method
Handwriting recognition and automatic scoring for descriptive answers in Japanese language tests
This paper presents an experiment of automatically scoring handwritten
descriptive answers in the trial tests for the new Japanese university entrance
examination, which were made for about 120,000 examinees in 2017 and 2018.
There are about 400,000 answers with more than 20 million characters. Although
all answers have been scored by human examiners, handwritten characters are not
labeled. We present our attempt to adapt deep neural network-based handwriting
recognizers trained on a labeled handwriting dataset into this unlabeled answer
set. Our proposed method combines different training strategies, ensembles
multiple recognizers, and uses a language model built from a large general
corpus to avoid overfitting into specific data. In our experiment, the proposed
method records character accuracy of over 97% using about 2,000 verified
labeled answers that account for less than 0.5% of the dataset. Then, the
recognized answers are fed into a pre-trained automatic scoring system based on
the BERT model without correcting misrecognized characters and providing rubric
annotations. The automatic scoring system achieves from 0.84 to 0.98 of
Quadratic Weighted Kappa (QWK). As QWK is over 0.8, it represents an acceptable
similarity of scoring between the automatic scoring system and the human
examiners. These results are promising for further research on end-to-end
automatic scoring of descriptive answers.Comment: Keywords: handwritten Japanese answers, handwriting recognition,
automatic scoring, ensemble recognition, deep neural networks; Reported in
IEICE technical report, PRMU2021-32, pp.45-50 (2021.12) Published after peer
review and Presented in ICFHR2022, Lecture Notes in Computer Science, vol.
13639, pp. 274-284 (2022.11
The Challenges of Recognizing Offline Handwritten Chinese: A Technical Review
Offline handwritten Chinese recognition is an important research area of pattern recognition, including offline handwritten Chinese character recognition (offline HCCR) and offline handwritten Chinese text recognition (offline HCTR), which are closely related to daily life. With new deep learning techniques and the combination with other domain knowledge, offline handwritten Chinese recognition has gained breakthroughs in methods and performance in recent years. However, there have yet to be articles that provide a technical review of this field since 2016. In light of this, this paper reviews the research progress and challenges of offline handwritten Chinese recognition based on traditional techniques, deep learning methods, methods combining deep learning with traditional techniques, and knowledge from other areas from 2016 to 2022. Firstly, it introduces the research background and status of handwritten Chinese recognition, standard datasets, and evaluation metrics. Secondly, a comprehensive summary and analysis of offline HCCR and offline HCTR approaches during the last seven years is provided, along with an explanation of their concepts, specifics, and performances. Finally, the main research problems in this field over the past few years are presented. The challenges still exist in offline handwritten Chinese recognition are discussed, aiming to inspire future research work