373,570 research outputs found
Vision based handwritten character recognition
Cataloged from PDF version of article.Online automatic recognition of handwritten text has been an ongoing research
problem for four decades. It is used in automated postal address and ZIP code and
form reading, data acquisition in bank checks, processing of archived institutional
records, automatic validation of passports, etc. It has been gaining more interest
lately due to the increasing popularity of handheld computers, digital notebooks
and advanced cellular phones. Traditionally, human-machine communication has
been based on keyboard and pointing devices. Online handwriting recognition
promises to provide a dynamic means of communication with computers through
a pen like stylus, not just an ordinary keyboard. This seems to be a more natural
way of entering data into computers.
In this thesis, we develop a character recognition system that combines the
advantage of both on-line and off-line systems. Using an USB CCD Camera,
positions of the pen-tip between frames are detected as they are written on a sheet
of regular paper. Then, these positions are used for calculation of directional
information. Finally, handwritten character is characterized by a sequence of
writing directions between consecutive frames. The directional information of
the pen movement points is used for character pre-classification and positional
information is used for fine classification. After characters are recognized they are
passed to LaTeX code generation subroutine. Supported LaTeX environments are
array construction, citation, section, itemization, equation, verbatim and normal
text environments. During experiments a recognition rate of 90% was achieved.
The main recognition errors were due to the abnormal writing and ambiguity
among similar shaped characters.Öksüz, ÖzcanM.S
On-line Handwritten Character Recognition: An Implementation of Counterpropagation Neural Net
On-line handwritten scripts are usually dealt with pen
tip traces from pen-down to pen-up positions. Time evaluation of the pen coordinates is also considered along with trajectory information. However, the data obtained needs a lot of preprocessing including filtering, smoothing, slant removing and size normalization before recognition process. Instead of doing such lengthy preprocessing, this
paper presents a simple approach to extract the useful character information. This work evaluates the use of the counter- propagation neural network (CPN) and presents feature extraction mechanism in full detail to work with on-line handwriting recognition. The obtained recognition rates were 60% to 94% using the CPN for different sets of character samples. This paper also describes a performance study in which a recognition mechanism with multiple hresholds is evaluated for counter-propagation architecture. The results indicate that the application of multiple thresholds has significant effect on recognition mechanism. The method is applicable for off-line character recognition as well. The technique is tested for upper-case English alphabets for a number of different styles from different peoples
An Efficient Hidden Markov Model for Offline Handwritten Numeral Recognition
Traditionally, the performance of ocr algorithms and systems is based on the
recognition of isolated characters. When a system classifies an individual
character, its output is typically a character label or a reject marker that
corresponds to an unrecognized character. By comparing output labels with the
correct labels, the number of correct recognition, substitution errors
misrecognized characters, and rejects unrecognized characters are determined.
Nowadays, although recognition of printed isolated characters is performed with
high accuracy, recognition of handwritten characters still remains an open
problem in the research arena. The ability to identify machine printed
characters in an automated or a semi automated manner has obvious applications
in numerous fields. Since creating an algorithm with a one hundred percent
correct recognition rate is quite probably impossible in our world of noise and
different font styles, it is important to design character recognition
algorithms with these failures in mind so that when mistakes are inevitably
made, they will at least be understandable and predictable to the person
working with theComment: 6pages, 5 figure
Diagonal Based Feature Extraction for Handwritten Alphabets Recognition System using Neural Network
An off-line handwritten alphabetical character recognition system using
multilayer feed forward neural network is described in the paper. A new method,
called, diagonal based feature extraction is introduced for extracting the
features of the handwritten alphabets. Fifty data sets, each containing 26
alphabets written by various people, are used for training the neural network
and 570 different handwritten alphabetical characters are used for testing. The
proposed recognition system performs quite well yielding higher levels of
recognition accuracy compared to the systems employing the conventional
horizontal and vertical methods of feature extraction. This system will be
suitable for converting handwritten documents into structural text form and
recognizing handwritten names
Turkish handwritten text recognition: a case of agglutinative languages
We describe a system for recognizing unconstrained Turkish handwritten text. Turkish has agglutinative morphology and theoretically an infinite number of words that can be generated by adding more suffixes to the word. This makes lexicon-based recognition approaches, where the most likely word is selected among all the alternatives in a lexicon, unsuitable for Turkish. We describe our approach to the problem using a Turkish prefix recognizer. First results of the system demonstrates the promise of this approach, with top-10 word recognition rate of about 40% for a small test data of mixed handprint and cursive writing. The lexicon-based approach with a 17,000 word-lexicon (with test words added) achieves 56% top-10 word recognition rate
ANN-based Innovative Segmentation Method for Handwritten text in Assamese
Artificial Neural Network (ANN) s has widely been used for recognition of optically scanned character, which partially emulates human thinking in the domain of the Artificial Intelligence. But prior to recognition, it is necessary to segment the character from the text to sentences, words etc. Segmentation of words into individual letters has been one of the major problems in handwriting recognition. Despite several successful works all over the work, development of such tools in specific languages is still an ongoing process especially in the Indian context. This work explores the application of ANN as an aid to segmentation of handwritten characters in Assamese- an important language in the North Eastern part of India. The work explores the performance difference obtained in applying an ANN-based dynamic segmentation algorithm compared to projection- based static segmentation. The algorithm involves, first training of an ANN with individual handwritten characters recorded from different individuals. Handwritten sentences are separated out from text using a static segmentation method. From the segmented line, individual characters are separated out by first over segmenting the entire line. Each of the segments thus obtained, next, is fed to the trained ANN. The point of segmentation at which the ANN recognizes a segment or a combination of several segments to be similar to a handwritten character, a segmentation boundary for the character is assumed to exist and segmentation performed. The segmented character is next compared to the best available match and the segmentation boundary confirmed
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