TY - JOUR
T1 - Keyword Extraction and Search Technique Using Transformation Angle Estimation to Candidate Character Set in Scene Image
AU - Suzuki, Akira
AU - Ando, Shingo
AU - Shimada, Satoshi
AU - Yonemura, Shunichi
PY - 2010
Y1 - 2010
N2 - This paper proposes an image search technology that processes character candidate sets by scanning scene images containing character strings such as signboard messages with a recognition dictionary. First, it extracts keywords composed of characters that are regularly aligned in the image by matching the word dictionary to the candidate character set. It then uses the user-input keywords in performing image search. We assume that the principal use of this technology is to retrieve images from data sets held by the user. The proposed technology has the feature that it can extract character strings even if they consist of shaded, three-dimensional characters, lie on a complex background, and are inclined, etc., attributes that cannot be offered by existing character recognition schemes for scene images. To overcome the problem of the background triggering the erroneous recognition of characters, we estimate the transformation angles of the candidate character from angular distributions of the gradient vector of pertinent areas, and add it to the limiting conditions used in determining the arrangement of character strings in the matching against the word dictionary process. Experiments on keyword extraction and image retrieval show that the proposed technology has practical performance in the application assumed, and that its estimation of the transformation angle of candidate characters is effective in decreasing keyword extraction errors.
AB - This paper proposes an image search technology that processes character candidate sets by scanning scene images containing character strings such as signboard messages with a recognition dictionary. First, it extracts keywords composed of characters that are regularly aligned in the image by matching the word dictionary to the candidate character set. It then uses the user-input keywords in performing image search. We assume that the principal use of this technology is to retrieve images from data sets held by the user. The proposed technology has the feature that it can extract character strings even if they consist of shaded, three-dimensional characters, lie on a complex background, and are inclined, etc., attributes that cannot be offered by existing character recognition schemes for scene images. To overcome the problem of the background triggering the erroneous recognition of characters, we estimate the transformation angles of the candidate character from angular distributions of the gradient vector of pertinent areas, and add it to the limiting conditions used in determining the arrangement of character strings in the matching against the word dictionary process. Experiments on keyword extraction and image retrieval show that the proposed technology has practical performance in the application assumed, and that its estimation of the transformation angle of candidate characters is effective in decreasing keyword extraction errors.
KW - character recognition in scene image
KW - estimation of transformation angles
KW - image retrieval
KW - word dictionary
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U2 - 10.11371/iieej.39.386
DO - 10.11371/iieej.39.386
M3 - Article
AN - SCOPUS:85024726874
VL - 39
SP - 386
EP - 398
JO - Journal of the Institute of Image Electronics Engineers of Japan
JF - Journal of the Institute of Image Electronics Engineers of Japan
SN - 0285-9831
IS - 4
ER -