Matching method for two-dimensional pattern, feature extracting method, appartus used for the methods, and programs
AssigneeNEC Corporation
InventorToshio Kamei
Life of this patent
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Abstract
A 2-dimensional pattern matching method contains a process of extracting a query feature data by projecting a vector representation of either of a query 2-dimensional pattern and a transformed query 2-dimensional pattern which is generated by transforming the query 2-dimensional pattern, to a feature space. An enrollment feature data as previously enrolled and a query feature data are inversely projected to the 2-dimensional pattern representation space which has the dimension of the vector representation and the similarity is calculated. The data size of a feature amount is small and a matching technique robust to the positional displacement and the image distortion is provided.
Claims25
A 2-dimensional pattern matching method comprising:
- previously enrolling an enrollment 5 feature data which is a vector data in a feature space;
- inputting a query 2-dimensional pattern;
- extracting a query feature data by projecting a vector representation of either of said query 2-dimensional pattern and a transformed query 2-dimensional pattern which is generated by transforming said query 2-dimensional pattern into the feature space;
- generating a enrollment 2-dimensional pattern and a reconstructed query 2-dimensional pattern by inversely projecting said enrollment feature data and said query feature data into a 2-dimensional pattern representation space which has dimensions of the vector representation;
- and
- calculating a similarity between said enrollment 2-dimensional pattern and said reconstructed query 2-dimensional pattern.
A 2-dimensional pattern matching apparatus which performs a matching of a query 2-dimensional pattern by using a enrollment feature data which is a vector data in a feature space and is enrolled in advance, said 2-dimensional pattern matching apparatus comprising:
- a linear transformation section configured to extract a query feature data by projecting a vector representation of either of said query 2-dimensional pattern and a transformed query 2-dimensional pattern which is generated by transforming said query 2 dimensional pattern, to said feature space;
- a reconstructing section configured to generate a enrollment 2-dimensional pattern and a reconstructed query 2-dimensional pattern by inversely projecting said enrollment feature data and said query feature data to a 2-dimensional pattern representation space which has dimensions of the vector representation;
- and a determining section configured to calculate a similarity between said enrollment 2-dimensional pattern and said reconstructed query 2-dimensional pattern.
A computer-readable recording medium which stores computer-executable code to cause a computer to execute a matching process program for a 2-dimensional pattern matching method in which a matching of a query 2-dimensional pattern is performed by using a enrollment feature data which is a vector data in a feature space and is enrolled in advance, said method comprising:
- inputting said query 2-dimensional pattern;
- extracting a query feature data by projecting a vector representation of either of said query 2-dimensional pattern and a transformed query 2-dimensional pattern which is generated by transforming said query 2-dimensional pattern, into a feature space;
- generating an enrollment 2-dimensional pattern and a reconstructed query 2-dimensional pattern by inversely projecting said enrollment feature data and said query feature data into a 2-dimensional pattern representation space which has dimensions of the vector representation;
- and
- calculating a similarity between said enrollment 2-dimensional pattern and said reconstructed query 2-dimensional pattern.
A computer-readable recording medium which stores computer-executable code to cause a computer to execute a feature extracting program for a feature extracting method which extracts a feature data of a 2-dimensional pattern and is used for a 2-dimensional matching method, said method comprising:
- generating said transformed query 2-dimensional pattern by extracting a 1-dimensional frequency feature for every horizontal line or vertical line of said query 2-dimensional pattern and generating the vector representation of said transformed query 2-dimensional pattern;
- and
- extracting said query feature data as said 2-dimensional pattern feature data by compressing the vector representation in dimension by a first linear transformation which is defined by a basis matrix.
A computer-readable recording medium which stores computer-executable code to cause a computer to execute a feature extracting program for a feature extracting method which extracts a feature data of a 2-dimensional pattern and is used for a 2-dimensional matching method, comprising:
- extracting a 1-dimensional frequency feature every horizontal line or vertical line of said query 2-dimensional pattern;
- generating said transformed query 2-dimensional pattern by combining said 1-dimensional frequency features extracted for every line by a first linear transformation which is defined by a first basis matrix, and generating the vector representation of said transformed query 2-dimensional pattern;
- and
- extracting said query feature data as said 2-dimensional pattern feature data by compressing the vector representation in dimension by a second linear transformation which is defined by a second basis matrix.
Dependencies are inferred from the claim text.