Character recognition apparatus and method for recognizing characters
First Claim
1. A character recognition apparatus that is used in performing coding of a pattern in accordance with the results of dividing a binary stationary image into patterns and performing pattern matching with respect to each of said divided patterns, said pattern extraction apparatus comprising:
- projection means for projecting black pixels in said binary stationary image and determining a histogram thereof;
document style determining means for determining, in accordance with said histogram, whether said binary stationary image is horizontally written text or vertically written text and for outputting a result of said determination of said document style determining means;
means for extracting a block from said image in accordance with said determination result;
pattern matching means for performing pattern matching operation by comparing said input pattern with a pattern as stored in a library;
coding means for coding said input pattern into coded data depending upon an off-set data and a result of said pattern matching operation;
means for extracting a pattern based on said block;
means for making a joining judgment which determines whether or not said extracted pattern is extracted as a unitary character;
means for joining extracted patterns in accordance with output from said means for making a joining judgment; and
means for calculating a relative distance between a currently extracted pattern and an immediately previously extracted pattern, as an offset.
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Accused Products
Abstract
In a projection means black pixel histograms of a binary stationary image are generated in both the vertical and the horizontal direction. In a text type judgment means, in accordance with these histograms, a determination is made of whether the image is vertical text or horizontal text. Based on the result of this determination, a pattern block extraction means extracts either a column or a row from the image. The block is further projected and divided into smaller blocks. Then projection is again applied to these divided blocks and patterns are extracted by a pattern extraction means. A judgment is made as to whether or not joining of the extracted patterns is to be performed and, if joining is required, they are joined by a pattern joining means and finally the offsets of all the extracted patterns are calculated, whereupon data (of extracted patterns) are sent to a pattern matching process.
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Citations
8 Claims
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1. A character recognition apparatus that is used in performing coding of a pattern in accordance with the results of dividing a binary stationary image into patterns and performing pattern matching with respect to each of said divided patterns, said pattern extraction apparatus comprising:
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projection means for projecting black pixels in said binary stationary image and determining a histogram thereof;
document style determining means for determining, in accordance with said histogram, whether said binary stationary image is horizontally written text or vertically written text and for outputting a result of said determination of said document style determining means;
means for extracting a block from said image in accordance with said determination result;
pattern matching means for performing pattern matching operation by comparing said input pattern with a pattern as stored in a library;
coding means for coding said input pattern into coded data depending upon an off-set data and a result of said pattern matching operation;
means for extracting a pattern based on said block;
means for making a joining judgment which determines whether or not said extracted pattern is extracted as a unitary character;
means for joining extracted patterns in accordance with output from said means for making a joining judgment; and
means for calculating a relative distance between a currently extracted pattern and an immediately previously extracted pattern, as an offset. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of character recognition for recognizing complex characters comprised of simpler patterns, said method comprising the steps of:
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projecting black pixels in said binary stationary image and determining a histogram thereof;
determining, in accordance with said histogram, whether said binary stationary image is horizontally written text or vertically written text and outputting a result;
extracting a block from said image in accordance with said result of said step of determining;
extracting a plurality of patterns in accordance with said block;
performing a pattern matching operation on each pattern in said block by comparing each pattern of said plurality of patterns with patterns stored in a library;
determining whether or not each extracted pattern corresponds to a unitary character;
joining extracted patterns based on said step of determining whether or not an extracted pattern corresponds to a unitary character;
coding said input pattern into coded data depending upon an off-set data and a result of said pattern matching operation; and
calculating a relative distance between a currently extracted pattern and an immediately previously extracted pattern, as an offset.
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8. A recording medium which stores a controlling program for character recognition from a binary stationary image which can be performed by a computer, wherein said program is for character recognition from a binary stationary image and is used in performing coding of a pattern in accordance with the results of dividing a binary stationary image into patterns and performing a pattern matching with respect to each of said divided patterns, said program comprising the steps of:
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projecting black pixels in said binary stationary image and determining a histogram thereof;
determining, in accordance with said histogram, whether said binary stationary image is horizontally written text or vertically written text and outputting a result;
extracting a block from said image in accordance with said result of said step of determining;
extracting a pattern in accordance with said block;
performing pattern matching operation by comparing said input pattern with a pattern as stored in a library;
coding said input pattern into coded data depending upon an off-set data and a result of said pattern matching operation;
determining whether or not an extracted pattern corresponds to a unitary character;
joining extracted patterns based on said step of determining whether or not an extracted pattern corresponds to a unitary character; and
calculating a relative distance between a currently extracted pattern and an immediately previously extracted pattern, as an offset.
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Specification