Recognizing text in a multicolor image
AssigneeAdobe Systems Incorporated
InventorJacob Stolin
Life of this patent
Estimating the term…
Abstract
A method and apparatus for recognizing text in a multicolor image stored in a computer. The image is separated into multiple blocks, and the color distributions of each of the blocks are analyzed. The blocks having two main colors are identified, and two-color blocks have similar colors are grouped into two-color zones. The two colors in each zone are converted to black and white to produce a black and white image. Text is identified in the two-color zones by performing optical character recognition of the black and white image.
Claims24
A computer-implemented method recognizing text in a multicolor image stored in a computer, the multicolor image comprising a plurality of pixels, each pixel having an associated color, the method comprising:
- separating the image into multiple blocks;
- analyzing color distributions of the pixels in each of the blocks;
- identifying blocks having two main colors;
- grouping two-color blocks having similar colors into two-color zones;
- identifying text in the two-color zones;
- mapping the pixels of each block to a three-dimensional color space;
- defining, for each two-color block, a cylinder that encloses the pixels, the cylinder having a height and a radius;
- classifying a block as a text block if the ratio of the radius to the height is less than a predefined value,
- wherein the text identifying step is performed in the text blocks.
A computer program residing on a computer-readable medium for recognizing text in a multicolor image, the multicolor image comprising a plurality of pixels, each pixel having an associated color, the computer program comprising instructions for causing the computer to:
- separate the image into multiple blocks;
- analyze color distributions of each of the blocks;
- identify blocks having two main colors;
- group two-color blocks having similar colors into two-color zones;
- and
- identify text in the two-color zones;
- map the pixels of each block to a three-dimensional color space;
- define, for each two-color block, a cylinder that encloses the pixels, the cylinder having a height and a radius;
- and
- classify a block as a text block if the ratio of the radius to the height is less than a predefined value,
- wherein the text is identified in the text blocks.
Apparatus to recognize text in a multicolor image, the multicolor image comprising a plurality of pixels, each pixel having an associated color, the apparatus comprising:
- storage medium to store the image;
- and
- a processor operatively coupled to the storage medium and configured to:
- separate the image into multiple blocks;
- analyze color distributions of each of the blocks;
- identify blocks having two main colors;
- group two-color blocks having similar colors into two-color zones;
- and
- identify text in the two-color zones;
- map the pixels of each block to a three-dimensional color space;
- define, for each two-color block, a cylinder that encloses the pixels, the cylinder having a height and a radius;
- and
- classify a block as a text block if the ratio of the radius to the height is less than a predefined value,
- wherein the text identifying step is performed in the text blocks.
A computer-implemented method recognizing text in a multicolor image stored in a computer, the multicolor image comprising a plurality of pixels, each pixel having an associated color, the method comprising:
- separating the image into multiple blocks;
- analyzing color distributions of each of the blocks;
- identifying blocks having two main colors;
- grouping two-color blocks having similar colors into two-color zones;
- identifying text in the two-color zones;
- representing each block as a vector in a three-dimensional color space, the vector originating at a point in a first group of pixels corresponding to a first color and terminating at a point in a second group of pixels corresponding to a second color;
- identifying clusters of vectors that point generally in the same directions;
- and
- marking blocks corresponding to clusters that contain more than a predefined number of vectors as text blocks.
A computer program residing on a computer-readable medium for recognizing text in a multicolor image, the multicolor image comprising a plurality of pixels, each pixel having an associated color, the computer program comprising instructions for causing the computer to:
- separate the image into multiple blocks;
- analyze color distributions of each of the blocks;
- identify blocks having two main colors;
- group two-color blocks having similar colors into two-color zones;
- identify text in the two-color zones;
- represent each block as a vector in a three-dimensional color space, the vector originating at a point in a first group of pixels corresponding to a first color and terminating at a point in a second group of pixels corresponding to a second color;
- identify clusters of vectors that point generally in the same directions;
- and
- mark blocks corresponding to clusters that contain more than a predefined number of vectors as text blocks.
Apparatus to recognize text in a multicolor image, the multicolor image comprising a plurality of pixels, each pixel having an associated color, the apparatus comprising:
- storage medium to store the image;
- and
- a processor operatively coupled to the storage medium and configured to:
- separate the image into multiple blocks;
- analyze color distributions of each of the blocks;
- identify blocks having two main colors;
- group two-color blocks having similar colors into two-color zones;
- identify text in the two-color zones;
- represent each block as a vector in a three-dimensional color space, the vector originating at a point in a first group of pixels corresponding to a first color and terminating at a point in a second group of pixels corresponding to a second color;
- identify clusters of vectors that point generally in the same directions;
- and
- mark blocks corresponding to clusters that contain more than a predefined number of vectors as text blocks.
Dependencies are inferred from the claim text.