Compact color feature vector representation
First Claim
1. A system, comprising:
- an image data store containing a plurality of images;
a global color table, wherein the global color table is calculated from the image data store by quantizing images in the image data store to determine a set of quantized image colors, and selecting colors for the global color table using the set of quantized image colors to minimize error across the image data store; and
a computer program comprising instructions operable to;
receive an original image having one or more colors from the image data store;
estimate a number of distinct colors in the original image;
use the estimated number to determine a quantization number for the original image;
determine a quantized image by quantizing the original image into the quantization number of quantized image colors; and
map each of the quantized image colors to a color of the global color table;
generate a color feature vector of one or more color descriptors to represent the original image, each color descriptor corresponding to quantized image color of the quantized image, each color descriptor comprising (i) a color index that references a location of the respective quantized image color in the global color table and (ii) a relative occurrence of the respective quantized image color within the quantized image.
2 Assignments
0 Petitions
Accused Products
Abstract
Methods and apparatus for representing images using a compact color feature vector. A color feature vector includes a color element for each color in an image-specific set of colors. A color element includes a color identifier and a relative color occurrence. A compact color feature vector may be used in a content-based image retrieval (CBIR) system. The CBIR system includes an image data store containing multiple images. A color feature vector data store includes a variable-length color feature vector for each image in the image data store. A computer program receives a query and uses the variable-length color feature vectors in the color feature vector data store to identify which images satisfy the query.
40 Citations
22 Claims
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1. A system, comprising:
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an image data store containing a plurality of images; a global color table, wherein the global color table is calculated from the image data store by quantizing images in the image data store to determine a set of quantized image colors, and selecting colors for the global color table using the set of quantized image colors to minimize error across the image data store; and a computer program comprising instructions operable to; receive an original image having one or more colors from the image data store; estimate a number of distinct colors in the original image; use the estimated number to determine a quantization number for the original image; determine a quantized image by quantizing the original image into the quantization number of quantized image colors; and map each of the quantized image colors to a color of the global color table; generate a color feature vector of one or more color descriptors to represent the original image, each color descriptor corresponding to quantized image color of the quantized image, each color descriptor comprising (i) a color index that references a location of the respective quantized image color in the global color table and (ii) a relative occurrence of the respective quantized image color within the quantized image. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A computer-implemented method comprising:
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generating a global color table from sample images, generating the global color table comprising quantizing the sample images to determine a set of quantized image colors, and selecting colors from the set of colors to minimize error across the sample images; estimating an estimated number of distinct colors in an original image; using the estimated number to determine a number N of colors to use to represent the original image as a quantized image; quantizing the original image into a quantized image of N colors; mapping each of the quantized image colors to a resultant color in the global color table; and generating a color feature vector of one or more color descriptors to represent the image, each color descriptor indicating a frequency of occurrence of a resultant color in the image. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A computer-program product, tangibly stored on machine-readable medium, the product comprising instructions to cause a computer to:
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retrieve images from an image data store; generate a global color table for the image data store; for each of a plurality of original images in the image data store, estimate an estimated number of distinct colors in an original image, use the estimated number to determine a number N of colors to use to represent the original image as a quantized image, quantize the original image into a quantized image of N colors, map each of the quantized image colors to a resultant color in the global color table, and generate a color feature vector of color descriptors to represent the image, each color descriptor indicating a frequency of occurrence of a resultant color in the image; receive from a user a query comprising a query image; use the query image to create a query color feature vector of one or more descriptors, each descriptor comprising (i) a color index that references a location of a color in the global color table and (ii) a relative occurrence of the color as a quantized color within the query image; and compare the query color feature vector to the color feature vectors of the plurality of images to identify images among the plurality of images that satisfy the query. - View Dependent Claims (18, 19, 20, 21, 22)
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Specification