IMAGE SEARCHING APPARATUS, CONTROL METHOD THEREOF, PROGRAM, AND STORAGE MEDIUM

• US 20080089615A1
• Filed: 09/25/2007
• Published: 04/17/2008
• Est. Priority Date: 10/13/2006
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Shiiyama, Hirotaka
• Granted Patent: US 7,953,299 B2
• Time in Patent Office: Days
• US Class Current: 382/305
• CPC Class Codes: G06V 10/50 by performing operations within image blocks; by using histograms, e.g. histogram of oriented gradients [HoG]; by summing image-intensity values; Projection analysis

Abstract

An image searching apparatus which searches for an image that is similar to a query image from among a plurality of images is provided. The apparatus derives a color similarity that denotes a degree of similarity and a luminance similarity that denotes a degree of similarity between the query image and each of the images to be compared with. Then, the apparatus transforms the luminance similarity of each of the grayscale images to be compared with and the query image into an integrated similarity that is integrated in accordance with a correspondence between the color similarity and the luminance similarity of each of the color images to be compared with, and outputs the images to be compared in order by similarity, using the color similarity of the color images to be compared and the integrated similarity of the grayscale images to be compared.

Claims

1. An image searching apparatus which searches for an image that is similar to a query image from among a plurality of images to be compared with, comprising:

an extraction unit adapted to extract a color feature parameter and a luminance feature parameter of the query image;

a first derivation unit adapted to compare the color feature parameter of the query image with the color feature parameter of each of color images to be compared with, and to derive a color similarity that denotes a degree of similarity therebetween;

a second derivation unit adapted to compare the luminance feature parameter of the query image with the luminance feature parameter of each of color images and grayscale images to be compared with, and to derive a luminance similarity that denotes a degree of similarity therebetween;

a transform unit adapted to transform the luminance similarity of each of the grayscale images to be compared with and the query image into an integrated similarity that is integrated in accordance with a correspondence between the color similarity and the luminance similarity of each of the color images to be compared with; and

an output unit adapted to output the images to be compared in order by similarity, using the color similarity of the color images to be compared that is derived by the first derivation unit, and the integrated similarity of the grayscale images to be compared that is transformed via the transform unit.

2. The image searching apparatus according to claim 1, further comprising:

a generating unit adapted to generate a correspondence information that denotes a correspondence between the color similarity and the luminance similarity, in accordance with a comparison between the color similarity and the luminance similarity of each of the color images to be compared, wherein

the transform unit transforms the luminance similarity for each of the respective grayscale images to be compared into an integrated color similarity in accordance with the correspondence information; and

the output unit performs the output in accordance with a comparison between the color similarity of each of the color images to be compared and the integrated similarity that is transformed from the luminance similarity by the transform unit.

3. The image searching apparatus according to claim 2, wherein:

the generating unit selects two or more of the color images to be compared, the color similarity whereof is greater than or equal to a predetermined threshold, and generates the correspondence information in accordance with the color similarity and the luminance similarity of the selected color images to be compared.

4. The image searching apparatus according to claim 3, wherein:

the generating unit selects the color image to be compared that has the greatest color similarity.

5. The image searching apparatus according to claim 1, wherein:

the transform unit performs the transform of the order of the integrated similarity of the grayscale image to be compared wherein the order of the luminance similarity is between a first order of the luminance similarity of the color image to be compared and a second order of the luminance similarity of the color image to be compared, by determining between the first order of color similarity of the color image to be compared and the second order of the color similarity of the color image to be compared.

6. The image searching apparatus according to claim 5, wherein:

an ordering of the first order of the luminance similarity of the color image to be compared and the second order of the luminance similarity of the color image to be compared match an ordering of the first order of color similarity of the color image to be compared and the second order of the color similarity of the color image to be compared.

7. The image searching apparatus according to claim 1, further comprising:

a display control unit adapted to display a listing of the images to be compared on a display device, in accordance with the similarity order of the images to be compared that is outputted by the output unit.

9. A program stored in a computer-readable storage medium that makes a computer function as the image searching apparatus according to claim 1.

10. A computer-readable storage medium storing the program according to claim 9.

8. A control method of an image searching apparatus which searches for an image that is similar to a query image from among a plurality of images to be compared with, comprising the steps of:

extracting a color feature parameter and a luminance feature parameter of the query image;

comparing the color feature parameter of the query image with the color feature parameter of each of color images to be compared with, and deriving a color similarity that denotes a degree of similarity therebetween;

comparing the luminance feature parameter of the query image with the luminance feature parameter of each of color images and grayscale images to be compared with, and deriving a luminance similarity that denotes a degree of similarity therebetween;

transforming the luminance similarity of the grayscale images to be compared with and the query image into an integrated similarity that is integrated in accordance with a correspondence between the color similarity and the luminance similarity of the color images to be compared with; and

outputting the images to be compared in order by similarity, using the color similarity of each of the color images to be compared that is derived by the first derivation step, and the integrated similarity of each of the grayscale images to be compared that is transformed via the transform step.