IMAGE PROCESSING APPARATUS, IMAGE PROCESSING METHOD AND PROGRAM

• US 20100104197A1
• Filed: 10/21/2009
• Published: 04/29/2010
• Est. Priority Date: 10/23/2008
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Matsushita, Masahiro, Magai, Koichi, Shiiyama, Hirotaka, Sohma, Hidetomo
• Granted Patent: US 8,385,656 B2
• Time in Patent Office: Days
• US Class Current: 382/195
• CPC Class Codes: G06F 16/532 Query formulation, e.g. graphical querying
• CPC Class Codes: G06V 10/462 Salient features, e.g. scale invariant feature transforms [SIFT]
• CPC Class Codes: G06V 10/52 Scale-space analysis, e.g. wavelet analysis multi-scale boundary representations G06V10/42

Abstract

An image processing apparatus reduces two input images to be compared by the predetermined number of times to generate two image groups, extracts a plurality of feature points and a local feature amount of each feature point from these image groups, and determines a combination of feature points in which local feature amounts are similar to each other, between the image groups. Then, the image processing apparatus determines a relation of a reasonable combination, assigns high weights to the reasonable combination, and calculates a similarity degree between the two input images.

Claims

1. An image processing apparatus comprising:

a conversion unit configured to reduce an input image by a predetermined number of times to generate an image group containing the input image;

an extraction unit configured to extract a plurality of feature points and a local feature amount of each feature point from the image group;

a first determination unit configure to compare a first image that a first image group generated from a first input image by the conversion unit includes, and a second image that a second image group generated from a second input image by the conversion unit includes, and to combine a feature point of the first image group and a feature point of the second image group;

a second determination unit configured to determine a relation between the first image and the second image in which a size of an object of the first image and that of the second image get closer; and

a calculation unit configured to assign high weights to a combination of feature points extracted from an image having the relation determined by the second determination unit to calculate a similarity degree between the first input image and the second input image.

2. The image processing apparatus according to claim 1, wherein the first determination unit determines a feature point of the second image group having a local feature amount similar to a local feature amount of each feature point of the first image group as a combination.

3. The image processing apparatus according to claim 1, wherein the extraction unit extracts a position of respective feature points and the calculation unit generates a transformation matrix based on a position relation of each feature point to calculate reasonableness of the transformation matrix as the similarity degree.

4. The image processing apparatus according to claim 1, further comprising:

an output unit configured to output information concerning the second image having an object similar to an object of the first image as a search result.

5. An image processing apparatus comprising:

a conversion unit configured to reduce an input image by a predetermined number of times to generate an image group containing the input image;

an extraction unit configured to extract a plurality of feature points and a local feature amount of each feature point from the image group;

a first determination unit configure to compare a first image that a first image group generated from a first input image by the conversion unit includes, and a second image that a second image group generated from a second input image by the conversion unit includes, and to combine a feature point of the first image group and a feature point of the second image group;

a second determination unit configured to determine a relation between the first image and the second image in which a size of an object of the first image and that of the second image get closer; and

a calculation unit configured to determine, as to the first image and the second image which are in the relation determined the second determination unit, a combination of feature points in which local feature amounts are similar to each other, and to calculate a similarity degree between the first input image and the second input image based on this combination.

6. An image processing method comprising:

reducing an input image by the predetermined number of times to generate an image group containing the input image;

extracting a plurality of feature points and a local feature amount of each feature point from the image group;

comparing a first image that a first image group generated from a first input image by the conversion unit includes, and a second image that a second image group generated from a second input image by the conversion unit includes, to combine a feature point of the first image group and a feature point of the second image group;

determining a relation between the first image and the second image s in which a size of an object of the first image and that of the second image get closer; and

assigning high weights to a combination of feature points extracted from an image having the relation determined by the second determination unit to calculate a similarity degree between the first input image and the second input image.

7. A computer-readable storage medium storing a program causing a computer to execute a method, the method comprising:

reducing an input image by a predetermined number of times to generate an image group containing the input image;

extracting a plurality of feature points and a local feature amount of each feature point from the image group;

comparing a first image that a first image group generated from a first input image by the conversion unit includes, and a second image that a second image group generated from a second input image by the conversion unit includes, to combine a feature point of the first image group and a feature point of the second image group;

determining a relation between the first image and the second image in which a size of an object of the first image and that of the second image close get closer; and

assigning high weights to a combination of feature points extracted from an image having the relation determined by the second determination unit to calculate a similarity degree between the first input image and the second input image.