US 8,577,152 B2 · Method of and apparatus for classifying image

Abstract

A method and apparatus that classify an image. The method extracts a feature vector from the image, wherein the feature vector includes a plurality of first features. The extracting of each of the first features includes: acquiring a difference between sums or mean values of pixels of the plurality of first areas in the corresponding combination to obtain a first difference vector in the direction of the first axis, and obtaining a second difference vector in the direction of the second axis. A first projection difference vector is acquired with a second projection difference vector. A sum of magnitudes of the first projection difference vector and the second projection difference vector as the first feature is obtained; and the image according to the extracted feature vector is classified.

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Claims16

Dependent claims

A method of classifying an image, comprising:

extracting a feature vector from the image, wherein the feature vector comprises a plurality of first features, each of the first features corresponds to a combination of a plurality of first areas arranged in the direction of a first axis, a plurality of second areas arranged in the direction of a second axis intersecting with the direction of the first axis, and one of a plurality of predetermined orientations, and the extracting of each of the first features comprises:
acquiring a difference between sums or mean values of pixels of the plurality of first areas in the corresponding combination to obtain a first difference vector in the direction of the first axis, and acquiring a difference between sums or mean values of pixels of the plurality of second areas in the corresponding combination to obtain a second difference vector in the direction of the second axis;
acquiring a first projection difference vector and a second projection difference vector projected by the first difference vector and the second difference vector on the line of the predetermined orientation in the corresponding combination;
and
acquiring the sum of magnitudes of the first projection difference vector and the second projection difference vector as the first feature;
and
classifying the image according to the extracted feature vector.

4 more elements

An apparatus for classifying an image, the apparatus extracting a feature vector from the image, wherein the feature vector comprises a plurality of first features, each of the first features corresponds to a combination of a plurality of first areas arranged in the direction of a first axis, a plurality of second areas arranged in the direction of a second axis intersecting with the direction of the first axis, and one of a plurality of predetermined orientations, and the apparatus comprises:

a difference calculating unit which with respect to each of the first features, acquires a difference between sums or mean values of pixels of the plurality of first areas in the corresponding combination to obtain a first difference vector in the direction of the first axis, acquires a difference between sums or mean values of pixels of the plurality of second areas in the corresponding combination to obtain a second difference vector in the direction of the second axis, and acquires a first projection difference vector and a second projection difference vector projected by the first difference vector and the second difference vector on the line of the predetermined orientation in the corresponding combination;
and
a feature calculating unit which acquires the sum of magnitudes of the first projection difference vector and the second projection difference vector as the first feature;
and
a classifying unit which classifies the image according to the extracted feature vector.

2 more elements

An apparatus for generating a classifier for discriminating object images from non-object images, the apparatus extracting a feature vector from an input image, wherein the feature vector comprises a plurality of first candidate features, each of the first candidate features corresponds to a candidate combination of a plurality of first areas arranged in the direction of a first axis, a plurality of second areas arranged in the direction of a second axis intersecting with the direction of the first axis, and one of a plurality of predetermined orientations, and the apparatus comprising:

a difference calculating unit which with respect to each of the first candidate features, acquires a difference between sums or mean values of pixels of the plurality of first areas in the corresponding candidate combination to obtain a first difference vector in the direction of the first axis, acquires a difference between sums or mean values of pixels of the plurality of second areas in the corresponding candidate combination to obtain a second difference vector in the direction of the second axis, and acquires a first projection difference vector and a second projection difference vector projected by the first difference vector and the second difference vector on the line of the predetermined orientation in the corresponding candidate combination;
and
a feature calculating unit which acquires the sum of magnitudes of the first projection difference vector and the second projection difference vector as the first candidate feature;
and
a training unit which trains the classifier according to the extracted feature vector.

2 more elements

Dependencies are inferred from the claim text.

Description17,845 words

Summary3,142 words

#The present invention relates to classifying videos or an images (determining whether objects are contained or not), i.e., detecting or recognizing objects in videos or images, and especially to a method of and an apparatus for generating a classifier for discriminating whether objects to be detected are contained in the videos or images, and a method of and an apparatus for classifying the images with the generated classifier.

#As widely spreading of applications such as video monitoring, artificial intelligence, computer vision or the like, there are increasing demands for techniques of detecting specific objects such as human, animal, vehicle or the like presenting in videos and images. Among methods of detecting objects in videos or images, there is a kind of methods where static image features are employed to create classifiers for discriminating whether objects or non-objects are contained in the videos or images, thereby employing the classifiers to classify the images, i.e., detecting objects in the images, whereas for the videos, the detecting is performed by regarding each frame as an image.

#One of such techniques has been disclosed in Paul Viola and Michael Jones, “Robust Real-time Object Detection”, Second International Workshop On Statistical And Computational Theories Of Vision—Modeling, Learning, Computing, And Sampling, Vancouver, Canada, Jul. 13, 2001. In the technique of Paul Viola et al., differences between pixel sums of rectangular blocks are extracted from images as features, features which are more suitable for discriminating object and non-objects are selected from the extracted features to form weak classifiers through the AdaBoost method, and the weak classifiers are merged to form a strong classifier. This kind of method are suitable for detecting objects such as human face from images, and their robustnesss in detecting objects such as human is not high.

Brief description of the drawings16 figures

#The above and/or other aspects, features and/or advantages of the present invention will be easily understood in view of the following description by referring to the accompanying drawings. In the accompanying drawings, identical or corresponding technical features or components will be represented with identical or corresponding reference numbers. In the accompanying drawings, it is not necessary to present size and relative position of elements in scale.

#FIG. 1 is a block diagram showing the structure of an apparatus for generating a classifier for discriminating object images and non-object images according to an embodiment of the present invention.

#FIG. 2 is a schematic diagram showing examples of layout of areas for a feature.

Detailed description14,146 words

#The embodiments of the present invention are below described by referring to the drawings. It is to be noted that, for purpose of clarity, representations and descriptions about those components and processes known by those skilled in the art but unrelated to the present invention are omitted in the drawings and the description.

#FIG. 1 is a block diagram showing the structure of an apparatus 100 for generating a classifier for discriminating object images and non-object images according to an embodiment of the present invention.

#As shown in FIG. 1, the apparatus 100 comprises a difference calculating unit 102, a feature calculating unit 103 and a training unit 104.

Facts

Application

13/040,912Filed 4 Mar 2011

Priority

CN 2010 1 01200035 Mar 2010

Published

US 2011/0216978 A18 Sep 2011

Granted

5 Nov 2013

Term ends

1 Feb 2032

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment, including 334 days of adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification4 codes

G06V 10/40
Arrangements for image or video recognition or understanding: extraction of image or video features
G06V 10/50
Extraction of image or video features: by performing operations within image blocks; by using histograms, e.g. histogram of oriented gradients…
G06V 10/467
Descriptors for shape, contour or point-related descriptors, e.g. scale invariant feature transform [SIFT] or bags of words [BoW]; Salient…:…
G06V
Image and video recognition

Timeline

5 Mar 2010Priority claimedCN 2010 1 0120003
4 Mar 2011Application filedUS 13/040,912
7 Mar 2011Assigned to Sony Corporationassignment of assignor's interest
8 Sep 2011PublishedUS 2011/0216978 A1
5 Nov 2013GrantedUS 8,577,152 B2
12 Oct 2026TodayWithin its term
1 Feb 2032Term endsEstimated, includes 334 days of adjustment

Method of and apparatus for classifying image

Life of this patent

Method of and apparatus for classifying image

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims16

Description17,845 words

Drawings

Classification4 codes

Life of this patent

Description17,845 words