IMAGE-CAPTURING APPARATUS AND METHOD, EXPRESSION EVALUATION APPARATUS, AND PROGRAM

• US 20110216217A1
• Filed: 05/17/2011
• Published: 09/08/2011
• Est. Priority Date: 08/02/2006
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Ogawa, Kaname
• Granted Patent: US 8,416,999 B2
• Time in Patent Office: Days
• US Class Current: 348/222.1
• CPC Class Codes: G06F 18/2132 based on discrimination criteria, e.g. discriminant analysis
• CPC Class Codes: G06V 10/7715 Feature extraction, e.g. by transforming the feature space, e.g. multi-dimensional scaling [MDS]; Mappings, e.g. subspace methods
• CPC Class Codes: G06V 40/175 Static expression
• CPC Class Codes: H04N 23/61 based on recognised objects
• CPC Class Codes: H04N 23/611 where the recognised objects include parts of the human body
• CPC Class Codes: H04N 23/633 for displaying additional information relating to control or operation of the camera

Abstract

An image-capturing apparatus for capturing an image by using a solid-state image-capturing device may include a face detector configured to detect a face of a human being on the basis of an image signal in a period until an image signal obtained by image capturing is recorded on a recording medium; an expression evaluation section configured to evaluate the expression of the detected face and to compute an expression evaluation value indicating the degree to which the detected face is close to a specific expression in relation to expressions other than the specific expression; and a notification section configured to notify notification information corresponding to the computed expression evaluation value to an image-captured person.

Claims

1. An image-capturing apparatus for capturing an image by using a solid-state image-capturing device, the image-capturing apparatus comprising:

a face detector configured to detect a face of a human being on the basis of an image signal in a period until an image signal obtained by image capturing is recorded on a recording medium;

an expression evaluation section configured to evaluate the expression of the detected face and to compute an expression evaluation value indicating the degree to which the detected face is close to a specific expression in relation to expressions other than the specific expression; and

a notification section configured to notify notification information corresponding to the computed expression evaluation value to an image-captured person,

wherein the expression evaluation section has prestored therein information on a determination axis obtained by performing linear discriminant analysis on the basis of a group of sample images of faces each corresponding to one of the specific expression and expressions other than the specific expression, and computes the expression evaluation value on the basis of the magnitude of projection components of a vector based on an image signal of the face detected by the face detector with respect to a vector on the determination axis.

2. The image-capturing apparatus according to claim 1, wherein the determination axis is computed on the basis of data such that data of a vector based on the sample images is dimension-compressed by principal component analysis.

3. The image-capturing apparatus according to claim 2, wherein the expression evaluation section has prestored therein data of a vector in the determination axis as data of a vector having a dimension before being dimension-compressed, and computes the expression evaluation value by computing an inner product of the vector having a dimension before being dimension-compressed and a vector based on an image signal of the face detected by the face detector.

4. The image-capturing apparatus according to claim 2, wherein the expression evaluation section normalizes the image signal of the face detected by the face detector to an image size of the sample image used when the determination axis was determined, and computes the expression evaluation value by using the image signal after the normalization.

5. The image-capturing apparatus according to claim 4, wherein the expression evaluation section performs, on the image signal after the normalization, a masking process for masking a signal in an image region that substantially does not exert an influence on expression determination, and computes the expression evaluation value by using the image signal after the masking process.