Signal processing apparatus, signal processing method and computer readable medium

• US 20090252389A1
• Filed: 04/01/2009
• Published: 10/08/2009
• Est. Priority Date: 04/02/2008
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Yamaguchi, Hiroshi
• Granted Patent: US 9,097,589 B2
• Time in Patent Office: Days
• US Class Current: 382/128
• CPC Class Codes: A61B 1/000094 extracting biological structures
• CPC Class Codes: A61B 1/0638 providing two or more wavelengths
• CPC Class Codes: A61B 1/0655 Control therefor
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/441 Skin evaluation, e.g. for skin disorder diagnosis
• CPC Class Codes: G01J 3/51 using colour filters
• CPC Class Codes: G01J 3/513 having fixed filter-detector pairs

Abstract

A signal processing apparatus includes an optical intensity detecting section that detects an intensity of light from a subject at a first wavelength and a second wavelength, where the first wavelength is different from the second wavelength, a pigment component identifying section that identifies a pigment component in the light from the subject, based on (i) a difference between a first absorptance of the subject at the first wavelength and a second absorptance of the subject at the second wavelength and (ii) a difference between the intensity at the first wavelength and the intensity at the second wavelength that are detected by the optical intensity detecting section, and an illumination light component identifying section that identifies an illumination light component in the light from the subject, based on a subject image obtained by image-capturing the subject and the pigment component identified by the pigment component identifying section.

Claims

1. A signal processing apparatus for separating light from a specified subject into an illumination light component and a pigment component, the illumination light component resulting from a color of light with which the subject is irradiated, the pigment component resulting from a color of a pigment of the subject, the signal processing apparatus comprising:

an optical intensity detecting section that detects an intensity of the light from the subject at a first wavelength and a second wavelength, the first wavelength being different from the second wavelength;

a pigment component identifying section that identifies the pigment component in the light from the subject, based on (i) a difference between a first absorptance of the subject at the first wavelength and a second absorptance of the subject at the second wavelength and (ii) a difference between the intensity at the first wavelength and the intensity at the second wavelength that are detected by the optical intensity detecting section; and

an illumination light component identifying section that identifies the illumination light component in the light from the subject, based on a subject image obtained by image-capturing the subject and the pigment component identified by the pigment component identifying section.

2. The signal processing apparatus as set forth in claim 1, wherein

the optical intensity detecting section detects the intensity of the light from the subject at the first wavelength, at which a light absorption characteristic of the subject takes a minimal value and at the second wavelength, at which the light absorption characteristic of the subject takes a maximal value.

3. The signal processing apparatus as set forth in claim 2, further comprising

a subject information storing section that stores color information of the subject in association with (i) the difference between the first absorptance and the second absorptance of the subject and (ii) the difference between the detected intensity at the first wavelength and the detected intensity at the second wavelength, wherein

the pigment component identifying section identifies the pigment component in the light from the subject, based on the color information stored in the subject information storing section.

4. The signal processing apparatus as set forth in claim 3, wherein

the optical intensity detecting section detects the intensity of the light from the subject at the first and second wavelengths in each of partial regions obtained by dividing the subject image,

the pigment component identifying section identifies the pigment component in the light from the subject in each of the partial regions, and

the illumination light component identifying section identifies the illumination light component in the light from the subject in each of the partial regions.

5. The signal processing apparatus as set forth in claim 4, further comprising

an illumination light image generating section that generates an image of the illumination light component identified by the illumination light component identifying section, by subtracting color information of the pigment component identified by the pigment component identifying section from color information of the subject image obtained by image-capturing the subject.

6. The signal processing apparatus as set forth in claim 4, further comprising

an illumination light component enhancing section that enhances, in the subject image obtained by image-capturing the subject, color information of the illumination light component identified by the illumination light component identifying section.

7. The signal processing apparatus as set forth in claim 4, further comprising

a pigment component enhancing section that enhances, in the subject image obtained by image-capturing the subject, color information of the pigment component identified by the pigment component identifying section.

8. A signal processing method for separating light from a specified subject into an illumination light component and a pigment component, the illumination light component resulting from a color of light with which the subject is irradiated, the pigment component resulting from a color of a pigment of the subject, the signal processing method comprising:

detecting an intensity of the light from the subject at a first wavelength and a second wavelength, the first wavelength being different from the second wavelength;

identifying the pigment component in the light from the subject, based on (i) a difference between a first absorptance of the subject at the first wavelength and a second absorptance of the subject at the second wavelength and (ii) a difference between the intensity at the first wavelength and the intensity at the second wavelength that are detected in the intensity detecting; and

identifying the illumination light component in the light from the subject, based on a subject image obtained by image-capturing the subject and the pigment component identified in the pigment component identifying.

9. A computer readable medium storing thereon a program for use with a signal processing apparatus that separates light from a specified subject into an illumination light component and a pigment component, the illumination light component resulting from a color of light with which the subject is irradiated, the pigment component resulting from a color of a pigment of the subject, the program causing a computer to function as:

an optical intensity detecting section that detects an intensity of the light from the subject at a first wavelength and a second wavelength, the first wavelength being different from the second wavelength;

a pigment component identifying section that identifies the pigment component in the light from the subject, based on (i) a difference between a first absorptance of the subject at the first wavelength and a second absorptance of the subject at the second wavelength and (ii) a difference between the intensity at the first wavelength and the intensity at the second wavelength that are detected by the optical intensity detecting section; and

an illumination light component identifying section that identifies the illumination light component in the light from the subject, based on a subject image obtained by image-capturing the subject and the pigment component identified by the pigment component identifying section.