Electronic camera which detects flash influence on an image and controls white balance in accordance with the flash influence

• US 7,148,922 B2
• Filed: 08/01/2002
• Issued: 12/12/2006
• Est. Priority Date: 08/02/2001
• Status: Expired due to Fees

• Current Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Original Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Inventors: Shimada, Yoshinao
• Primary Examiner(s): GILES, NICHOLAS G
• Application Number:
  US10/210,234
• Publication Number:
  US 20030025822A1
• Time in Patent Office: 1,594 Days
• Field of Search: 348/224.1, 348/223.1, 348/370, 348/371
• US Class Current: 348/224.1
• CPC Class Codes: H04N 23/88 for colour balance, e.g. white-balance circuits or colour temperature control

Abstract

There is disclosed a constitution in which an area with strobe light rays dominant therein, which corresponds to strobe light dominant area, is extracted in accordance with various extraction conditions, and a white balance adjustment suitable for a property of the area is set in order to enhance a result of an indoor strobe photographing. Moreover, it is judged whether or not correction is appropriate for each white balance area in accordance with a result of evaluation exposure of a steady light amount.

Claims

1. An electronic camera for electrically photographing a subject, comprising:

an illuminating unit configured to illuminate the subject with preliminary light rays, and to illuminate the subject with main light rays for actual exposure after illumination by the preliminary light rays;

an exposure control section configured to control an exposure of an image of the subject illuminated with the preliminary light rays to generate preliminary light image data, and to control an exposure of an image of the subject illuminated with the main light rays to generate main image data;

an extracting section configured to extract first block areas from the preliminary image data such that the first block areas correspond to a part of the subject which is mainly illuminated with the preliminary light rays in the preliminary image data; and

a setting section configured to set a first white balance adjustment which is applied to second block areas in the main image data that correspond to the first block areas in the preliminary image data;

wherein the first white balance is set before the exposure of the image of the subject illuminated with the main light rays, and a white balance of the second block areas in the main image data is adjusted in accordance with the first white balance adjustment.

2. The electronic camera according to claim 1, wherein said setting section further sets a second white balance adjustment different from said first white balance adjustment with respect to a remaining area of the main image data other than the second block areas.

3. The electronic camera according to claim 1, wherein the first block areas are extracted so as to satisfy a predetermined condition determined from the preliminary image data.

4. The electronic camera according to claim 1, wherein the exposure control section calculates an average value of predetermined block areas in the preliminary image data and the first block areas are extracted based on the average value and the preliminary image data.

5. An electronic camera for electrically photographing a subject in an environment illuminated by steady light rays, comprising:

an illuminating unit configured to illuminate the subject with preliminary light rays, and to illuminate the subject with main light rays for actual exposure after illumination by the preliminary light rays;

an exposure control section configured to control an exposure of an image of the subject illuminated with the preliminary light rays to generate preliminary image data, and to control an exposure of an image of the subject illuminated with the main light rays to generate main image data, said preliminary image data including first block areas corresponding to a part of the subject which is mainly illuminated with the preliminary light rays and a first remaining area corresponding to a remaining part of the subject which is mainly illuminated with the steady light rays, and said main image data including second block areas corresponding to the first block areas and a second remaining area corresponding the first remaining area;

an extracting section configured to extract the first block areas from the preliminary image data; and

a setting section configured to set the exposure control section in a first white balance adjustment mode after the extraction of the first block areas, in which the exposure control section applies a first white balance adjustment to the second block areas and a second white balance adjustment to the second remaining area.

6. The electronic camera according to claim 5, wherein said exposure control section controls an exposure of an image of the subject in which the subject is illuminated by the steady light rays and not preliminary light rays and no main light rays to acquire steady light image data, and said exposure control section calculates a target light illumination amount for an actual exposure period for causing the subject to be illuminated with the main light rays for the actual exposure, based on the steady light image data and the preliminary image data, and the first block areas are extracted based on the steady light image data and the target light illuminating amount for the actual exposure period.

7. The electronic camera according to claim 5, wherein the first block areas are extracted so as to satisfy a predetermined condition determined from the preliminary image data.

8. The electronic camera according to claim 5, wherein the exposure control section calculates an average value of predetermined block areas in the preliminary image data and the first block areas are extracted based on the average value and the preliminary image data.

9. An electronic camera for electronically photographing a subject in an environment illuminated by steady light rays, comprising:

an illuminating unit configured to illuminate the subject with preliminary light rays, and to illuminate the subject with main light rays for actual exposure after illumination by the preliminary light rays;

an exposure control section configured to control an exposure of an image of the subject illuminated with the preliminary light rays to generate preliminary image data, and to control an exposure of an image of the subject illuminated with the main light rays to generate main image data, said preliminary image data including first block areas corresponding to a part of the subject which is mainly illuminated with the preliminary light rays and a first remaining area corresponding to a remaining part of the subject which is mainly illuminated with the steady light rays, and said main image data including second block areas corresponding to the first block areas and a second remaining area corresponding the first remaining area;

an extracting section configured to extract the first block areas from the preliminary image data;

a counting section configured to count a number of the extracted first block areas;

a setting section configured to set the exposure control section in a first white balance adjustment mode if the number of the extracted first block areas is not less than a predetermined value, and to set the exposure control section in a second white balance adjustment mode if the number of the extracted first block areas is less than the predetermined value;

wherein in the first white balance adjustment mode the exposure control section applies a first white balance adjustment to the second block areas and applies a second white balance adjustment to the second remaining area, and in the second white balance adjustment mode the exposure control section applies the second white balance adjustment to both the second block areas and the second remaining area.

10. The electronic camera according to claim 9, wherein the first block areas are extracted so as to satisfy a predetermined condition determined from the preliminary image data.

11. The electronic camera according to claim 9, wherein the exposure control section calculates an average value of predetermined block areas in the preliminary image data and the first block areas are extracted based on the average value and the preliminary image data.

12. The electronic camera according to claim 11, wherein said exposure control section controls an exposure of an image of the subject in which the subject is illuminated by the steady light rays and not preliminary light rays and no main light rays to acquire steady light image data, and said exposure control section calculates a target light illumination amount for an actual exposure period for causing the subject to be illuminated with the main light rays for the actual exposure, based on the steady light image data and the preliminary image data, and the first block areas are extracted based on the steady light image data and the target light illuminating amount for the actual exposure period.