Image processing system, image capturing apparatus and system and method for detecting backlight status

• US 7,304,682 B2
• Filed: 12/27/2002
• Issued: 12/04/2007
• Est. Priority Date: 01/07/2002
• Status: Expired due to Fees

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Sugimoto, Masahiko, Fukuda, Hiroshi, Ishihara, Atsuhiko, Sakamoto, Koichi, Nihei, Kaname, Takemura, Kazuhiko
• Primary Examiner(s): Ometz; David
• Assistant Examiner(s): Tran; Nhan T.
• Application Number:
  US10/329,335
• Publication Number:
  US 20030128281A1
• Time in Patent Office: 1,803 Days
• Field of Search: 348/239, 348/362, 348/370
• US Class Current: 348/362
• CPC Class Codes: G06T 5/94 based on local image properties, e.g. for local contrast enhancement
• CPC Class Codes: G06T 7/194 involving foreground-background segmentation
• CPC Class Codes: H04N 23/71 Circuitry for evaluating the brightness variation
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means
• CPC Class Codes: H04N 23/76 by influencing the image signals

Abstract

An image processing system for properly correcting brightness of a subject area and a background area of a captured image. The image processing system includes an image capturing apparatus, including: an image capturing instruction unit for generating a first instruction signal and a second instruction signal for instructing a capturing of the subject; and an image pick-up unit for capturing a first image of the subject in response to the first instruction signal, and a second image of the subject in response to the second instruction signal. The image processing system also includes an image processing apparatus, including: a backlight status detector for detecting backlight status based on the first image and the second image; and a correction unit for correcting the second image when the backlight status detector detects the backlight status.

Claims

1. An image processing system comprising:

an image capturing apparatus for capturing an image of a subject, comprising;

an image capturing instruction unit for generating a first instruction signal and a second instruction signal for instructing capturing of the subject;

an image pick-up unit for capturing a first image of the subject in response to the first instruction signal, and a second image of the subject in response to the second instruction signal; and

a backlight status detector for detecting backlight status based on the first image and the second image; and

an image processing apparatus for performing image processing on the image captured by said image capturing apparatus, comprising;

a correction unit for correcting the second image when said backlight status detector detects the backlight status;

wherein said image capturing apparatus further comprises a extracting unit for extracting a second subject area which is an area indicating the subject and a second background area which is an area indicating a background of the subject,

wherein said correction unit corrects brightness of the second subject area based on a first table which stores a correlation between brightness before the correction and brightness after the correction, and corrects brightness of the second background area based on a second table which stores a correlation between brightness before the correction and brightness after the correction, the second table being different from the first table.

3. The image processing system as claimed in claim 1 or claim 2, wherein said image capturing apparatus further comprises a storing unit for associating the second image and detecting result of the backlight status detected by said backlight status detector and storing the second image and the detecting result.

4. The image processing system as claimed in claim 1 or in claim 2, wherein said image capturing apparatus further comprises an electric flash for flashing light in response to the second instruction signal.

5. The image processing system as claimed in claim 3, wherein

said image capturing apparatus further comprises an electric flash for flashing light in response to the second instruction signal,

said extracting unit further extracts a first subject area which is an area corresponding to the second subject area, and a first background area which is an area corresponding to the second background area from the first image, and

when a brightness of the first subject area is lower than that of the first background area by a first predetermined value, and a brightness of the second subject area is higher than that of the first subject area by a second predetermined value, said backlight status detector judges such the status as the backlight status.

6. The image processing system as claimed in claim 5, wherein said correction unit heightens the brightness of the second subject area when said backlight status detector detects the backlight status and the brightness of the second subject area is lower than a third predetermined value.

7. The image processing system as claimed in claim 6, wherein

said image capturing apparatus further includes an electric flash for flashing light in response to the second instruction signal, and

said correction unit lowers brightness of the second subject area when the brightness of the second subject area is higher than a fourth predetermined value.

2. An image processing system comprising:

an image capturing apparatus for capturing an image of a subject, comprising;

an image capturing instruction unit for generating a first instruction signal and a second instruction signal for instructing capturing of the subject;

an image pick-up unit for capturing a first image of the subject in response to the first instruction signal, and a second image of the subject in response to the second instruction signal; and

a backlight status detector for detecting backlight status based on the first image and the second image; and

an image processing apparatus for performing image processing on the image captured by said image capturing apparatus, comprising;

a correction unit for correcting the second image when said backlight status detector detects the backlight status;

wherein said image capturing apparatus further comprises a extracting unit for extracting a second subject area which is an area indicating the subject and a second background area which is an area indicating a background of the subject;

wherein said extracting unit further extracts the first background area, which is an area corresponding to the second background area, from the first image, and

said correction unit generates a composite image based on the second subject area and the first background area when said backlight status detector detects the backlight status.