Imaging apparatus having an image correction function and method for controlling the same

• US 8,471,935 B2
• Filed: 09/28/2009
• Issued: 06/25/2013
• Est. Priority Date: 09/29/2008
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kosaka, Takashi
• Primary Examiner(s): Hernndez Hernndez, Nelson D.
• Assistant Examiner(s): HOGUE, DENNIS A
• Application Number:
  US12/568,647
• Publication Number:
  US 20100079617A1
• Time in Patent Office: 1,366 Days
• Field of Search: 348/207.99, 348/208.99, 348/221.1, 348/222.1, 348/255, 348362-368, 348/229.1, 348/251, 396/153, 396213-262, 382/274, 382270-273, 358/461, 358/446, 358/521, 250/214.AG
• US Class Current: 348/255
• CPC Class Codes: H04N 23/611 where the recognised objects include parts of the human body
• CPC Class Codes: H04N 23/71 Circuitry for evaluating the brightness variation
• CPC Class Codes: H04N 23/76 by influencing the image signals

Abstract

An imaging apparatus includes an image sensor configured to capture an object image, a selection unit configured to automatically select a sensitivity of the image sensor from a predetermined selectable range, and an image processing unit configured to execute correction processing in which a signal of an image captured by the image sensor which has the sensitivity selected by the selection unit is amplified. When the image processing unit is set to execute the correction processing, the selection unit sets an upper limit of the selectable range lower, compared with the upper limit thereof when the image processing unit is not set to execute the correction processing.

Claims

1. An imaging apparatus comprising:

an image sensor configured to capture an object image;

a selection unit configured to automatically select a sensitivity of the image sensor from a predetermined selectable range; and

an image processing unit configured to execute correction processing for correcting a decrease in marginal illumination based on a lens used when capturing the object image in which a signal of a part of an image captured by the image sensor which has the sensitivity selected by the selection unit is amplified,

wherein, when the image processing unit performs correction processing for correcting the decrease in marginal illumination based on the lens, the selection unit sets an upper limit of the selectable range lower, compared with the upper limit thereof when the image processing unit performs correction processing for correcting distortion based on the lens.

2. The imaging apparatus according to claim 1, wherein, when the image processing unit performs the correction processing for correcting the decrease in marginal illumination based on the lens, the selection unit sets the selectable range narrower, compared with the selectable range when the image processing unit performs the correction processing for correcting distortion based on the lens.

3. The imaging apparatus according to claim 1, wherein the correction processing is a correction of luminance of a part of captured image.

4. The imaging apparatus according to claim 1, wherein the correction processing is a correction of decrease in marginal illumination executed on image data output from the image sensor based on information about marginal illumination of an imaging optical system.

5. The imaging apparatus according to claim 1 further comprising a face detection unit configured to detect a human face area from image data output from the image sensor,

wherein the image processing unit corrects the face area of the image data to set luminance of the face area to be at an appropriate level.

6. An imaging apparatus comprising:

an image sensor configured to capture an object image;

a selection unit configured to automatically select a sensitivity of the image sensor from a first selectable range;

an image processing unit configured to execute correction processing based on the lens used when capturing the object image in which a signal of a part of an image captured by the image sensor which has the sensitivity selected by the selection unit is amplified; and

a warning unit configured to issue a warning when the image processing unit performs correction processing for correcting a decrease in marginal illumination based on the lens and the sensitivity selected by the selection unit exceeds an upper limit of a second selectable range, which is set lower than an upper limit of the first selectable range.

7. A method for capturing an image comprising:

automatically selecting a sensitivity of an image sensor configured to capture an object image from a predetermined selectable range; and

executing correction processing to correct a decrease in marginal illumination based on a lens used when capturing the object image in which a signal of a part of an image captured by the image sensor which has the selected sensitivity is amplified,

wherein, when the selection is made and the correction processing is performed to correct the decrease in marginal illumination based on the lens, an upper limit of the selectable range is set lower, compared with the upper limit thereof when correction processing for correcting distortion based on the lens is performed.

8. A method for capturing an image comprising:

automatically selecting a sensitivity of an image sensor configured to capture an object image from a first selectable range;

executing correction processing for correcting a decrease in marginal illumination based on a lens used when capturing the object image in which a signal of a part of an image captured by the image sensor which has the selected sensitivity is amplified; and

giving a warning when the correction processing for correcting the decrease in marginal illumination based on the lens in performed and the selected sensitivity exceeds an upper limit of a second selectable range, the upper limit of which is set lower than an upper limit of the first selectable range when correction processing for correcting distortion based on the lens is performed.