Image pick-up apparatus with a shake reducing function

• US 8,305,465 B2
• Filed: 05/28/2009
• Issued: 11/06/2012
• Est. Priority Date: 06/17/2005
• Status: Active Grant

• Current Assignee: Casio Computer Company Limited
• Original Assignee: Casio Computer Company Limited
• Inventors: Yuyama, Masami, Matsunaga, Tsuyoshi, Kato, Yoshiyuki, Tsukagoshi, Takeshi, Onozawa, Masaru, Sakamoto, Shohei
• Primary Examiner(s): Moe, Aung S
• Assistant Examiner(s): Dagnew, Mekonnen
• Application Number:
  US12/473,537
• Publication Number:
  US 20090231448A1
• Time in Patent Office: 1,258 Days
• Field of Search: 348/240.2, 348/240.1, 348/234, 348273-283, 348/308, 348/208.6, 348/216.1, 348/208.2, 348/220.1, 348/441, 348/240.3, 348/369, 396121-123, 396/60, 396 72- 88, 250/208.1, 359/354, 359/676
• US Class Current: 348/240.1
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/684 performed by controlling the image sensor readout, e.g. by controlling the integration time
• CPC Class Codes: H04N 23/71 Circuitry for evaluating the brightness variation
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: H04N 23/76 by influencing the image signals
• CPC Class Codes: H04N 23/815 for controlling the resolution by using a single image
• CPC Class Codes: H04N 23/843 Demosaicing, e.g. interpolating colour pixel values
• CPC Class Codes: H04N 25/134 based on three different wavelength filter elements
• CPC Class Codes: H04N 25/46 by combining or binning pixels

Abstract

When a hand shake reducing mode has been set for shooting a subject, an exposure is controlled in accordance with a program diagram (solid line) B for the shake reducing mode, which is different from a program diagram (broken line) A for a normal mode. In a state where a shutter speed is set to less than “ 1/80”, two-pixel addition and/or four-pixel addition is executed on an imaging signal to amplify subject luminance, raising ISO sensitivity. A shutter speed set to fall in a high speed range reduces deterioration in image quality due to hand shake and/or subject movement during a shooting operation.

Claims

1. An image pick-up apparatus comprising:

a pixel adding unit which generates a pixel addition image by executing a pixel addition process for an image shot by an image pick-up element;

a luminance obtaining unit which obtains a subject luminance;

a pixel addition ratio changing unit which changes a pixel addition ratio of the pixel addition process by the pixel adding unit from a ratio of 1 to a ratio other than 1, in accordance with the subject luminance obtained by the luminance obtaining unit;

a size setting unit which sets a pixel size at a time of image recording to a pixel size designated by a user;

an enlarging unit which enlarges a pixel size of the pixel addition image generated by the pixel adding unit in accordance with a predetermined enlarging ratio, when the pixel addition ratio is changed to a ratio other than 1 by the pixel addition ratio changing unit; and

an enlarging ratio changing unit which changes the predetermined enlarging ratio to an enlarging ratio at which the pixel size of the pixel addition image is enlarged to the pixel size set by the size setting unit, when the pixel addition ratio is changed to a plurality of ratios other than 1 by the pixel addition ratio changing unit.

2. The image pick-up apparatus according to claim 1, wherein the enlarging ratio changed by the enlarging ratio changing unit includes an enlarging ratio of not larger than “

1”

(excluding “

0”

).

3. The image pick-up apparatus according to claim 1, wherein the enlarging unit enlarges the shot image separately in vertical and horizontal directions, and the enlarging ratio changing unit changes enlarging ratios separately of the vertical and horizontal directions of the enlarging unit.

4. An image processing method for an image pick-up apparatus which records an image for which a pixel addition process is executed, the method comprising:

generating a pixel addition image by executing a pixel addition process for an image shot by an image pick-up element;

obtaining a subject luminance;

changing a pixel addition ratio of the pixel addition process from a ratio of 1 to a ratio other than 1, in accordance with the obtained subject luminance;

setting a pixel size at a time of image recording to a pixel size designated by a user;

enlarging a pixel size of the generated pixel addition image in accordance with a predetermined enlarging ratio, when the pixel addition ratio is changed to the ratio other than 1; and

changing the predetermined enlarging ratio to an enlarging ratio at which the pixel size of the pixel addition image is enlarged to the set pixel size, when the pixel addition ratio is changed to a plurality of ratios other than 1.