Image capturing apparatus and image capturing method

Patent metadata

Field	Value
Publication number	US-9232131-B2
Application number	US-201414295209-A
Country	US
Kind code	B2
Filing date	Jun 3, 2014
Priority date	Jun 10, 2013
Publication date	Jan 5, 2016
Grant date	Jan 5, 2016

Abstract

An image capturing apparatus performs rough detection through high-speed focus detection targeting on a face contour portion and then performs focusing through high-precision focus detection targeting on a face-included portion set inside the face contour.

First claim

What is claimed is:

1. An image capturing apparatus comprising:
a focal point adjusting unit configured to perform focal point adjustment based on a contrast evaluation value of a subject generated using an image signal output from an image sensor;
a first area setting unit configured to set a first focal point detection area including a contour portion of the subject for use in focal point detection by use of the image signal output from the image sensor; and
a second area setting unit configured to set a second focal point detection area including a portion inside a contour of the subject and excluding the contour portion,
wherein the focal point adjusting unit includes a mode in which after a first focal point adjustment process is carried out based on a contrast evaluation value of the first focal point detection area, a second focal point adjustment process is carried out based on a contrast evaluation value of the second focal point detection area, and
wherein an amount of step drive of a focus lens in the second focal point adjustment process is smaller than an amount of step drive of the focus lens in the first focal point adjustment process.

2. An image capturing apparatus comprising:
a focal point adjusting unit configured to perform focal point adjustment based on a contrast evaluation value of a subject generated using an image signal output from an image sensor;
a first area setting unit configured to set a first focal point detection area including a contour portion of the subject for use in focal point detection by use of the image signal output from the image sensor; and
a second area setting unit configured to set a second focal point detection area including a portion inside a contour of the subject and excluding the contour portion,
wherein the focal point adjusting unit includes a mode in which after a first focal point adjustment process is carried out based on a contrast evaluation value of the first focal point detection area, a second focal point adjustment process is carried out based on a contrast evaluation value of the second focal point detection area, and
wherein a driving speed of a focus lens in the second focal point adjustment process is lower than a driving speed of the focus lens in the first focal point adjustment process.

3. An image capturing apparatus comprising:
a focal point adjusting unit configured to perform focal point adjustment based on a contrast evaluation value of a subject generated using an image signal output from an image sensor;
a first area setting unit configured to set a first focal point detection area including a contour portion of the subject for use in focal point detection by use of the image signal output from the image sensor; and
a second area setting unit configured to set a second focal point detection area including a portion inside a contour of the subject and excluding the contour portion,
wherein the focal point adjusting unit includes a mode in which after a first focal point adjustment process is carried out based on a contrast evaluation value of the first focal point detection area, a second focal point adjustment process is carried out based on a contrast evaluation value of the second focal point detection area, and
wherein the first focal point detection area is smaller than the second focal point detection area.

4. The image capturing apparatus according to claim 1 , wherein each of the first focal point detection area and the second focal point detection area is selected from a plurality of focal point detection areas arranged in advance in a lattice-like pattern.

5. An image capturing apparatus comprising:
a focal point adjusting unit configured to perform focal point adjustment based on a contrast evaluation value of a subject generated using an image signal output from an image sensor;
a first area setting unit configured to set a first focal point detection area including a contour portion of the subject for use in focal point detection by use of the image signal output from the image sensor; and
a second area setting unit configured to set a second focal point detection area including a portion inside a contour of the subject and excluding the contour portion,
wherein the focal point adjusting unit includes a mode in which after a first focal point adjustment process is carried out based on a contrast evaluation value of the first focal point detection area, a second focal point adjustment process is carried out based on a contrast evaluation value of the second focal point detection area, and
wherein if an index value for changing a driving speed of a focus lens that is calculated using the image signal is larger than a predetermined threshold value, the first focal point adjustment process is switched to the second focal point adjustment process.

6. The image capturing apparatus according to claim 1 , wherein the contour of the subject is a contour of a face of the subject, and the portion inside the contour of the subject is a portion inside the contour of the face.

7. The image capturing apparatus according to claim 1 , wherein the contour of the subject is a contour of at least one body site, and the portion inside the contour of the subject is a portion inside the contour of the body site.

8. An image capturing method comprising:
performing focal point adjustment based on a contrast evaluation value of a subject generated using an image signal output from an image sensor;
first area setting to set a first focal point detection area including a contour portion of the subject for use in focal point detection by use of the image signal output from the image sensor; and
second area setting to set a second focal point detection area including a portion inside a contour of the subject and excluding the contour portion,
wherein the focal point adjusting unit includes a mode in which after a first focal point adjustment process is carried out based on a contrast evaluation value of the first focal point detection area, a second focal point adjustment process is carried out based on a contrast evaluation value of the second focal point detection area, and
wherein an amount of step drive of a focus lens in the second focal point adjustment process is smaller than an amount of step drive of the focus lens in the first focal point adjustment process.

9. An image capturing method comprising:
performing focal point adjustment based on a contrast evaluation value of a subject generated using an image signal output from an image sensor;
first area setting to set a first focal point detection area including a contour portion of the subject for use in focal point detection by use of the image signal output from the image sensor; and
second area setting to set a second focal point detection area including a portion inside a contour of the subject and excluding the contour portion,
wherein the focal point adjusting unit includes a mode in which after a first focal point adjustment process is carried out based on a contrast evaluation value of the first focal point detection area, a second focal point adjustment process is carried out based on a contrast evaluation value of the second focal point detection area, and
wherein a driving speed of a focus lens in the second focal point adjustment process is lower than a driving speed of the focus lens in the first focal point adjustment process.

10. An image capturing method comprising:
performing focal point adjustment based on a contrast evaluation value of a subject generated using an image signal output from an image sensor;
first area setting to set a first focal point detection area including a contour portion of the subject for use in focal point detection by use o

Assignees

• Canon Kk

Inventors

• Kawarada Masahiro

Classifications

• H04N23/635

  Region indicators; Field of view indicators · CPC title

• H04N23/61

  based on recognised objects · CPC title

• H04N23/673 Primary

  based on contrast or high frequency components of image signals, e.g. hill climbing method · CPC title

• H04N5/23212 Primary

  Electricity · mapped topic