Device and method for detecting focus of electronic device

1. An electronic device comprising:

a memory storing instructions;

a display;

a camera; and

at least one processor operatively coupled to the display, the camera, and the memory, the at least one processor configured to execute the instructions to:

display a preview image regarding an image being acquired through the camera;

detect brightness information on a plurality of areas of the preview image;

identify, among the plurality of areas of the preview image, a first area for determining an auto focus (AF) area, based on an attribute of each of the plurality of areas;

identify, among the plurality of areas, at least one area with a second attribute corresponding to a first attribute of the first area; and

display, over the preview image, a second area including the at least one area as the AF area,

wherein the first attribute is regarding first brightness information comprised in the brightness information on the plurality of areas, and

wherein the second attribute is regarding second brightness information comprised in the brightness information on the plurality of areas.

2. The electronic device of claim 1 , wherein the at least one area is disposed on a surrounded area of the first area, and wherein the second area further comprises the first area.

3. An electronic device comprising:

a memory;

a camera;

an input/output module; and

at least one processor operatively coupled to the memory, configured to:

acquire an image through the camera including a first focus detection area while the electronic device is in a first focus state;

display the image on the input/output module;

detect brightness information on a plurality of areas of the image;

detect an input for tracking a subject depicted in the image, wherein the input selects a first area regarding a first attribute in the image in which the subject is depicted;

change the first focus state to a second focus state for tracking the subject in response to the input, wherein the second focus state is associated with a second focus detection area regarding a second attribute; and

change the first focus detection area to a second focus detection area based on the brightness information,

wherein the first attribute is regarding first brightness information comprised in the brightness information on the plurality of areas, and

wherein the second attribute is regarding second brightness information comprised in the brightness information on the plurality of areas.

4. The electronic device of claim 3 , wherein when the electronic device is in the first focus state, the focus detection area is located in a central position of the image.

5. The electronic device of claim 3 , wherein detecting the input for changing the first focus state to the second focus state includes sensing a signal generated by the input/output module and identifying a location of the input based on the signal.

6. The electronic device of claim 3 , wherein the at least one processor is further configured to identify the subject based on the input.

7. The electronic device of claim 3 , wherein the at least one processor is further configured to change the first focus state to the second focus state in response to detecting a sub-sequent input.

8. A method for an electronic device comprising:

displaying a preview image regarding an image being acquired through a camera of the electronic device;

detecting brightness information on a plurality of areas of the preview image;

identifying, among the plurality of areas of the preview image, a first area for determining an auto focus (AF) area, based on an attribute of each of the plurality of areas;

identifying, among the plurality of areas, at least one area with a second attribute corresponding to a first attribute of the first area; and

displaying, over the preview image, a second area including the at least one area as the AF area,

wherein the first attribute is regarding first brightness information comprised in the brightness information on the plurality of areas, and

wherein the second attribute is regarding second brightness information comprised in the brightness information on the plurality of areas.

9. The method of claim 8 , wherein the at least one area is disposed on a surrounded area of the first area, and

wherein the second area further comprises the first area.

10. A method for use in an electronic device, comprising:

acquiring an image including a first focus detection area while the electronic device is in a first focus state;

displaying the image on a display of the electronic device;

detecting brightness information on a plurality of areas of the image;

detecting an input for tracking a subject depicted in the image, wherein the input selects a first area regarding a first attribute in the image in which the subject is depicted;

changing the first focus state to a second focus state for tracking the subject in response to the input, wherein the second focus state is associated with a second focus detection area regarding a second attribute; and

changing the first focus detection area to a second focus detection area based on the brightness information associated with the area,

wherein the first attribute is regarding first brightness information comprised in the brightness information on the plurality of areas, and

wherein the second attribute is regarding second brightness information comprised in the brightness information on the plurality of areas.

11. The method of claim 10 , wherein when the electronic device is in the first focus state, the focus detection area is located in a central position of the image.

12. The method of claim 10 , wherein detecting the input for changing the first focus state to the second focus state includes sensing a signal generated by an input/output module of the electronic device and identifying a location of the input based on the signal.

13. The method of claim 10 , further comprising moving the focus detection area in accordance with movement of the subject while the electronic device is in the second focus state.

14. The method of claim 10 , further comprising changing the first focus state to the second focus state in response to detecting a subsequent input.