Camera device and information prompt method for distance measurement

• US 8,842,885 B2
• Filed: 10/07/2008
• Issued: 09/23/2014
• Est. Priority Date: 10/10/2007
• Status: Active Grant

• Current Assignee: Lenovo (Beijing) Limited (Lenovo Group Ltd.)
• Original Assignee: Lenovo (Beijing) Limited (Lenovo Group Ltd.)
• Inventors: Zhu, Honglei, Chi, Hai, Lu, Lu, Wang, Yuancheng
• Primary Examiner(s): Alavi, Amir
• Assistant Examiner(s): CESE, KENNY A
• Application Number:
  US12/246,629
• Publication Number:
  US 20090097716A1
• Time in Patent Office: 2,177 Days
• Field of Search: 382106-118
• US Class Current: 382/106
• CPC Class Codes: G06F 3/012 Head tracking input arrangements
• CPC Class Codes: G06F 3/013 Eye tracking input arrangements G06F3/015 takes precedence
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80
• CPC Class Codes: G06V 40/16 Human faces, e.g. facial parts, sketches or expressions
• CPC Class Codes: G06V 40/171 Local features and components; Facial parts eye characteristics G06V40/18; Occluding parts, e.g. glasses; Geometrical relationships

Abstract

The invention discloses a camera device that contains an image capture module for capturing image data including a user; an information processing module for obtaining human face image data from the image data, and obtaining a distance information between a human face corresponding to the human face image data and the camera device according to the human face image data; a decision module for determining whether the distance corresponding to said distance information is less than a predetermined value, and generating a prompt information while the distance corresponding to said distance information is less than a predetermined value; and a prompt output module for outputting said prompt information based on said distance information, said prompt information is configured to give a prompt to said user. The invention also discloses an information prompt method. The technical solution of the present invention can obtain and output a distance between a human face and the camera device, so as to prevent and prompt that a user is too close to a display screen, and thereby protect eyesight of the user.

Claims

1. A camera device comprising:

an image capture module for capturing image data including a user;

an information processing module for obtaining human face image data from the image data, and

obtaining a distance information between a human face corresponding to the human face image data and the camera device according to the human face image data, wherein the information processing module comprises;

a human face identification module for identifying human face image data in the image data obtained by the image capture module;

a particular area identification module for identifying image data of a human face particular area in the human face image data identified by the human face identification module;

a pixel calculation module for calculating a number of pixels of the image data in the human face particular area identified by the particular area identification module; and

a distance obtaining module for obtaining a distance between a human face and the camera device corresponding to the number of the pixels calculated by the pixel calculation module,

according to a predetermined corresponding relationship between the number of pixels of the image data in the human face particular area as well as the distance between the human face and the camera device;

a decision module for determining whether the distance corresponding to said distance information is less than a predetermined value, and generating a prompt information while the distance corresponding to said distance information is less than a predetermined value; and

a prompt output module for outputting said prompt information based on said distance information, said prompt information is configured to give a prompt to said user;

wherein the particular area identification module is a pupil identification module for identifying image data between the two pupils in the identified human face image data identified by the human face identification module; and

the pixel calculation module is for calculating a number of pixels of the image data between the two pupils identified by the pupil identification module;

characterized in that the calculation formula is;

Distance from Human Face to Camera Device=(Number of Pixels−

Reference Number of Pixels)×

Coefficient+Reference Distance+Corrected Value.

2. The camera device according to claim 1, characterized in that said prompt information is a voice prompt information, the prompt output module is a voice prompt module for outputting the voice prompt information.

3. The camera device according to claim 1, characterized in that said prompt information is a display prompt information, the prompt output module is an information display module connected to a display screen for outputting said display prompt information to the display screen.

4. The camera device according to claim 1, characterized in that the information processing module further comprises:

a setting module connected to the distance obtaining module, for pre-storing or modifying a corresponding relationship between the predetermined number of the pixels of the image data in the human face particular area and the distance between the human face and the camera device.

5. The camera device according to claim 1, characterized in that the distance obtaining module includes a lookup module for looking up a pre-stored distance between the human face and the camera device corresponding to the number of the pixels calculated by the pixel calculation module.

6. The camera device according to, claim 1 characterized in that the distance obtaining module includes a calculation module for calculating a distance between the human face and the camera device corresponding to the number of the pixels calculated by the pixel calculation module, according to a predetermined calculation formula.

7. An information prompt method, comprising:

image capture step of capturing image data including a user by a camera device;

information processing step of obtaining human face image data from the image data and obtaining a distance information between a human face corresponding to the human face image data and the camera device according to the human face image data, wherein the information processing step comprises;

human face identification step of identifying human face image data in the image data obtained in the image capture step;

particular area identification step of identifying image data of a human face particular area in the human face image data identified in the human face identification step;

pixel calculation step of calculating a number of pixels of the image data in the human face particular area identified in the particular area identification step; and

distance obtaining step of obtaining a distance between a human face and the camera device corresponding to the number of the pixels calculated in the pixel calculation step, according to a predetermined corresponding relationship between the number of pixels of the image data in the human face particular area as well as the distance between the human face and the camera device;

decision step of determining whether the distance corresponding to said distance information is less than a predetermined value and generating a prompt information while the distance corresponding to said distance information is less than a predetermined value; and

prompt output step of outputting said prompt information based on said distance information, said prompt information is configured to give a prompt to said user;

wherein the particular area identification step is a pupil identification step of identifying image data between the two pupils in the identified human face image data identified in the human face identification step; and

the pixel calculation step is for calculating a number of pixels of the image data between the two pupils identified in the pupil identification step;

characterized in that the calculation formula is;

Distance between Human Face and Camera Device=(Number of Pixels−

Reference Number of Pixels)×

Coefficient+Reference Distance+Corrected Value.

8. The information prompt method according to claim 7, characterized in that said prompt information is voice prompt information, and the voice prompt information is outputted in the prompt output step.

9. The information prompt method according to claim 7, characterized in that said prompt information is display prompt information, and the display prompt information is outputted in the prompt output step to a display screen.

10. The information prompt method according to claim 7, characterized in that the information processing step further comprises:

setting step of pre-storing or modifying a corresponding relationship between the predetermined number of the pixels of the image data in the human face particular area and the distance between the human face and the camera device.

11. The information prompt method according to claim 7, characterized in that the distance obtaining step includes a lookup step of looking up a pre-stored distance between the human face and the camera device corresponding to the number of the pixels calculated in the pixel calculation step.

12. The information prompt method according to, claim 7 characterized in that the distance obtaining step includes a calculation step of calculating a distance between the human face and the camera device corresponding to the number of the pixels calculated in the pixel calculation step, according to a predetermined calculation formula.