Image capturing device and method for adjusting a position of a lens of the image capturing device
A method for adjusting a position of a lens of an image capturing device obtains a plurality of images of a monitored scene by the lens, detects a motion area in the monitored scene, and detects if a human face is in the motion area. The method further moves the lens according to movement data of the human face if the human face is detected, or moves the lens according to movement data of the motion area if the human face is not detected.
1. An image capturing device, comprising:
a lens operable to obtain a plurality of images of a monitored scene;
a motion area detection module operable to detect a motion area in the monitored scene;
a face detection module operable to detect a human face in the motion area; and
a lens adjustment module operable to move the lens according to movement data of the human face if the human face is detected, or move the lens according to movement data of the motion area if the human face is not detected.
2. The image capturing device according to claim 1 , wherein the motion area detection module detects the motion area in the monitored scene by:
obtaining a first image of the monitored scene at a first time from the plurality of images, and calculating characteristic values of the first image;
obtaining a second image of the monitored scene at a second time continuous with the first time, and calculating the characteristic values of the second image;
matching the first image and the second image via an autocorrelation of the characteristic values of the first image and the second image, to obtain a corresponding area in both of the first image and the second image; and
comparing the characteristic values of the corresponding area in both of the first image and the second image, to obtain a motion area of the monitored scene, with different characteristic values of the corresponding area in the first image and the second image.
3. The image capturing device according to claim 1 , wherein the movement data comprises a movement direction, a movement angle, and a movement distance.
4. The image capturing device according to claim 3 , wherein the lens adjustment module moves the lens according to movement data of the human face if the human face is detected, or moves the lens according to movement data of the motion area if the human face is not detected by:
moving the lens according to the movement data of the human face to focus the lens on the human face if the human face is detected, and zooming in a focal length of the lens; or
moving the lens according to the movement data of the motion area to focus the lens on the motion area if the human face is not detected, and zooming in the focal length of the lens.
5. A method for adjusting a position of a lens of an image capturing device, comprising:
obtaining a plurality of images of a monitored scene by the lens;
detecting a motion area in the monitored scene;
detecting if a human face is in the motion area; and
moving the lens according to movement data of the human face if the human face is detected, or moving the lens according to movement data of the motion area if the human face is not detected.
6. The method according to claim 5 , wherein the step of detecting the motion area in the monitored scene comprises:
obtaining a first image of the monitored scene at a first time from the plurality of images, and calculating characteristic values of the first image;
obtaining a second image of the monitored scene at a second time continuous with the first time, and calculating the characteristic values of the second image;
matching the first image and the second image via an autocorrelation of the characteristic values of the first image and the second image, to obtain a corresponding area in both of the first image and the second image; and
comparing the characteristic values of the corresponding area in both of the first image and the second image, to obtain a motion area of the monitored scene, with different characteristic values of the corresponding area in the first image and the second image.
7. The method according to claim 5 , wherein the movement data comprises a movement direction, a movement angle, and a movement distance.
8. The method according to claim 7 , wherein the step of moving the lens according to movement data of the human face if the human face is detected, or moving the lens according to movement data of the motion area if the human face is not detected comprises:
moving the lens according to the movement data of the human face to focus the lens on the human face if the human face is detected, and zooming in a focal length of the lens; or
moving the lens according to the movement data of the motion area to focus the lens on the motion area if the human face is not detected, and zooming in the focal length of the lens.
9. A non-transitory storage medium having stored thereon instructions that, when executed by a processor of an image capturing device, causes the processor to perform a method for adjusting a position of a lens of the image capturing device, the method comprising:
obtaining a plurality of images of a monitored scene by the lens;
detecting a motion area in the monitored scene;
detecting if a human face is in the motion area; and
moving the lens according to movement data of the human face if the human face is detected, or moving the lens according to movement data of the motion area if the human face is not detected.
10. The non-transitory storage medium according to claim 9 , wherein the step of detecting the motion area in the monitored scene comprises:
obtaining a first image of the monitored scene at a first time from the plurality of images, and calculating characteristic values of the first image;
obtaining a second image of the monitored scene at a second time continuous with the first time, and calculating the characteristic values of the second image;
matching the first image and the second image via an autocorrelation of the characteristic values of the first image and the second image, to obtain a corresponding area in both of the first image and the second image; and
comparing the characteristic values of the corresponding area in both of the first image and the second image, to obtain a motion area of the monitored scene, with different characteristic values of the corresponding area in the first image and the second image.
11. The non-transitory storage medium according to claim 9 , wherein the movement data comprises a movement direction, a movement angle, and a movement distance.
12. The non-transitory storage medium according to claim 11 , wherein the step of moving the lens according to movement data of the human face if the human face is detected, or moving the lens according to movement data of the motion area if the human face is not detected comprises:
moving the lens according to the movement data of the human face to focus the lens on the human face if the human face is detected, and zooming in a focal length of the lens; or
moving the lens according to the movement data of the motion area to focus the lens on the motion area if the human face is not detected, and zooming in the focal length of the lens.