Method and apparatus for controlling zoom using touch screen

1. A method of controlling zoom of an input image having an input image area using a touch screen displaying the input image, the method comprising:

detecting a face region in the input image;

inputting a zooming gesture consisting of a figure smaller than the input image by defining a touch region corresponding to the zooming gesture using a touch screen of a digital photographing apparatus;

calculating the area of the touch region; and

if a face region is detected, controlling the zooming operation of the digital photographing apparatus to adjust the image size according to the ratio of the area of the touch region to the area of the detected face region.

2. The method of claim 1 , wherein the controlling the zooming operation is performed by controlling a zoom motor that operates an optical zoom lens of the digital photographing apparatus to move to a tele-end with respect to the touch region when the calculated area of the touch region is greater than the area of the detected face region.

3. The method of claim 1 , wherein the controlling the zooming operation is performed by controlling a zoom motor that operates an optical zoom lens of the digital photographing apparatus to move to a wide-end with respect to the touch region when the calculated area of the touch region is less than the area of the detected face region.

4. The method of claim 1 , wherein the controlling the zooming operation is performed by controlling a digital zooming operation to zoom in on the input image with respect to the touch region when the calculated area of the touch region is greater than the area of the detected face region.

5. The method of claim 1 , wherein the controlling the zooming operation is performed by controlling a digital zooming operation to zoom out of the input image with respect to the touch region when the calculated area of the touch region is less than the area of the detected face region.

6. The method of claim 1 , wherein, if a face region is not detected, the controlling the zooming operation is performed according to a ratio of the calculated area of the touch region to the area of the input image.

7. The method of claim 6 , wherein the controlling the zooming operation is performed by controlling a zoom motor that operates an optical zoom lens of the digital photographing apparatus to move to a tele-end with respect to the touch region when the ratio of the calculated area of the touch region to the area of the input image is greater than a predetermined threshold value, and

controlling the zoom motor to move to a wide-end with respect to the touch region when the ratio of the calculated area of the touch region to the area of the input image is less than the threshold value.

8. The method of claim 6 , wherein the controlling the zooming operation is performed by controlling a digital zooming operation to zoom in on the input image with respect to the touch region when the ratio of the calculated area of touch region to the area of the input image is greater than a predetermined threshold value, and

controlling a digital zooming operation to zoom out of the input image with respect to the touch region when the ratio of the calculated area of the touch region to the area of the input image is less than the threshold value.

9. The method of claim 1 , wherein the input image is a preview image or a reproduced image.

10. The method of claim 1 , wherein the zooming operation comprises an optical zoom or a digital zoom of the digital photographing apparatus.

11. The method of claim 1 , wherein the zooming gesture is a figure with a predetermined shape input by a user using the touch screen of the digital photographing apparatus.

12. A non-transitory computer-readable recording medium having recorded thereon a computer executable program to perform a method for controlling zoom of an input image having an input image area comprising:

detecting a face region in the input image;

inputting a zooming gesture consisting of a figure smaller than the input image by defining a touch region corresponding to the zooming gesture on a touch screen of a digital photographing apparatus;

calculating the area of the touch region; and

if a face region is detected, controlling a zooming operation of the digital photographing apparatus to adjust the image size according to the ratio of the area of the touch region to the area of the detected face region.

13. An apparatus for controlling zoom of an input image having an input image area using a touch screen, the apparatus comprising:

a face region detector configured to detect a face region in the input image;

a touch region calculation unit configured to calculate an area of a touch region smaller than the input image corresponding to a zooming gesture input using a touch screen of a digital photographing apparatus; and

a controller configured to control a zooming operation of the digital photographing apparatus to adjust the image size if a face region is detected based on the ratio of the area of the detected face region and the calculated are of the touch region.

14. The apparatus of claim 13 , wherein the controller is configured to control a zoom motor to operate an optical zoom lens of the digital photographing apparatus to move to a tele-end with respect to the touch region when the calculated area of the touch region is greater than the area of the detected face region, and

configured to control the zoom motor to move to a wide-end with respect to the touch region when the calculated area of the touch region is less than the area of the detected face region.

15. The apparatus of claim 13 , further comprising an image signal processor configured to zoom in on or out of the input image according to the control of the controller,

wherein the controller is configured to control the image signal processor to zoom in on the input image with respect to the touch region when the calculated area of the touch region is greater than the area of the detected face region, and configured to control the image signal processor to zoom out of the input image with respect to the touch region when the calculated area of the touch region is less than the area of the detected face region.

16. The apparatus of claim 15 , wherein, if a face region is not detected, the controller is configured to control the zooming operation of the digital photographing apparatus according to a ratio of the calculated area of the touch region to the area of the input image.

17. The apparatus of claim 16 , wherein the controller is configured to control a zoom motor that operates an optical zoom lens of the digital photographing apparatus to move to a tele-end with respect to the touch region when the ratio of the calculated area of the touch region to the area of the input image is greater than a predetermined threshold value, and

configured to control the zoom motor that operates the optical zoom lens of the digital photographing apparatus to move to a wide-end with respect to the touch region when the ratio of the calculated area of the touch region to the area of the input image is less than the threshold value.

18. The apparatus of claim 16 , wherein the controller is configured to control the image signal processor to zoom in on the input image with respect to the touch region when the ratio of the calculated area of the touch region to the area of the input image is greater than a predetermined threshold value, and

configured to control the image signal processor to zoom out of the input image with respect to the touch region when the ratio of the calculated area of the touch region to the area of the input image is less than the threshold value.

19. The method of claim 1 , wherein the controlling the zooming operation is performed based on the ratio of the number of pixels encircled by the zooming gesture and the number of pixels in the input image.

20. A method of controlling zoom of an input image having an input image area using a touch screen, the method comprising:

receiving a signal representing a zooming gesture input smaller than the input image using the touch screen of a digital photographing apparatus;

calculating a first amount of surface area corresponding to the zooming gesture by calculating the area or number of pixels encircled by the zooming gesture; and

controlling a zooming operation of the digital photographing apparatus according to the calculated first amount.