KR101396335B1 - Apparatus and method for detecting face - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a digital image processing apparatus and method, and more particularly, to a face recognition apparatus and method for providing a face recognition function during a digital zoom so that a face of a subject can be recognized from a long distance. The face recognition apparatus is a digital image processing apparatus that provides an optical zoom function for enlarging an image by adjusting a focal distance by a movement of a lens combination, and a digital zoom function for enlarging an image from a CCD. When entering the digital zoom mode, And a digital signal processing means for moving the zoom region to the face recognition region through face recognition of the enlarged image and performing digital zoom around the moved zoom region.

Face Recognition, Digital Zoom

Description

[0001] APPARATUS AND METHOD FOR DETECTING FACE [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a digital image processing apparatus and method, and more particularly, to a face recognition apparatus and method for providing a face recognition function during a digital zoom so that a face of a subject can be recognized from a long distance.

A typical digital image processing apparatus is equipped with a zoom function, and is used when a distant subject is enlarged and photographed close to the subject.

Such a zoom function is generally divided into an optical zoom and a digital zoom.

The optical zoom operates the zoom lens to reduce the focal distance, thereby enlarging and displaying the subject. Since the optical zoom lens moves the lens by driving the motor, the lens can not be moved at a high speed, there is a limit to the production of a lens having a high magnification, and the volume and weight of the employed set increases according to the high magnification of the lens. So that the subject can not be enlarged beyond a certain magnification.

In order to overcome the limitations of optical zoom lens, digital zoom is born. Digital zoom is a technology to enlarge a certain window on a screen detected by CCD without moving lens by motor. It is possible to use digital zoom even in short focus lens which can not be used. Digital zoom has the advantage of being able to zoom in or zoom out of a distant subject, but it has the disadvantage that the resolution is much lower than the original image due to the nature of the digital zoom.

A digital image processing apparatus equipped with a face recognition function prevents a digital zoom entry and does not provide a face recognition function in digital zooming. However, when the user wants to recognize a face of a subject at a distance, the user feels uncomfortable.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a face recognition device and a method for recognizing a face of a subject at a long distance by providing a face recognition function during digital zooming.

According to an aspect of the present invention, there is provided a face recognition apparatus comprising: an optical zooming function for enlarging an image by adjusting a focal distance by movement of a lens combination; and a digital image processing And a digital zooming unit for moving the zooming region to the face recognition region through the face recognition of the enlarged image at the last stage of the optical zooming and moving the zooming region around the moved zooming region, And a signal processing means.

In the present invention, the digital signal processing means may include a face recognition unit for performing face recognition of an enlarged image at a final stage of the optical zoom to generate face position information; A zoom area moving unit moving a zoom area around the generated face position; And an image size adjusting unit for enlarging the size of the image around the moved zoom area.

In the present invention, the image size adjusting unit adjusts the size of the image by multiplying the face position generated by the face recognizing unit by a digital zoom magnification at the digital zooming.

In the present invention, the digital signal processing means displays identification information for guiding movement of the digital image processing apparatus so that the position of the moved zoom region coincides with the position of the previously stored zoom region.

A face recognition method for solving the technical problem to be accomplished by the present invention includes an optical zoom function for enlarging an image by adjusting a focal distance by movement by lens combination and a digital image processing for providing a digital zoom function for enlarging an image in a CCD A method of operating an apparatus, the method comprising: (a) generating face position information by performing face recognition of an image magnified at a final stage of the optical zoom at the time of entering the digital zoom mode after performing the optical zoom; (b) moving a zoom area around the generated face position; And (c) enlarging the size of the image around the moved zoom area.

In the step (c), the size of the image may be adjusted by multiplying the face position generated by the face recognition unit and the digital zoom magnification at the time of performing the digital zoom.

The method may further include displaying identification information for guiding movement of the digital image processing apparatus so that the position of the moved zoom region is different from the position of the previously stored zoom region .

According to the present invention, a face recognition function can be provided at the time of digital zooming to efficiently perform facial recognition, and a user-friendly effect can be provided by recognizing a face of a subject at a long distance.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing the front and top contours of a digital image processing apparatus. Fig.

The shutter-release button 11 is opened and closed to expose the CCD or film to light for a predetermined time, and the image is recorded on the CCD by appropriately exposing the subject in cooperation with the aperture (not shown).

The shutter-release button 11 generates the first and second image pickup signals by the photographer input. When the first shutter-release button 11 is input as a half-shutter signal, the digital image processing apparatus focuses and adjusts the amount of light. At this time, the display unit 25 is lit with a green light . When the focus of the first shutter-release button 11 is focused and the amount of light is adjusted, a second shutter-release button 11 as a full shutter signal is input to capture an image.

The power button 13 is inputted to supply power to the digital image processing apparatus and operate it.

The flash 15 illuminates bright light momentarily when shooting in a dark place. The flash mode includes auto flash, forced flash, no flash, red-eye reduction, and slow synchro flash.

The auxiliary light 17 supplies light to the subject so that the digital image processing apparatus automatically catches the focus quickly and accurately when the light amount is insufficient or at night.

The lens unit 19 receives light from an external light source and processes the image.

FIG. 2 is a rear view showing the rear external appearance of the digital image processing apparatus shown in FIG. 1. The wide-angle zoom button 21w, the telephoto-zoom button 21t, the display unit 23, Input buttons B1 to B14 (hereinafter referred to as buttons B1 to B14).

The wide angle-zoom button 21w or the telephoto-zoom button 21t is a button for changing the shooting angle of view. When the angle-zoom button 21t is depressed, the focal length of the zoom lens is shortened, , When the telephoto-zoom button 21t is depressed, the focal length of the zoom lens becomes long and the angle of view becomes narrow.

The buttons B1 to B14 are provided in the rows and columns of the display unit 23. The buttons B1 to B14 provided in the row and column of the display unit 23 are provided with a touch sensor (not shown) or a contact type switch (not shown).

That is, the touch sensors are provided on the buttons B1 to B14 to move up / down / left / right while touching the buttons B1 to B7 of the horizontal row or the buttons B8 to B14 of the vertical row, It is possible to select any value (e.g., color or brightness) of the items, or activate a submenu icon included in the main menu icon.

In addition, the button frames (B1 to B14) are provided with contact switches so that the main menu icon and the sub menu icon can be directly selected to execute the corresponding function. The touch sensor requires a relatively weak touch compared to the contact switch input, but the contact switch input requires a relatively strong touch compared to the touch sensor input.

3 is a block diagram showing a configuration of a face recognition apparatus according to the present invention and includes a display unit 23, a user input unit 31, an image pickup unit 33, an image processing unit 35, a storage unit 37, And a processing unit 39.

The user input unit 31 includes a shutter release button 11 that is opened and closed to expose a CCD or a film to light for a predetermined period of time, a power button 13 that inputs power to supply power, Zoom button 21w and telephoto-zoom button 21t for narrowing down the screen and a touch sensor or contact type switch provided in the horizontal and vertical columns around the display unit 23 for character input or menu selection and execution, And button buttons (B1 to B14).

The imaging section 33 includes a shutter, a lens section, a diaphragm, and a charge coupled device (CCD) and an ADC (not shown). The shutter is a mechanism that adjusts the amount of light that is exposed with the iris. The lens unit receives light from an external light source and processes the image. At this time, the diaphragm adjusts the amount (light amount) of the incident light according to the degree of opening and closing. The opening / closing degree of the diaphragm is controlled by the digital signal processing section 39. [

The CCD accumulates the amount of light input through the lens unit and outputs the image captured by the lens unit according to the accumulated light amount in accordance with the vertical synchronization signal. Image acquisition of a digital image processing apparatus is performed by a CCD which converts light reflected from a subject into an electrical signal. In order to obtain a color image using a CCD, a color filter is required. Mostly, a filter (not shown) called CFA (Color Filter Array) is employed. CFA has a regularly arranged structure that passes only light that represents one color per pixel, and it has various forms according to the arrangement structure. The ADC converts the analog video signal output from the CCD into a digital signal.

The image processing unit 35 processes the digitally converted RAW data so that it can be displayed. The image processing unit 35 removes a black level due to the dark current generated in the CCD and the CFA filter which are full of temperature change. The image processing unit 35 performs gamma correction to encode information in accordance with the nonlinearity of human vision. The image processing unit 35 performs CFA interpolation for interpolating a Bayer pattern implemented with RGA and RGB lines of gamma-corrected predetermined data into RGB lines. The image processing unit 35 converts the interpolated RGB signals into YUV signals, performs edge compensation for filtering the Y signals by a high-pass filter, and calculates color values of the U and V signals using a standard color coordinate system Corrects the color correction, and removes these noises. The image processing unit 35 compresses and processes the Y, U, and V signals from which the noise has been removed to generate a JPEG file, and the generated JPEG file is displayed on the display unit 23 and stored in the storage unit 37 . All the operations of the image processing unit 35 operate under the control of the digital signal processing unit 39. [

The digital signal processing unit 39 provides an optical zoom function for enlarging an image by adjusting a focal distance by movement of a lens combination, and a digital zoom function for enlarging an image from a CCD. In the digital image processing unit 39, , The zoom area is moved to the face recognition area through the face recognition of the enlarged image at the last stage of the optical zoom, and the digital zoom is performed around the moved zoom area.

The digital signal processing unit 39 includes a face recognition unit 39-1, a zoom area conversion unit 39-2, an image size adjustment unit 39-3, and a control unit 39-4 for controlling the blocks .

4A shows a general zoom area (ZA) for a live view image. The general zoom area has fixed start coordinates, horizontal and vertical sizes, and is defined in advance in the table. Accordingly, the zooming operation is performed by retrieving the fixed coordinates and size information from the table at the time of zooming.

When the telephoto-zoom button 21t is input to enlarge the live view image displayed on the display unit 23, optical zoom is performed, and when the telephoto-zoom button 21t is input again at the last stage of the optical zoom, Moves to the digital zoom mode. In the digital zoom mode, the CCD detects and magnifies the final image of the optical zoom.

FIG. 4B shows a screen in which optical zooming is performed by inputting the telephoto-zoom button 21t in the live image of FIG. 4A. The live view image can be enlarged by re-entering the telephoto-zoom button 21t to the optical zoom magnification supported by the digital image processing apparatus. In the optical zoom step, a zoom operation is performed around the normal zoom area ZA. In the present invention, it is assumed that FIG. 4B is the last stage of optical zoom. When the telephoto-zoom button 21t is input again at the last stage of the optical zoom, digital zoom is performed while the digital image processing apparatus is converted into the digital zoom mode.

When the telephoto-zoom button 21t is again input at the last stage of the optical zoom, the face recognition unit 39-1 controls the face recognition of the image enlarged at the last stage of the optical zoom under the control of the control unit 39-4 Thereby generating face position information. FIG. 4C shows a face recognition area (FDA) in the live image of the last stage of the optical zoom.

The face recognition unit 39-1 detects face information, that is, the size, position, and direction of the face from the enlarged live view image of the last optical zoom step. The facial recognition unit 39-1 can detect the face area based on the color or detect the face area based on the edge at the time of detecting the size of the face, and at the time of detecting the face position, And the center of the display unit 23, and the face direction can be detected in the form of a triangle composed of the eyes and mouth from the extracted face at the time of detecting the direction of the face. Since details of the face information detection by the face recognition unit 39-1 are well known in the art, a detailed description thereof will be omitted.

The zoom area converter 39-2 moves the zoom area around the face position information generated by the face recognition unit 39-1 under the control of the control unit 39-4. As described above, the normal zoom area ZA has fixed start coordinates, horizontal and vertical sizes as shown in Figs. 4A and 4B. However, in the present invention, the zoom area converter 39-2 moves the zoom area around the face position information, that is, the face recognition area FDA. The start coordinates and the horizontal and vertical sizes for positioning the zoom area in the face recognition area FDA are calculated so that the face recognition area FDA is located at the center of the moved zoom area. The zoom area moved in the present invention is used in digital zooming and is therefore referred to as a digital zoom area (DZA).

The image size adjustment unit 39-3 enlarges the size of the live view image around the digital zoom area DZA under the control of the control unit 39-4 according to the input of the telephoto-zoom button 21t. The image size adjustment unit 39-3 enlarges the size of the live view image by multiplying the size of the face recognition area FDA recognized at the last step of the optical zooming by the input digital zoom magnification.

4D shows a state in which the zoom area is moved (digital zoom area DZA) to the face recognition area FDA and then the telephoto-zoom button 21t is input so that the live view image is displayed on the face recognition area FDA, .

As described above, the face recognition function is provided at the time of digital zooming, so that the face recognition can be efficiently performed, and the face of the subject can be recognized even at a long distance.

5 illustrates an example of a moving direction of the digital image processing apparatus when face recognition is performed outside the digital zoom region. In performing digital zoom, the subject often moves off the display unit 23 even if the digital image processing apparatus is moved a little. 5, when the face recognition area FDA deviates from the center of the display unit 23 in the digital zoomed live image, the digital zoom area DZA deviates from the center of the display unit 23, I will not. In such a case, the control unit 39-4 may display identification information (guide information such as arrows) to move the digital image processing apparatus downward, and guide the user to move the digital image processing apparatus.

Hereinafter, a face recognition method according to the present invention will be described in detail with reference to FIG. The method of recognizing a face of a digital image processing apparatus according to the present invention can be performed in an image processing apparatus as shown in FIG. 3. According to an embodiment, And may be performed in the digital signal processing unit 39.

When the live view image is displayed on the display unit 23 in step 601, the user inputs the telephoto-zoom button 21t to enlarge the image, and the digital signal processing unit 39 receives the telephoto-zoom button 21t in step 603.

When the telephoto-zoom button 21t is received, the digital signal processing unit 39 controls the image pickup unit 33 and the image processing unit 23 so that optical zooming is performed to enlarge and display the enlarged live view image (605 step). When optical zooming is performed, optical zooming is performed centering on a zoom area ZA having a fixed size (start coordinates, horizontal and vertical sizes fixed) as shown in FIG. 4A.

To re-expand the image, the digital signal processing unit 39 receives the re-input of the tele-zoom button 21t and controls the image pickup unit 33 and the image processing unit 23 to display a further enlarged live image (Step 607). FIG. 4B shows a screen in which optical zooming is performed by inputting the telephoto-zoom button 21t in the live image of FIG. 4A. The live view image can be enlarged by re-entering the telephoto-zoom button 21t to the optical zoom magnification supported by the digital image processing apparatus.

Thereafter, the digital signal processing unit 39 determines whether it is the last optical zoom step by re-inputting the telephoto-zoom button 21t (step 609). If the last optical zoom step is not performed, the digital signal processing unit 39 enlarges the image by optical zoom, In the last optical zoom step, the digital zoom mode is entered (step 611).

Upon entering the digital zoom mode, the digital image processing unit 39 performs face recognition on the enlarged live image of the last optical zoom step (step 613). When the telephoto-zoom button 21t is again input at the last stage of the optical zoom, the face recognition unit 39-1 controls the face recognition of the image enlarged at the last stage of the optical zoom under the control of the control unit 39-4 Thereby generating face position information. FIG. 4C shows a face recognition area (FDA) in the live image of the last stage of the optical zoom.

Then, the digital signal processing unit 39 moves the zoom area around the face recognition area FDA (step 615). As shown in FIGS. 4A and 4B, the normal zoom area ZA has fixed start coordinates, horizontal and vertical sizes. However, in the present invention, the zoom area converter 39-2 moves the zoom area around the face position information, that is, the face recognition area FDA. The start coordinates and the horizontal and vertical sizes for positioning the face recognition area FDA in the center of the zoom area are calculated and the face recognition area FDA is positioned at the center of the zoom area. The zoom area moved in the present invention is used in digital zooming and is therefore referred to as a digital zoom area (DZA).

After the digital zoom area DZA is generated and the input of the telephoto-zoom button 21t is received in step 617, the digital signal processing unit 39 enlarges the image around the digital zoom area DZA (Step 619). The image size adjustment unit 39-3 enlarges the size of the live view image by multiplying the size of the face recognition area FDA recognized at the last step of the optical zooming by the input digital zoom magnification. 4D shows a state in which the zoom area is moved (digital zoom area DZA) to the face recognition area FDA and then the telephoto-zoom button 21t is input so that the live view image is displayed on the face recognition area FDA, .

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing the front and top contours of a digital image processing apparatus. Fig.

FIG. 2 is a rear view showing the rear external appearance of the digital image processing apparatus shown in FIG. 1. FIG.

3 is a block diagram showing a configuration of a face recognition apparatus according to the present invention.

4 is a view illustrating an embodiment for explaining face recognition in digital zooming in the apparatus of FIG.

FIG. 5 is a view showing an embodiment of presenting a moving direction of a digital image processing apparatus when facial recognition is performed outside the digital zoom region in the apparatus of FIG. 3. FIG.

6 is a flowchart illustrating an operation of the face recognition method according to the present invention.

Claims (7)

An optical image processing apparatus for providing an optical zoom function for enlarging an image by adjusting a focal distance by movement of a lens combination, and a digital zoom function for enlarging an image in a CCD, A digital signal processing means for moving a zoom region to a face recognition region through face recognition of an image enlarged at the last stage of the optical zoom and performing digital zoom around the moved zoom region, A digital image processing apparatus comprising: The digital signal processing means Wherein when the digital zooming region is moved in accordance with the movement of the digital image processing apparatus, identification information for inducing movement of the digital image processing apparatus is displayed so that the position of the moved zooming region coincides with the position of the previously stored zooming region And the digital image processing apparatus. The digital signal processing apparatus according to claim 1, wherein the digital signal processing means A face recognition unit for generating face position information by performing face recognition of an enlarged image at a final stage of the optical zoom; A zoom area moving unit moving a zoom area around the generated face position; And And an image size adjusting unit for enlarging the size of the image around the moved zoom area. 3. The apparatus of claim 2, wherein the image size adjustment unit Wherein the digital image processing unit adjusts the size of the image by multiplying the size of the face recognition area generated by the face recognition unit and the digital zoom magnification at the digital zooming. delete 1. An operation method of a digital image processing apparatus that provides an optical zoom function for enlarging an image by adjusting a focal distance by movement of a lens combination, and a digital zoom function for enlarging an image in a CCD, (a) generating face position information by performing face recognition of an enlarged image at a final stage of the optical zooming at the time of entering the digital zooming mode after performing the optical zooming; (b) moving a zoom area around the generated face position; And (c) enlarging the size of the image around the moved zoom area, the method comprising: Wherein when the digital zooming region is moved in accordance with the movement of the digital image processing apparatus, identification information for inducing movement of the digital image processing apparatus is displayed so that the position of the moved zooming region coincides with the position of the previously stored zooming region The method further comprising the steps of: 6. The method of claim 5, wherein in the step (c) Wherein the image size is adjusted by multiplying a size of a face recognition area generated by the face recognition unit by a digital zoom magnification at the time of digital zooming. delete

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