KR20090032295A - Apparatus and method for detecting face - Google Patents

Abstract

A face recognition device and a method thereof are provided to enhance the user's convenience by recognizing the face of a subject which is located in a distant place. An image pickup part(33) comprises a shutter, a lens unit, an iris, a CCD(Charge Coupled Device) and an ADC. The opened/closed degree of the iris is controlled by a digital signal processing unit(39). An image processing unit(35) signal-processes raw data which is digital-converted so as to be displayed, and compresses and signal-processes Y, U and V signals in which noise is removed to generate a JPEG file. The generated JPEG file is displayed in a display unit(23) and stored in a storage unit(37). The whole operations of the image processing unit are controlled by the digital signal processing unit.

Description

Apparatus and method for detecting face

The present invention relates to an apparatus and method for digital image processing, and more particularly, to a face recognition apparatus and method for providing a face recognition function during digital zoom so as to recognize a face of a subject from a long distance.

A general digital image processing apparatus is equipped with a zoom function, which is used when zooming in on a distant subject as if it is taken up close.

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

Optical zoom magnifies and displays the subject by reducing the focal length by operating the zoom lens. Since the optical zoom lens moves the lens by driving the motor, it cannot move the lens at a high speed, and there is a limitation in manufacturing a high magnification lens, and the volume and weight of the set are increased according to the high magnification ratio of the digital image processing apparatus. The production cost of the camera will increase, so it is impossible to enlarge the subject by a certain magnification.

To overcome this limitation of optical zoom lenses, digital zoom was created. Digital zoom is a technology that enlarges a window on a screen detected by a CCD without moving the lens by a motor. Digital zoom can be used even with short focal length lenses. Digital zoom has an advantage of allowing the user to see or enlarge a distant subject up close, but has a disadvantage in that the resolution is much lower than that of the original image due to the characteristics of the digital zoom.

A digital image processing apparatus having a face recognition function does not provide a face recognition function at the time of digital zoom by preventing the digital zoom from entering. However, if the user wants to recognize the face of a remote object, the user may feel uncomfortable.

The technical problem to be achieved by the present invention is to provide a face recognition apparatus and method for providing a face recognition function during digital zoom to recognize the face of the subject from a long distance.

The face recognition apparatus for solving the technical problem to be achieved by the present invention is a digital image processing that provides an optical zoom function for enlarging the image by adjusting the focal length by the movement of the lens combination and a digital zoom function for enlarging the image in the CCD An apparatus, comprising: a digital device configured to move a zoom region to a face recognition region through face recognition of an image enlarged in the last step of the optical zoom when the digital zoom mode is entered, and perform digital zoom around the moved zoom region It is preferable to include signal processing means.

In the present invention, the digital signal processing means includes a face recognition unit for generating face position information by performing face recognition of an enlarged image in the last step of the optical zoom; A zoom region moving unit which moves a zoom region around the generated face position; And an image size adjusting unit which enlarges the size of the image around the moved zoom region.

The image size adjusting unit may adjust the size of the image by multiplying the face position generated by the face recognition unit with the digital zoom magnification when the digital zooming is performed.

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

The face recognition method for solving the technical problem to be achieved by the present invention is a digital image processing that provides an optical zoom function to enlarge the image by adjusting the focal length by the movement of the lens combination and a digital zoom function to enlarge the image in the CCD A method of operating an apparatus, comprising: (a) generating face position information by performing face recognition of an image magnified in the last step of the optical zoom when 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 region.

In the step (c), when performing the digital zoom, the size of the image is adjusted by multiplying the face position generated by the face recognition unit with the digital zoom magnification.

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

According to the present invention, face recognition can be efficiently performed by providing a face recognition function at the time of digital zoom, and a convenient effect can be provided to a user by recognizing a face of a subject at a long distance.

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

1 is a perspective view showing the front and the top of the digital image processing apparatus.

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

The shutter release button 11 generates the first and second image capturing signals by a photographer input. When the first shutter release button 11 as a half shutter signal is input, the digital image processing apparatus focuses and adjusts the amount of light, and when the focus is achieved, the green light is turned on in the display unit 25. . When focus is achieved by the input of the first shutter release button 11 and the amount of light is adjusted, the second shutter release button 11 as a full shutter signal is input to capture an image.

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

The flash 15 brightens the bright light instantly when shooting in a dark place. Flash modes include auto flash, forced flash, flash off, red-eye reduction, and slow synchro.

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

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

FIG. 2 is a rear view of the rear surface of the digital image processing apparatus shown in FIG. 1. The wide-zoom button 21w, the tele-zoom button 21t, the display unit 23 and the touch sensor or the contact switch may be The provided input buttons B1 to B14 (hereinafter referred to as buttons B1 to B14) are provided.

The wide-zoom button 21w or the tele-zoom button 21t is a button for changing the shooting angle of view. When the angle-zoom button 21t is pressed, the focal length of the zoom lens is shortened to widen the angle of view. When the telephoto-zoom button 21t is pressed, the focal length of the zoom lens becomes longer and the angle of view becomes narrower.

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

That is, the buttons B1 to B14 are provided with a touch sensor to move up / down / left / right in a state where the buttons B1 to B7 in the horizontal row or the buttons B8 to B14 in the vertical row are touched. You can select any value (eg, color or brightness) from the items, or activate the submenu icons included in the main menu icon.

In addition, the button frame (B1 ~ B14) is provided with a contact switch, it is possible to directly select the main menu icon and sub-menu icon to execute the corresponding function. The touch sensor requires only a weak touch relative 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, wherein the display unit 23, the user input unit 31, the image pickup unit 33, the image processing unit 35, the storage unit 37, and the digital signal are shown. It includes a processor 39.

The user input unit 31 has a shutter release button 11 that opens and closes to expose the CCD or film to light for a predetermined time, a power button 13 that inputs to supply power, and widens the angle of view according to the input, Wide-zoom button 21w and tele-zoom button 21t for narrowing the distance, and touch sensors or contact switches provided in horizontal and vertical columns around the display unit 23 for character input or menu selection and execution. There are buttons provided with a button frame (B1 ~ B14).

The imaging unit 33 includes a shutter, a lens unit, an aperture, a charge coupled device (CCD), and an ADC, which are not shown in the figure. The shutter is a mechanism for adjusting the amount of light exposed together with the aperture. The lens unit receives light from an external light source and processes an image. At this time, the iris adjusts the amount of light incident (light quantity) according to the degree of opening and closing. The opening and closing degree of the iris is controlled by the digital signal processing unit 39.

The CCD accumulates the amount of light input through the lens unit and outputs an image captured by the lens unit in accordance with the accumulated light amount in accordance with the vertical synchronization signal. Image acquisition of the digital image processing apparatus is performed by a CCD that converts light reflected from a subject into an electrical signal. Color filters are required to obtain color images using CCDs, and most of them employ a filter (not shown) called a color filter array (CFA). CFA has a structure arranged regularly by passing only one color light per pixel, and has various shapes according to the arrangement structure. The ADC converts an analog video signal output from the CCD into a digital signal.

The image processor 35 performs signal processing to display the digitally converted RAW data. The image processor 35 removes the black level caused by the dark current generated by the CCD and the CFA filter that are sensitive to the temperature change. The image processor 35 performs gamma correction to encode information according to nonlinearity of human vision. The image processor 35 performs CFA interpolation to interpolate the Bayer pattern implemented by the RGRG line and the GBGB line of the gamma corrected predetermined data into the RGB line. The image processing unit 35 converts the interpolated RGB signal into a YUV signal and filters the Y signal by a high band filter to clearly process the image, and uses the standard color coordinate system to adjust the color values of the U and V signals. Perform color correction to correct and remove their noise. The image processor 35 compresses and signals the Y, U, and V signals from which the noise is 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 of the operations of the image processor 35 operate under the control of the digital signal processor 39.

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

To this end, the digital signal processor 39 controls the face recognition unit 39-1, the zoom region converter 39-2, the image size adjusting unit 39-3, and the controller 39-4 for controlling the blocks. Include.

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

When the tele-zoom button 21t is input for the enlargement of the live view image displayed on the display unit 23, the optical zoom is performed, and when the tele-zoom button 21t is input again at the last step of the optical zoom, Move to digital zoom mode. In the digital zoom mode, the CCD detects and magnifies the image of the last step of the optical zoom.

FIG. 4B shows a screen on which the optical zoom is performed by inputting the tele-zoom button 21t in the live image of FIG. 4A. The live view image may be enlarged by inputting the tele-zoom button 21t again to the optical zoom magnification supported by the digital image processing apparatus. In the optical zooming step, the zooming operation is performed around the general zoom area ZA. In the present invention, assume that FIG. 4B is the last step of the optical zoom. When the telephoto-zoom button 21t is input again at the last step of the optical zoom, the digital image processing apparatus is switched to the digital zoom mode, and digital zoom is performed.

When the telephoto-zoom button 21t is input again at the last step of the optical zoom, the face recognition unit 39-1 performs face recognition of an image enlarged at the last step of the optical zoom under the control of the controller 39-4. Perform face location information. 4C shows a face detection area (FDA) for face recognition in a live image of the last step of optical zoom.

The face recognition unit 39-1 detects face information, that is, a size, a position, and a direction of the face from the enlarged live view image of the last step of the optical zoom. In the case of detecting the size of the face, the piercing recognition unit 39-1 may detect the face region based on the color, or detect the face region based on the edge, and when detecting the position of the face, the center of the extracted face. The position of the face may be calculated based on the distance between the center of the display unit 23 and the preset display unit 23. When detecting the direction of the face, the face direction may be detected in the form of a triangle formed of eyes and mouth from the extracted face. The information on the face information detection of the face recognizing unit 39-1 is already well known, and thus detailed description thereof will be omitted.

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

The image size adjusting unit 39-3 enlarges the size of the live view image centering on the digital zoom area DZA under the control of the controller 39-4 according to the input of the telephoto-zoom button 21t. The image size adjusting unit 39-3 enlarges the size of the live view image by multiplying the size of the face recognition area FDA recognized in the last step of the optical zoom with the input digital zoom magnification.

In FIG. 4D, after the zoom area is moved to the face recognition area FDA (digital zoom area DZA), the tele-zoom button 21t is input to zoom the live view image around the face recognition area FDA. Shows what happened.

As shown in the above, the face recognition function can be efficiently provided during digital zoom, and thus the face of the subject can be recognized even at a long distance.

As another embodiment, FIG. 5 is a diagram illustrating an example of a moving direction of the digital image processing apparatus when face recognition is performed outside the digital zoom region. When performing the digital zoom, even if the digital image processing apparatus is slightly moved, the subject often leaves the display unit 23. When the face recognition area FDA moves away from the center of the display unit 23 in the digital zoomed live image as shown in FIG. 5, the digital zoom area DZA is moved out of the center of the display unit 23 to efficiently perform digital zoom. There will be no. In this case, the controller 39-4 may display the identification information (guide information such as an arrow) to move the digital image processing apparatus downward to induce 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. 6. The face recognition method of the digital image processing apparatus according to the present invention may be performed inside the image processing apparatus as shown in FIG. 3. According to an embodiment, the main algorithm of the operation method may be performed by the help of peripheral components in the apparatus. It may be performed in the digital signal processor 39.

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

When the telephoto-zoom button 21t is received, the digital signal processor 39 controls the image capturing unit 33 and the image processor 23 to perform optical zoom and enlarges and displays the enlarged live view image (605). step). When performing the optical zoom, as shown in FIG. 4A, the optical zoom is performed centering on the zoom area ZA having a fixed size (fixed size of the starting coordinate, horizontal and vertical).

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

Thereafter, the digital signal processor 39 determines whether the optical zoom step is the last optical zoom step by re-input of the telephoto-zoom button 21t (step 609), and if not, the digital signal processor 39 enlarges the image by the optical zoom. In the case of the last optical zoom step, the digital zoom mode is entered (step 611).

When the digital zoom mode is entered, the digital image processor 39 performs face recognition on the enlarged live image of the last optical zoom step (step 613). When the telephoto-zoom button 21t is input again at the last step of the optical zoom, the face recognition unit 39-1 performs face recognition of an image enlarged at the last step of the optical zoom under the control of the controller 39-4. Perform face location information. 4C shows a face detection area (FDA) for face recognition in a live image of the last step of optical zoom.

In operation 615, the digital signal processor 39 moves the zoom area around the face recognition area FDA. As shown in FIGS. 4A and 4B, the general zoom area ZA has fixed starting coordinates and horizontal and vertical sizes. However, in the present invention, the zoom region converter 39-2 moves the zoom region around the face position information, that is, the face recognition region FDA. The face recognition area FDA is positioned at the center of the moved zoom area by calculating start coordinates and horizontal and vertical sizes for positioning the face recognition area FDA at the center of the zoom area. In the present invention, since the zoomed area is used for digital zooming, it is referred to as a digital zoon area (DZA).

After the digital zoom area DZA is generated, when the input of the tele-zoom button 21t is received (step 617), the digital signal processor 39 enlarges the image around the digital zoom area DZA. Display (step 619). The image size adjusting unit 39-3 enlarges the size of the live view image by multiplying the size of the face recognition area FDA recognized in the last step of the optical zoom with the input digital zoom magnification. In FIG. 4D, after the zoom area is moved to the face recognition area FDA (digital zoom area DZA), the tele-zoom button 21t is input to zoom the live view image around the face recognition area FDA. Shows what happened.

1 is a perspective view showing the front and the top of the digital image processing apparatus.

FIG. 2 is a rear view illustrating a rear shape of the digital image processing apparatus of FIG. 1.

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

4 is a diagram illustrating an embodiment for describing face recognition during digital zoom in the apparatus of FIG. 3.

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

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

Claims (7)

A digital image processing apparatus which provides an optical zoom function for enlarging an image by adjusting a focal length by movement by a lens combination and a digital zoom function for enlarging an image in a CCD. Digital signal processing means for moving the zoom area to the face recognition area by performing face recognition of the image enlarged in the last step of the optical zoom when the digital zoom mode is entered, and performing digital zoom around the moved zoom area. Face recognition device comprising a. The method of claim 1, wherein the digital signal processing means A face recognition unit generating face position information by performing face recognition of an enlarged image in the last step of the optical zoom; A zoom region moving unit which moves a zoom region around the generated face position; And And an image size adjusting unit configured to enlarge the size of the image around the moved zoom region. The apparatus of claim 2, wherein the image resizing unit And, when performing the digital zoom, adjust the size of the image by multiplying the face position generated by the face recognition unit with the digital zoom magnification. The method of claim 1, wherein the digital signal processing means And displaying identification information for guiding the movement of the digital image processing apparatus such that the position of the zoomed region coincides with a previously stored position of the zoomed region. An operation method of a digital image processing apparatus which provides an optical zoom function for enlarging an image by adjusting a focal length by movement by 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 image magnified in the last step of the optical zoom after entering the digital zoom mode after performing the optical zoom; (b) moving a zoom area around the generated face position; And and (c) enlarging the size of the image around the moved zoom region. The method of claim 5, wherein in step (c), And performing a digital zoom to adjust the size of the image by multiplying a face position generated by the face recognition unit with a digital zoom magnification. The method of claim 5, And if the position of the moved zoom region is different from the previously stored position of the zoom region, displaying identification information for inducing the movement of the digital image processing apparatus so that they match.

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