KR20090039051A - Apparatus for processing digital image and method for controlling the same - Google Patents

Abstract

An apparatus for processing a digital image and a method for controlling the same are provided to extract a representative image from a moving picture automatically in a short time by comparing specific regions of still images in the moving picture and selecting the representative image. It is judged whether or not the number of representative images is larger than the number of setup representative images(S405). If so, the first and last frames are reselected as representative images(S410) and the representative images are reselected in the order of the comparison value(S420). Otherwise, the number of representative images which are to be added is calculated(S430). In addition, the time interval among the selected representative images is calculated and the representative images are added to the addition interval(S440,S450).

Description

Apparatus for processing digital image and method for controlling the same}

The present invention relates to a digital image processing apparatus and a control method thereof, and more particularly, to a digital image processing apparatus capable of capturing a moving image and extracting a still image from the moving image and a control method thereof.

In general, a digital image processing apparatus includes any apparatus that processes an image of a digital camera, a personal digital assistant (PDA), a phone camera, a PC camera, or uses an image recognition sensor.

In some cases, the digital image processing apparatus may capture not only a still image but also a moving image and store it as a file. In addition, there are cases where a moving image file is printed or an album of a still image is generated from the moving image. To this end, it is necessary to extract a still image from the video file.

Meanwhile, a printer may be connected to the digital image processing apparatus, and a video file may be output through the printer. In this case, the video file may include a still image image in frame units of a set time interval. Accordingly, in order to output the moving image file, the representative image may be selected from all still image images included in the moving image file, and the representative image may be output.

To this end, in the conventional digital image processing apparatus, in order to obtain a still image from a moving image file, the user may directly generate a still image by determining a representative image while directly examining the moving image.

However, when the user directly extracts the representative image by directly examining the video, there is an inconvenience in that the user must select the desired still image one by one while watching the video directly.

The present invention provides a digital image processing apparatus and a control method thereof, by selecting a representative image by comparing only specific regions of respective images in a moving image, and extracting the representative image based on the characteristics of the respective images constituting the moving image. It aims to do it.

According to an embodiment of the present invention, a display unit which selects at least one or more frames from among frames included in a moving image as a representative image of a still image, and displays the moving image; And extracting a face area of a person from each frame of the video image, comparing the face areas in two consecutive frames at a set time or frame interval, and determining that the angle change of the face is greater than a set reference value. It provides a digital image processing apparatus having a control unit for selecting at least one of the representative image.

The apparatus may further include a printing unit configured to output the representative image.

The pixel value may be obtained by the sum of the gray level values of each pixel of the face area, and the angle change of the face may be obtained from the difference between the pixel values of the two consecutive frames.

Another aspect of the present invention is to select at least one frame from among the frames included in the moving image as a representative image of the still image, setting the number of the representative image to be selected; Extracting a face region of a person from each frame of the moving image; Extracting pixel values of the face area in each of the frames; Extracting a comparison value from the difference between the pixel values of two consecutive frames at a set time or frame interval; And selecting the representative image by comparing the comparison value with a set reference value.

The method may further include printing the representative image.

The method may further include selecting a method of extracting the representative image, and the method of extracting the representative image may include any one of a frame number unit, a change in the number of people, and a change in face angle.

If the number of the selected representative image does not match the set number of the representative image, the method may further include adjusting the number of the selected representative image.

According to the digital image processing apparatus and the control method thereof according to the present invention, a representative image can be automatically extracted within a short time by selecting a representative image by comparing only a specific region of each image in a moving image.

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

FIG. 1 is a rear view of a digital camera 100 which is an embodiment of a digital image processing apparatus according to the present invention.

Referring to the drawings, on the back of the digital camera 100, the direction button 21, the menu-OK button 22, the wide angle (Zoom) button (W), the telephoto (Zoom) ) Button T, the display panel 25 and the like. In addition, the printer 150 capable of outputting an image file of an image input from the outside or an image stored therein may be connected to the digital camera 100.

The direction button 21 may include four buttons, an up button 21a, a down button 21b, a left button 21c, and a right button 21d. The direction button 21 and the menu-OK button 22 are keys input for executing various menus relating to the operation of the digital image processing apparatus such as a digital camera.

The wide-angle zoom button W or the tele-zoom button T has a wider angle of view or a narrower angle of view depending on its input. In particular, it may be used to change the size of the selected exposure area. In this case, when the wide-zoom button W is input, the size of the selected exposure area is reduced, and when the tele-zoom button T is input, the size of the selected exposure area may be increased. As the display panel 25, an image display device such as a liquid crystal display (LCD) may be used.

The display panel 25 may be included in a display unit of the digital image processing apparatus of the present invention, and a moving image may be displayed on the display unit by manipulation of a user's direction button 21 and a menu-OK button 22.

In addition, at least a part of the still images included in the moving image may be selected as the representative image by manipulation of the user's direction button 21 and the menu-OK button 22, and the selected representative images may be selected as the printer 150. Can be printed through

Meanwhile, a shutter release button 26, a flash (not shown), a power switch (not shown), and a lens unit (not shown) may be provided on the front or top surface of the digital camera 100. In addition, the front and rear of the digital camera 100 may be provided with an objective lens and an eyepiece of the viewfinder 27.

The shutter release button 26 is opened and closed to expose the film or an image pickup device such as a charge coupled device (CCD) for a predetermined time. In addition, the shutter release button records an image on the image pickup device by properly exposing a subject in conjunction with an aperture (not shown).

Also, a video may be captured according to the operation of the shutter release button 26 according to the setting of the digital camera 100.

As an embodiment of a digital image processing apparatus to which the present invention can be applied, a digital camera, a control apparatus, and a control method thereof are disclosed in US Patent Application Publication No. 2004/0130650 (name: automatic using a secondary function of the camera). Method of automatically focusing using a quadratic function in camera.

Matters relating to the digital camera, the control apparatus, and the control method disclosed in the above-mentioned US application will be included in the present specification, the detailed description thereof will be omitted.

2 is a block diagram of a control device 200 for controlling a digital image processing device, which is a preferred embodiment of the present invention. The digital image processing apparatus 200 may be mounted in the digital camera 100 of FIG. 1.

Referring to the drawing, an optical system OPS including a lens unit and a filter unit optically processes light from a subject. The lens unit of the optical system OPS includes a zoom lens, a focus lens, and a compensation lens. When the user presses the wide-angle zoom button W or the tele-zoom button T included in the user input unit INP, a signal corresponding thereto is input to the microcontroller 512.

Accordingly, as the microcontroller 212 controls the lens driver 210, the zoom motor M _Z is driven to move the zoom lens. That is, when the wide-zoom button W is pressed, the focal length of the zoom lens is shortened to widen the angle of view, and when the tele-zoom button T is pressed, the focal length of the zoom lens is increased, thereby narrowing the angle of view.

On the other hand, in the auto focusing mode, the main controller embedded in the digital signal processor 207 controls the lens driver 210 through the microcontroller 212, whereby the focus motor M _F is driven. do.

The compensation lens compensates for the overall refractive index and is not driven separately. Reference numeral M _A denotes a motor for driving an aperture (not shown).

In the filter section of the optical system OPS, an optical low pass filter removes optical noise of high frequency components. Infra-Red cut filter cuts the infrared component of the incident light.

The photoelectric conversion unit OEC may include an imaging device such as a charge coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS). The photoelectric conversion unit OEC converts light from the optical system OPS into an electrical analog signal.

The analog-to-digital converter may include a CDS-ADC (Correlation Double Sampler and Analog-to-Digital Converter) device 201. The analog-to-digital converter processes the analog signal from the photoelectric converter (OEC), removes the high frequency noise, adjusts the amplitude, and converts the analog signal into a digital signal. Here, the digital signal processor 207 controls the timing circuit 202 to control the operation of the photoelectric converter OEC and the analog-to-digital converter 201.

The real time clock 203 provides time information to the digital signal processor 207. The digital signal processor 207 processes digital signals from the CDS-ADC element 201 to generate digital image signals classified into luminance (Y value) and chromaticity (R, G, B) signals.

The light emitting unit LAMP driven by the microcontroller 212 under the control of the main controller built in the digital signal processor 207 includes a self-timer lamp, an auto-focus lamp, a mode indicating lamp, a flash standby lamp, and the like. May be included. The user input unit INP may include a direction button 21, a wide-angle zoom button W, a telephoto-zoom button T, and the like.

The digital image signal from the digital signal processor 207 is temporarily stored in the DRAM (Dynamic Random Access Memory) 204. The EEPROM (Electrically Erasable and Programmable Read Only Memory) 205 stores algorithms and setting data such as a boot program and a key input program required for the operation of the digital signal processor 207. In the memory card interface 206, a user's memory card may be attached or detached.

The digital image signal from the digital signal processor 207 is input to the display panel driver 214, whereby the image is displayed on the display panel 25.

On the other hand, the digital image signal from the digital signal processor 207 can be transmitted by serial communication via a universal serial bus (USB) connection portion 31a or an RS232C interface 208 and the connection portion 31b thereof, and a video filter ( 209 and through the video output unit 31c. Here, the digital signal processor 207 may have a microcontroller therein.

The audio processor 213 outputs the audio signal from the microphone MIC to the digital signal processor 207 or the speaker SP, and outputs the audio signal from the digital signal processor 207 to the speaker SP.

The printing unit 216 may be controlled by the digital signal processor 207 and / or the microcontroller 212 to print at least one frame among the frames included in the moving image as a representative image of the still image. have. In this case, an image may be printed to the printer 150 of FIG. 1 through the printing unit 216.

The digital image processing apparatus 200 selects at least one or more frames among frames included in a moving image as a representative image of a still image, and includes a display unit; Control unit; And a printing unit 215.

The display unit displays a moving image. The printing unit 215 outputs the selected representative image. The controller extracts the face region of the person from each frame of the video image, compares the face regions in two consecutive frames at a set time or frame interval, and determines that the change in the angle of the face is greater than the set reference value. At least one is selected as the representative image.

Two consecutive frames at a set time or frame interval may be selected as a pair of frames to be compared. That is, two consecutive frames may be representatively extracted at a predetermined time or frame interval.

In this case, two frames consecutively set at a set time or frame interval may be representative frames extracted on a section having a subtle difference, and may be frames of one second interval or two frames of 30 frame intervals. Alternatively, it may be a frame of 30 second intervals or two frames of 30 × 30 frame intervals. Alternatively, the frame may be one minute interval or two frames at 60 × 30 frame intervals.

The display units 214 and 215 may include a display panel driver 214 and a display panel 215, and may be controlled by the digital signal processor 207 and / or the microcontroller 212. As the display panel 215, the LCD 25 may be used as in the digital camera of FIG. 1.

In addition, the digital signal processor 207 and / or the microcontroller 212 may be a control unit of the present invention. That is, the digital signal processor 207 and / or the microcontroller 212 may select at least one or more frames among the frames included in the moving image as the representative image of the still image. In addition, the printing unit 215 may be controlled to print representative images.

The digital image processing apparatus 200 extracts a face region of a person from each frame of a moving image, detects a change in face angle between successive frames, and displays a frame with a large change when the face angle change is large. A representative image is printed.

That is, by extracting an image of a still image that can automatically represent the moving image from the moving image, the user can automatically select the representative image without the manual operation of selecting the desired representative image while playing the moving image directly. Therefore, user convenience for moving image printing can be improved.

In addition, a representative image of a still image based on a person's behavior may be selected and output from a moving image in a short time.

To this end, first, a face region of a person is extracted from each frame of the moving image. In this case, face region detection may use a conventional face region detection algorithm. As an example, the area where the face color is intensively distributed among the entire images may be searched to detect the area as the face area.

In addition, the pixel value of the face region can be obtained for each frame. In this case, the pixel value may be obtained by the sum of the gray level values of each pixel in the face region. Here, the change in the angle of the face can be obtained from the difference between the pixel values of two consecutive frames at a set time or frame interval.

That is, when the face angle is large by comparing the face regions in two consecutive frames at a set time or frame interval, one of the two frames, preferably the following frame, may be selected as the representative image. To this end, if a reference pixel value corresponding to the reference value is set, and a comparison value corresponding to a difference between pixel values of two consecutive frames at a set time or frame interval is larger than the reference pixel value, the subsequent frame is determined to be a large change image. Can be a representative image.

In this case, the reference pixel value may be determined according to the selected number as the number of representative images to be selected. As one embodiment, according to the order in which the comparison values for all the frames constituting the video are larger, a pair of frames to be compared with each other by the set number of representative images is selected, and at least one of the following frames is preferably represented. Can be selected as the image. A method of selecting a representative image by such a method is illustrated in the control method of the digital image processing apparatus of FIG. 5.

In another embodiment, a reference pixel value according to the number of representative images is stored in a table in advance, and a representative image is selected in a frame pair in which a comparison value is larger than a reference pixel value, and the number of the selected representative images is set. If the number is different from the number, the number of representative images is adjusted to match the number of the selected representative images by the number of the set representative images. A method of selecting a representative image by such a method is illustrated in the control method of the digital image processing apparatus of FIGS. 3 and 4.

Meanwhile, the first frame and the last frame of the video image may be basically selected as the representative image. In this case, the number of images except the first frame and the last frame is selected from the number of representative images set in the representative image selection method described above.

In addition, when a person is not included in the video image, the representative image may be selected in units of frames. That is, the frames may be selected at intervals to select the set number of representative images from all the frames constituting the video, and the images of the frames may be selected as the representative images.

The digital image processing apparatus 200 according to the present invention may be controlled by the control methods S300 and S500 of the digital image processing apparatus illustrated in FIGS. 3 to 5.

3 is a flowchart of a control method (S300) of a digital image processing apparatus according to an exemplary embodiment of the present invention. 4 is a flowchart illustrating a representative image number adjustment step S400 selected in the control method S300 of the digital image processing apparatus of FIG. 3.

Referring to the drawings, the control method (S300) of the digital image processing apparatus selects at least one or more frames among the frames included in the moving image image as the representative image of the still image, and setting the number of the representative image setting step (S320); Setting a reference value (S330); Face region extraction step (S340); Pixel value and comparison value extraction step (S350); Representative image selection step (S360); A printing step (S370); And a representative image adjusting step (S400).

The control method (S300) of the digital image processing apparatus extracts a face area of a person from each frame of a moving image, detects a change in face angle between successive frames, and a frame having a large change when a change in face angle is large. Is printed as a representative image which is a still image.

In this case, if the difference in the pixel value of the face region between the pair of frames to be compared is greater than the reference pixel value corresponding to the reference value, it is determined that the face angle change is large, and at least one of the following pairs of frames is preferably The frame can be selected as the representative image.

That is, by extracting an image of a still image that can automatically represent the moving image from the moving image, the user can automatically select the representative image without the manual operation of selecting the desired representative image while playing the moving image directly. Therefore, user convenience for moving image printing can be improved.

In addition, a representative image of a still image based on a person's behavior may be selected and output from a moving image in a short time.

The control method (S300) of the digital image processing apparatus is performed by the control apparatus 200 of the digital image processing apparatus illustrated in FIG. 2. For the same items as those of FIG. 2, the description thereof will be referred to.

In the set representative image number setting step (S320), the set representative image number corresponding to the number of representative images to be selected is set. In this case, a predetermined value may be set as the default number of representative images, and a specific value desired by the user may be set by the user.

In operation S311, a moving image may be played according to a user's selection in advance. At this time, any one frame in the moving image may be displayed as a still image. When a print command is input by a user input while the moving image is displayed (S312), and when the moving image is selected (S313), the representative image of the still image may be selected and only the representative images may be printed.

In addition, a step (S325) of selecting a method of extracting the representative image may be further provided. In this case, as the method of extracting the representative image, any one of a frame number unit, a change in the number of people, and a change in the face angle may be selected. In this case, however, the representative image extraction method according to the change of the facial angle may be designated as a default.

In addition, when the method of extracting the representative image is set to detect the change in the angle of the face, the reference value setting step S330 to the pixel value and the comparison value extraction step S350 may be performed.

In the reference value setting step S330, a reference pixel value may be set according to the set number of representative images. To this end, the reference pixel value according to the number of preset representative images is stored as a table, and the reference pixel value may be selected according to the number of representative images set in the table.

In the face region extraction step (S340), the face region of the person is extracted from each frame of the moving image. In this case, face region detection may use a conventional face region detection algorithm. As an example, the area where the face color is intensively distributed among the entire images may be searched to detect the area as the face area.

Meanwhile, when a person is not included in the video image, the representative image may be selected in units of frames. That is, the frames may be selected at intervals to select the set number of representative images from all the frames constituting the video, and the images of the frames may be selected as the representative images.

In the extracting the pixel value and the comparison value (S350), the pixel value of the face region may be extracted from each frame, and the comparison value may be extracted from the difference between the pixel values of two consecutive frames at a predetermined time or frame interval. In this case, the pixel value may be obtained by the sum of the gray level values of each pixel in the face region.

In the representative image selection step (S360), the representative image may be selected by comparing the comparison value with a set reference pixel value (S355). In this case, the angle change of the face may be obtained from the difference between the pixel values of two consecutive frames at a predetermined time or frame interval.

That is, in the case where the angle change of the face is large by comparing the face regions in the two frames to be compared, one of the two frames, preferably the following frame, may be selected as the representative image. To this end, when the comparison value corresponding to the difference between the pixel values of the two frames to be compared is larger than the reference pixel value, the subsequent frame may be determined as an image having a large change, and may be a representative image.

Meanwhile, the first frame and the last frame of the video image may be basically selected as the representative image. In this case, the number of images except the first frame and the last frame is selected from the number of representative images set in the representative image selection method described above.

The face region extraction step S340 to the representative image selection step S360 may be performed in units of frames. Therefore, by determining whether the current frame is the last frame (S361), the face region extraction step S340 to the representative image selection step S360 may be performed until the last frame is compared. When the current frame is not the last frame, the face region extraction step S340 to the representative image selection step S360 may be performed with respect to the next frame S380.

In the representative image adjustment step (S400), it is determined whether the number of the selected representative image matches the number of the set representative image (S362), and the number of the selected representative image is adjusted when not recorded. That is, once the representative values are selected in a frame pair in which the comparison value is larger than the reference pixel value, and if the number of the selected representative images is different from the set number of representative images, the number of representative images is adjusted (S400). The number of images is adjusted to the number of set representative images.

A method of adjusting the number of representative images by this method is illustrated in FIG. 4.

In the printing step S370, a representative image is printed. In this case, the number of representative images that can be output may be the number of set representative images. Also, a plurality of representative images may be output on the index screen.

Representative image adjustment step (S400) is a step of determining whether the number of the selected representative image is larger than the set representative image (S405), the re-selection step (S410, S420 when the number of the selected representative image is larger than the set representative image number) And a reselection step (S430, S440, S450) when the number of the selected representative image is smaller than the set representative image number.

If it is determined whether the number of the selected representative image is larger than the set representative image (S405), and if the number is larger, the first frame and the last frame are reselected as the representative image (S410), and the comparison value among the selected representative images is larger. The representative image is reselected up to the number of the representative images set in order (S420).

If it is determined by determining whether the number of the selected representative image is larger than the set representative image (S405), the number of representative images to be added is calculated (S430), the time interval of the selected representative images is obtained, and the representative to be added. According to the number of images, additional intervals are selected in order of intervals having a long time interval (S440), and a representative image is added in the additional interval (S450).

5 is a flowchart of a control method S500 of a digital image processing apparatus according to another exemplary embodiment of the present invention.

Referring to the drawings, the control method (S500) of the digital image processing apparatus selects at least one or more frames from among the frames included in the moving image image as the representative image of the still image, the setting representative image number setting step (S520); Face region extraction step (S540); A pixel value calculating step (S545); Comparison value calculating step (S550); Representative image selection step (S560); And a printing step (S370).

In the present embodiment, with respect to the control method (S300) of the digital image processing apparatus illustrated in FIGS. 3 and 4, first, a comparison value is obtained in frames compared in all the frames constituting the moving image. According to the large order, as many pairs of frames to be compared as the set representative images are selected, and at least one of the following frames is preferably selected as the representative images.

For the present embodiment, the same matters as in the control method (S300) of the digital image processing apparatus are referred to the description thereof, and a detailed description thereof will be omitted.

In the setting representative image number setting step (S520), the number of setting representative images corresponding to the number of representative images to be selected is set.

In operation S511, a moving image may be reproduced according to a user's selection in advance. When a moving command is input by a user input while the moving image is displayed (S512), and when the moving image is selected (S513), the representative image of the still image may be selected and only the representative images may be printed.

In addition, a step (S525) of selecting a method of extracting the representative image may be further provided. In this case, as the method of extracting the representative image, any one of a frame number unit, a change in the number of people, and a change in the face angle may be selected. In addition, when the method of extracting the representative image is set to detect the change in the facial angle, the face region extraction step S540 to the comparison value calculation step S550 may be performed.

In the face region extraction step (S540), the face region of the person is extracted from each frame of the video image. Meanwhile, when a person is not included in the video image, the representative image may be selected in units of frames.

In the pixel value calculating step S545, the pixel value of the face region is calculated in each frame. In this case, the pixel value may be obtained by the sum of the gray level values of each pixel in the face region. In the comparison value calculating step S550, a comparison value may be calculated from a difference between pixel values of two consecutive frames at a set time or frame interval.

In the representative image selection step (S560), the representative images are selected by the number of the set representative images in the order of the large comparison value. That is, according to the order in which the comparison values are large, the frame pairs to be compared with each other by the set number of representative images can be selected, and the following frames can be selected as the representative images.

In the printing step S370, a representative image is printed.

At this time, by extracting the image of the still image that can automatically represent the moving image from the moving image, the user can automatically select the representative image without the manual operation of selecting the desired representative image while playing the video directly. Therefore, user convenience for moving image printing can be improved.

In addition, a representative image of a still image based on a person's behavior may be selected and output from a moving image in a short time.

Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, it is merely an example, and those skilled in the art may realize various modifications and equivalent other embodiments therefrom. I can understand. Accordingly, the true scope of protection of the invention should be defined only by the appended claims.

1 is a diagram illustrating a rear surface of a digital camera as an embodiment of a digital image processing apparatus according to the present invention.

FIG. 2 is a block diagram schematically illustrating a control device of the digital image processing apparatus of FIG. 1.

3 is a flowchart schematically illustrating a control method of a digital image processing apparatus as a preferred embodiment according to the present invention.

FIG. 4 is a flowchart schematically illustrating an operation of adjusting the number of representative images selected in the control method of the digital image processing apparatus of FIG. 3.

5 is a flowchart schematically illustrating a control method of a digital image processing apparatus according to another exemplary embodiment of the present invention.

Claims (8)

By selecting at least one frame from among the frames included in the video image as a representative image of the still image, A display unit displaying the moving image; And When the face area of the person is extracted from each frame of the video image, and the face area is determined to be larger than the set reference value by comparing the face areas in two consecutive frames at a set time or frame interval, And a controller for selecting at least one of the representative images. The method of claim 1, And a printing unit for outputting the representative image. The method of claim 1, The pixel value is obtained by the sum of the gray level values of each pixel of the face region, And obtaining a change in angle of the face from the difference between the pixel values of the two consecutive frames. By selecting at least one frame from among the frames included in the video image as a representative image of the still image, Setting the number of representative images to be selected; Extracting a face region of a person from each frame of the moving image; Extracting pixel values of the face area in each of the frames; Extracting a comparison value from the difference between the pixel values of two consecutive frames at a set time or frame interval; And And selecting the representative image by comparing the comparison value with a set reference value. The method of claim 4, wherein And controlling the representative image to be printed. The method of claim 4, wherein And selecting at least one of two frames from which the comparison value is calculated as the representative image when the comparison value is larger than the reference value. The method of claim 4, wherein Selecting a method of extracting the representative image; The method of extracting the representative image, the control method of the digital image processing apparatus, any one of the number of frames, the number of people, and the change of the face angle can be selected. The method of claim 4, wherein And adjusting the number of the selected representative images when the number of the selected representative images does not match the set number of the representative images.

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