KR101396345B1 - Apparatus for processing digital image and method for controlling the same - Google Patents

Abstract

The present invention relates to a control apparatus and method for a digital image processing apparatus capable of extracting a representative image based on characteristics of respective images constituting a moving image by comparing only specific areas of respective images in moving images to select representative images . The present invention is characterized in that at least one frame among frames included in a moving image is selected as a representative image of a still image, the display unit displaying the moving image; Extracting a face region of a person in each frame of the moving image, comparing the face region in two consecutive frames at a predetermined time or frame interval, and when it is determined that the angle change of the face is larger than a set reference value, And a control unit for selecting at least one of the representative images as the representative image.

Description

[0001] Digital image processing apparatus and control method thereof [0002]

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

Typically, the digital image processing apparatus includes all devices that process images of a digital camera, a PDA (personal digital assistant), a phone camera, a PC camera, or the like and use an image recognition sensor.

In a digital image processing apparatus, there are cases where not only a still image but also a moving image can be taken and stored as a file. There is also a case where a movie file is printed or an album of a still image is generated from a movie. To do this, it is necessary to extract still images from video files.

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

For this purpose, in a conventional digital image processing apparatus, a user can directly view a moving image and determine a representative image to generate a still image in order to obtain a still image from the moving image file.

However, when the user directly examines the moving image and directly extracts the representative image, there is an inconvenience that the user must directly select a desired still image while viewing the moving image.

The present invention provides a digital image processing apparatus and a control method thereof that can extract a representative image based on characteristics of respective images constituting a moving image by comparing only specific areas of respective images in moving images to select representative images .

The present invention is characterized in that at least one frame among frames included in a moving image is selected as a representative image of a still image, the display unit displaying the moving image; Extracting a face region of a person in each frame of the moving image, comparing the face region in two consecutive frames at a predetermined time or frame interval, and when it is determined that the angle change of the face is larger than a set reference value, And a controller for selecting at least one of the representative images as the representative image.

And a printing unit for outputting the representative image.

A pixel value may be obtained by summing the gray level values of the respective pixels of the face region and an angle change of the face may be obtained from a difference between the pixel values of the two consecutive frames.

According to another aspect of the present invention, there is provided a method of generating a still image, the method comprising: setting at least one frame among frames included in a moving image as a representative image of a still image; Extracting a face region of a person in each frame of the moving image; Extracting pixel values of the face region in each of the frames; Extracting a comparison value from a difference between the pixel values of two consecutive frames at a set time or frame interval; And comparing the comparison value with a preset reference value to select the representative image.

And printing the representative image.

And selecting a method of extracting the representative image, wherein the method of extracting the representative image may be selected from among a change in the number of frames, a change in the number of people, and a change in the face angle.

And adjusting the number of the representative images if the number of representative images does not match the number of the representative images.

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

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

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 FIG. 1, a direction button 21, a menu-OK button 22, a wide angle-zoom button W, a telephoto-zoom button Zoom ) Button T, a display panel 25, and the like. In addition, the digital camera 100 may be connected to a printer 150 capable of outputting an image inputted from the outside or an image file of an image stored therein.

The direction button 21 may include a total of four buttons including 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 for inputting various menus related to the operation of the digital image processing apparatus such as a digital camera.

Wide angle-zoom button W or telephoto-zoom button T widens the view angle or narrows the view angle depending on the input. In particular, it can be used to change the size of the selected exposure area. At this time, when the wide-angle zoom button W is input, the size of the selected exposure area is reduced, and when the telephoto-zoom button T is input, the size of the selected exposure area may be enlarged. 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 the display unit of the digital image processing apparatus of the present invention and the moving image may be displayed on the display unit by operations of the direction button 21 and the menu-OK button 22 of the user.

Also, at least some of the still images included in the moving image may be selected as the representative image by the operation of the direction button 21 and the menu-OK button 22 of the user, Lt; / RTI >

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

The shutter release button 26 is opened and closed to expose an image pickup element or film such as a CCD (Charge Coupled Device) to light for a predetermined time. Further, the shutter release button interlocks with an iris (not shown) to appropriately expose the subject to record the image on the imaging element.

Also, according to the setting of the digital camera 100, the moving picture may be photographed according to the operation of the shutter release button 26. [

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

The digital camera, its control device, and control method disclosed in the above-mentioned U.S. application are incorporated in this specification, and a detailed description thereof will be omitted.

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

Referring to the drawings, 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-zoom button W or telephoto-zoom button T included in the user input unit INP, a corresponding signal is input to the micro controller 512. [

Accordingly, as the microcontroller 212 controls the lens driving unit 210, the zoom motor M _Z is driven to move the zoom lens. That is, when the wide-angle zoom button W is depressed, the focal length of the zoom lens is shortened to enlarge the angle of view, and when the telephoto-zoom button T is depressed, the focal length of the zoom lens becomes long and the angle of view becomes narrow.

Meanwhile, in the auto focusing mode, the main controller built in the digital signal processor 207 controls the lens driving unit 210 through the micro controller 212, so that the focus motor M _F is driven do.

The compensation lens compensates for the overall refractive index and is not driven separately. Reference symbol 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 a high frequency component. Infra-red cut filter blocks the infrared component of incident light.

The photoelectric conversion unit OEC may include an image pickup device such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal-Oxide-Semiconductor). The photoelectric conversion unit OEC converts light from the optical system OPS into an electrical analog signal.

The analog-to-digital conversion unit may include a CDS-ADC (Correlation Double Sampler and Analog-to-Digital Converter) 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 operations of the photoelectric conversion unit (OEC) and the analog-digital conversion unit 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 device 201 to generate digital image signals classified into luminance (Y value) and chromaticity (R, G, B) signals.

A self-timer lamp, an auto-focus lamp, a mode indicating lamp, a flash standby lamp, and the like are connected to the light emitting unit (LAMP) driven by the microcontroller 212 under the control of the main controller incorporated in the digital signal processor 207 . The user input unit INP may include a direction button 21, a wide-angle zoom button W, a tele-zoom button T, and the like.

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

The digital image signal from the digital signal processor 207 is input to the display panel driver 214, whereby an 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 through a USB (Universal Serial Bus) connection part 31a or an RS232C interface 208 and its connection part 31b, 209 and the video output unit 31c as video signals. Here, the digital signal processor 207 may incorporate a micro controller 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 is 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. At this time, the printer 150 of FIG. 1 can print an image through the printing unit 216.

The digital image processing apparatus 200 selects at least one frame among the frames included in the moving image as a representative image of the still image. A control unit; And a printing unit 215, as shown in FIG.

A moving image is displayed on the display section. The printing unit 215 outputs the selected representative image. The control unit extracts the face region of the person in each frame of the moving image and compares the face region in two consecutive frames at a predetermined time or frame interval. When it is determined that the angle change of the face is larger than the set reference value, Select at least one representative image.

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

In this case, two consecutive frames at a set time or frame interval may be representative frames extracted on an interval having a subtle difference, and may be frames of 1 second interval or two frames of 30 frame interval. Alternatively, it may be a frame of 30 seconds interval or two frames of 30 占 30 frame interval. Alternatively, it may be a frame of 1 minute interval or two frames of 60 占 30 frame interval.

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. The display panel 215 may be an LCD 25 as in the digital camera of Fig.

In addition, the digital signal processor 207 and / or the microcontroller 212 may be the control unit of the present invention. That is, the digital signal processor 207 and / or the microcontroller 212 can select at least one frame among the frames included in the moving image as the representative image of the still image. In addition, the representative image can be printed by controlling the printing unit 215. [

The digital image processing apparatus 200 extracts a face region of a person in each frame of the moving image and detects a change in the face angle between consecutive frames. When the change in the face angle is large, As a representative image.

That is, by extracting an image of a still image that can automatically represent a moving image from a moving image, the representative image can be automatically selected without manually performing a manual selection of a desired representative image while the user directly plays the moving image. Therefore, user convenience for moving picture printing can be improved.

In addition, a representative image of a still image based on the behavior of a person can be selected and output from a moving image within a short period of time.

To do this, the face region of the person is first extracted in each frame of the moving image. At this time, a normal face region detection algorithm can be used for face region detection. In one embodiment of the present invention, an area in which a face color is intensively distributed can be searched in the entire image, and the area can be detected as a face area.

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

That is, when two or more consecutive frames are compared at a set time or frame interval, and the face angle is changed, the next frame, preferably one of the two frames, may be selected as the representative image. For this purpose, a reference pixel value corresponding to the reference value is set, and if the comparison value corresponding to the difference between the pixel values of two consecutive frames at the set time or frame interval is larger than the reference pixel value, And can be a representative image.

At this time, the reference pixel value may be determined according to the number of representative images to be selected. According to one embodiment, a frame pair is selected such that the number of frames to be compared is the same as the number of set representative images, and at least one of the frames, Images can be selected. A method of selecting representative images by such a method is shown in the control method of the digital image processing apparatus of Fig.

In another embodiment, a representative image is selected in a frame pair in which a reference pixel value according to the number of representative images is stored in advance as a table, a comparison value is once greater than a reference pixel value, and a representative image is selected. The number of representative images is adjusted so that the number of representative images is equal to the number of representative images. A method of selecting representative images by such a method is shown in the control method of the digital image processing apparatus of Figs. 3 and 4. Fig.

On the other hand, the first frame and the last frame of the moving image can be basically selected as representative images. In this case, the number of images excluding the first frame and the last frame is selected from the number of representative images set in the representative image selecting method described above.

If the moving image does not include a person, the representative image can be selected in units of frames. That is, a frame can be selected at intervals such that a set number of representative images can be selected from all the frames constituting a moving image, and an image of the frame can be selected as a representative image.

The digital image processing apparatus 200 according to the present invention can be controlled by the control method (S300, S500) of the digital image processing apparatus shown in FIG. 3 to FIG.

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

Referring to the drawings, a control method of a digital image processing apparatus (S300) is a method of selecting a representative image of a still image by selecting at least one frame among frames included in a moving image. A reference value setting step S330; A face region extraction step (S340); Extracting a pixel value and a comparison value (S350); A representative image selection step S360; Printing step S370; And a representative image adjusting step S400.

A control method S300 of a digital image processing apparatus extracts a face region of a person in each frame of a moving image and detects a change in a face angle between consecutive frames. When a change in a face angle is large, As a representative image which is a still image.

At this time, if the difference between the pixel values of the face region between the pair of frames to be compared is larger than the reference pixel value corresponding to the reference value, it is determined that the face angle change is large, Frame can be selected as the representative image.

That is, by extracting an image of a still image that can automatically represent a moving image from a moving image, the representative image can be automatically selected without manually performing a manual selection of a desired representative image while the user directly plays the moving image. Therefore, user convenience for moving picture printing can be improved.

In addition, a representative image of a still image based on the behavior of a person can be selected and output from a moving image within a short period of time.

The control method (S300) of the digital image processing apparatus is performed in the control apparatus 200 of the digital image processing apparatus shown in Fig. 2, and the same explanation as that of Fig. 2 is referred to the description thereof.

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

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

In addition, a step of selecting a method of extracting the representative image (S325) may be further provided. At this time, a method of extracting the representative image may be selected from among the number of frames, the number of persons, and the change of the face angle. However, in this case, the representative image extraction method according to the change of the face angle can be designated as a default.

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

In the reference value setting step S330, the reference pixel value may be set according to the set representative image number. For this purpose, a reference pixel value according to the number of preset representative images is stored as a table, and a reference pixel value can be selected according to the number of set representative images 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. At this time, a normal face region detection algorithm can be used for face region detection. In one embodiment of the present invention, an area in which a face color is intensively distributed can be searched in the entire image, and the area can be detected as a face area.

On the other hand, if the moving image does not include a person, representative images can be selected in units of frames. That is, a frame can be selected at intervals such that a set number of representative images can be selected from all the frames constituting a moving image, and an image of the frame can be selected as a representative image.

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

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

That is, when comparing face regions in two frames to be compared, it is possible to select one of the two frames, preferably a subsequent frame, as a representative image when the angle change of the face is large. For this, if the comparison value corresponding to the difference between the pixel values of the compared two frames is larger than the reference pixel value, the following frame can be regarded as an image having a large change and become a representative image.

On the other hand, the first frame and the last frame of the moving image can be basically selected as representative images. In this case, the number of images excluding the first frame and the last frame is selected from the number of representative images set in the representative image selecting method described above.

The face region extraction step S340 to the representative image selection step S360 may be performed on a frame-by-frame basis. Accordingly, it is determined whether the current frame is the last frame (S361), and the face region extraction step S340 to the representative image selection step S360 may be performed until the last frame is compared. If the current frame is not the last frame, the face region extraction step (S340) to the representative image selection step (S360) may be performed for the next frame (S380).

In the representative image adjustment step (S400), it is determined whether the number of the representative images selected matches the number of the set representative images (S362). If not, the number of representative images selected is adjusted. That is, the representative images are selected in a frame pair whose comparison value is larger than the reference pixel value, and when the number of 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 representative images.

A method of adjusting the number of representative images by this method is shown in Fig.

In the printing step (S370), the representative image is printed. At this time, the number of representative images that can be output can be the number of set representative images. Also, a plurality of representative images can be output as an index screen.

In the representative image adjustment step S400, it is determined whether or not the number of the representative images selected is larger than the number of the representative images. If the number of the selected representative images is greater than the number of the representative images, (S430, S440, S450) when the number of selected representative images is smaller than the number of set representative images.

If it is determined in step S405 that the number of selected representative images is larger than the set representative image number, the first frame and the last frame are re-selected as the representative image in step S410. The representative images are re-ordered up to the number of representative images set in the order (S420).

If it is determined in step S405 that the number of selected representative images is larger than the set representative image number, the number of representative images to be added is calculated in step S430. In step S440, an additional section is selected in a section having a long time interval according to the number of images, and a representative image is added in an additional section S450.

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

Referring to FIG. 5, a control method (S500) of a digital image processing apparatus selects at least one frame among frames included in a moving image as a representative image of a still image. A face region extraction step (S540); Pixel value calculation step S545; Calculating a comparison value (S550); A representative image selection step S560; And a printing step (S370).

In the present embodiment, the comparison method in the frames compared in all the frames constituting the moving image is obtained for the control method (S300) of the digital image processing apparatus shown in Figs. 3 and 4, In accordance with a large order, a number of mutually compared frame pairs is selected, and at least one of the frames is preferably selected as the representative image.

The same elements as those in the control method (S300) of the digital image processing apparatus according to the present embodiment will be described with reference to the description thereof, and a detailed description thereof will be omitted.

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

The moving image can be reproduced according to the user's selection in the pre-operation (S511). When a moving image is displayed, a printing command is inputted by an input of a user (S512). When a moving image is selected (S513), a representative image of a still image is selected and only representative images can be printed.

In addition, a step of selecting a method of extracting the representative image (S525) may be further included. At this time, a method of extracting the representative image may be selected from among the number of frames, the number of persons, and the change of the face angle. Also, when the method of extracting the representative image is set to detect a change in the face angle, the face region extraction step S540 to the comparison value calculation step S550 may be performed.

In the face region extracting step (S540), the face region of the person is extracted in each frame of the moving image. On the other hand, if the moving image does not include a person, representative images can be selected in units of frames.

In the pixel value calculation step S545, the pixel value of the face area is calculated in each frame. At this time, the pixel value can be obtained by adding the gray level values in each pixel in the face area. In the comparison value calculation step (S550), a comparison value can 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 set representative images according to the order of comparison values. That is, according to the order in which the comparison values are large, frame pairs that are compared with each other for the set number of representative images are selected, and the following frame can be selected as the representative image.

In the printing step (S370), the representative image is printed.

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

In addition, a representative image of a still image based on the behavior of a person can be selected and output from a moving image within a short period of time.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, You will understand. Accordingly, the true scope of protection of the present invention should be determined only by the appended claims.

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

2 is a block diagram schematically showing a control apparatus of the digital image processing apparatus of FIG.

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

4 is a flowchart schematically showing a step of adjusting the number of representative images selected in the control method of the digital image processing apparatus of FIG.

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

Claims (8)

At least one frame among the frames included in the moving image is selected as the representative image of the still image, A display unit for displaying the motion image; And Extracting a face region of a person in each frame of the moving image, comparing face regions in two consecutive frames at a predetermined time or frame interval, and determining that the face angle is larger than a set reference value, And a control unit for selecting at least one representative image. The method according to claim 1, And a printing unit for outputting the representative image. The method according to claim 1, A pixel value is obtained by summing the gray level values of the respective pixels of the face region, And obtains a change in the angle of the face from a difference between the pixel values of the two consecutive frames. At least one frame among the frames included in the moving image is selected as the representative image of the still image, Setting a number of representative images to be selected; Extracting a face region of a person in each frame of the moving image; Extracting pixel values of the face region in each of the frames; Extracting a comparison value from a difference between the pixel values of two consecutive frames at a set time or frame interval; And Comparing the comparison value with a preset reference value and selecting at least one of the two frames from which the comparison value is calculated when the comparison value is greater than the reference value as the representative image . 5. The method of claim 4, And printing the representative image. delete 5. The method of claim 4, Further comprising the step of selecting a method of extracting the representative image, Wherein the method for extracting the representative image can select any one of a change in the number of frames, a change in the number of people, and a change in a face angle. 5. The method of claim 4, And adjusting the number of the representative images when the number of the representative images does not match the number of the representative images.

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