KR101467873B1 - Apparatus and method for capturing digital image according to detecting hand shake - Google Patents

Abstract

The present invention relates to a digital image photographing apparatus and method having an image shake detecting function. The digital video image pickup apparatus according to the shaking motion includes a digital signal processing means for comparing the previous live view image data with the current live view image data to determine hand shake and shooting a single image by automatic exposure in the case where no shaking has occurred do.

Camera shake determination, shooting control, noise reduction

Description

 BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for capturing a digital image,

The present invention relates to a digital image photographing apparatus and method having an image shake detecting function.

An electronic image stabilization method for correcting an unintentional hand movement using two images of a long exposure and a short exposure, an optical image stabilizer (OIS) method for shifting a lens or an image pickup element to correct an unintentional hand movement, There is a high-sensitivity photographing method for correcting an unintentional hand movement using a noise removing filter.

However, in the case of the electronic image stabilization method, since the two images of the short exposure and the long exposure are used, the data transmission time becomes longer and the performance may be poor in terms of the speed recognized by the user. In addition, the image stabilization methods of the OIS method are disadvantageous in that power consumption is large compared with the conventional technique for driving a separate hardware device, and image quality deteriorates due to micro-vibration noise. Also, in the case of the camera shake correction method using the high-sensitivity shooting, since the noise is reduced by using the noise reduction filter, the image quality may deteriorate.

The technical problem to be solved by the present invention is to provide a digital image photographing apparatus and method according to the camera shake detection for determining whether or not the camera shake prevention function is applied using the camera shake after the camera shake in the live view image stage .

According to an aspect of the present invention, there is provided a digital video image pickup apparatus for detecting camera shake according to the first exemplary embodiment of the present invention, which compares previous live view image data with current live view image data to determine camera shake, And a digital signal processing means for photographing a single image by automatic exposure if the image is not recorded.

In the present invention, the digital signal processing unit may include a shaking motion determining unit for comparing the previous live view image data with the current live view image data to determine hand shake; An image capturing control section for capturing a single image by automatic exposure by a first control signal and capturing two images of different exposure by a second control signal; And a control unit for outputting a first control signal to the photographing control unit when no camera shake is detected as a result of the shaking motion and outputting a second control signal to the photographing control unit when the shaking motion occurs.

In order to solve the technical problem to be solved by the present invention, the digital video image pickup apparatus according to the second embodiment of the present invention is configured to compare the previous live view image data with the current live view image data to determine hand shake, And digital signal processing means for photographing the image without removing the noise of the image if it is not performed.

In the present invention, the digital signal processing unit may include a shaking motion determining unit for comparing the previous live view image data with the current live view image data to determine hand shake; A noise removing filter for performing the noise removing operation by a second control signal without performing a noise removing operation for lowering the resolution of the image by a first control signal; And a controller for outputting the first control signal to the noise elimination filter when no camera shake is generated as a result of the shaking motion and outputting a second control signal to the noise elimination filter when the shaking motion occurs.

According to an exemplary embodiment of the present invention, the shaking motion determiner may include a calculator for calculating a difference between pixel values of the previous live view image and a current live view image; The control unit may output the first control signal when the difference between the pixel values is smaller than the reference value, and may output the first control signal when the difference between the pixel values is less than the reference value The second control signal may be output.

In the present invention, the shaking motion determining unit may include: a block setting unit that divides the pixels of the live view image into a plurality of blocks; An operation unit for calculating a difference between pixel values of the previous live view image and the current live view image for each block; A comparison unit comparing the pixel value difference (Error) with a reference value for each block; A counting unit counting the number of blocks having the same comparison result; And a number determination unit for comparing the number of the counted blocks with a reference number, and the controller may output the first control signal when the number of the counted blocks is larger than the reference number, The second control signal may be output when the number of the first control signals is not greater than the reference number.

In the present invention, the shaking motion determiner may include a calculator for calculating a difference between pixel values of the live view images; A comparing unit comparing the difference of the pixel values with a reference value to determine that the correlation between the live view images is high if the difference between the pixel values is smaller than the reference value and determining that the correlation between the live view images is low if the difference is not small; And a maintenance determination unit for determining whether the correlation determination result between the previous live view image and the current live view image matches the correlation determination result between the current live view image and the next live view image, According to the determination result, the first or second control signal may be output if they match, the second control signal may be output if the last live view image is input, and if the last live view image is input, the second control signal may be output.

According to an embodiment of the present invention, there is provided a digital image capturing method according to an exemplary embodiment of the present invention. The digital image capturing method includes: determining a shaking motion by comparing previous live view image data with current live view image data; And a photographing step of photographing a single image by automatic exposure in the case where no camera-shake is detected as a result of the shaking motion, and photographing two images of different exposure in the case where the camera-shake occurs.

According to another aspect of the present invention, there is provided a digital image capturing method according to the second exemplary embodiment for determining hand shake when comparing previous live view image data with current live view image data; A noise removing step of performing the noise removing operation when the camera shake is detected as a result of the shaking motion determination without performing a noise removing operation to lower the resolution of the image when the shaking motion does not occur as a result of the shaking motion determination; And a photographing step of photographing the image in which the noise is not removed or the noise is removed.

In the present invention, the shaking motion determination step may include calculating a difference between pixel values of the previous live view image and a current live view image, Comparing the difference of the pixel values with a reference value; And determining that no camera shake has occurred when the difference between the pixel values is smaller than the reference value and determining that the shaking has occurred if the difference between the pixel values is not smaller than the reference value.

In the present invention, the shaking motion determination step may include: dividing the pixels of the live view image into a plurality of blocks; Calculating a difference between pixel values of the previous live view image and the current live view image for each block; Comparing the pixel value difference (Error) with a reference value for each block; Counting the number of blocks having the same comparison result; Comparing the number of the counted blocks with a reference number; And determining that no camera shake has occurred when the number of the counted blocks is greater than the reference number and determining that camera shake has occurred if the number of the counted blocks is not greater than the reference number.

In the present invention, the shaking motion determination step may include calculating a difference between pixel values of the live view images; Comparing the difference of the pixel values with a reference value, determining that the correlation of the live view images is high if the difference of the pixel values is smaller than the reference value, and determining that the correlation of the live view images is low if the difference is not small; Determining whether a result of correlation between the previous live view image and the current live view image and a result of correlation between the current live view image and the next live view image match; And judging whether or not the camera shake occurs when the correlation determination results are coincident with each other. If the camera shake does not coincide, it is determined whether the last live view image is input, and if the last live view image is input, it is determined that camera shake has occurred.

As described above, according to the present invention, it is possible to determine whether or not the image stabilization function is applied by performing the camera-shake determination in the live view image stage before shooting, It is possible to improve the processing speed by shooting only a single image with automatic exposure and shortening the data transmission time without needing to capture the other two images.

In addition, in the case where no camera shake occurs in the camera shake correction method using the high-sensitivity shooting, the operation of the noise reduction filter can be stopped to obtain a good image without deterioration of image quality.

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

1 is a perspective view showing the front and upper contours of a digital image photographing apparatus.

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

The shutter-release button 11 generates the first and second image pickup signals by the photographer input. When the first shutter-release button 11 is input as a half-shutter signal, the digital image processing apparatus focuses and adjusts the amount of light. At this time, the display unit 23 is lit with a green light . When the focus of the first shutter-release button 11 is focused and the amount of light is adjusted, a second shutter-release button 11 as a full shutter signal is input to capture an image.

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

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

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

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

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

The wide-angle zoom button 21w or the telephoto-zoom button 21t widens the view angle or narrows the view angle depending on the input, in particular, when the size of the selected exposure area is to be changed. When the wide angle-zoom button 21w is input, the size of the selected exposure area is reduced, and when the telephoto-zoom button 21t is input, the size of the selected exposure area is increased.

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

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

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

FIG. 3 is a block diagram showing a configuration of a digital image photographing apparatus according to the present invention. The display unit 23, the user input unit 31, the image pickup unit 33, the image processing unit 35, 37 and a digital signal processing unit 39. [

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

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

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

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

The digital signal processing unit 39 judges camera shake by comparing the previous live view image data with the current live view image data, and when a camera shake does not occur, it takes one image by automatic exposure, The live view image data is compared to judge the camera shake, and when the camera shake does not occur, the image is captured without removing the noise of the image.

To this end, the digital signal processing unit 39-1 includes a shaking motion determining unit 39-1, a photographing control unit 39-2, a noise removing unit 39-3, and a control unit 39-4.

In the present invention, two embodiments are proposed for digital image capturing according to shaking motion detection. The first embodiment is a digital image photographing apparatus according to the camera-shake detection by the electronic camera-shake correcting method including the shaking motion judging unit 39-1, the photographing control unit 39-2 and the control unit 39-4, The example is a digital image photographing apparatus according to the camera shake detection by the camera shake correction method through the high-sensitivity photographing including the shaking motion determining unit 39-1, the noise removing unit 39-3, and the control unit 39-4.

First, the first embodiment will be described.

The shaking motion determiner 39-1 compares the previous live view image data with the current live view image data to determine hand shake.

The photographing control section 39-2 photographs one image of the image by the automatic exposure in accordance with the first control signal and controls the photographing section 33 and the photographing section 33 to photograph two images of different exposure by the second control signal, And controls the processing unit 35. Here, the first control signal and the second control signal are outputted from the control unit 39-4.

The control unit 39-4 receives the shaking motion determination result from the shaking motion determination unit 39-1 and outputs the first control signal to the imaging control unit 39-2 when no shaking motion occurs, And outputs a second control signal to the control unit 39-2.

In this way, if there is no camera shake, only one image with automatic exposure is shot, without needing to take two images with different exposure, so that the data transmission time is shortened and the processing speed can be improved.

4A to 4C show detailed structures of the shaking motion determiner 39-1 of the first to third embodiments.

The shaking motion determining unit 39-1 according to the first embodiment shown in FIG. 4A includes a computing unit 39-11 and a comparing unit 39-12.

The calculating unit 39-11 calculates the difference between the pixel value of the previous live view image input in the previous time and the pixel value of the current live view image input later. The previous live view image and the current live view image may be image data of consecutive frames in time, but are not limited thereto. The operation unit 39-11 squares the pixel value difference between the previous live view image and the current live view image, and repeatedly performs the above operation on all the pixels to sum the squared values.

The difference in pixel values (Error) is a sum of sequard differences (SSD) summing the square of the pixel value difference of each pixel of live view images. Therefore, if the correlation between the previous and current live view images is high, the pixel value difference is small, and if the correlation is low, the pixel value difference is large. That is, when the correlation is high, the previous live view image is almost similar to the current live view image, and the probability of occurrence of the shaking motion is low as in the case of inputting the live view images using the tripod. On the contrary, if the correlation is low, it can be determined that the live view images are being input while the previous live view image is different from the current live view image. Or the subject may be moved to determine that the correlation is low. Therefore, when the correlation is high, no camera shake will occur, so that it is not necessary to shoot two images with different exposure and synthesize them, and one image can be photographed by automatic exposure. Therefore, the case where the correlation is high enough not to cause the camera shake can be determined based on the previous experience rule, and the high and low of the correlation can be determined. That is, a reference value in which no camera shake occurs, such as the use of a tripod, is set in advance, and a difference between the pixel values is compared with the reference value. This can be done in the comparator 39-12.

If the difference (Error) of the pixel values in the comparing unit 39-12 is smaller than the reference value, it is determined to be 1; otherwise, it is determined to be 0. Here, 1 has information that does not cause camera shake like using a tripod, and 0 has information that camera shake occurs. At this time, the reference value is set differently according to the noise level of the live view image.

Generally, when the sensitivity of the image is increased, the noise is increased. Therefore, the reference value is determined by measuring the noise level of the image according to the sensitivity. As a method of measuring the noise level, it is possible to measure the SSD between two live view images of the same sensitivity and histogramize the SSD.

The comparison result of the comparison unit 39-12, that is, 0 and 1, is transmitted to the control unit 39-4.

When receiving 0 as the comparison result of the comparison unit 39-12, the control unit 39-4 controls the imaging control unit 39-2 to shoot two images with different exposure in view of the case where the camera shake occurs , And if the camera shake does not occur, the imaging control unit 39-2 controls to shoot one image by automatic exposure.

The shaking motion determiner 39-1 according to the second embodiment shown in FIG. 4B includes a block setting unit 39-13, an operation unit 39-14, a comparison unit 39-15, and a counting unit 39-16 And a number determination unit 39-17.

The block setting unit 39-13 divides the image data constituting one frame into N blocks.

The calculating unit 39-14 calculates a difference (error) between pixel values of the corresponding block in the previous live view image and the current live view image. At this time, the pixel value difference is a sum of the pixel value of the previous live view image and the pixel value difference of the current live view image, and is calculated by performing the above calculation on the pixels of the corresponding block.

When a pixel value difference is obtained for each block, the comparison unit 39-15 compares the pixel value with a reference value. The comparator 39-15 writes 1 if the error of the pixel value of the block is smaller than the reference value, and writes 0 otherwise. Here, 1 is information indicating that no camera shake has occurred, and 0 is information indicating that a shaking motion has occurred.

The counting unit 39-16 counts the number of blocks in which 1 and / or 0 data are written. For example, the number of blocks written with 1 is counted, and if it is larger than a predetermined number, it is determined that the correlation between the previous live view image and the current live view image is high. Or if the number of blocks written with 1 is not greater than the predetermined number, it is determined that the correlation between the previous live view image and the current live view image is low. The number judging unit 39-17 judges the number of written and counted numbers as the reference number.

As a result of the determination by the number determination unit 39-17, if the sum of the number of blocks is larger than the reference number, it is determined as 1. Otherwise, the determination is made as 0. Here, 1 indicates that no camera shake has occurred since the previous live view image has a high correlation with the current live view image, such as using a tripod, and 0 indicates that camera shake has occurred. The determination result of the number determination unit 39-17 is transmitted to the control unit 39-4.

When the control unit 39-4 receives 0 as a result of the determination by the number determination unit 39-17, the control unit 39-2 instructs the imaging control unit 39-2 to perform control If the camera shake does not occur when 1 is received, the image capturing control unit 39-2 controls the image capturing unit 39-2 to capture one image by automatic exposure.

The shaking motion determiner 39-1 according to the third embodiment shown in FIG. 4C includes a calculating unit 39-18, a comparing unit 39-19, and a holding determining unit 39-20.

In FIG. 4C, not only the correlation between the previous live view image and the current live view image, but also the correlation between the next live view images are determined and the camera shake is determined according to the correlation maintained when the correlation is maintained.

Here, the live view image is generated when the shutter release signal is input, and the live view image can be continuously generated and input until the capture image data for capturing the subject is generated. Therefore, the live view image generated after the current live view image can be referred to as the next live view image.

The calculating unit 39-18 calculates the difference between the pixel values of the live view images input in real time. The difference in pixel value is calculated by calculating the difference between the previous live view image and the current live view image for each of the pixels constituting one frame image, and adding the difference by squaring the difference.

The comparator 39-19 judges whether the difference of the pixel values is smaller or smaller than the reference value. If the difference between the pixel values is smaller than the reference value, the correlation of the determined live view images is high. If the difference is not small, it is determined that the correlation of the determined live view images is low.

The maintenance determining unit 39-20 determines whether the correlation between the previous live view image and the current live view image matches the current live view image and the next live view image. It is possible to set the correlation judgment to judge the live view images constituting the five frames. That is, it is possible to set the correlation to only five live view images.

As a result of the determination by the maintenance determination unit 39-20, if the correlation is maintained, the control unit 39-4 can control the imaging control unit 39-2 according to the determination result that the correlation is maintained.

Specifically, if the pixel value difference between the previous live view image and the current live view image is smaller than the reference value and is determined as 1, and the pixel value difference between the current live view image and the next live view image is smaller than the reference value, The judging unit 39-20 judges that the judgment result indicating that the hand shake has not occurred is equal to 1. Here, 1 includes information indicating that no shaking occurred.

In accordance with the determination result of the maintenance determination unit 39-20, the control unit 39-4 controls the imaging control unit 39-2 to shoot one image by automatic exposure. Or whether or not the first determination result on whether or not the camera shake correction operation is performed between the previous live view image and the current live view image and the second determination result on whether the camera shake correction operation between the current live view image and the next live view image are not the same, The unit 39-20 determines whether the last live view image has been input, and if the last live view image has been input, the control unit 39-4 controls the shooting control unit 39-2 to shoot two images with different exposure .

If the last live view image is not input, the control unit 39-4 controls the next live view image to be received. The calculation unit 39-18, the comparison unit 39-19 and the maintenance determination unit 39-20 derive the determination result on whether or not the camera shake correction operation is performed between the next live view image and the next live view image, It is continuously determined whether the result is the same as the previous determination result. Repeat until the last live view image is input and judged.

Next, a second embodiment will be described.

The shaking motion determiner 39-1 compares the previous live view image data with the current live view image data to determine hand shake.

The noise remover 39-3 turns off the operation by the first control signal and starts the operation by the second control signal. When the noise removing unit 39-3 is operated, the noise removing unit 39-3 removes the noise of the image due to the artifacts of the noise removing unit 39-3. The image quality deteriorates. Here, the first control signal and the second control signal are outputted from the control unit 39-4.

The control unit 39-4 receives the shaking motion determination result from the shaking motion determination unit 39-1 and outputs the first control signal to the noise removing unit 39-3 when no shaking motion occurs, It outputs a second control signal to the noise removing unit 39-3.

In this way, when the camera shake is judged at the time of high-sensitivity photographing, if the shaking motion does not occur, the operation of the noise removing unit 39-3 is stopped to obtain a good image without deterioration of the image quality.

Figs. 4A to 4C show detailed structures of the shaking motion determiner 39-1 according to the first to third embodiments. The details of the shaking motion determiner 39-1 are the same as those described above. The noise removing unit 39-3, (39-4) will be described below.

In the shaking motion determiner 39-1 according to the first embodiment shown in FIG. 4A, when the control unit 39-4 receives 0 as the comparison result of the comparison unit 39-12, The boa noise canceling unit 39-3 is operated to remove the noise of the image, and if the camera shake does not occur, the operation of the noise removing unit 39-3 is stopped.

In the shaking motion determiner 39-1 according to the second embodiment shown in FIG. 4B, when the controller 39-4 receives 0 as the determination result of the number determining unit 39-17, The noise removing unit 39-3 is operated to remove the noise of the image, and when receiving 1, the operation of the noise removing unit 39-3 is stopped in the case where no camera shake occurs.

4C, if the correlation is maintained as a result of the determination by the maintenance determination unit 39-20, the controller 39-4 determines that the correlation is maintained in the controller 39-4 The operation of the noise removing unit 39-3 can be controlled.

Specifically, if the pixel value difference between the previous live view image and the current live view image is smaller than the reference value and is determined as 1, and the pixel value difference between the current live view image and the next live view image is smaller than the reference value, The judging unit 39-20 judges that the judgment result indicating that the hand shake has not occurred is equal to 1. Here, 1 includes information indicating that no shaking occurred. The control unit 39-4 controls whether or not the noise removing unit 39-3 operates according to the determination result of the maintenance determining unit 39-20.

Or whether or not the first determination result on whether or not the camera shake correction operation is performed between the previous live view image and the current live view image and the second determination result on whether the camera shake correction operation between the current live view image and the next live view image are not the same, The unit 39-20 determines whether the last live view image has been input. If the last live view image is input, the control unit 39-4 controls the noise canceling unit 39-3 to remove the noise of the image .

If the last live view image is not input, the control unit 39-4 controls the next live view image to be received. The calculation unit 39-18, the comparison unit 39-19 and the maintenance determination unit 39-20 derive the determination result on whether or not the camera shake correction operation is performed between the next live view image and the next live view image, It is continuously determined whether the result is the same as the previous determination result. Repeat until the last live view image is input and judged.

Hereinafter, a digital image capturing method according to the present invention will be described in detail with reference to FIGS. 5 to 9. FIG. The digital image capturing method according to the present invention can be performed in the digital image processing apparatus as shown in FIG. 3. According to the embodiment, the main algorithm of the operation method is to support the peripheral elements in the apparatus And can be performed in the digital signal processing unit 39.

FIG. 5 is a flowchart illustrating an operation of the digital image capturing method according to the first exemplary embodiment of the present invention. When a live view image is displayed on the display unit 23 in operation 501, View image data and the current live-view image data to determine hand shake (Step 503).

If it is determined in step 505 that the camera shake has occurred in the live view image as a result of the camera shake determination, the digital signal processing unit 39 captures and synthesizes the two images with different exposure in step 507.

However, if no camera-shake occurs in the live view image as a result of the shaking motion determination, the digital signal processing unit 39 captures one image by automatic exposure (step 509).

In this way, if there is no camera shake, only one image with automatic exposure is shot, without needing to take two images with different exposure, so that the data transmission time is shortened and the processing speed can be improved.

FIG. 6 is a flowchart illustrating the operation of the digital image capturing method according to the second exemplary embodiment of the present invention. When a live view image is displayed on the display unit 23 in step 601, View image data and current live-view image data to determine camera-shake (Step 603).

When a camera shake occurs in the live view image as a result of the shaking motion determination (Step 605), the digital signal processing portion 39 operates a noise removing filter (noise removing portion 39-3 in Fig. 3) (Step 607). The noise elimination filter performs a function of eliminating noise of the image at high sensitivity photographing. When the noise elimination filter is operated, the image quality of the image deteriorates due to artifacts of the noise elimination filter.

However, if no camera-shake occurs in the live view image as a result of the shaking motion determination, the digital signal processing unit 39 turns off the operation of the noise removing filter provided therein to omit the image noise removing operation (step 609).

Thereafter, the digital signal processing unit 39 captures an image in which noise has been removed or noise has not been removed (step 611).

As described above, when the camera shake is judged at the time of high-sensitivity photographing and the camera shake is not generated, the operation of the noise canceling filter is stopped to obtain a good image without deterioration of the image quality.

FIG. 7 is a detailed flowchart of the shake determination method according to the first embodiment of FIGS. 5 and 6, wherein the digital signal processing unit 39 receives the first live view image in a state where the live view image is displayed (Step 701) . Here, the live view image represents video information forming one frame, and may be a video signal processed in a predetermined manner.

When the shutter-release button 11 input signal is received (step 703), the digital signal processor 39 receives the second live view image (step 705). Here, the second live view image is input later than the second live view image, and may be an image of successive frames, but the present invention is not limited thereto.

Then, the digital signal processor 39 calculates an error between pixel values of the first live view image input temporally earlier and the second live view image input later (step 707). The digital signal processing unit 39 squares the pixel value difference between the first live view image and the second live view image and repeatedly performs the above operation on all the pixels to sum up the squared values. The difference in pixel values (Error) is a sum of sequard differences (SSD) summing the square of the pixel value difference of each pixel of live view images.

Then, the digital signal processing unit 39 compares the difference of pixel values with a reference value (step 709). A reference value, such as the use of a tripod, which does not cause camera shake is set in advance and compared with the difference of pixel values.

When the difference (Error) between the pixel values is smaller than the reference value, the digital signal processing unit 39 determines that no camera shake occurs as in the case of using a tripod (step 711).

However, if the difference (Error) between the pixel values is not smaller than the reference value, the digital signal processing unit 39 determines that a camera-shake occurs as in the case of using a tripod (step 713).

When an unintentional hand movement occurs, the digital signal processing unit 39 captures and synthesizes two images of different exposure, or operates the noise removal filter to remove noise of the image. However, when no camera shake occurs, the digital signal processing unit 39 captures an image by automatic exposure or stops the operation of the noise reduction filter.

FIG. 8 is a detailed flowchart of the shake determination method according to the second embodiment of FIGS. 5 and 6, in which the digital signal processing unit 39 receives the first live view image in a state where the live view image is displayed (Step 801 ).

When the shutter-release button 11 input signal is received (step 803), the digital signal processing unit 39 receives the second live-view image (step 805).

Subsequently, the digital signal processing unit 39 divides the image data constituting one frame into N blocks (Step 807).

When the block is divided, the digital signal processing unit 39 calculates an error between pixel values of the corresponding block in the first live view image and the second live view image (Step 809). At this time, the pixel value difference is a sum of the pixel value of the previous live view image and the pixel value difference of the current live view image, and is calculated by performing the above calculation on the pixels of the corresponding block.

When a pixel value difference of a block is calculated by calculating a pixel value for each block, the digital signal processor 39 compares the pixel value with a reference value (step 811).

If the error of the pixel value of the block is smaller than the reference value, the digital signal processing unit 39 writes X, that is, 1 in the corresponding block (step 813), otherwise writes Y or 0 in the corresponding block ). Here, 1 is information indicating that no camera shake has occurred, and 0 is information indicating that a shaking motion has occurred.

The digital signal processing unit 39 counts the number of blocks in which the 1 and / or 0 data are written (step 819). For example, the number of blocks written with 1 is counted, and if it is larger than a predetermined number, it is determined that the correlation between the previous live view image and the current live view image is high. Or if the number of blocks written with 1 is not greater than the predetermined number, it is determined that the correlation between the previous live view image and the current live view image is low.

The digital signal processing unit 39 determines whether the number of the written and counted reference number is greater (step 821).

If it is determined that the sum of the number of blocks is larger than the reference number, the digital signal processor 39 determines that no camera shake has occurred because the correlation between the first live view image and the second live view image is high as in the case of using a tripod (Step 823).

If it is determined that the sum of the number of blocks is not greater than the reference number, the digital signal processor 39 determines that hand shake has occurred (step 825).

When an unintentional hand movement occurs, the digital signal processing unit 39 captures and synthesizes two images of different exposure, or operates the noise removal filter to remove noise of the image. However, when no camera shake occurs, the digital signal processing unit 39 captures an image by automatic exposure or stops the operation of the noise reduction filter.

FIG. 9 is a detailed flowchart of the shake determination method according to the third embodiment of FIGS. 5 and 6, in which the n-1 live view image is received (Step 901). The input n-1 live view image can be arbitrarily stored for a predetermined time.

When the shutter-release button 11 input signal is received (step 903), at least n live view images are received at or after the shutter-release signal is received (step 905).

Then, the digital signal processor 39 compares the pixel value difference (Error) between the n-1 live view image and the n live view image data (step 907). This step is referred to as a first image comparison judgment. The pixel value difference (Error) may follow the method shown in Fig. 7 or Fig. 8 described above. Here, n can be regarded as the time at which the live view image is generated and input most closely when the shutter release signal is input or thereafter.

Thereafter, the digital signal processing unit 39 receives the (n + 1) live view image (Step 909).

Upon completion of the reception, the digital signal processing unit 39 performs a second image data comparison determination to compare the n value of the live view image with the n + 1 live view image (step 911).

Next, the digital signal processing unit 39 determines whether the correlation between the first image data comparison determination and the second image data comparison determination is maintained (step 913).

If the correlation is maintained, the digital signal processing unit 39 determines whether or not the shaking motion has occurred according to the result of the shaking (step 915).

If the correlation is not maintained, the digital signal processing unit 39 determines whether the last live view image is input (step 917).

If the last live view image has been input, the digital signal processing unit 39 determines that hand shake has occurred (step 919).

If the last live view image is not input, the digital signal processing unit 39 receives n + 2 live view image data (step 921). In step 911, the n + 1 live view image, which is the live view image of the previous frame of the (n + 2) live view image, is compared with the pixel value. Then, it is repeatedly executed whether the correlation is maintained or not.

In the present embodiment, the correlation between the live view images that are temporally continuous is determined, but the present invention is not limited thereto, and the correlation between the live view images at predetermined intervals may be determined.

1 is a perspective view showing the front and upper contours of a digital image photographing apparatus.

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

3 is a block diagram showing a configuration of a digital image photographing apparatus according to the present invention.

4 is a detailed configuration diagram of the first to third embodiments of the shaking motion determining unit in Fig.

5 is a flowchart illustrating an operation of the digital image capturing method according to the first exemplary embodiment of the present invention.

6 is a flowchart illustrating an operation of the digital image capturing method according to the second exemplary embodiment of the present invention.

FIG. 7 is a detailed flowchart of the shaking motion judging method according to the first embodiment of FIGS. 5 and 6. FIG.

FIG. 8 is a detailed flowchart of the shaking motion judging method according to the second embodiment of FIGS. 5 and 6. FIG.

FIG. 9 is a detailed flowchart of the shaking motion judging method according to the third embodiment of FIGS. 5 and 6. FIG.

Claims (12)

And a digital signal processing means for comparing the previous live view image data with the current live view image data to determine hand shake and taking a single image by automatic exposure in the case where no shaking has occurred, The digital signal processing means A shaking motion determining unit for comparing the previous live view image data with the current live view image data to determine the shaking motion; An image capturing control section for capturing a single image by automatic exposure by a first control signal and capturing two images of different exposure by a second control signal; And And a control unit for outputting a first control signal to the imaging control unit when no camera shake is detected as a result of the shaking motion and outputting a second control signal to the imaging control unit when the shaking motion occurs, The shaking motion determining unit A block setting unit for dividing the pixels of the live view image into a plurality of blocks; An operation unit for calculating a difference between pixel values of the previous live view image and the current live view image for each block; A comparison unit comparing the pixel value difference (Error) with a reference value for each block; A counting unit counting the number of blocks having the same comparison result; And And a number determination unit for comparing the number of the counted blocks with a reference number, The control unit And outputs the first control signal when the number of the counted blocks is larger than the reference number and outputs the second control signal when the number of the counted blocks is not larger than the reference number. And a digital camera. delete And digital signal processing means for comparing the previous live view image data with the current live view image data to determine an unintentional hand shake and taking the image without removing the noise of the image when no camera shake occurs, Sudan A shaking motion determining unit for comparing the previous live view image data with the current live view image data to determine the shaking motion; A noise removing filter for performing the noise removing operation by a second control signal without performing a noise removing operation for lowering the resolution of the image by a first control signal; And And a controller for outputting the first control signal to the noise elimination filter when no camera shake is generated as a result of the shaking motion and outputting a second control signal to the noise elimination filter when the shaking motion occurs, The shaking motion determining unit An operation unit for calculating a difference between pixel values of the live view images; A comparing unit comparing the difference of the pixel values with a reference value to determine that the correlation between the live view images is high if the difference between the pixel values is smaller than the reference value and determining that the correlation between the live view images is low if the difference is not small; And And a maintenance determining unit for determining whether a result of the correlation between the previous live view image and the current live view image and the correlation determination result between the current live view image and the next live view image coincide with each other, The control unit If it is determined that the last live view image is not matched, it is determined whether the last live view image is input. If the last live view image is input, the second control signal is output And the camera shake detection means detects the camera shake. delete delete And digital signal processing means for comparing the previous live view image data with the current live view image data to determine an unintentional hand shake and taking the image without removing the noise of the image when no camera shake occurs, Sudan A shaking motion determining unit for comparing the previous live view image data with the current live view image data to determine the shaking motion; A noise removing filter for performing the noise removing operation by a second control signal without performing a noise removing operation for lowering the resolution of the image by a first control signal; And And a controller for outputting the first control signal to the noise elimination filter when no camera shake is generated as a result of the shaking motion and outputting a second control signal to the noise elimination filter when the shaking motion occurs, The shaking motion determining unit A block setting unit for dividing the pixels of the live view image into a plurality of blocks; An operation unit for calculating a difference between pixel values of the previous live view image and the current live view image for each block; A comparison unit comparing the pixel value difference (Error) with a reference value for each block; A counting unit counting the number of blocks having the same comparison result; And And a number determination unit for comparing the number of the counted blocks with a reference number, The control unit And outputs the first control signal when the number of the counted blocks is larger than the reference number and outputs the second control signal when the number of the counted blocks is not greater than the reference number. And a digital camera. And a digital signal processing means for comparing the previous live view image data with the current live view image data to determine hand shake and taking a single image by automatic exposure in the case where no shaking has occurred, The digital signal processing means A shaking motion determining unit for comparing the previous live view image data with the current live view image data to determine the shaking motion; An image capturing control section for capturing a single image by automatic exposure by a first control signal and capturing two images of different exposure by a second control signal; And And a control unit for outputting a first control signal to the imaging control unit when no camera shake is detected as a result of the shaking motion and outputting a second control signal to the imaging control unit when the shaking motion occurs, The shaking motion determining unit An operation unit for calculating a difference between pixel values of the live view images; A comparing unit comparing the difference of the pixel values with a reference value to determine that the correlation between the live view images is high if the difference between the pixel values is smaller than the reference value and determining that the correlation between the live view images is low if the difference is not small; And And a maintenance determining unit for determining whether a result of the correlation between the previous live view image and the current live view image and the correlation determination result between the current live view image and the next live view image coincide with each other, The control unit If it is determined that the last live view image is not matched, it is determined whether the last live view image is input. If the last live view image is input, the second control signal is output And the camera shake detection means detects the camera shake. A camera-shake determining step of comparing the previous live view image data with the current live view image data to determine camera shake; And And a photographing step of photographing one piece of the image by automatic exposure when no camera shake has occurred as a result of the shaking motion and photographing two images of different exposure when the shaking occurs, The shaking motion determination step Dividing the pixels of the live view image into a plurality of blocks; Calculating a difference between pixel values of the previous live view image and the current live view image for each block; Comparing the pixel value difference (Error) with a reference value for each block; Counting the number of blocks having the same comparison result; Comparing the number of the counted blocks with a reference number; And Determining that no camera shake has occurred when the number of the counted blocks is greater than the reference number and determining that camera shake has occurred when the number of the counted blocks is not greater than the reference number, A digital image capturing method according to detection. A camera-shake determining step of comparing the previous live view image data with the current live view image data to determine camera shake; A noise removing step of performing the noise removing operation when the camera shake is detected as a result of the shaking motion determination without performing a noise removing operation to lower the resolution of the image when the shaking motion does not occur as a result of the shaking motion determination; And And a photographing step of photographing the image in which the noise is not removed or the noise is removed, Calculating a difference of pixel values between the live view images; Comparing the difference of the pixel values with a reference value, determining that the correlation of the live view images is high if the difference of the pixel values is smaller than the reference value, and determining that the correlation of the live view images is low if the difference is not small; Determining whether a result of correlation between the previous live view image and the current live view image and a result of correlation between the current live view image and the next live view image match; And Determining whether or not a camera shake has occurred when the correlation determination results are coincident with each other, determining whether a camera shake has occurred, determining whether a last live view image is input if it does not match, and determining that camera shake has occurred when a last live view image is input A digital image capturing method according to shaking motion detection. delete A camera-shake determining step of comparing the previous live view image data with the current live view image data to determine camera shake; A noise removing step of performing the noise removing operation when the camera shake is detected as a result of the shaking motion determination without performing a noise removing operation to lower the resolution of the image when the shaking motion does not occur as a result of the shaking motion determination; And And a photographing step of photographing the image in which the noise is not removed or the noise is removed, The shaking motion determination step Dividing the pixels of the live view image into a plurality of blocks; Calculating a difference between pixel values of the previous live view image and the current live view image for each block; Comparing the pixel value difference (Error) with a reference value for each block; Counting the number of blocks having the same comparison result; Comparing the number of the counted blocks with a reference number; And Determining that no camera shake has occurred when the number of the counted blocks is greater than the reference number and determining that camera shake has occurred when the number of the counted blocks is not greater than the reference number, A digital image capturing method according to detection. A camera-shake determining step of comparing the previous live view image data with the current live view image data to determine camera shake; And And a photographing step of photographing one image by automatic exposure in the case where no camera shake has occurred as a result of the shaking motion and photographing two images with different exposure in the case where the shaking motion occurs, Calculating a difference of pixel values between the live view images; Comparing the difference of the pixel values with a reference value, determining that the correlation of the live view images is high if the difference of the pixel values is smaller than the reference value, and determining that the correlation of the live view images is low if the difference is not small; Determining whether a result of correlation between the previous live view image and the current live view image and a result of correlation between the current live view image and the next live view image match; And Determining whether or not a camera shake has occurred when the correlation determination results are coincident with each other, determining whether a camera shake has occurred, determining whether a last live view image is input if it does not match, and determining that camera shake has occurred when a last live view image is input A digital image capturing method according to shaking motion detection.

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