KR100203274B1 - Handshake correction system by changing the correction coefficient - Google Patents

Abstract

The disclosed contents disclose a technique for eliminating a blurring phenomenon that occurs when a motion of a camcorder or the like using a hand as a support and a great motion for shooting and a shaking motion exceed a correction range, The present invention relates to an image stabilization system using a correction coefficient variable capable of obtaining an image. The system includes a sensor unit for sensing the movement of the camcorder in the horizontal and vertical directions, a motion / camera shake discriminator for discriminating artificial movements and camera shake of the camcorder according to the waveform of the sense signal of the sensor unit, A controller for controlling the camera shake correction to be performed for the camera shake within the correction range and appropriately changing the correction coefficient for the camera shake or motion exceeding the correction range, And a correcting unit for correcting the shaking motion. Therefore, the disclosed contents can be appropriately corrected for an artificial movement of the camcorder or a camera-shake exceeding a correction range, thereby providing a natural image without blurring of the image.

Description

Correction coefficient Variable camera shake correction system

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera-shake correction system for a camcorder, and more particularly to a camera-shake correction system for a camcorder, which discriminates a shaking motion of a user of a camcorder and an artificial motion for photographing and changes a correction coefficient according to artificial motion and degree of shaking, ≪ / RTI >

As the size of the camcorder is reduced, the user's hand is used as a support for the camcorder. When the subject is photographed using a camcorder, the user often shakes the screen due to the 'shaking' of the user's hand. Therefore, in most camcorders, the camera shake correction system is used to compensate for the shaking of the screen by such a shaking motion.

However, it is necessary to accurately distinguish the shaking phenomenon and the artificial motion for the shake correction, and if the artificial motion and the shaking motion exceed the correction range, if the correction value is not adjusted appropriately, the shaking phenomenon of the image appears. In this case, there is a problem that an unnatural image is obtained by performing the correction of the shaking motion.

An object of the present invention is to provide a camera shake correction system capable of eliminating the above problems and obtaining a natural image without image blurring.

1 is a state diagram showing an object-shake correction range and a subject position on the screen,

2 is a block diagram showing an image stabilization system according to the present invention;

Fig. 3 is an output timing diagram of the sensor section in the system of Fig. 2,

FIG. 4 is a flowchart for explaining the operation of the control unit of the system of FIG. 2;

FIGS. 5A and 5B are flowcharts showing subroutine 1 and subroutine 2 in FIG. 4,

Figs. 6A and 6B are graphs showing variation curves of the shaking motion correction coefficients.

DESCRIPTION OF THE REFERENCE NUMERALS

10: Sensor unit 11, 12: Gyro sensor

20: control unit 21: motion / camera shake discriminator

22: motion amount / shake amount calculator 30:

Therefore, in the camera shake correction system of the camcorder, the camera shake correction system according to the present invention includes a sensor unit for sensing movement or tremor of the camcorder, and a controller for receiving a sensing signal of the sensor unit, And a correction unit for correcting the shaking of the screen caused by the shaking according to the correction coefficient varying by the control unit.

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

FIG. 1 is a state diagram showing an object-shake correction range and an object position on the screen, and a correction range is determined in the horizontal and vertical directions in the signal processing process (see FIG. 1A). 1B and 1C, if the subject is positioned within the correction range (indicated by a dotted line), the shaking of the screen can be prevented even by the correction of the general shaking motion. On the other hand, as in the case of Figs. 1D to 1F, the subject may be located outside the correction range. This occurs when the user moves artificially for shooting or when the degree of camera shake is severe.

To this end, the camera shake correction system according to the present invention shown in Fig. 2 is provided with a sensor unit (not shown) composed of a plurality of gyro sensors 11, 12 for detecting the movement of the camcorder in the horizontal and vertical directions 10). A gyro sensor is a sensor that uses an angular momentum to sense angular motion based on inertial space around one or more axes perpendicular to the spin axis. The sensor unit 10 receives a detection signal indicating the movement of the camcorder in the horizontal and vertical directions detected by the gyro sensors 11 and 12 to distinguish the shaking motion from the artificial motion. And a controller 20 (20) that includes a motion / camera shake dividing unit 21 for calculating the amount of shaking motion and a motion amount / shake amount calculator 22, and determines whether the calculated shaking motion amount or motion amount exceeds a predetermined correction range ). The controller (20) is configured to be connected to a correcting unit (30) for correcting camera shake according to a determined correction coefficient.

The operation of the camera shake correction system according to the present invention configured as described above will now be described in more detail.

First, when the photographer is in the shooting mode, he / she shoots while moving at an arbitrary speed while viewing the electronic viewfinder screen on the camcorder. Thus, the gyro sensors 11 and 12 of the sensor unit 10 detect the horizontal and vertical shake of the camcorder. The gyro sensors 11 and 12 constituting the sensor unit 10 output a constant output with respect to the angular velocity and output an angular velocity formed when the camcorder moves horizontally and an angular velocity formed when the camcorder moves vertically. The output of the gyro sensors 11 and 12 corresponding to the motion of the camcorder at the time of photographing varies as shown in Fig. 3, and the motion / camera shake discriminator 21 of the control unit 20 detects It distinguishes between motion and hand shake through waveform of detection signal. Generally, in the case of a hand shake, the sensing signal appears as a periodic waveform having a certain frequency component, and in the case of an artificial motion, the sensing signal appears as a waveform having a constant amplitude without a frequency component. The motion / shake discriminator 21 recognizes that the motion is continuously artificially moved in one direction when a sensing signal of the type shown in (2) of FIG. 3 is input. When the sensing signal of (3) , It is recognized that camera shake has occurred while the camcorder is stopped. The movement / camera shake separator 21 recognizes that the shake continues beyond the correction range when a periodic detection signal exceeding the correction limit? Is input as shown by? Or? In Fig. 3, Likewise, when the periodic detection signal within the compensation range is input, it is recognized as a general camera-shake shape. The motion amount / shake amount calculator 22 integrates the sensing signals of the gyro sensors 11 and 12, that is, the angular velocity data, and calculates the area and the motion amount or the shake amount. The amount is limited to the maximum movement correction distance at which the image can be moved for image stabilization. That is, when the maximum movement correction distance of the image provided by the shaking motion correction system is determined, the sensitivity of the angular velocity data inputted from the gyro sensors 11 and 12 is also determined so as to determine how much the shake of the image is to be corrected, And if it is exceeded, a stable screen can be obtained through the present invention. The control unit 20 stops the camera-shake correction and returns the current correction value to the stop state value when recognizing that the camera / shake discriminator 21 continues to artificially move in one direction (see (2) in Fig. 3) . The control unit 20 also performs normal correction when it recognizes that the camera shake has occurred while the camcorder is stopped in an artificial movement in the movement / camera shake separator 21 (refer to 3 in Fig. 3). The control unit 20 corrects by applying the correction coefficient B shown in Fig. 6B if the motion / shake discriminator 21 recognizes that the shake continues beyond the correction range (see (1) or (5) in Fig. 3). The controller 20 recognizes the general shaking motion (see (4) in FIG. 3) in the motion / shake discriminator 21 so that the screen remains in a stopped state. The operation of the control unit 20 will be described in more detail with reference to FIG. 4 through FIG.

4 is a flowchart for explaining the operation of the control unit 20 in the system of FIG.

First, the control unit 20 determines whether the current camcorder is in an artificial motion state (step 100). This is recognized from the waveform of the sensing signal of the sensor unit 10 in the motion / camera shake discriminator 21. In step 100, the controller 20 performs subroutine 1 if it is judged to be an artificial motion state, and judges whether the shake amount is within the correction range (step 110). Here, the shaking motion amount is obtained by integrating the angular velocity, which is the output of the gyro sensors 11 and 12, in the motion amount / shake amount calculator 22 and obtaining the area. In step 110, if the shaking motion amount is within the correction range, the control unit 20 performs normal correction for the shaking motion correction and a predetermined amount of correction to the center (step 120). If the shaking motion amount exceeds the correction range, (Step 130). In step 130, the control unit 20 performs subroutine 1 if the current direction of movement is the same as the previous state (step 140), and performs subroutine 2 if the current direction of movement is opposite to the previous state (step 150) . Here, the subroutine 1 is executed when it moves continuously in one direction in a state where it exceeds the artificial motion and the correction range, and when the subroutine 2 is an artificial motion and the direction is changed in the opposite direction .

FIG. 5A is a flowchart showing a process of subroutine 1 in FIG. 4, and FIG. 5B is a flowchart illustrating a process of subroutine 2 in FIG.

5A, the control unit 20 determines whether the current correction value of the correction unit 30 for performing camera-shake correction on a signal photographed through the camera is larger than the correction value of the screen-stopped state (step 141) The stop state correction value is set as the current correction value so that the screen in the stop state is maintained (step 144). If the current correction value is greater than the stop state correction value, the control unit 20 sets the current correction value by multiplying the current correction value by a correction coefficient A having the characteristic as shown in FIG. 6A so that the screen can be put into a stop state (step 142) . Then, it is determined whether the current correction value is smaller than the stop state correction value (step 143). If the current correction value is smaller than the stop state correction value, the current correction value is set to the stop state correction value (step 144) If it is large, finish subroutine 1 process.

Next, in subroutine 2, the control unit 20 determines whether the current correction value is greater than the stop state correction value (step 151), and if not, sets the stop state correction value as the current correction value (step 154). If the current correction value is greater than the stop state correction value, the control unit 20 multiplies the current correction value by a correction coefficient B having the characteristic as shown in FIG. 6B to variably set the current correction value (step 152). Then, it is determined whether the current correction value is smaller than the stop state correction value (step 153), and if so, the current correction value is set as the stop state correction value (step 154). If the current correction value is larger than the stop state correction value, the process of step 2 is finished.

6A and 6B show the change curves of the correction coefficients A and B. The values of the correction coefficients A and B are between 1 and 0.96 (1? Correction coefficient A, B? 0.96) Move it to the extent that the phenomenon of the image does not appear while reverting. At this time, the correction of the shaking motion is synchronized with the vertical synchronization signal (Vsync), and the amount of movement of the vertical synchronization signal without returning is determined. That is, if the amount that can be shifted in units of the vertical synchronizing signal (Vsync) is small, the phenomenon of image blurring does not appear but the frequency response characteristic deteriorates. Therefore, the rate of change of the correction coefficients A and B is variably corrected to the curves of Figs. 6A and 6B according to the frequency and the movement amount, and is compared with the experimental values to determine the optimal state.

2, the correction unit 30 corrects the photographed subject according to the correction coefficient set by the control unit 20, and maintains a stable state without any screen shake.

As described above, the present invention relates to an image stabilization system based on a correction coefficient variable. The image stabilization system adjusts an appropriate correction coefficient for an artificial motion and an image of a hand- It has an effect of obtaining an image.

An object of the present invention is to provide an image processing apparatus and an image processing method which can distinguish an artificial motion and a hand shake for photographing and correct the artificial motion and the shaking motion exceeding the correction range by varying the correction coefficient, And an image stabilization system.

Claims (8)

In a camera-shake correction system of a camcorder, A sensor unit for detecting movement or tremor of the camcorder; A control unit for receiving a sensing signal of the sensor unit and determining an artificial motion and a case of a camera shake exceeding a predetermined correction range to vary a correction coefficient; And And a correction unit for correcting the shaking of the screen caused by the shaking according to the correction coefficient varied by the control unit. The system of claim 1, wherein the sensor unit comprises a plurality of gyro sensors for detecting movement or tremor of the camcorder in horizontal and vertical directions. The apparatus of claim 1, wherein the control unit A motion / shake discriminator for discriminating an artificial motion and a shaking motion according to an input sensed signal being a periodic waveform having a certain frequency component with respect to a shaking motion and a waveform having a constant amplitude without a frequency component with respect to an artificial motion; And And a motion amount / shake amount calculator for calculating an amount of motion or shake amount by integrating the input sensed signal to obtain an area thereof. The image processing apparatus according to claim 3, wherein the control unit determines whether the calculated shaking amount exceeds a predetermined correction range in the horizontal and vertical directions, and performs shaking correction if the shaking motion is within the correction range And changes the correction coefficient so that the current correction value becomes the value of the camcorder stop state when the shaking motion exceeds the correction range. 5. The apparatus according to claim 4, wherein when the controller moves continuously in one direction while the artificial motion or the shaking motion exceeds the correction range, the control unit compares the current correction value with the correction value in the stop state. If the current correction value is smaller than the stop state correction value The current correction value is varied to the stop state correction value, and if the current correction value is larger than the stop state correction value, the current correction value is multiplied by the correction coefficient A to vary the current correction value. The apparatus of claim 4, wherein the control unit compares the current correction value with the stop state correction value when the direction is reversed in the unintentional hand movement state over the correction range, and stops the current correction value when the current correction value is smaller than the stop state correction value And the current correction value is varied by multiplying the current correction value by the correction coefficient B to vary the current correction value. Correction system. The image processing apparatus according to claim 5, wherein the correction coefficient A has a characteristic capable of restoring a screen in the case where artificial motion or hand movement continues in one direction in a state where the hand movement exceeds the correction range, Camera shake correction system. The system according to claim 6, wherein the correction coefficient B has a characteristic capable of returning the screen in the case where the direction of the hand movement is reversed in the hand movement state exceeding the correction range to the stop state.