KR100498042B1 - Device and method capable of acquisition stbilization image - Google Patents

Abstract

An image acquisition system for performing image correction to stably output a captured image is disclosed. Image acquisition system is composed of blocks for normal shooting, horizontal and vertical motion sensors for detecting the shaking of the device body for image correction, image memory for storing the image output through the CCD, motion sensor A hybrid motion detector for calculating an approximate motion vector in the image by using output data of a predetermined time, and adding and storing the motion vector detected by the motion sensor with respect to the current image stored in the image memory, and a hybrid motion detector. And an image controller for reading out the previous image and the current image stored at field or frame time intervals and controlling the apparatus to perform image correction according to the difference between the two images. The image controller considers the moving object as a moving object in a section in which the difference between the previous and present two images is greater than or equal to a predetermined level so that the image correction is performed. Such an image acquisition system can achieve high performance image stabilization at a minimum cost by fusing a correction method using a motion sensor and a correction method through image processing.

Description

Image Acquisition System for Stable Image Acquisition and Stabilization Method {Device and method capable of acquisition stbilization image}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image acquisition system and an image processing method thereof, and more particularly, to an image acquisition system for performing image correction in order to stably output a photographed image, and a stabilization method thereof.

In addition to traditional video cameras, various devices capable of capturing images, such as digital cameras and mobile phones with built-in cameras, are being released. As the devices capable of acquiring images are diversified, ordinary people without professional shooting knowledge have more shooting opportunities, and thus, image acquisition systems are increasingly required to be highly functionalized. In other words, recently acquired image acquisition systems often include a function of automatically adjusting the shooting state in response to the surrounding environment, and also adopts a high magnification optical system to zoom in / out function for long distance shooting. Is supported.

However, while the conventional image capturing apparatuses can obtain relatively high quality images by adding various functions, it is not easy to obtain stable images due to unintentional shaking of the user when shooting in a moving vehicle or during long distance shooting. There was this. That is, when shooting in a moving vehicle, the output image is displayed in a state of shaking with the vibration of the vehicle due to the vibration of the vehicle, and in the case of long distance shooting, the image is greatly shaken even by the minute hand shake of the photographer as the optical magnification is increased. The problem of outputting to a state has occurred. Such vibration is caused by six degrees of freedom (three-way displacement tremor, three-way angular tremor), and the image quality is greatly deteriorated by the horizontal yaw and vertical pitch tremors. Therefore, expensive cameras are usually equipped with a function for correcting horizontal and vertical angle image blur.

As described above, various correction methods have been proposed to obtain a stable image against generation of image shaking. The image correction method can be largely classified into a correction method through image signal processing and a correction method through a physical shaking sensor.

1 is a block diagram of an image acquisition system for performing image stabilization through image signal processing. The system can be largely divided into a video signal processing part and a control part. The image signal processing part 110 includes an optical system 105, a charge coupled device (CCD) 112, an S (sample) / H (hold) circuit, an AGC (Auto Gain Control) circuit unit 114, and an analog-to-digital converter (A). / D: 116, an image processing unit 118, and a vertical moving unit 119. The control part 120 includes a command input unit 122, a motion detector 124, an image memory 125, an image controller 126, and a camera controller 128.

The CCD 112 converts the optical image of the subject input through the optical system 105 into an electrical signal.

The S / H and AGC circuitry 114 automatically adjusts the gain for the electrical signal transmitted from the CCD 112, and converts the analog signal into a digital signal with the A / D 116.

The image processing unit 118 adds an address to the digital signal converted through the A / D 116 to be stored in the image memory 125, and the image according to the image stabilization information provided from the image control unit 126. A video signal processor 118-1 for performing processing, a video encoder 118-2 for converting a signal transmitted from the video signal processor 118-1 to a standard video signal so that it can be output to a screen, and a video signal A timing generator 118-3 for providing a timing signal to determine an operation time point of the processing unit 118-1 and the CCD 112, and a sink generator 118- for providing a synchronization signal to the timing generator 118-3. 4).

The vertical moving unit 119 receives the timing signal from the timing generator 118-3, and synchronizes the signal to the CCD 112 so that the electric image signal can be output in units of horizontal lines from the image captured by the CCD 112. To provide.

The command input unit 122 receives various commands related to the use of the camera from the user and transmits the various commands to the camera controller. For example, a camera shake correction command and a zoom in / out command are input.

The image memory 125 stores an image output from the CCD 112 through the image signal processor 118-1.

The motion detector 124 calculates the difference between the previous image and the current image by comparing the previous field or the previous frame image in the image sequentially stored in the image memory 125 from the CCD 112. The subject includes a photographing subject and a background.

The image controller 126 calculates a correction value according to the difference between the two images detected by the motion detector 124, and controls the image signal processor 118-1 to perform image correction according to the calculated correction value. To control.

The camera controller 128 controls the entire apparatus in response to a command and a detection signal input through the command input unit 122. That is, the camera shake control signal is transmitted to the image controller in response to the shake correction command, and the control signal is output to a motor (not shown) for moving the lens of the optical system 105 in response to the zoom in / out command. In addition, the camera is controlled in response to the external environment. That is, a lens driving control signal (motor driving control signal) and a shutter control signal are output for controlling the focus according to the distance to the subject and the operation of the iris to adjust the amount of light according to the external illumination.

The above system stores images captured by the CCD 112 in the memory 125 sequentially, and performs correction by comparing previous image information with current image information in units of fields or frames through an image processing algorithm. . An example of a system for performing correction through image signal processing is disclosed in US Pat. The system disclosed in US5832101 projects two-dimensional light and dark images into vertical and horizontal line memories P'v and P'h to form one-dimensional data as shown in FIG. 2A, and the one-dimensional data is horizontally formed in a previous field or frame. And a motion vector is obtained by searching for the best matching position compared with the vertical line data Pv and Ph. FIG. 2B shows a graph showing an optimal motion vector using the difference between fields obtained in FIG. 2A and an equation for obtaining the optimal motion vector. Such a system can perform near perfect correction when the information of the image is good.

However, the correction method through the above image signal processing is a correction method designed on the assumption that the subjects are all fixed. In the image having a moving object or no feature at all, the image having a repetitive pattern, the image having very low illumination, etc. There was a problem in that the correction ability was remarkably inferior to the image quality deterioration caused by camera shake. Recently, as image processing is advanced, a method of selectively determining a moving object and a fixed object in an image and detecting a moving vector based on the fixed object has been proposed. However, a problem requiring expensive processing costs occurs.

On the other hand, the image correction method through the detection of the physical shake of the camera, by detecting the angular velocity of the camera shake itself through the sensor, integrating it over time in the field period, and multiplying the resultant value by the correction coefficient, The amount of movement of the CCD image is calculated. The correction is performed by moving the imaging area by driving the lens of the optical system in real time according to the calculated value. The image correction method through the physical shake detection of the camera is commonly called an electronic image stabilization method.

3 is a block diagram of an image acquisition system using an electronic image stabilization method. The image processing system is composed mostly of the same components as the image acquisition system shown in FIG. However, in the system of FIG. 1, the A / D converter 326 and the vertical and horizontal motion sensors 322 and 324 replace the motion detector 124 and the image memory 125. There is a difference in that a skip line control signal is output from the timing generator 118-3 to the vertical drive unit 119. In addition, although not shown, the image acquisition system includes a motor for moving the optical system 105, and the camera controller 128 includes a motor according to the amount of vibration detected through the horizontal and vertical motion sensors 322 and 324. It is designed to output a motor control signal for driving the.

US4637571 is a system that uses the electronic image stabilization method as described above, and US4637571 obtains an angular velocity through a gyro sensor to compensate for camera shake in a missile main body, and integrates the obtained angular velocity to the vertical and horizontal coils of a video camera. By controlling the control, a stable image is obtained.

However, the image acquisition system using the electronic image stabilization method requires that the imaging area is larger than the image actually output in consideration of the movement of the subject. Therefore, the number of CCD elements for acquiring an image increases more than the actual image area, resulting in an increase in cost.

On the other hand, a technique capable of preventing the image area from increasing as described above is disclosed in US4623930. US4623930 proposes an optical image stabilization method which detects a shake of a camera lens through a sensor and changes the optical path of the shake directly to a prism so that the image is captured on a fixed image plane. Furthermore, US6429895 proposes an optical correction method for obtaining a high resolution image in the optical image stabilization method.

However, the optical image stabilization method is used in an expensive device such as a broadcast video camera since the prism driving device for controlling the optical path and the control device are expensive.

In addition, US5282044 proposes a method of improving the accuracy of optical correction by combining a correction method using image processing and an optical correction method using a gyro sensor to solve the drift problem occurring in the gyro sensor. However, US5282044 is limited in solving the drift problem of the gyro sensor, and also uses a rotating mirror, which not only increases the volume of the system but also increases the cost.

In addition, in the above-mentioned conventional electronic or optical image stabilization techniques, a small gyro sensor (for example, a piezoelectric vibrating gyro sensor) is mostly used as a sensor for detecting tremor, which is caused by drift of the gyro sensor. The fluctuation and the high frequency component of 15 kHz or more have a problem in that a phase delay occurs in the output of the gyro signal, thereby degrading the correction capability. In addition, the electronic image stabilization technology has a disadvantage in that when there is a high frequency vibration, a difference occurs between an image pickup time point and a correction signal detection time point through a gyro sensor, and thus correction is not performed at an accurate time point. In addition, the piezoelectric vibratory gyro has a disadvantage in that the sensitivity of the converging sensitivity changes up to 15% according to the temperature change (-5 ° C. to 75 ° C.) of the use environment.

The object of the present invention is not only to increase the volume of the system in order to solve the above problems, but also advantageous in terms of cost, and an image acquisition system and stabilization method capable of obtaining a more stable image even against temperature changes and high frequency vibrations. To provide.

The image acquisition system of the present invention for achieving the above object, the solid-state imaging device for converting the image of the subject according to the light incident on the optical system into an electrical signal and outputs; A vibration sensor unit for outputting electrical signals according to vertical and horizontal vibrations of the system body; A memory for storing an image photographed by the solid state image pickup device; The motion vector of the subject is calculated by integrating the vertical and horizontal shaking signals transmitted from the shaking sensor unit for a predetermined time interval, and horizontal and vertical two-dimensional field / frame image data photographed by the solid state image pickup device. A hybrid motion detector for projecting one-dimensional data in a direction; And horizontal and vertical projection data in which the horizontal and vertical projection data of a current field / frame is moved by the motion vector value during the predetermined time interval detected by the hybrid motion detector, and horizontal and vertical projection data of the previously projected field / frame. And an image controller for comparing the two and performing image correction according to the difference between the two comparison data.

Here, the predetermined time interval for calculating the motion vector performs integration during a unit field / frame interval. This is because the electronic image stabilization method performs real time correction and outputs an image, whereas the correction through image processing outputs an image with a time delay of one field or one frame, and according to the correction method through image processing, one field or one frame is used. This is to perform delayed correction.

The hybrid motion detection unit may include: an offset controller which automatically calculates an offset to extract only a signal according to a shake from the detection signal output from the shake sensor unit; A gain controller for determining gain in each pixel unit of the image photographed by the solid state image pickup device according to the magnitude and phase of the detection signal output through the offset controller; A motion signal integrator configured to calculate a motion vector by integrating the detection signal output from the gain controller for a predetermined time; A field / frame movement vector buffer for storing the integration result value during the previous field / frame period and the integration result value during the current field / frame period respectively calculated through the motion signal integrator; And horizontal and vertical projection line buffers respectively storing horizontal and vertical line data of each of the previous two-dimensional field / frame image and the current two-dimensional field / frame image photographed by the solid state image pickup device.

The hybrid motion detection unit may further include: an auxiliary buffer configured to store new horizontal and vertical data for a portion of the current field / frame moved according to the motion vector whose difference with a previous field / frame is greater than or equal to a predetermined level.

The image control unit corrects the image to a position where the correlation error between the two comparison data is minimum with respect to the difference generated as a result of the comparison of the two projection data. The image controller considers that no difference is generated in a section in which the difference generated as a result of the comparison between the two projection data is greater than or equal to a predetermined level, and the new horizontal and vertical line data of the current field / frame to which the motion vector is added. After generating new horizontal and vertical line data of a previous field / frame and storing it in the auxiliary buffer, image correction is performed to a position where correlation error is minimal with respect to the data stored in the auxiliary buffer. This is because the movement of the entire image is detected by the shaking sensor unit, so that the image change according to the moving object is excluded from the correction target.

An image stabilization method of an image acquisition system according to the present invention for achieving the above object comprises the steps of: calculating a motion vector of a subject by integrating vertical and horizontal shaking signals for a predetermined time period during shooting; Projecting the photographed two-dimensional field / frame image data into one-dimensional data in horizontal and vertical directions, respectively; Comparing the horizontally and vertically projected data of the current field / frame by moving the horizontal and vertical projection data by the motion vector value during the predetermined time interval with the previously projected field / frame horizontally and vertically projected data, respectively; And performing image correction according to the difference between the two comparison data.

In the calculating of the motion vector, the motion vector is calculated by integrating the detection signal during a unit / field frame period.

The calculating of the motion vector may include: calculating an offset to extract only a signal according to shaking from the detection signal; Determining gain in each pixel unit of the captured image according to the magnitude and phase of the detection signal caused by the offset; And integrating the detection signal output according to the gain for a predetermined time.

In the performing of the image correction, the image correction is performed to a position where the correlation error between the two comparison data is minimum with respect to the difference generated as a result of the comparison of the two projection data. In addition, the performing of the image correction, it is assumed that the difference does not occur in a section where the difference generated as a result of the comparison of the two projection data is more than a predetermined level, the new horizontal and vertical of the current field / frame to which the motion vector is added Generating and storing line data and new horizontal and vertical line data of the previous field / frame; And performing image correction on the newly generated data to a position where the correlation error is minimum.

The image acquisition system and output image stabilization method as described above are equipped with additional sensors and driving devices to enhance the image stabilization performance in the existing image acquisition system, whereas the correction method and the motion sensor through the image signal processing By adjusting the electronic image stabilization method through the image stabilization to compensate for the image, it is possible to obtain a more stable image while minimizing the cost.

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

4 is a schematic block diagram of an image acquisition system according to the present invention. The system can be largely divided into a video signal processing part 410 and a control part. The image signal processing part 410 includes an optical system 405, a charge coupled device (CCD) 412, a sample / H (hold) circuit, an AGC (auto gain control) circuit unit 414, and a first analog-to-digital converter. (A / D: 416), an image processing unit 418, and a vertical moving unit 419. The control part 420 may include a command input unit 422, horizontal and vertical motion sensors 424-1 and 424-2, a second A / D 424-3, an image memory 424-4, and a hybrid motion detection unit ( 424-5), an image controller 426, and a camera controller 428.

The CCD 412 converts the optical image of the subject incident through the optical system 405 into an electrical signal.

The S / H and AGC circuit unit 414 operates to automatically adjust gain with respect to the electrical signal transmitted from the CCD 412, and converts the analog signal into a digital signal together with the first A / D 416. .

The image processor 418 adds an address to the digital signal converted through the first A / D 416 to be stored in the image memory 424-4, and performs image processing according to the image stabilization information. A video signal processor 418-1, a video encoder 418-2 for converting a signal transmitted from the video signal processor 418-1 to a standard video signal so as to be output on a screen, and a video signal processor 418-1. And a timing generator 418-3 for providing a timing signal to determine an operation time of the CCD 412, and a sink generator 418-4 for providing a synchronization signal to the timing generator 418-3. .

The vertical driving unit 419 receives a timing signal from the timing generator 418-3, and outputs a timing signal to the CCD 412 so that an electrical image signal can be output in units of horizontal lines from the image captured by the CCD 412. To provide.

The command input unit 422 receives various commands related to the use of the camera from the user and transmits the various commands to the camera controller 428. For example, a camera shake correction command and a zoom in / out command are input.

The horizontal and vertical motion sensors 424-1 and 424-2 detect the shaking of the apparatus body and output an electrical signal. The horizontal and vertical motion sensors 424-1 and 424-2 are used with gyro sensors.

The image memory 424-4 stores the digital image signal output from the CCD 412 through the image signal processor 418-1.

The hybrid motion detector 424-5 detects the horizontal and vertical motion vectors of the subject based on the horizontal and vertical shaking signals transmitted from the horizontal and vertical motion sensors 424-1 and 424-2. In this case, the hybrid motion detector 424-5 stores the motion vector calculated by integrating the signals output from the horizontal and vertical motion sensors 424-1 and 424-2, respectively, during the unit field or the unit frame period. Meanwhile, the hybrid motion detector 424-5 projects the two-dimensional data photographed through the CCD 412 as one-dimensional data in the horizontal and vertical directions, respectively.

The image controller 426 may compare the previous image and the current image by comparing the data of the position moved by the motion vector calculation value to the current field or frame image projected on the hybrid motion detector 424-5 and the previous field or frame image. Calculate the difference between After calculating the correction value using the calculated difference, the image signal processor 418-1 is controlled to perform image correction according to the correction value. In this case, the image controller 426 controls the image signal processor 418-1 to exclude and process a section in which a difference of a predetermined level or more is generated between the previous image and the current image as a correction target.

The camera controller 428 controls the entire camera in response to a command input through the command input unit 422 and detection signals from sensors mounted in the apparatus. That is, the camera shake control signal is transmitted to the image controller 426 in response to the shake correction command, and the control signal is sent to a motor (not shown) for moving the lens of the optical system 405 in response to the zoom in / out command. Output In addition, the camera is controlled in response to the external environment. In addition, the camera controller 428 outputs a lens driving control signal (motor driving control signal) and a shutter control signal for controlling the operation of the iris and the like to adjust the focus according to the distance to the subject and the amount of light according to the external illumination. .

FIG. 5 is a detailed block diagram of the hybrid motion detector of FIG. 4. The hybrid motion detection unit 428-5 includes a filter 5a, an offset controller 5b, a gain controller 5c, a motion signal integrator 5d, a field / frame motion vector buffer 5f, and a horizontal projection line buffer 5g. ) And the auxiliary buffer 5h.

The filter 5a performs filtering such as removing noise from the motion detection signal of the horizontal and vertical gyro sensors output from the second A / D 424-3.

The offset controller 5b automatically calculates the offset to extract only the signal according to the movement from the filtered signal. Since the offset of the signal changes, it is necessary to automatically calculate the offset.

The gain controller 5c determines the gain in pixel units of the CCD 412 according to the magnitude and phase of the sensor signal. The gain depends on the zoom factor and, if applied to the actual device, may be determined according to a predetermined gain conversion table.

The motion signal integrator 5d integrates the motion detection signal of the gyro sensor output from the gain controller 5c for a predetermined time to calculate horizontal and vertical motion vectors Sh (k) and Sv (k).

The field / frame motion vector buffer integrates the resultant values Sh (k-1) and Sv (k-1) during the past time interval calculated by the motion signal integrator 5d and the resultant values S _h (for the current time section). k), S _v (k) is stored.

The horizontal projection line buffer 5e stores the horizontal line data Ph (k) and Ph (k-1) of the field / frame transferred from the CCD 412 through the image processor 418. The first horizontal projection line buffer 5e-1 and the second horizontal projection line buffer 5e-2 alternately store the current field / frame data Ph (k) and the previous field / frame data Ph (k-1). Done.

The vertical projection line buffer 5f stores the vertical line data Pv (k) and Pv (k-1) of the field or frame transferred from the CCD 412 through the image processor 418. The first vertical projection line buffer 5f-1 and the second horizontal projection line buffer 5f-2 alternately store the current field / frame data Pv (k) and the previous field / frame data Pv (k-1). Done.

In the image acquisition system as described above, when the user inputs the image stabilization command through the command input unit 422, the camera controller 428 controls the hybrid motion detector 424-5 and the image controller 426 according to the user's image correction command. The signal is output to correct the image.

FIG. 6 is a timing diagram showing processing operations according to image input and output of the image acquisition system shown in FIG. Here, the time T0 is a field unit of the input image, and the odd field and even field of the image are divided and output by the vertical synchronization signal. In addition, the electronic shutter is operated within a given time, and the charge accumulated in the CCD 412 by the operation of the electronic shutter constitutes the next field. In addition, the image signal output from the CCD 412 is immediately stored in the horizontal and vertical projection line buffers 5e and 5f shown in FIG. 5 through the image signal processing unit 418. It becomes an image.

 7 is a flowchart illustrating a correction operation of the image acquisition system shown in FIG. 4. First, when the image stabilization command is input from the user through the command input unit 422, and when shooting is started, the hybrid motion detection unit 424-5 is transmitted from the horizontal and vertical gyro sensors 424-1 and 424-2, respectively. The angular velocity is integrated for a predetermined time, for example, in a unit field section, to calculate and store horizontal and vertical motion vectors Sh and Sv (S710). In addition, the hybrid motion detector 424-5 obtains the horizontal and vertical line data Ph (k) and Pv (k) output from the CCD 412 (S720). At this time, the image I (k-1) before one field as shown in FIG. 8A is already stored in the horizontal and vertical projection line buffers 5e and 5f. 8B illustrates an image I (k) according to horizontal and vertical projection data acquired in a current field. In the two field images shown in FIGS. 8A and 8B, the current field image I (k) is shifted by Sh in the horizontal direction and -Sv in the vertical direction with respect to the previous field image I (k-1). This is the result of the fixed background image being moved in the horizontal and vertical directions by the camera shake. However, although the background image is moved in the horizontal and vertical directions, it can be seen that the object A displayed on the right side of the projected image is slightly changed in shape and position. This indicates that the object A displayed on the right is a moving object.

When the motion vectors Sh and Sv are calculated by the hybrid motion detector 424-5 as described above (S710), and the image output from the CCD is stored in the horizontal and vertical projection line buffers 5e and 5f (S720), the image controller ( 426 is data obtained by adding the motion vectors Sh and Sv to the current fields stored in the horizontal and vertical projection line buffers 5e and 5f, that is, the data Ph (k) + Sh, Pv (k The difference value is calculated by comparing S + with the horizontal and vertical line data Ph (k-1) and Pv (k-1) of the previous field (S730). 8C is a graph showing horizontal line data Ph (k) -Sh of the current field and horizontal line data Ph (k-1) of the previous field. Then, the image controller 426 takes the absolute value of the difference between the two field images, and then determines whether there is a section having a difference between the horizontal and vertical line data of the two field images equal to or greater than a predetermined level as shown in FIG. 8D ( S740). If a section having a predetermined level or more exists, the horizontal and vertical line data sections of the two field images are masked with respect to the generation section B as shown in FIG. 8E (S750). Thereafter, new line data of each field is calculated for the masked section (S760). That is, if there is a moving object in the current field image, the difference between the previous field and the current field data may increase. Therefore, the moving object is considered to exist for the section with large level difference, and the difference is not generated for the section, and then new data is generated for the current field and the previous field, respectively, and stored in the auxiliary buffer. (S770). Next, the image controller 426 adjusts the horizontal and vertical fine correction values -Uv * and Uh * according to the difference between the horizontal and vertical data between the previous field and the current field for the remaining sections except the masked section B. FIG. Are calculated through the equation shown in S772 (S770), and new correction values -Sv (k-1) + Uv * and -Sh (k-1) + Uh are calculated (S780).

Next, the image controller 426 designates the start position of the image to be output from the image memory 424-4 according to the new correction value. Here, if there is no difference occurrence interval of a predetermined level or more from the calculated absolute value of the difference value, the image controller 426 immediately performs fine correction according to the calculated correction value according to the difference value of the comparison data between the previous field and the current field. .

Here, the image controller 426 takes an absolute value of the difference value between the projection data of the previous field and the current field, and if it is larger than the set allowance value, the image controller 426 considers that the change of the image is severe by the moving object, etc. The section is deleted. Because the present invention aims to obtain a fine correction, the data of a severe motion portion is removed and image correction is performed. Then, since the projected data portion remaining after deletion is generated by an error of the motion sensor, it is corrected through image processing. In this case, as shown in FIG. 2B, a difference correlation method is used to obtain a point U * at which the pattern difference between the two lines of the previous field and the current field is minimized in the given search section.

Meanwhile, in the above description, the setting time for obtaining the integrated signal from the motion sensor and the storage unit of the CCD output image are described in field units, but each can be set in frame units.

According to the image acquisition system and the stabilization method of the present invention as described above, to obtain a rough motion vector of the image by using the output data of a certain time of the motion sensor, the fine motion information is compared to the image stored at the field time interval of the image By using the accurate motion vector, high-performance image stabilization can be achieved.

In addition, since only a rough motion vector is obtained through a motion sensor (gyro sensor), it is insensitive to temperature and high frequency vibration, thereby reducing the occurrence of errors.

In addition, since the general image acquisition system includes a CCD element, by utilizing image stabilization through image processing, additional costs can be minimized.

In the above description of the preferred embodiment of the present invention, the present invention is not limited to the above-described specific embodiment, it is common in the art to which the invention belongs without departing from the spirit of the invention claimed in the claims. Various modifications can be made by those skilled in the art, and such changes are within the scope of the claims.

1 is a block diagram of an image acquisition system using an image stabilization method through conventional image processing;

2A is a view for explaining an image projection method;

2b is a graph and equation for calculating an optimal motion vector using difference correlation;

3 is a block diagram of an image acquisition system using a conventional electronic image stabilization method;

4 is a block diagram of an image acquisition system according to the present invention;

5 is a detailed block diagram of the hybrid motion detection unit of FIG. 4;

FIG. 6 is a timing diagram showing processing operations according to image input and output of an image acquisition system of the image acquisition system shown in FIG. 4;

7 is a flowchart illustrating an image correction operation of the image acquisition system shown in FIG. 4;

8A and 8B show images and projection data of previous and current fields stored in horizontal and vertical projection line buffers; and

8C to 8E are diagrams illustrating a masking process according to a difference between two field images shown in FIGS. 8A and 8B.

* Description of the symbols for the main parts of the drawings *

105, 405: Optical system 112, 412: CCD

114, 414: S / H and AGC circuits 116, 326, 416, 424-3: A / D

118, 418: image processor 118-1, 418-1: image signal processor

118-2, 418-2: Video decoder 118-3, 418-3: Typing generator

118-4, 418-4: Sink generator 122, 422: Command input unit

124: motion detection unit 125, 424-4: image memory

126, 426: image controller 128, 428: camera controller

424: vibration detection unit 424-1, 424-2: motion sensor

424-5: hybrid motion detection unit 5a: filter

5b: offset controller 5c: gain controller

5d: motion signal integrator 5e: field / frame motion vector buffer

5f: horizontal projection line buffer 5g: vertical projection line buffer

5h: auxiliary buffer

Claims (10)

A solid state image pickup device for converting an image of a subject according to light incident on an optical system into an electrical signal and outputting the electrical signal; A vibration sensor unit for outputting electrical signals according to vertical and horizontal vibrations of the system body; A memory for storing an image photographed by the solid state image pickup device; The motion vector of the subject is calculated by integrating the vertical and horizontal shaking signals transmitted from the shaking sensor unit for a predetermined time interval, and horizontal and vertical two-dimensional field / frame image data photographed by the solid state image pickup device. A hybrid motion detector for projecting one-dimensional data in a direction; And The horizontal and vertical projection data and the previously projected field / frame horizontal and vertical projection data are moved by moving the horizontal and vertical projection data of the current field / frame by the motion vector value during the predetermined time interval detected by the hybrid motion detector. And an image control unit for comparing the two and performing image correction according to the difference between the two comparison data. The method of claim 1, And the predetermined time interval is a unit field / frame interval. The method of claim 1, wherein the hybrid motion detection unit, An offset controller which automatically calculates an offset to extract only a signal according to a vibration from the detection signal output from the vibration sensor unit; A gain controller for determining gain in each pixel unit of the image photographed by the solid state image pickup device according to the magnitude and phase of the detection signal output through the offset controller; A motion signal integrator configured to calculate a motion vector by integrating the detection signal output from the gain controller for a predetermined time; A field / frame movement vector buffer for storing the integration result value during the previous field / frame period and the integration result value during the current field / frame period respectively calculated through the motion signal integrator; And And horizontal and vertical projection line buffers for storing horizontal and vertical line data of each of the previous two-dimensional field / frame image and the current two-dimensional field / frame image photographed by the solid state image pickup device, respectively. system. The method of claim 3, wherein And the image control unit corrects the image to a position where the correlation error between the two comparison data is minimum with respect to the difference generated as a result of the comparison between the two projection data. The method of claim 1, The hybrid motion detection unit may further include: an auxiliary buffer configured to store new horizontal and vertical data for a portion of the current field / frame moved according to the motion vector with a difference from a previous field / frame greater than or equal to a predetermined level. The image controller considers that no difference is generated in a section in which a difference generated as a result of the comparison between the two projection data is greater than or equal to a predetermined level, and the new horizontal and vertical line data and the previous field of the current field / frame to which the motion vector is added. And generating new horizontal and vertical line data of a frame / frame and storing it in the auxiliary buffer, and then performing image correction to a position where the correlation error is minimal with respect to the data stored in the auxiliary buffer. Calculating a motion vector of the subject by integrating the vertical and horizontal shaking signals during a predetermined time period during shooting;  Projecting the photographed two-dimensional field / frame image data into one-dimensional data in horizontal and vertical directions, respectively; Comparing the horizontally and vertically projected data of the current field / frame by moving the horizontal and vertical projection data by the motion vector value during the predetermined time interval with the previously projected field / frame horizontally and vertically projected data, respectively; And Performing image correction according to the difference between the two comparison data; and stabilizing the output image of the image acquisition system. The method of claim 6, The calculating of the motion vector may include calculating the motion vector by integrating a detection signal during a unit / field frame period. The method of claim 7, wherein Computing the motion vector, Calculating an offset to extract only a signal according to shaking from the detection signal; Determining gain in each pixel unit of the captured image according to the magnitude and phase of the detection signal caused by the offset; And integrating the detection signal output according to the gain for a predetermined time. The method of claim 8, The performing of the image correction, the output image stabilization method of the image acquisition system, characterized in that for performing the image correction to the position where the correlation error of the two comparison data is minimum with respect to the difference generated as a result of the comparison of the two projection data. The method of claim 9, The image correction performing step, It is assumed that no difference is generated for a section in which the difference generated as a result of the comparison of the two projection data is greater than or equal to a predetermined level, and new horizontal and vertical line data of the current field / frame to which a motion vector is added and new of the previous field / frame are added. Generating and storing horizontal and vertical line data; And And performing image correction on the newly generated data at a position at which a correlation error is minimum.