KR20010094612A - apparatus compressing data in the data recording system and method therefor - Google Patents

Abstract

PURPOSE: A data compressing apparatus in a digital recording system and a control method thereof are provided to prevent an unnecessary capacity consumption of a storage medium and prolong a lifespan of the storage medium. CONSTITUTION: An image signal processor(1) converts an analog image signal into a digital signal and processes the digital image signal to output image data. An image recording controller(2) compresses and controls the image data from the image signal processor(1). The image recording controller(2) includes a central processing unit, a ROM, a RAM, and a bus. A memory(3) stores a signal or data generated during a compressing operation of the image recording controller(2) in a designated address. A compression image storage section(4) stores the image data compressed by an operation of the image recording controller(2).

Description

Apparatus compressing data in the data recording system and method therefor}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital recording system (DRS), and more specifically, to digital recording for compressing digital image information of a video by wavelet and fractal image compression. A data compression apparatus in a system and a method thereof.

The present invention also relates to a data compression apparatus and method in a digital recording system for preventing unnecessary compression operations in the digital recording system to avoid unnecessary failures and shortening of lifespan.

The digital recording system is an apparatus for storing and transmitting image information in a digital state instead of the analog recording method. Such digital recording systems are used in various fields using video transmission such as video conferencing systems, unmanned store management systems, and traffic control systems.

However, in order to efficiently store a large amount of digital image data, such a digital recording system compresses and stores the image data, restores the compressed image to the original image, and outputs the compressed image.

Techniques for compressing image data converted into a digital state generally include MPEG, MJPEG, wavelets, and fractals.

MPEG or MJ pack compresses a moving image, and performs a compression operation by comparing image data of the previous image and the current image for each pixel, which requires a lot of compression time and a large storage capacity.

In addition, when reconstructing a compressed image, a lot of image information is lost, so that a blockage phenomenon occurs in the reconstructed image, which deteriorates the image quality of the reconstructed image, and causes an economic burden because a large usage fee is required. The disadvantage arises.

On the other hand, wavelet or fractal compression techniques are used to compress still images on a frame-by-frame basis, which saves data processing time when compressing or restoring the data. .

However, since it is a compression technique for compressing only still images, there is a problem in that a video cannot be compressed, and there is a difficulty in use because there is no international standard.

In addition, when a digital recording system is mainly installed in an unmanned store or an unmanned bank store, even if there are not many users at night, the digital recording system continues to operate to compress the image data without any special changes even when no special change occurs. Repeat the saving operation.

Therefore, since a compression operation on the same video data is repeatedly executed and continuously stored on a storage medium such as an optical disk or a hard disk, a problem of consuming storage capacity of an unnecessary storage medium occurs, resulting in unnecessary storage operation of the same video. This results in a problem of shortening the life of the storage medium.

Therefore, a technical problem of the present invention is to compress a video using a wavelet method and a fractal method, thereby shortening the compression time, improving the compression efficiency, and reducing the storage space required for image compression.

In addition, the technical problem to be achieved by the present invention is to prevent the compression control and the storage operation when there is no image change, to prevent unnecessary capacity consumption of the storage medium and to extend the life of the storage medium.

1 is a block diagram of a data compression apparatus in a digital recording system according to a first embodiment of the present invention,

2 is an operation flowchart of a data compression control method in a digital recording system according to a first embodiment of the present invention;

3 shows a motion history index table according to the first embodiment of the present invention,

4 is a block diagram of a data compression apparatus in a digital recording system according to a second embodiment of the present invention,

5 is an operational flowchart of a data compression control method in a digital recording system according to a second embodiment of the present invention.

The data compression device in the digital recording system according to the present invention for solving this problem,

By dividing the input image data by the set type, the image information about each input object is calculated to determine whether there is a moving object, and when the moving object exists, the image information about the moving object is calculated, It determines whether the corresponding information exists in the image information, and if the image information of the previous image information and the moving object exists, only the converted image information is recorded again, and the image information of the moving object does not exist in the previous image information. If not, all the image data on the moved object is recorded again, and includes an image recording control unit which generates and compresses the currently input image using all the image data and the image information.

Preferably, the video recording control unit compresses the image using the previous state information when there is no moving object, and compares the movement of the object with the setting value when the moving object occurs. If it is determined that the object has moved, it is determined that the object has moved. If the object does not move beyond the set value, it is determined that the object has moved.

Data compression control method in a digital recording system according to the present invention for solving this problem,

Calculating image information about each input object;

Determining whether a moved object exists using the calculated image information;

Calculating image information corresponding to the moved object when the moved object exists;

Determining whether the image information calculated in the previous image information already exists;

If the calculated image information already exists in the previous image information, rewriting only the converted image information;

If the calculated image information does not already exist in the previous image information, generating an approximated object using all the calculated image information and comparing it with the input real object;

Rewriting only the converted image information when the approximated object is similar to the real object, and recording all image data about the approximated object when the approximated object is not similar to the real object;

Generating an image currently input using the recorded image information;

And compressing the generated image.

Preferably, the method further comprises the step of compressing by using the image information of the previous state, if there is no moving object.

In addition, the data compression control device in the digital recording system according to the present invention for solving this problem,

A subject photographing unit which photographs an image of a subject by an image capturing unit and outputs a corresponding video signal;

An image signal processor configured to image the image signal output from the subject photographing unit and output corresponding image data;

A sound detector for detecting a sound and outputting a corresponding signal;

When it is determined that the sound is generated by the signal output from the sound detection unit, the data recording control unit for performing the compression control of the video data output from the video signal processing unit.

Preferably, the control unit further comprises a mode setting unit for changing the operation state by the user to determine the operation mode selected by the user, the operation control unit in the night mode according to the signal input from the mode setting unit in the sound detection unit It is determined whether sound is generated by using the output signal.

Preferably, when the sound is generated by the signal output from the sound detection unit, the operation controller determines whether the generated sound is greater than or equal to the set size. By comparing the data, it is determined whether a change in the image data has occurred, and if a change occurs between the image data of the previous frame and the image data of the current frame, compression control to high quality is executed.

In addition, the data compression control method in the digital recording system according to the present invention for solving this problem,

Determining whether sound is generated by the sound detection signal;

If it is determined that sound is generated, executing compression control of the input image data;

If no sound is generated, a step of not performing compression control on the input image data is included.

Preferably, when it is determined that the sound is generated, in the step of performing compression control of the input image data,

Comparing the volume of the generated sound with a set size;

If the compared loudness exceeds a predetermined size, comparing the image data of the previous frame with the image data of the current frame to determine whether the image data has changed;

If the image data is changed, the method further comprises the step of performing compression control to a high picture quality.

Then, the present invention can be easily implemented by those skilled in the art with respect to a data compression apparatus and a control method in a digital recording system according to an embodiment of the present invention with reference to the accompanying drawings. The most preferred embodiment present will be described in detail.

1 is a block diagram of a data compression apparatus in a digital recording system according to a first embodiment of the present invention, and FIG. 2 is an operation flowchart of a data compression control method in a digital recording system according to a first embodiment of the present invention. 3 shows an example of a motion history index table according to the first embodiment of the present invention.

1 is a block diagram of a data compression apparatus in a digital recording system according to a first embodiment of the present invention, in which an image signal processor 1 to which an image signal is input and an image connected to the image signal processor 1 are shown. And a recording control unit 2, a memory 3 connected to the image recording control unit 2, and a compressed image storage unit 4 connected to the image recording control unit 2. FIG.

The video signal processor 1 converts an input analog video signal into a digital state, and outputs the converted video data by processing the converted video signal in a general manner. The video recording controller 2 compresses and controls the video data output from the video signal processor 1, and the memory 3 stores signals or data generated during the compression operation of the video recording controller 2 at the corresponding address. do. The compressed image storage unit 4 stores the image data compressed by the operation of the image recording control unit 2.

The video recording control unit 2 has a general structure including a central processing unit (CPU), a ROM, a RAM, a bus, and the like.

An operation according to the first embodiment of the present invention having such a structure will be described in detail with reference to FIGS. 1 to 3.

First, the video signal is input to the video signal processor 1. In this case, the video signal is a signal generated by capturing the object using an imaging device such as a CD, etc., and the video signal processor 1 is a digital signal capable of using an analog video signal. After converting the video signal of the state, the video signal is processed to output the corresponding video data.

As a result, the video recording control unit 2 executes a control operation for compressing the input video data.

Therefore, the operation of the video recording control unit 2 for compressing the video data will be described in detail with reference to FIG.

First, when the operation is started (S10), the image recording controller 2 reads the image data, and converts the input image data into vertical data and horizontal data using a conventional wavelet transform method, and a core image of the input image data. The data is divided into data (S11).

Then, the image recording control unit 2 compares the wavelet-converted image data with all the image data stored at the corresponding address of the memory 3 (S12), where the object's occurrence position, size data, color, and occurrence are generated. Image information of a motion history index required for the motion history index table shown in FIG. 3 is calculated by using a fractal transformation for determining image information such as probability (S13).

Then, it is detected whether a moving object has occurred in the image of the previous state (S14).

When it is determined that the moved object has occurred, the image recording control unit 2 stores the currently input image data in the corresponding address of the memory 3, and stores the image data stored in the memory 3 or the buffer in the current image data. Changed to the input image data (S15), and determines the number of objects moved (S16).

Then, the degree of movement of each moved object is compared with the preset value (S17).

When the degree of movement of each moved object changes by more than a preset value, the video recording control section 2 determines that the object has moved.

However, when the degree of movement of the object does not exceed the set value, it is determined that the object is not moved because the degree of movement is insufficient.

Therefore, the video information of the previous state is used as it is (S26).

However, when an object whose degree of movement is greater than or equal to a set value is generated by comparing the previous image with the currently input image, the image recording control unit 2 determines that the moved object has occurred and calculates image information on the moving object. (S18).

Accordingly, the image recording control unit 2 calculates image information regarding a generation area, a moving distance, an image data size, a color, a generation position and a probability of occurrence of the moving object.

Then, it is determined whether all of the image information on the moving object is present in the motion history index table calculated in step S13 in the image information on the moving object (S19).

When the video information about the object moving in the motion history index information exists in the motion history index table at the same value, the video recording control unit 2 determines that the same object is in a changed state only.

Therefore, the video recording control unit 2 newly records only the video information converted from the history index information, that is, the changed position information, the generation area, the occurrence probability, etc. (S20), and the same video information as the previous state is the video of the previous state. Make information available.

However, when there is no video information on the moving object in the motion history index information, the video recording control unit 2 determines that a new object that does not exist in the previous video is generated.

Therefore, the image recording control unit 2 calculates the image information on the newly generated object once again, and then generates an approximated moving object using the calculated image information (S21).

Then, the calculated approximated moving object and the currently input real object corresponding to the image data input in the above step (S11) are compared (S22) to determine whether they are similar objects (S23).

When it is determined that the approximated object and the real object are similar to each other, the image recording controller 2 records the calculated image information on the approximated object in the motion histories index table of the memory 3 (S24).

However, when the compared approximated object and the real object are not similar to each other, since the approximated object is a new image, all of the image data corresponding to the approximated object is stored in the motion history index table. Record (S25).

As shown in Fig. 3, the index value of the motion history index table is " N " at this time, indicating that a completely new object has occurred.

As described above, when a moving object occurs in the current image data when compared with all the image data, the image recording controller 2 calculates image information about the moving object, and calculates an approximated image corresponding to the actual input image. Do it.

However, when the moving object does not occur in the image data corresponding to the input image compared with the image data of the previous image in step S14, the image recording control unit 2 does not exist the previous image and the changed image Judging by.

Therefore, the video recording control unit 2 records the frame check bit designated at the corresponding address of the memory 3 as a set value so that the video data corresponding to the entire video can be used as it is. The previous video information can be used immediately without executing the calculation operation (S26).

As shown in FIG. 3, the index value of the motion history index table is set to "0" so that the previous image information is used as it is with the same object as the previous object.

In the embodiment of the present invention, when no moving object is generated in step S14, the video recording control unit 2 rearranges the indexes in the order of the highest occurrence probability, so that the motion history index table always has a high probability of occurrence. Since the object is sequentially searched to determine the moving state of the object, the search time can be reduced.

As such, when all the image information on the moving object of the image data currently input is calculated, the image recording control unit 2 generates the image currently input (S27).

That is, the image recording control unit 2 is currently input by using the image data of all the images stored in the corresponding address of the memory 3, the information of the calculated motion history index, and the image information about the newly generated object. Create an image.

Then, the image recording control unit 2 compresses the generated image and outputs it to the compressed image storage unit 4 (S28 and S29).

Then, the compressed image storage unit 4 sequentially stores the compressed image output from the image recording control unit 2 at the corresponding address.

Therefore, the compressed image storing unit 4 sequentially stores the compressed image of the input video at the corresponding address, and outputs the compressed image stored at the corresponding address when reconstructing the compressed image. Restore to the image.

Next, a data compression apparatus and a control method thereof in the digital recording system according to the second embodiment of the present invention will be described with reference to FIGS. 4 and 5.

4 is a block diagram of a data compression apparatus in a digital recording system according to a second embodiment of the present invention, and FIG. 5 is a flowchart of an operation of a data compression control method in a digital recording system according to a second embodiment of the present invention. .

As shown in Fig. 4, the structure of the data compression control apparatus in the digital recording system according to the second embodiment of the present invention is a lens unit 10 and an imaging unit to which an image formed in the lens unit 10 is input ( 20, a signal processing unit 30 to which the output of the imaging unit 20 is input, an image signal processing unit 40 to which the output signal of the signal processing unit 30 is input, and a sound sensing unit sensing and outputting ambient sounds A mode recording switch SW1 for selecting an operation mode, a data recording control unit 60 connected to the image signal processing unit 40, a sound sensing unit 50, and a mode setting switch SW1, and a data recording control unit ( The compressed image storage unit 70 receives an output of the input unit 60.

When the lens unit 10 forms an image of a subject (not shown) to be photographed, the imaging unit 20 receives an image formed by the lens unit 10 to generate a corresponding electric image signal. The signal processor 30 removes noise components included in the image signal output from the imaging unit 20, amplifies the weak signal, converts the analog signal state into a digital state, and converts the signal into an available state. 40).

The video signal processor 40 processes the input video signal in a general manner and outputs the video data to the data recording controller 60.

In addition, the sound detection unit 50 is composed of a high-performance speaker, and senses the surrounding sound and outputs it to the data recording control unit 60.

The mode setting switch SW1 selects a day mode or a night mode as an operation mode of the data recording system by the user and outputs a signal of a corresponding state.

The data recording controller 60 has a general structure including a central processing unit (CPU), a ROM, a RAM, an A / D converter, and the like, and detects image data and sound of each frame input from the image signal processor 40. The video compression state is controlled by using the sound generation state and the degree of motion of the image when it is set to the night mode by using the signal input from the unit 50 and the mode setting switch SW1.

The compressed image storage unit 70 is composed of a hard disk or an optical disk, and the image compressed by the data recording control unit 60 is stored at a corresponding address.

The operation according to the second embodiment of the present invention having such a structure will be described with reference to FIG.

As shown in FIG. 5, when power required for operation is supplied, operation starts (S1000), and the signal input from the mode setting switch SW1 is read (S111). Then, the state of the signal applied by the read mode setting switch SW1 is judged to determine whether the operation mode selected by the user is a night mode or a day mode (S112, S113).

When the operation mode selected by the user according to the operation of the mode setting switch SW1 is determined to be a night mode, the data recording control unit 60 reads a signal output from the sound detection unit 50 (S115) and sounds from the outside. It is determined whether or not (S116, S117) has occurred.

However, when the determined operation mode is the day mode, the data recording control unit 60 executes general compression control (S114), and sequentially stores the compressed image in the compressed image storage unit 70 at the corresponding address.

If the operation mode determined in step S113 is determined to be no sound in the surroundings by the signal output from the sound detection unit 50 in the night mode, the data recording control unit 60 does not change the surrounding situation. It judges that it is not.

Therefore, the data recording control unit 60 reads only the signal input from the video signal processing unit 40 and switches to the recording sleep mode in which the compression control is not executed (S118), until it is determined that the surrounding situation is changed. No compression control is performed on the input video signal.

However, if it is determined that the sound is generated by the signal output from the sound detection unit 50, the data recording control unit 60 determines whether the loudness (dB) of the generated sound is more than the set size (dB) (S119). .

When the volume of the generated sound does not exceed the set size, the data recording controller 60 compresses and controls the video data input through the video signal processor 40 in a normal state, and compresses the compressed video data into a compressed video storage unit. In operation 70, it is stored in (70).

However, if the determined sound volume is large enough to exceed the set size, the data recording control unit 60 controls the image data of the current frame output from the video signal processing unit 40 and the previous frame stored in the memory such as RAM. The image data is compared to determine whether a change occurs in the image data to determine whether the motion of the captured image is generated (S121).

When the difference between the image data of the previous frame and the image data corresponding to the currently input frame does not occur, the data recording controller 60 does not generate a motion between the image of the previous frame and the image of the currently captured frame. It is judged that it is not. Therefore, the data recording control unit 60 compresses and controls the image data input in the normal state, and stores the compressed image to the compressed image storage unit 70 (S120).

However, when a change occurs between the image data of the previous frame and the image data of the current frame, the data recording controller 60 determines that the motion occurs in the captured image.

Therefore, the data recording control unit 60 controls the compression state in a fine mode, more precisely controls the compression control than in the normal mode, and stores the compressed image in the compressed image storage unit 70.

Therefore, by the reconstruction operation, it is possible to easily and accurately perform screen analysis on the image in which the motion occurs when the image is reproduced.

In this way, the effect of the present invention does not need to compress each generated image, and does not need to compare each generated image data with all image data to calculate the current image using only the information converted from all the images. After compression, the entire image is used as it is without any change. Therefore, the compression time is shortened to improve the signal processing efficiency and the compression efficiency, and also reduce the required storage capacity.

In addition, since the conventional compression method is not used, unnecessary cost of payment is reduced, thereby realizing cost reduction.

In addition, since unnecessary compression control is prevented at night when movement or sound is not generated, unnecessary capacity reduction of the storage medium for storing the compressed image is prevented and the life is extended.

Claims (7)

In the data compression device for compressing digital image data of a moving picture comprising a video recording control unit for compressing the input video data and a compressed video storage unit for storing the compressed video, The video recording control unit, Splits the input image data by the set type, calculates image information about each input object, determines whether there is a moved object using the calculated image information, and if the moved object exists, Image information is calculated to determine whether the corresponding information exists in the previous image information, and if the image information of the previous image information and the moving object exists, only the converted image information is recorded again, If there is no video information about the object that has moved in the previous video information, all the image data about the moving object is recorded again. And a current compression image is generated using all the image data and the image information and compressed. The method of claim 1, wherein the video recording control unit, When a moving object occurs, the degree of movement of the object is compared with the set value, If it is determined that the object has moved above the set value, it is determined that the object has moved. If the object does not move more than the set value, the data compression device characterized in that it is not determined as a moved object. According to an aspect of the present invention, there is provided a data compression device in a digital recording system, the method comprising: dividing input image data by a set type and dividing the image data input to each input object by type; Calculating image information about each input object; Determining whether a moved object exists using the calculated image information; Calculating image information corresponding to the moved object when the moved object exists; Determining whether the image information calculated in the previous image information already exists; If the calculated image information already exists in the previous image information, rewriting only the converted image information; If the calculated image information does not already exist in the previous image information, generating an approximated object using all the calculated image information and comparing it with the input real object; Rewriting only the converted image information when the approximated object is similar to the real object, and recording all image data about the approximated object when the approximated object is not similar to the real object; Generating an image currently input using the recorded image information; A data compression control method comprising the step of compressing the generated image. A subject photographing unit which photographs an image of a subject by an image capturing unit and outputs a corresponding video signal; An image signal processor configured to image the image signal output from the subject photographing unit and output corresponding image data; A sound detector for detecting a sound and outputting a corresponding signal; A data recording control unit for performing compression control of the video data output from the video signal processing unit when it is determined that the sound is generated by the signal output from the sound detection unit; And a compressed image storage unit for storing the compressed image output from the data recording controller. The method of claim 9, wherein the operation control unit If the sound is generated by the signal output from the sound detection unit, it is determined whether the generated sound is greater than or equal to the set size. If the generated sound is greater than or equal to the set size, the image data is compared by comparing the image data of the previous frame with the image data of the input current frame. And determining whether a change has occurred, and if the change occurs between the image data of the previous frame and the image data of the current frame, compression control to a high quality. Determining whether sound is generated by the sound detection signal; If it is determined that sound is generated, executing compression control of the input image data; And if no sound is generated, not performing compression control on the input video data. The method of claim 13, wherein if it is determined that the sound is generated, in the step of performing compression control of the input image data, Comparing the volume of the generated sound with a set size; If the compared loudness exceeds a predetermined size, comparing the image data of the previous frame with the image data of the current frame to determine whether the image data has changed; And if the image data is changed, executing compression control to a high picture quality.