KR20040020273A - Apparatus and Method of Multi-Channel Video Encoding of Spatial Split Video - Google Patents

Abstract

PURPOSE: A multichannel motion-picture coding system using space division images and a method therefor are provided to compress space-divided input images of a plurality of channels. CONSTITUTION: A multichannel motion-picture coding system includes a storage unit(307), a control information generator, an image compressing unit(301), a controller(302), and an output unit(308). The storage unit receives space-divided video data from an external image divider and stores the video data. The control information generator generates control information for dividing the video data stored in the storage unit depending on channels and compressing the divided video data. The video compressing unit compresses the space-divided video data according to the control information. The controller controls the control information generator and video compressing unit, transmits the compressed video data, and requests an external device to deliver the compressed video data. The output unit receives the compressed video data and outputs the data at the request of the external device.

Description

Apparatus and Method of Multi-Channel Video Encoding of Spatial Split Video}

The present invention relates to a multi-channel video compression apparatus and method for performing image compression on input images of spatially divided channels. A multi-channel image compression apparatus and method using an image, and a computer-readable recording medium recording a program for realizing the method.

Recently, the demand for multi-channel digital video recording devices (DVR) is increasing rapidly, especially in the surveillance system field. Surveillance systems need to store input from multiple video cameras at the same time. However, since image data is much larger than other media data, it must be stored after compression. To this end, an image compression device using technologies such as wavelets, M-JPEG, and MPEG is required. The easiest way to implement a device for recording multiple video channels at the same time is to use an image compressor as many as the number of input channels, but there is a problem that the cost increases with the use of multiple image compressors. Therefore, in order to solve this problem, a method of simultaneously compressing several channels using one image compressor has been proposed.

The methods of compressing several channels simultaneously by using the proposed single image compressor can be divided into two types. That is, a method of time division multiplexing the input images of multiple channels using an image multiplexer and compressing them with a conventional video compression apparatus, and a method of compressing the input images of multiple channels using a video splitting apparatus and then compressing them with an existing video compression apparatus. to be.

First of all, the input video of multiple channels are time-division-multiplexed using an image multiplexer and compressed with a conventional video compression device because the limited time is divided by the desired channel. There is a problem that the time resolution is lowered depending on the number of input channels. In addition, in order to increase the temporal resolution by decreasing the spatial resolution, there is a problem that the format of the input image must be transformed into a format other than the standard.

In addition, the method of spatially dividing an input image of multiple channels using an image splitter and then compressing the image with an existing image compression apparatus is a method of performing image compression by spatially dividing the input image of multiple channels on a single screen. In contrast, unlike the method of using a time-division image, when the spatial resolution of the input image is lowered, even if several channels are simultaneously compressed, the time resolution does not decrease, and there is no need to modify the input format. However, the image compression methods proposed until now are spatial division

Since the screen is compressed into one screen without dividing the channels of the screen, it is difficult to classify the compressed data for each channel or to apply compression-related settings differently for each channel.

The present invention has been proposed to solve the above problems, space division

A multi-channel image compression apparatus and method using a spatially divided image for storing an input image and dividing and storing the stored input image data into divided image units by using the set position and size information, and a program for realizing the method. Its purpose is to provide a computer-readable recording medium having recorded thereon.

1 is a configuration diagram of an image compression system using a multi-channel image compression apparatus according to the present invention.

FIG. 2 is a diagram illustrating an embodiment of spatial division input image processing of an image splitting apparatus in an image compression system to which the present invention is applied; FIG.

Figure 3 is a configuration diagram of an embodiment of a multi-channel video compression apparatus according to the present invention.

4 is an exemplary signal diagram when a spatially divided input image is stored in a frame memory through an image splitting apparatus in an image compression system to which the present invention is applied;

FIG. 5 is an exemplary signal diagram when a spatially divided input image is read out from a frame memory in an image compression system to which the present invention is applied. FIG.

6 is an explanatory diagram illustrating a process of compressing a spatially divided image in a multi-channel image compression apparatus according to the present invention with reference to a synchronization signal;

7 is a flowchart illustrating an embodiment of a process of compressing a spatially divided image in a multi-channel image compression apparatus according to the present invention.

* Explanation of symbols on the main parts of the drawing

301: image compression device 302: processor

303: channel information 304: starting position

305: Sync signal generator 306: Address generator

307: frame memory 308: output register

309: buffer memory 310: MUX (multiplexer)

According to an aspect of the present invention, there is provided a multichannel image compression apparatus comprising: first storage means for receiving and transmitting spatially divided image data from an external image splitting apparatus; Control information generating means for generating control information for separating and compressing the spatially divided image data stored in the first storage means according to a channel; Image compression means for compressing and delivering the spatially divided image data stored in the first storage means by the control information generated by the control information generation means; Receiving an image synchronization signal from the external image splitting device to control the control information means and the image compression means, and when the image compression means completes the compression, transfers the data information accordingly and compresses the image data to the external device. Control unit for requesting the transmission of; And output means for receiving the compressed image data from the image compression means and data information according to the compression by the image compression means from the controller and outputting the data information according to a request of the external device.

In addition, the present invention provides a multi-channel video compression method comprising: a first step of initializing channel information and waiting for a synchronization signal input; Setting compression information according to a channel of an input multichannel image according to the synchronization signal input; A third step of compressing the image using the compression information set in the second step, and storing the image compressed data and the information data according to the image compression; A fourth step of multiplexing and outputting the image compressed data stored in the third step and information data according to the image compression according to a request of an external image device; And a fifth step of repeatedly performing the processes of the second to fourth steps to the last channel.

The present invention also provides a video compression system having a processor, comprising: a first function for initializing channel information and waiting for a synchronization signal input; A second function of setting compression information according to a channel of an input multichannel image according to the synchronization signal input; A third function of performing image compression using the compression information set by the second function, and storing the image compressed data and the information data according to the image compression accordingly; A fourth function of multiplexing and outputting the image compressed data stored by the third function and information data according to the image compression according to a request of an external image device; And a computer-readable recording medium having recorded thereon a program for realizing a fifth function for repeatedly performing the processes of the second to fourth functions to the last channel.

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

In the embodiment of the present invention, in order to propose a multi-channel image compression apparatus and method for processing a spatially divided input image, the number of channels is four, and the number of channels may vary according to the application of the present invention. In addition, since the apparatus and method proposed by the present invention can be used with various compression techniques, the individual compression methods are not described in detail in the following detailed description.

1 is a configuration diagram of an image compression system using a multi-channel image compression apparatus according to the present invention.

In the video compression system using the multi-channel video compression apparatus according to the present invention, the video decoder 11 for receiving the allocated video per channel and converting it into a digital video is transmitted, and the digital video information of the plurality of video decoders 11 is received. A video splitting apparatus 12 for spatially dividing and transmitting a video into a screen of a multi-channel video compression apparatus for performing image compression so as to be separated per channel by using image data transmitted from the image splitting apparatus 12 and an image synchronization signal. 13) and a host 14 for outputting the compressed image from the multi-channel image compression device 13.

Looking at the overall operation in more detail, the analog video signal input through the camera is converted into a digital image through the four-channel video decoder 11, the four-channel digital image converted through the video decoder 11 is divided into images. After the image is converted into a spatially divided image through the apparatus 12, the image data and the image synchronization signal are divided and input to the multi-channel image compression apparatus 13.

The multi-channel image compression device 13 stores the divided images in the frame memory of the apparatus, reads and compresses each of the divided images one by one, and stores the compressed data in the buffer memory.

Each time the compression of the divided image is completed, the multi-channel image compression apparatus 13 records the size and channel number of the compressed image data and causes the host 14 to read the value through the interrupt signal.

The host 14 reads the compressed image data from the multi-channel image compressor 13 as much as the size of the compressed image data and processes the compressed image data according to the channel number.

FIG. 2 is a diagram illustrating an embodiment of spatial division input image processing of an image splitting apparatus in an image compression system to which the present invention is applied.

When the four channels of input images 21 through 24 pass through the image splitting device 12, a spatially divided image 25 is created, and each of the input images 21 through 24 is reduced to divide the divided image 25. One in each quadrant. Therefore, the time resolution of each channel is maintained as it is.

3 is a block diagram of an embodiment of a multi-channel video compression apparatus according to the present invention.

In the multi-channel image compression apparatus according to the present invention, a frame memory 307 for receiving and transmitting spatially divided image data through the image splitting apparatus 12, and stores setting values such as starting positions and sizes of all channels and compression ratios. And a setting value of a channel to be compressed before receiving the image synchronization signal through the channel information unit 303 and the image splitting device 12 and transmitting the image data of each channel from the channel information unit 303 to the processor 302. Control the controller to set the necessary values for the start position unit 304, the image compressor 301 and the synchronization signal generator 305, and store the data according to the image compression in the output register 308 and host 14 Processor 302 generating an interrupt signal to receive the output data for the address, indicating the start position of the channel to be compressed in the spatially divided image data under the control of the processor 302 A synchronizing signal necessary for compressing the image data under the control of the start position unit 304 and the processor 302, which is transmitted to the device 306, and transmitted to the image compressor 301 and the address generator 306. The image to be read or written using the synchronization signal generated from the synchronization signal generator 305 and the information on the position where the image data of the channel to be compressed transmitted from the synchronization signal generator 305 and the start position unit 304 starts. Compress the spatially divided image data stored in the frame memory 307 by the synchronization signal indicating the start of the compressed image data generated by the address generator 306 and the synchronization signal generator 306 for generating the address of the data. Image compression device 301 for processing and delivering to the buffer memory 309, buffer memory 309 temporarily stored before outputting the compressed image data, the size of the compressed data each time the compression of one image is finished And a multiplexer for outputting one of the information stored in the output register 308 and the buffer memory 309 according to the address register 308 for receiving and storing the channel number from the processor 302 and the address information from the host 14. 310.

Looking at each component in more detail, the image compression device 301 is a device for compressing data input from the frame memory 307 in accordance with the synchronization signal generated by the synchronization signal generation device 306.

The channel information unit 303 stores setting values such as the start position, size, and compression ratio of all video channels to be compressed, and the start position unit 304 indicates a start position of a channel to be compressed in the divided input image.

Then, the processor 302 reads the setting value of the channel to be compressed from the channel information unit 303 before compressing the image data of each channel from the image compressor 301, the synchronization signal generator 305, and the start position 304. Control to set the required value. In particular, the processor 302 causes the synchronization signal generation device 306 to generate a picture synchronization signal indicating the start of the compressed image data in consideration of the size of the image to be compressed based on the image synchronization signal of the input image. In addition, the processor 302 stores the size and channel number of the compressed data in the output register 308 every time compression of one image is completed, and generates an interrupt so that an external device (host: 14) is buffered. Information in the memory 307 or information stored in the output register 308 is read.

The synchronization signal generation device 306 generates a synchronization signal necessary for compressing the image data and supplies the same to the image compression device 301 and the address generation device 306. At this time, the picture synchronizing signal among the synchronizing signals generated by the synchronizing signal generating device 306 indicates the start of the compressed video data, and is generated according to a control command from the processor 302.

In addition, the address generator 306 generates an address of data to be read or written by using a synchronization signal and information about a position at which a channel to be compressed starts.

In addition, the frame memory 307 is used to store the spatially divided image through the input image splitter 12, and the buffer memory 307 temporarily stores the compressed data before outputting the compressed data from the image compressor 301. Used for the purpose.

FIG. 4 is a diagram illustrating a signal when an input image divided by a video splitter is stored in a frame memory in an image compression system to which the present invention is applied.

As shown in FIG. 4, when storing a space-divided input image through a video splitting apparatus in a frame memory, the space-divided image is not separately stored for each channel and stored as one image data. In other words, it recognizes as one signal from the beginning to the end.

FIG. 5 is a diagram illustrating a signal when a spatially divided input image is read from a frame memory in an image compression system to which the present invention is applied. FIG.

When reading the image data stored in the frame memory to compress the image, as shown in FIG. 5, the image data is read in order by channel using the start position and size information of the divided image. According to the compression method, it is necessary to reconstruct the compressed data into image data and store it again. When storing the reconstructed image data in the frame memory, the regions are divided and stored as described above.

6 is an exemplary view illustrating a process of compressing a spatially divided image based on a synchronization signal in the multi-channel image compression apparatus according to the present invention.

The image synchronization signal 61 is one of synchronization signals input together with an externally divided input image. The picture synchronizing signal 62 is a synchronizing signal generated by the synchronizing signal generating apparatus described with reference to FIG. 3 and is a signal indicating the start of image data to be compressed. In the four-channel compression according to the embodiment of the present invention, four picture synchronization signals 62 are generated during one period of the image synchronization signal 61, and four divided images together with each picture synchronization signal 62 are generated. This is compressed one by one. The interrupt 63 is generated every time the compression of the image data is completed, and causes the external device (host: 14) to read the compressed data.

As described above, by compressing the space-divided screen using the method according to the present invention, compressed data can be separated for each channel. Therefore, it is possible to select and compress only some channels or to vary the degree of compression for each channel. In addition, the temporal resolution of the compressed data does not decrease according to the number of channels, and there is no need to modify the image input format.

7 is a flowchart illustrating an embodiment of a process of compressing a spatially divided image in a multi-channel image compression apparatus according to the present invention.

First, channel information such as a start position, a size, and a compression ratio of each channel is determined for each channel, stored in the channel information unit, and the channel information is initialized (701).

The apparatus waits until the video synchronization signal is input through the video splitting apparatus (702). When the video synchronization signal is input, the channel number "n" is initialized to "0" (703).

Then, the processor causes the synchronization signal generation device to generate a picture synchronization signal indicating the start of the image data to be compressed (704).

In operation 705, a start position, a size, and a compression ratio of the channel n are received from the channel information unit, and a start position and a size value are set, and a compression ratio of the image compressor is set (706).

Then, the image is read as much as the given size value from the start position of the frame memory and compressed for the channel (707), and the compressed data is stored in the buffer memory (708).

After the above compression is completed, the size and channel number of the compressed data stored in the buffer memory are recorded in the output register (708).

After storing the data by compression, the processor generates an interrupt to cause the host to receive the stored data (709).

According to the address information from the host, the size and channel number of the compressed data stored in the buffer memory or the recorded data recorded in the output register are output (710).

Then, process 704 to process 710 are repeated to the last channel (711, 712).

As described above, the method of the present invention may be implemented as a program and stored in a recording medium (CD-ROM, RAM, floppy disk, hard disk, magneto-optical disk, etc.) in a computer-readable form.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

As described above, the present invention does not use an image compression device as many as the number of input channels, but uses a spatially divided image, so that multiple channels are simultaneously compressed using one image compression device without having to change the input format. It can be effected.

In addition, in the present invention, since a channel is divided and compressed using channel information in compressing a spatially divided image, the compressed data may be classified for each channel or compression-related settings may be applied differently for each channel.

Claims (11)

In the multi-channel video compression apparatus, First storage means for receiving and transmitting spatially divided image data from an external image splitting apparatus; Control information generating means for generating control information for separating and compressing the spatially divided image data stored in the first storage means according to a channel; Image compression means for compressing and delivering the spatially divided image data stored in the first storage means by the control information generated by the control information generation means; Receiving an image synchronization signal from the external image splitting device to control the control information means and the image compression means, and when the image compression means completes the compression, transfers the data information accordingly and compresses the image data to the external device. Control unit for requesting the transmission of; And Output means for receiving the compressed image data from the image compression means and the data information according to the compression by the image compression means from the control unit for outputting at the request of the external device Multi-channel video encoding apparatus using a spatial segmented image comprising a. The method of claim 1, The control information generating means, Channel information means for storing a setting value including a start position, a size, and a compression ratio according to the divided channels of the spatially divided image data, and transmitting the set value to the controller; A starting position means for delivering to the first storage means a starting position indicating a memory position of a signal start of each channel to be compressed in the spatially divided image data under the control of the controller; Synchronizing signal generating means for generating a synchronizing signal for compressing the spatially divided image data and transmitting the synchronizing signal to the image compression device and the address generating means under the control of the controller; And The address generating means for generating an address of the image data to be read or written using the start position information from the start position means and the sync signal from the sync signal generation means; Multi-channel video encoding apparatus using a spatial segmented image comprising a. The method of claim 2, The synchronization signal for compressing the spatially divided image data, 24. A multi-channel video encoding apparatus using a spatially divided image, wherein the signal indicates the start of image data to be compressed and occurs as many as the number of channels to be compressed during one period of the image synchronization signal received from the outside. The method according to any one of claims 1 to 3, The output means, Second storage means for storing the compressed image data from the image compression means; Third storage means for receiving and storing data information according to compression by the image compression means from the controller; And Multiplexing means for outputting any one of the image data stored in the second storage means to the data information stored in the third storage means at the request of an external imaging device Multi-channel video encoding apparatus using a spatial segmented image comprising a. The method of claim 4, wherein The data information is a multi-channel video encoding apparatus using a spatial segmented video, characterized in that it comprises the size of the compressed image data generated each time the compression of the image corresponding to one channel and the corresponding channel number. In the multi-channel video compression method, A first step of initializing channel information and waiting for a synchronization signal input; Setting compression information according to a channel of an input multichannel image according to the synchronization signal input; A third step of compressing the image using the compression information set in the second step, and storing the image compressed data and the information data according to the image compression; A fourth step of multiplexing and outputting the image compressed data stored in the third step and information data according to the image compression according to a request of an external image device; And Fifth step of repeating the process of the second step to the fourth step to the last channel Multi-channel video encoding method using a spatial segmented image comprising a. The method of claim 6, The second step, According to the synchronization signal input of the first step, A sixth step of generating a picture synchronization signal indicating the start of the compressed data to be compressed for the compressed image; And A seventh step of setting information including a start position, a size, and a compression ratio according to a channel for the input multichannel image; Multi-channel video encoding method using a spatial segmented image comprising a. The method according to claim 6 or 7, The fourth step, An eighth step of generating an interrupt signal upon completion of image compression to output the image compressed data stored in the third step and information data according to the image compression to an external image device; And A ninth step of multiplexing and outputting the image compressed data stored in the third step and information data according to the image compression according to a control signal from the external image device receiving the interrupt signal of the eighth step; Multi-channel video encoding method using a spatial segmented image comprising a. The method according to claim 6 or 7, The information data according to the image compression of the fourth step, And a channel number and size information of the compressed image data. The method of claim 7, wherein And the picture synchronization signal is set to occur as many as the number of channels during one period of the synchronization signal input in the first step. In an image compression system having a processor, A first function of initializing channel information and waiting for a synchronization signal input; A second function of setting compression information according to a channel of an input multichannel image according to the synchronization signal input; A third function of performing image compression using the compression information set by the second function, and storing the image compressed data and the information data according to the image compression accordingly; A fourth function of multiplexing and outputting the image compressed data stored by the third function and information data according to the image compression according to a request of an external image device; And A fifth function for repeating the processes according to the second to fourth functions to the last channel; A computer-readable recording medium having recorded thereon a program for realizing this.