KR100953508B1 - Digital video transmission and reception method and system - Google Patents

Abstract

The present invention relates to an apparatus and method for processing a digital image, and to efficiently use only an image processing processor, a transmission bandwidth, and a display by selecting and encoding only an image of a predetermined region or transmitting only an image of a predetermined region. To this end, the present invention includes an input unit for receiving a digital image, an encoder for encoding only a predetermined region of the digital image, and an output unit for receiving and outputting the encoded image.

Digital image processing, display, HD, high quality

Description

Method and system for transmitting and receiving digital video {Method and System for Transmitting and Receiving Digital Video Stream}

The present invention relates to an apparatus and method for processing a digital image, and more particularly, to a technique for maximizing the efficiency of an image processing processor, a transmission bandwidth, and a display by encoding only an image of a certain region or transmitting only an image of a certain region. .

With the development of digital video and broadcasting system technology, high definition (HD) video is becoming more common than standard definition (SD) video in terms of its quality, and further, digital video of improved quality such as quad HD or UHDV has been proposed. As technology advances, higher quality digital images are required, and this trend will accelerate further.

However, the higher quality video requires a higher performance image processing processor, the system construction cost for high quality image processing is significantly higher. In addition, even in the transmission of digital video, the higher the quality of the video, the greater the bandwidth required for transmission, which makes it difficult to efficiently use limited network resources. With the spread of high-quality video, consumers are demanding bigger and clearer screens.However, display devices such as LCDs and PDPs can not increase their size because power consumption and price increase exponentially as the display screen size increases. have.

Accordingly, an object of the present invention is to provide a technique of selecting and encoding only an image of a certain region or a technique of transmitting only an image of a certain region in order to efficiently use an image processing processor and a network resource and a display required for transmission.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention which are not mentioned above can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. It will also be readily apparent that the objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

In order to achieve the above object, the present invention provides a method of processing a digital image, the method comprising: receiving a digital image, selecting a predetermined region of the digital image, and encoding only an image of the selected constant region And transmitting the encoded image to an output unit.

In another aspect, the present invention provides a method for processing a digital image, receiving a digital image, encoding the image, selecting a predetermined region of the encoded image, and outputs the image of the selected constant region to the output unit It is another feature to include the step of delivering.

According to another aspect of the present invention, there is provided an apparatus for processing a digital image, the input unit including a digital image, an encoding unit encoding only a predetermined region of the digital image, and an output unit receiving and outputting the encoded image. It is done.

In addition, the present invention provides a remote multimedia transmission and reception system, receiving a digital image, selecting a predetermined region of the digital image, encoding only the image of the selected constant region, and transmits the encoded image to the output unit It is another feature to include the step of doing.

According to the present invention as described above, compared to the existing technology of encoding all the digital images, it is possible to process the high-quality image containing the contents required by the user even with a relatively low-end processor by reducing the throughput in digital image processing In the case of transmitting using the same bandwidth, it is possible to transmit relatively high quality images or to transmit multiple images at the same time as compared to the existing technology. You can play the video.

In particular, teleconferencing systems, telemedicine systems, real-time medical imaging systems, real-time two-way tele-education systems, full-scale video telephony systems, two-way multimedia broadcasting, panel discussion broadcasting, election return broadcasting, home shopping broadcasting, etc. Therefore, the system construction cost can be significantly lowered, and the high quality video system can be quickly spread.

The above objects, features, and advantages will be described in detail with reference to the accompanying drawings, whereby those skilled in the art to which the present invention pertains may easily implement the technical idea of the present invention. In describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Define the terminology used herein.

As used herein, "image" refers to a sequence of images represented in analog or digital form. Examples of images include image sequences from cameras or other observation equipment, television programs, movies, and computer generated image sequences. Video is recorded on real-time video recording device, camera, storage device, video playback device, S-Video, RGB Composite, SD-SDI, HD-SDI, HDMI, IEEE 1394 interface, USB interface, video digitizer, computer graphics engine, network connection, etc. Can be obtained through.

As used herein, a "digital image" is a series of images represented in a digital form, and includes digitally converted analog images as well as digitally produced since the image was first made.

As used herein, "image processing" refers to all organization and analysis of an image, including compression, editing, monitoring, inspection, and the like.

As used herein, the term "frame" refers to a specific image of a series of images forming an image.

As used herein, "camera" refers to an image recording apparatus. Examples of cameras include video cameras, digital video cameras, camcorders, digital camcorders, high definition television (HDTV) cameras, ENG cameras, standard studio cameras, DVCAM cameras, DVRAM cameras, PC cameras, webcams, infrared video cameras, lightweight video cameras, Thermal video cameras, closed-loop televisions (CCTVs), pan-tilt-zoom cameras (PTZ Cameras), endoscope attachment cameras, cameras for mobile phones, and camera modules for digital devices.

As used herein, the term " image reproducing apparatus " refers to any apparatus for reading an image from a multimedia medium in which video and audio signals are recorded. Examples of the image reproducing apparatus may include a multimedia reproducing apparatus including a memory such as a DVD player, a VCD player, a video player, a computer, a Blu-ray player, a portable media player (PMP), a projector, and the like.

1 is a block diagram of an image processing apparatus according to the present invention. As illustrated, the image processing apparatus 100 includes an input unit 102, an encoder 104, a frame adjuster 106, and an output unit 108.

The input unit 102 transfers the received digital image to the encoder 104 or the frame controller 106. In this case, the image received by the input unit 102 may be input from an image recording apparatus such as a camera, or may be input from an image reproducing apparatus that reads an image recorded on a storage medium. In addition, the input unit 102 may receive a digitally converted image through an analog to digital image data conversion apparatus existing outside the image processing apparatus 100.

The encoder 104 selects a predetermined region from the digital image received from the input unit 102 and encodes only an image of the selected region. Herein, the term “constant area” does not mean a part of a series of images constituting an image, but rather an area occupying a part of a range of an image shown to a user. That is, a method of selecting and encoding only a predetermined region where a main subject is mainly expressed among regions where an image is expressed, and excluding an image of a region where unnecessary information other than the remaining main subject is represented is encoded. In particular, in the case of a system in which the main subject is mainly a person, in particular, a system in which one person is the main subject, both sides of the existing horizontally long screens are often unnecessary parts, and thus the present invention is particularly useful in such a system. . In this case, encoding refers to encoding including compression of an image, and an encoding method may vary according to an image format to be used.

The frame adjuster 106 reduces or increases the frame rate of the image received from the input unit 102 or the encoder 104 in accordance with the image format to be used. The number of frames per second is different for each image format, and this is the same in a video recording apparatus such as a camera, and thus a frame adjusting unit 106 is required. When the frame controller 106 directly receives an image from the input unit 102, the frame controller 106 adjusts the frame rate in the image before encoding and transmits the frame rate to the encoder 104, and the frame controller 106 encodes the encoder 104. When receiving an image from the video frame, the frame rate of the encoded image is adjusted only in a certain region. Meanwhile, the frame controller 106 may be configured as one module in the encoder 104.

The output unit 108 adjusts the frame from the encoder 104 and receives an image in which only the selected region is encoded. The received image is transmitted to another image processing device through the Internet, a network, a cable, or a display device such as a monitor, a TV, or a projector.

2A and 2B are configuration diagrams of a digital image and a selected region according to the present invention. Referring to FIG. 1, the selection of a certain area of an image according to the present invention will be described below.

As described above, the encoder 104 according to the present invention selects and encodes only a predetermined region in which the main subject is represented in the entire image 200. As shown in FIG. 2A, the entire image 200 represents a digital image that the encoder 104 receives from the input unit 102. In the entire image 200, the constant region 220 in which the main subject is represented is encoded, and the unnecessary remaining region 210 shown as hatched in FIG. 2A is not encoded.

As an embodiment of the present invention, the ratio of the horizontal length A _o to the vertical length B _o of the entire image 200 is a ratio of the horizontal length A ₁ to the vertical length B ₁ of the predetermined region 220. It can be configured to be opposite to. If this is expressed easily as equation (1).

In Equation 1, A _o , A ₁ , B _o , and B ₁ are as shown in FIG. 2B, and a and b are specific constants that may vary depending on a system.

Currently used video formats generally have a fixed aspect ratio such as 16: 9, 4: 3, 3: 2, 1.85: 1, and 2.35: 1. The entire image 200 is being cut without encoding unnecessary remaining region 210, to increase the compatibility by using an image format within the overall video system in bulk, the width of the entire image 200 (A _o) for the ratio of the height (B _o) is such that the ratio as opposed to the width (a ₁₎ for the height (B ₁₎ of a given area (220). On the screen that the user actually sees, the ratio of horizontal to vertical length is reversed, and if the original full image 200 is a horizontally long image, the constant region 220 will be a vertically long image, but the image is rotated by 90 degrees. This is because the same ratio can be used in the same image format in the process of image processing or transmission.

That is, the entire image 200 having a 16: 9 aspect ratio encodes only a constant region 220 of 9:16, and the entire image 200 having a 4: 3 encodes only a constant region 220 of 3: 4. It is. When configured as shown in Equation 1, when the aspect ratio of the entire image 200 is 16: 9, the area of the constant region 220 is 31.6% or less of the area of the entire image 200, and the entire image ( When the aspect ratio of the line 200 is 4: 3, the area of the constant area 220 is 56.3% or less of the area of the entire image 200. Therefore, the amount of image processing to be processed by the encoder 104 is also reduced to 31.6% and 56.3% or less, respectively. Even though the encoder 104 uses a processor having a lower performance than when encoding the entire image 200. Images of the same quality can be encoded.

Meanwhile, as an embodiment of the present invention, since the area containing the main subject may vary according to the system to be implemented, the vertical length B ₁ of the predetermined region 220 is the vertical length B _o of the entire image 200. 30% or more and 100% or less). In addition, although the center of the predetermined region 220 and the center of the entire image 200 generally coincide with each other, it may be easily determined differently to those skilled in the art to which the present invention pertains. .

By selecting and encoding only a certain region 220 of the entire image 200 as described above, it is possible to reduce the cost of the image processing apparatus while transmitting all the information on the main subject actually needed by the user.

In addition, the problem that the amount of transmission is increased while using a high quality image is solved, and efficient use of the transmission bandwidth is possible. As an embodiment of the present invention, in the case of constructing an interactive distance learning system in which several people are trained together, various materials necessary for the education system are transmitted together in the form of documents, videos, etc. by reducing the amount of data while reducing unnecessary parts of the image. In addition, it is possible to simultaneously transmit screens for multiple students to be transmitted to the teacher without increasing the transmission bandwidth.

Also, in the display device, the display size required to express the subject in the same size can be reduced. That is, in a case in which the constant area 200 except for the unnecessary area 210 is implemented in a vertical form, when a display device with a pivot function, which is a display rotation function, or a display device that can be installed vertically is used, The main subject can be expressed largely without increasing the size. As an embodiment of the present invention, when a bust of a person is represented on a display in a full-size video call system, a display having a size of 36 inches or more is required when a general horizontal display is used, but when using a vertical display according to the present invention, 22 persons A 24-inch display is sufficient. Display devices such as LCDs and PDPs have a significant effect due to the present invention because the power consumption and price increases exponentially as the screen size increases.

3 is a flowchart illustrating an image processing method according to the present invention.

First, a digital image is input (300). Next, a predetermined area of the received digital image is selected 310. Here, the selection of the constant region 310 has been described above with reference to FIGS. 2A and 2B. After the frame rate is adjusted 320 according to an image format to use an image of a certain region, the encoding is performed 330. The frame rate is adjusted only in the selected area and the encoded image is output (340). In this case, as described above, the output 340 may be an output to another image processing apparatus remotely transmitted through the encoded data through a network, or may be an output to another image processing apparatus connected locally. May be output to a furnace.

4 is a flowchart illustrating an image processing method according to the present invention. The image processing method according to the present invention will be described below with reference to FIGS. 2A to 3.

The method illustrated in FIG. 3 first selects a certain region 310 to adjust 320 the frame rate of the image of the portion 320 and encodes 330. However, the method illustrated in FIG. 4 first inputs a digital image 400. After receiving the frame rate according to the image format to be used (410), the image is encoded (420) to select a predetermined region in the encoded image (430) to output only the selected region (440). That is, after encoding the entire image 200 first, only a predetermined region 220 is selected and transmitted or output to a display. In the method shown in FIG. 4, although the processor used for encoding is not used efficiently as in the method shown in FIG. 3, the effect of efficiently using the transmission bandwidth and the display is as it is.

5 is a configuration diagram of a display screen according to an embodiment of the present invention.

A full-scale image display system according to an embodiment of the present invention is implemented. The camera captures the subject as a main subject, encodes the rest of the image by subtracting unnecessary areas, and decodes the image data through a process such as transmitting the image to the 22-inch wide monitor 500. Compared with the cigarette case 530, it can be seen that the main subject is output in a size similar to the actual size. Since the subject can be represented largely even with a smaller display than using a conventional horizontal display, a high-quality image can be realized at a low cost even if a full-scale display system is configured.

By receiving a person in another area simultaneously with the main screen, the display 520 is displayed at the bottom right of the screen 510, and a person who is the main subject is not cut even if the unnecessary area is not displayed by using an image encoded only in a certain area of the present invention. You can see that everything is expressed. The present invention can reduce the unit cost required for the construction of a high quality video system and make it possible to efficiently use it, thereby greatly contributing to the dissemination of a high quality video system, and can be utilized for various types of applications.

6 is a block diagram of a remote video conferencing system according to an embodiment of the present invention.

The image processing apparatuses 602, 612, 622, and 632 according to the present invention are connected through the network 600, and each image processing apparatus 100 is user A 600 located in Seoul, New York, Paris, and Sydney. ), B 610, C 630, and D 640. Cameras 601, 611, 621, and 631 are connected to each image processing apparatus 100, and displays 605, 615, 625, 633, 634, and 635 are connected, respectively. The cameras 601, 611, 621, and 631 may be different types of cameras, and the displays 605, 615, 625, 632, 633, and 635 may also be different types.

The camera 601 photographs the A 600 in Seoul and transfers the image to the image processing apparatus 602 according to the present invention. The image processing apparatus 602 selects and encodes only an area in which the main subject A 600 is represented and encodes the encoded image through the network 600 in New York, Paris, and Sydney. 632 respectively. At this time, although not shown in the drawing, the image processing apparatus 602 directly transmits to the remote image processing apparatuses 612, 622, and 632 via the server, instead of directly transmitting to the remote image processing apparatuses 612, 622, and 632. It can also be configured to send. The image processing apparatuses 612, 622, and 632 that have received the image of A 600 are decoded and output the decoded images to the displays 615, 625, and 635, respectively. In the same way, the image processing apparatus 612 encodes and transmits an image of B 610 in New York, and the image processing apparatus 622 encodes and transmits an image of C 620 in Paris, and sends it to Sydney. The image processing apparatus 632 encodes and transmits an image of the D 630. Each image processing device 602, 612, 622, 632 outputs the received images.

The image processing apparatus 602 in Seoul outputs the received images to each of the three vertical displays 605, and the image processing apparatus 612 in New York divides and outputs the regions on the general horizontal TV display 615. The image processing device 622 in Paris outputs the image of A 600 to the main screen 625 on one vertical display 625, and outputs the images of B 610 and D 630 to two images. The partial screen 626 is output. The image processing apparatus 632 in Sydney outputs the image of the A 600 to the main screen 637 on one horizontal display 635, and outputs multimedia data necessary for the conference to the sub screen 636. In addition, the images of B 610 and D 630 are output to the vertical display 633 and the vertical display 634, respectively.

As such, when a video conferencing system is implemented as an embodiment of the present invention, various multimedia data such as documents and videos required for a conference can be transmitted together with remaining transmission bandwidth while reducing unnecessary portions of the video, and the entire video can be encoded. In this case, even if the bandwidth required is used as it is, multiple images can be transmitted simultaneously within the same bandwidth. In the former case, the received data may be displayed on the display 635 together with the image, such as Sydney's D 630. In the latter case, multiple vertical images transmitted simultaneously, such as B's 610 in New York, may be displayed on a single display ( 615 together.

The apparatus and system described above may be implemented in hardware, software, or a combination thereof. In a hardware implementation, the modules used for digital image processing include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing units (DSPDs), programmable logic units (PLDs), field programmable gates. Array (FPGA), processor, controller, micro-controller, microprocessor, other electronic unit designed to perform the functions described herein, or a combination thereof. The software may be implemented through a module that performs the functions described herein. Software code may be stored in memory units and executed by a processor. The memory unit may be implemented inside or outside the processor, in which case the memory may be coupled to the processor via various known means.

On the other hand, the method of the present invention as described above can be written in a computer program. And the code and code segments constituting the program can be easily inferred by a computer programmer in the art. In addition, the written program is stored in a computer-readable recording medium (information storage medium), and read and executed by a computer to implement the method of the present invention. And the recording medium includes all types of recording media (intangible medium such as a carrier wave as well as tangible media such as CD and DVD) readable by a computer.

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

The present invention can be applied to any system that receives and transmits a digital image or outputs it on a display, and in particular, a teleconference system using a high quality image, a remote medical system, a real-time medical imaging system, a real-time two-way remote education system, and a full-scale system. It can be used for a video call system, two-way multimedia broadcasting, panel debate relay broadcasting, election election broadcasting, home shopping broadcasting, and the like.

1 is a block diagram of an image processing apparatus according to the present invention.

2A is a block diagram of a digital image and a selected region according to the present invention;

2b is a block diagram of a digital image and a selected region according to the present invention;

3 is a flowchart illustrating an image processing method according to the present invention.

4 is a flowchart illustrating an image processing method according to the present invention.

5 is a configuration diagram of a display screen according to an embodiment of the present invention.

6 is a block diagram of a remote video conferencing system according to an embodiment of the present invention.

Claims (13)

In a video transmitting and receiving system comprising a video transmitting apparatus and a video receiving apparatus, Acquiring a digital image by the image transmitting apparatus; Selecting, by the image transmitting apparatus, a partial region having a predetermined size at a predetermined position of the digital image, extracting a partial image, and encoding and transmitting the partial image; Receiving and decoding the encoded partial image by the image receiving apparatus; And The image receiving apparatus divides an output screen into a plurality of regions, displays the decoded partial image in a first region, and reference data transmitted by the image transmitting apparatus in a second region or an image transmitted by a third apparatus. Displaying; Image transmission and reception method comprising a. In a video transmitting and receiving system comprising a video transmitting apparatus and a video receiving apparatus, Acquiring and encoding a digital image by the image transmitting apparatus; Extracting and transmitting the encoded partial image by selecting a partial region having a constant size at a predetermined position of the encoded image by the image transmitting apparatus; Receiving and decoding the encoded partial image by the image receiving apparatus; And The image receiving apparatus divides an output screen into a plurality of regions, displays the decoded partial image in a first region, and reference data transmitted by the image transmitting apparatus in a second region or an image transmitted by a third apparatus. Displaying; Image transmission and reception method comprising a. The method according to claim 1 or 2, The digital image has an aspect ratio of a to b, And the partial image has an aspect ratio of b to a. The method of claim 3, And a vertical length of the partial image is 30 percent or more and 100 percent or less of the vertical length of the digital image. The method of claim 1, And a center of the partial image is the same point as the center of the digital image. The method of claim 1 or 2, wherein the encoding step Adjusting a frame rate of the encoded video; Image transmission and reception method comprising a. An image transmitting / receiving system comprising an image transmitting apparatus and an image receiving apparatus, The video transmitter An input unit for receiving a digital image; An encoder which extracts a partial image by selecting a partial region having a constant size at a predetermined position of the digital image, and encodes the partial image; And An output unit for transmitting the encoded partial image; Including, The video receiving apparatus A display unit; And Receives and decodes the encoded partial image, divides the output screen to be displayed on the display into a plurality of regions, displays the decoded partial image in a first region, and transmits the image to the second region. An image processor configured to display reference images or images transmitted by the third apparatus; Image transmission and reception system comprising a. The method of claim 7, wherein The digital image has an aspect ratio of a to b, And the partial image has an aspect ratio of b to a. The method of claim 8, And a vertical length of the partial image is 30 percent or more and 100 percent or less of the vertical length of the digital image. The method of claim 7, wherein And a center of the partial image is the same as a center of the digital image. The method of claim 7, wherein A frame rate controller for adjusting a frame rate of the digital image; Video transmission and reception system further comprising. In a computer capable of operating as a video transmitter and video receiver, In the computer, as the video transmission device, Obtaining a transmission digital image; And Selecting a partial area having a predetermined size from a predetermined position of the transmission digital image to extract a transmission partial image, and encoding and transmitting the transmission partial image; Run it, In the computer, as the video receiving device, Receiving and decoding an encoded received partial image from a first remote transmitting apparatus; And The output screen is divided into a plurality of areas, and the decoded reception partial image is displayed in a first area, and reference data transmitted by the first remote transmission device or a second reception from a second remote transmission device are displayed in a second area. Displaying a partial image; A computer-readable recording medium having recorded thereon a program for executing the program. delete

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