KR20190067577A - Apparatus and method for encoding and decoding of data - Google Patents

Abstract

According to an embodiment of the invention, provided is an apparatus for encoding data which comprises: a first database having synchronized data stored therein; a reference frame generating unit selecting at least one frame from the synchronized data and generating a reference frame by calculating a similarity among the selected frame, the data, and a target video; a list data writing unit generating list data for each frame included in the reference frame; and an encoding unit generating a compressed video of target data by enabling a frame which does not use redundancy between other frames among frames included in the target data to use the reference frame.

Description

[0001] APPARATUS AND METHOD FOR ENCODING AND DECODING OF DATA [0002]

An embodiment of the present invention relates to a data encoding and decoding apparatus and method, and relates to a data encoding and decoding apparatus and method that can be used for compressing image or image data and restoring compressed data.

As information and communication technologies including the Internet are developed, video and communication as well as text and voice are increasing. Conventional character-oriented communication methods are not enough to meet various needs of consumers. Accordingly, multimedia services capable of accommodating various types of information such as text, images, and music are increasing.

The amount of multimedia data is so large that it needs a large capacity storage medium and requires a wide bandwidth in transmission. Therefore, it is necessary to use a compression coding technique to transmit multimedia data including characters, images, and audio.

The basic principle of compressing data is the process of eliminating redundancy. Spatial redundancy such that the same color or object is repeated in an image, temporal redundancy such as when the adjacent frame in the moving picture frame has little change, or the same sound is continuously repeated in the audio, or at a high human visual and perceptual frequency The data can be compressed by eliminating the psychological visual overlap considering the insensitivity.

Among these principles, motion compensation performs image compression by predicting each pixel macroblock from a similar segment of a reference video frame that was recently coded in a video frame. For example, the background portion is often the same when moving from one frame to the next, so there is no need to retransmit each frame.

There are basically three types of frames, namely I-frame, P-frame and B-frame, in the known MPEG / H.26x video coding standard for standardization of such moving picture compression techniques.

When a video decoder decodes a bitstream on a frame-by-frame basis to restore video, the decryption should always start with an I-frame. P-frames and B-frames, when used, must be decoded as reference frames.

As described above, in the moving image encoding, it is necessary to periodically insert an I-frame for access or refresh. However, referring to FIG. 1, it is necessary to improve the I-frame in terms of efficiency since the I-frame has a large amount of codes and can not utilize redundancy between frames.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a data encoding and decoding apparatus and method capable of greatly improving a data compression rate while maintaining random access characteristics of an I-frame.

According to an embodiment of the present invention, there is provided an information processing apparatus comprising: a first database in which synchronized data is stored; A reference frame generation unit for selecting at least one frame among the synchronized data, calculating a similarity between the selected frame and data, and a target moving image to generate a reference frame; A list data generating unit for generating list data for each frame included in the reference frame; And an encoding unit for generating a compressed moving picture for the object data by using the reference frame in a frame that does not utilize redundancy among other frames among the frames included in the object data.

The reference frame generation unit may extract a predetermined number of frames in the ascending order of the degree of similarity calculated among the selected frames and generate the reference frames by sorting the extracted frames according to the similarity order.

The reference frame generation unit may include a method of calculating the degree of similarity using the cosine similarity between distribution vectors using a color distribution, a method of calculating similarities between the tags after the tags are analyzed by analyzing the frames on an object basis, The degree of similarity may be calculated according to at least one of a method of calculating the degree of similarity according to the method of calculating the degree of similarity and a method of calculating the degree of similarity by extracting the contour and color features of the frames and performing shape matching.

The list data creation unit may generate reference information for each frame included in the reference frame and generate the list data by arranging the reference information in the order of the respective frames included in the reference frame.

And a data transmission unit for transmitting the compressed moving picture and the list data.

The frame that can not use the redundancy may be an I-frame.

According to an embodiment of the present invention, there is provided an information processing apparatus comprising: a database storing synchronized data; A data receiving unit for receiving the compressed moving picture and the list data; A reference frame reconstructing unit for sequentially inquiring frames corresponding to the list data in the synchronized data, and sequentially combining the frames to generate reference frames; And a decoding unit decoding the compressed moving image using the reference frame and generating an original image of the compressed moving image.

According to an embodiment of the present invention, there is provided a method of generating a synchronization frame, the method comprising: selecting at least one frame among data synchronized with a reference frame generator; Generating a reference frame by calculating a degree of similarity between the selected frame and data and the target moving image; Generating list data for each frame included in the reference frame; And generating a compressed moving picture for the target data by causing the encoding unit to use the reference frame in which a redundancy among other frames among the frames included in the target data can not be used.

Wherein the generating of the reference frame comprises: extracting a predetermined number of frames in descending order of the degree of similarity calculated among the selected frames; And sorting the extracted frames according to the similarity order to generate a reference frame.

The generating the list data may include generating reference information for each frame included in the reference frame; And generating the list data by arranging the reference information in a sort order of each frame included in the reference frame.

And the data transmission unit may transmit the compressed moving picture and the list data.

According to an embodiment of the present invention, there is provided a data distribution method including: receiving a compressed moving picture and list data; The reference frame restoring unit sequentially inquiring frames corresponding to the list data from the synchronized data stored in the database; Generating reference frames by sequentially combining the frames that are referred to by the reference frame reconstructing unit; And a decoding unit decoding the compressed moving image using the reference frame and generating an original image of the compressed moving image.

The data encoding and decoding apparatus and method of the present invention can greatly improve the compression rate of data.

In addition, the compression ratio of the I-frame can be greatly improved while maintaining the random access characteristic of the I-frame.

In addition, the transmission bandwidth of the data can be greatly reduced.

FIG. 1 is a diagram for explaining data according to an encoding method according to the related art,
2 is a conceptual diagram of a data encoding apparatus and a decoding apparatus according to an embodiment of the present invention,
3 is a block diagram of a data encoding apparatus according to an embodiment of the present invention,
4 is a block diagram of a data decoding apparatus according to an embodiment of the present invention,
5 is a view for explaining the operation of the data encoding apparatus according to an embodiment of the present invention,
6 and 7 are views for explaining compression efficiency of a data encoding apparatus according to an embodiment of the present invention,
8 is a flowchart of a data encoding method according to an embodiment of the present invention,
9 is a flowchart of a data decoding method according to an embodiment of the present invention.

The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated and described in the drawings. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms including ordinal, such as second, first, etc., may be used to describe various elements, but the elements are not limited to these terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be referred to as a first component, and similarly, the first component may also be referred to as a second component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings, wherein like or corresponding elements are denoted by the same reference numerals, and redundant description thereof will be omitted.

2 is a conceptual diagram of a data encoding apparatus and a decoding apparatus according to an embodiment of the present invention. Referring to FIG. 2, the encoding apparatus 100 and the decoding apparatus 200 of the present invention may be connected through a network or may be implemented in one electronic apparatus. The electronic device includes, but is not limited to, a computer, a laptop, a mobile device, a portable device, an Internet protocol television, a portable media player, and a Personal Digital Assistants (PDA). The network may be, for example, a local area network (LAN), a wireless local area network (WLAN), a wide area network (WAN), the Internet, a small area network ). ≪ / RTI > The electronic device may also be connected to other electronic devices or servers (not shown) via the network.

In the embodiment of the present invention, the encoding apparatus 100 and the decoding apparatus 200 are implemented in different electronic apparatuses to perform data communication through a network. However, it is contemplated that the encoding apparatus 100 and the decoding apparatus 200 may be embodied in one electronic device.

In an embodiment of the present invention, the data may refer to multimedia content. Such multimedia content includes, but is not limited to, for example, still images, animation, video, and interactive content forms, or combinations thereof. The multimedia content may comprise a plurality of groups of pictures (GOPs). The picture groups are divided into an I-frame (I-frame) representing a fixed image, a P-frame (P-frame) having motion-compensated difference information from a preceding I or P- P-Frame), a section including some or all of the frames classified into B-frames (difference-predictive coded frames: B-frames) having difference information from preceding and succeeding I or P-frames.

The I-frame is also referred to as a key frame as data representing coordinate information of all the pixels obtained by coding the entire image taken by the camera. The I-frame has the best image quality but the largest capacity compared to other frames. The I-frame has full frame information and does not require any other information from the screen before or after the video is properly played back. That is, the I-frame is an independent frame and a frame capable of random access. An I-frame is a frame which is the most basic frame and can be encoded and decoded regardless of the front and back frames. That is, compression is performed only on the information in the current image. Due to its compression nature, I-frames are often used to realize random access or fast playback for FF / REW.

A P-frame is a frame obtained by finding a common point with reference to a previously coded I-frame or P-frame, and coding only for a part that is not common. That is, the P-frame is a frame based on the information of the key frame that has been previously obtained, and the image quality and capacity are the middle level between the I-frame and the B-frame. As described above, the P-frame does not represent information on the entire screen but only changes information of the preceding I-frame following the I-frame. The P-frame is also called a delta frame, and the P-frame uses a motion compensation technique. In the P-frame, the error between the previous frame and the current frame is calculated. If the error between the previous frame and the corresponding block is larger than the threshold, DCT is performed. If the error is smaller than the threshold, use

The P-frame only transmits the motion vector values from the I-frame and the reference is always the most recent I-frame.

The B-frame is a frame formed based on the information of the I-frame and the P-frame before and after. That is, the B-frame is a frame predicted in two directions, and is made by referring to the I-frame and the P-frame before and after the B-frame. The B-frame is a frame having only the information excluding the overlapped part by searching for the common I-frame or P-frame and the next I-frame or P-frame to find a common part. Therefore, since B-frames have many references, the overlapping parts are excluded and only the changed parts are displayed. Therefore, when the number of B-frames increases, the compression ratio is improved. Instead, it takes a long time because the prediction time of the reference frame becomes longer when compressed. The B-frame has the lowest image quality and capacity compared to the I-frame and the P-frame. The B-frame does not represent the full screen information, but the screen information predicted by both sides of previous frames and next frames .

3 is a block diagram of a data encoding apparatus according to an embodiment of the present invention.

3, the data encoding apparatus 100 includes a first data base 110, a reference frame generator 120, a list data generator 130, an encoding unit 140, and a data transmitter 150 do.

The first database 110 may store synchronized data. The synchronized data may be pre-synchronized and stored in the data encoding apparatus 100 and the decoding apparatus 200, respectively. The first database 110 may include a memory (e.g., random access memory (RAM)) coupled to store the required information. The memory may be used to store temporal information required by the data encoding device 100. The first database 110 may further include a read only memory (ROM) connected to store static information required by the data encoding apparatus 100. For example, a storage unit such as a magnetic disk, a hard disk or an optical disk may be provided and connected via a bus for information storage.

The reference frame generation unit 120 may select at least one frame from the synchronized data, and calculate the similarity between the selected frame and the target moving image. The reference frame generation unit 120 may extract a predetermined number of frames from the selected frames in descending order of degree of similarity and generate reference frames by sorting the extracted frames according to the similarity order. The reference frame is selected from the synchronized data and can be a set of frames having high similarity to the target video. The reference frame may, for example, consist of a collection of all pre-compression frames of synchronized moving images.

The reference frame generation unit 120 may include a method of calculating similarity using the cosine similarity between distribution vectors using a color distribution, a method of calculating similarities between the tags after the tags are analyzed on an object-by-object basis, The degree of similarity can be calculated according to at least one of a method of calculating the degree of similarity according to the matching ratio and a method of extracting the contour and color characteristics of the frames and calculating the similarity through shape matching.

The list data creation unit 130 can generate list data for each frame included in the reference frame. The list data creation unit 130 may generate reference information for each frame included in the reference frame and generate list data by arranging the reference information in the order of the respective frames included in the reference frame.

The encoding unit 140 may generate a compressed moving picture for the target data by using a frame that can not use the redundancy among other frames among the frames included in the target data to use the reference frame. A frame that does not utilize redundancy may be an I-frame. The encoding unit 140 can use the I-frame to use the reference frame in the encoding process, thereby greatly reducing the I-frame ratio of the entire frame and greatly improving the data compression rate.

The data transmission unit 150 may, for example, transmit the compressed moving image and the list data. The data transmitter may be configured to include an integrated services digital network (ISDN) card, a modem, a local area network (LAN) card, an infrared port, a Bluetooth port, a zigbee port, But is not limited thereto.

4 is a block diagram of a data decoding apparatus according to an embodiment of the present invention. Referring to FIG. 4, the data decoding apparatus 200 includes a second data base 210, a data receiving unit 220, a reference frame restoring unit 230, and a decoding unit 240.

The second database 210 may store synchronized data. The second database 210 may include a memory (e.g., random access memory (RAM)) coupled to store the required information. The memory may be used to store temporary information required by the data decoding apparatus. The second database 210 may further include a read only memory (ROM) connected to store static information required by the data decoding apparatus. For example, a storage unit such as a magnetic disk, a hard disk or an optical disk may be provided and connected via a bus for information storage.

The data receiving unit 220 may receive compressed moving pictures and list data. The data receiving unit 220 may, for example, transmit the compressed moving image and the list data. The data receiving unit 220 may include an integrated services digital network (ISDN) card, a modem, a local area network (LAN) card, an infrared port, a Bluetooth port, a zigbee port, But is not limited thereto.

The reference frame restoring unit 230 sequentially inquires the frames corresponding to the list data in the synchronized data, and sequentially generates the reference frames by combining the frames. The reference frame restoring unit 230 retrieves and extracts frames corresponding to the list data from among the synchronized data stored in the second database 210 and combines the extracted frames according to the order of the frames listed in the list data, Can be generated.

The decoding unit 240 may decode the compressed moving image using the reference frame and generate an original image of the compressed moving image. The decoding unit 240 may convert a compressed moving image into an original image by using a reference frame that can not utilize the redundancy among other frames in compressed moving image decoding. A frame that does not utilize redundancy may be an I-frame.

5 is a view for explaining the operation of a data encoding apparatus according to an embodiment of the present invention. Referring to FIG. 5, one group of pictures (GOP) includes a plurality of frames. Each picture group includes an I-frame, a P-frame with motion compensation difference information from the preceding I or P-frame, and a B-frame with difference information from the preceding and subsequent I or P-frames. In addition, a reference frame generated by using the selected frame in the data synchronized separately from the image group is constituted. The reference frame may be composed of a combination of frames selected according to the degree of similarity between the data to be encoded and the synchronized data. The reference frame may, for example, consist of a collection of all pre-compression frames of synchronized moving images. I-frames use reference frames generated during data encoding or decoding. Conventionally, in the encoding or decoding process, the I-frame is encoded or decoded without reference to other frames or reference processes, but in the embodiment of the present invention, reference frames generated based on the similarity between synchronized data and target data are referred to The data proportion of the I-frame can be greatly reduced. That is, an I-frame that fails to reference other frames in order to guarantee random access or an error rate of a certain video can refer to an existing synchronized frame stored in the encoding device and the decoding device, The compression rate can be greatly increased without losing the characteristics of the I-frame. Accordingly, the existing random access characteristics are maintained and the same image quality can be maintained.

6 and 7 are views for explaining compression efficiency of a data encoding apparatus according to an embodiment of the present invention. Referring to FIG. 6 (a), the capacity of the I-frame is reduced by 39.2% and the capacity of the entire frame is reduced to 14.8% in comparison with the encoding method according to H.265 for the web drama. Referring to FIG. 6B, in the case of a variety show, the capacity of the I-frame is reduced by 23.0% and the capacity of the entire frame is reduced to 7.6% compared with the encoding method according to H.265 . Also, referring to FIG. 7, it can be seen that the frame sizes of the original image are 47.5 KB and 45.8 KB, respectively, whereas when the reference frame is applied, the frame sizes are reduced to 6.09 KB and 28.8 KB, respectively.

8 is a flowchart of a data encoding method according to an embodiment of the present invention. Referring to FIG. 8, first, the reference frame generator selects at least one frame among the synchronized data.

Next, the reference frame generator calculates a similarity between the selected frame and data and the target moving image to generate a reference frame. The reference frame generation unit extracts a predetermined number of frames from the selected frames in descending order of the degree of similarity calculated, and arranges the extracted frames according to the order of similarity to generate reference frames.

Next, the list data creation unit generates list data for each frame included in the reference frame. The list data generation unit generates reference information for each frame included in the reference frame, and generates the list data by arranging the reference information in the sort order of each frame included in the reference frame.

Next, the encoding unit generates a compressed moving picture for the target data by using the reference frame, which is not able to use the redundancy among the other frames, included in the target data. Accordingly, by using an I-frame to use a reference frame in the encoding process, the ratio of I-frames in the entire frame can be greatly reduced, and the data compression ratio can be greatly improved.

9 is a flowchart of a data decoding method according to an embodiment of the present invention. Referring to FIG. 9, a data receiver receives compressed moving pictures and list data. The data receiving unit receives the compressed moving image and the list data transmitted from the data transmitting unit of the data encoding apparatus. When the data encoding device and the data decoding device are implemented in one electronic device, the compressed moving picture and the list data can be transmitted and received through the data bus (BUS) without going through a separate communication unit.

Next, the reference frame restoring unit sequentially inquires the frames corresponding to the list data in the synchronized data stored in the database, and the reference frame restoring unit sequentially combines the searched frames to generate reference frames. The reference frame restoration unit retrieves and extracts a frame corresponding to the list data from the synchronized data stored in the second database, and combines the extracted frames according to the order of the frames listed in the list data to generate a reference frame.

Next, the decoding unit decodes the compressed moving image using the reference frame and generates an original image of the compressed moving image. The decoding unit converts a compressed moving image into an original image by using a reference frame to use a frame that can not use the redundancy among other frames in compressed moving picture decoding.

As used in this embodiment, the term " portion " refers to a hardware component such as software or an FPGA (field-programmable gate array) or ASIC, and 'part' performs certain roles. However, 'part' is not meant to be limited to software or hardware. &Quot; to " may be configured to reside on an addressable storage medium and may be configured to play one or more processors. Thus, by way of example, 'parts' may refer to components such as software components, object-oriented software components, class components and task components, and processes, functions, , Subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and components may be further combined with a smaller number of components and components or further components and components. In addition, the components and components may be implemented to play back one or more CPUs in a device or a secure multimedia card.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims It can be understood that

100: Data encoding device
110: first database
120: Reference frame generation unit
130:
140:
150: Data transmission unit
200: Data decoding device
210: second database
220: Data receiving unit
230: reference frame restoring unit
240:

Claims (12)

A database in which synchronized data is stored;
A reference frame generator for generating at least one frame from the synchronized data, calculating a similarity between the selected frame and the target moving picture to generate a reference frame,
A list data generating unit for generating list data for each frame included in the reference frame; And
And an encoding unit configured to generate a compressed moving picture for the target data by using the reference frame in a frame that does not utilize redundancy among other frames among the frames included in the target data.
The method according to claim 1,
Wherein the reference frame generation unit comprises:
Extracting a predetermined number of frames in descending order of the degree of similarity calculated among the selected frames, and arranging the extracted frames in order of similarity to generate a reference frame.
3. The method of claim 2,
Wherein the reference frame generation unit comprises:
A method of calculating the degree of similarity by using the cosine similarity between distribution vectors using a color distribution, a method of calculating the similarity between the tags after the tags are analyzed by analyzing the frames on an object basis, and the degree of similarity is calculated according to the bitstream matching ratio of the frames And a method of extracting a contour and a color feature of the frames and calculating a similarity through shape matching are used to calculate the degree of similarity according to at least one method.
3. The method of claim 2,
Wherein the list data generation unit generates reference information for each frame included in the reference frame and generates the list data by arranging the reference information in the order of sorting the frames included in the reference frame.
The method according to claim 1,
And a data transmission unit for transmitting the compressed moving picture and the list data.
The method according to claim 1,
Wherein the frame which can not use the redundancy is an I-frame.
A database in which synchronized data is stored;
A data receiving unit for receiving the compressed moving picture and the list data;
A reference frame reconstructing unit for sequentially inquiring frames corresponding to the list data in the synchronized data, and sequentially combining the frames to generate reference frames; And
And a decoding unit decoding the compressed moving image using the reference frame and generating an original image of the compressed moving image.
Selecting at least one frame among the synchronized data by the reference frame generator;
Generating a reference frame by calculating a degree of similarity between the selected frame and data and the target moving image;
Generating list data for each frame included in the reference frame; And
And generating a compressed moving picture for the target data by causing the encoding unit to use the frame in which the redundancy among other frames among the frames included in the target data can not be used.
9. The method of claim 8,
Wherein the step of generating the reference frame comprises:
Extracting a preset number of frames in descending order of the degree of similarity calculated among the selected frames; And
And arranging the extracted frames in order of similarity to generate a reference frame.
10. The method of claim 9,
Wherein the generating the list data comprises:
Generating reference information for each frame included in the reference frame; And
And generating the list data by arranging the reference information in a sort order of each frame included in the reference frame.
9. The method of claim 8,
And the data transmission unit transmits the compressed moving picture and the list data.
Receiving a compressed moving image and list data by a data receiving unit;
The reference frame restoring unit sequentially inquiring frames corresponding to the list data from the synchronized data stored in the database;
Generating reference frames by sequentially combining the frames that are referred to by the reference frame reconstructing unit; And
Wherein the decoding unit decodes the compressed moving image using the reference frame and generates an original image of the compressed moving image.

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