CN114339220A - A kind of image data encoding method - Google Patents

Abstract

The invention provides an image data encoding method, which includes: acquiring each encoding unit of image data to be encoded; performing frequency domain conversion on each encoding unit to obtain an encoding matrix of each encoding unit; and determining the texture of each encoding unit according to the encoding matrix. According to the texture features, the candidate division methods of each coding unit are respectively determined; for each coding unit, the candidate division methods corresponding to the coding units are traversed in turn, and the corresponding division methods of each coding unit are determined; Encoding is performed to obtain an encoding result, and by executing the image data encoding method provided by the present invention, the texture feature of the encoding unit can be determined by the encoding matrix corresponding to the encoding unit, and the division mode of the encoding unit is limited according to the texture feature of the encoding unit, and then The number of times of traversing the division method is reduced, and the time for encoding the image data is shortened.

Description

A kind of image data encoding method

technical field

The invention belongs to the field of multimedia, and in particular relates to an image data encoding method.

Background technique

At present, the mainstream video coding protocol standards in the world are H.264, H.265/HEVC, H.266/VVC, and the mainstream audio and video coding protocol standards in my country are AV1, AVS2, AVS3, and H.266/VVC is being developed internationally. AVS3 is a new generation of audio and video coding protocol standards being developed in my country. The new generation of audio and video coding standards has greatly improved video compression performance.

However, the improvement of compression performance often comes at the expense of higher time complexity. To determine the division method of an image block in the audio and video coding process of AVS3, it is necessary to traverse all the division methods and calculate the corresponding The rate distortion cost (RD cost) is the rate distortion cost, and the optimal division method of the image block can only be determined after comparing each rate distortion cost, resulting in high time complexity of AVS3 video coding.

SUMMARY OF THE INVENTION

Therefore, in view of the problems in the prior art, the present invention provides an image data encoding method to solve the problems in the prior art.

In a first aspect, the present invention provides an image data encoding method, comprising: acquiring each encoding unit of image data to be encoded; performing frequency domain conversion on each encoding unit to obtain an encoding matrix of each encoding unit; and determining each encoding unit according to the encoding matrix. The texture feature of the unit; determine the candidate division method of each coding unit according to the texture feature; for each coding unit, traverse the candidate division method corresponding to the coding unit in turn to determine the corresponding division method of each coding unit; combine the division method of each coding unit to treat The encoded image data is encoded to obtain an encoded result.

Optionally, in the image data encoding method provided by the present invention, the texture features of the encoding units are respectively determined according to the encoding matrix, including: determining the horizontal element array and the vertical element array in the encoding matrix; The ratio of the sum of the values to the sum of the absolute values of the elements in the vertical element array determines the texture characteristics of the coding unit.

Optionally, in the image data encoding method provided by the present invention, the texture features include horizontal textures, and the candidate division modes of the coding units are respectively determined according to the texture features, including: if the texture features are horizontal textures, no division and horizontal expansion Tree division and horizontal binary tree division are determined as candidate division manners of coding units.

Optionally, in the image data encoding method provided by the present invention, the texture features include vertical textures, and the candidate division modes of the coding units are respectively determined according to the texture features, including: if the texture features are vertical textures, no division and vertical expansion Tree division and vertical binary tree division are determined as candidate division methods of coding units.

Optionally, in the image data encoding method provided by the present invention, after the step of acquiring the encoding unit of the image to be encoded, and before the step of performing frequency domain conversion on the encoding unit, the method further includes: determining encoding unit information; determining according to the encoding unit information. The size of the coding unit. If the size of the coding unit is equal to the first preset value, the step of performing frequency domain conversion on the coding unit is performed.

Optionally, in the image data encoding method provided by the present invention, it further includes: if the size of the encoding unit is larger or smaller than the first preset value, no division, quadtree division, horizontal expansion quadtree division, vertical expansion are performed. The quadtree division, the horizontal binary tree division and the vertical binary tree division are determined as candidate division modes of the coding unit; the step of traversing the candidate division modes corresponding to the coding units to determine the division mode corresponding to each coding unit is performed.

Optionally, in the image data encoding method provided by the present invention, after the step of performing frequency domain conversion on the encoding unit to obtain the encoding matrix of the encoding unit, and before the step of determining the texture feature of the encoding unit according to the encoding matrix, the method further includes: The coding matrix extracts the complexity coefficient matrix; if the sum of the absolute values of the elements in the complexity coefficient matrix is less than the second preset value, the coding matrix determines the texture feature of the coding unit.

Optionally, in the image data encoding method provided by the present invention, it also includes: if the sum of the absolute values of the elements in the complexity coefficient matrix is greater than or equal to the second preset value, no division, quadtree division, horizontal The extended quad-tree division, the vertically extended quad-tree division, the horizontal binary tree division, and the vertical binary tree division are determined as the candidate division modes of the coding unit; the steps of traversing the candidate division modes corresponding to the coding units in turn, and determining the corresponding division modes of each coding unit are performed. .

In a second aspect, the present invention provides a computer-readable storage medium, where the computer-readable storage medium stores computer instructions, and the computer instructions are executed by a processor according to the image data encoding method provided by the present invention.

In a third aspect, the present invention provides a computer device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are processed by the at least one processor The image data encoding method as provided by the present invention is executed by the processor.

The technical scheme of the present invention has the following advantages:

In the image data encoding method provided by the present invention, each encoding unit of the image data to be encoded is obtained, the encoding matrix of each encoding unit is obtained by performing frequency domain conversion on the encoding unit, the texture feature of each encoding unit is determined by the encoding matrix, and the The texture feature of the coding unit defines the division mode of each coding unit, which reduces the number of division modes of each coding unit, and determines the final division mode for each coding unit according to the limited division mode, which reduces the number of traversals for the division mode. , thereby shortening the encoding time of image data.

Description of drawings

In order to illustrate the specific embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the specific embodiments or the prior art. Obviously, the accompanying drawings in the following description The drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

1 is a flowchart of a specific example of an image data encoding method in an embodiment of the present invention;

2 is a flowchart of a specific example of an image data encoding method in an embodiment of the present invention;

3 is a schematic structural diagram of a specific example of an image data encoding apparatus in an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a specific example of a computer device in an embodiment of the present invention.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Unless clearly required by the context, words such as "including", "comprising" and the like throughout the specification and claims should be construed in an inclusive rather than an exclusive or exhaustive sense; that is, "including but not limited to" meaning.

In the description of the present invention, it should be understood that the terms "first", "second" and the like are used for descriptive purposes only, and should not be construed as indicating or implying relative importance. Also, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

An embodiment of the present invention provides a method for encoding image data. As shown in FIG. 1 , the method includes:

Step S1: Obtain each coding unit of the image data to be coded.

In an optional embodiment, in the process of encoding the image data to be encoded by the standard audio and video coding protocol (AVS3), the image data to be encoded is divided into several non-overlapping coding tree units (LCU or CTU), Then recursively divide the coding tree unit to obtain multiple coding units (CUs).

Step S2: Perform frequency domain conversion on each coding unit to obtain a coding matrix of each coding unit.

In an optional embodiment, discrete cosine transform is used to perform frequency domain conversion on each coding unit to obtain a coding matrix corresponding to each coding unit.

The discrete cosine transform has the property of orthogonal transformation, and the basis vector of its transformation matrix is similar to the eigenvector of the Toeplitz matrix, which can reflect the relevant characteristics of the image signal. Cosine transform is a quasi-optimal transform, and the conversion efficiency of image signals can be improved by performing discrete cosine transform.

Step S3: Determine the texture feature of each coding unit according to each coding matrix.

The texture feature includes the texture direction, and the texture direction includes the horizontal direction and the vertical direction.

Step S4: Determine the candidate division manner of each coding unit according to the texture feature.

In an optional embodiment, if the texture direction is the horizontal direction, the horizontal division is preferred, and if the texture direction is the vertical direction, the vertical division is preferred.

In an optional embodiment, the standard audio and video coding protocol provides six ways for the division of coding units, specifically: no division, quadtree division, horizontally extended quadtree division, vertically extended quadtree division, horizontal Binary tree division and vertical binary tree division, in the process of coding the coding unit through the standard audio and video coding protocol, it is necessary to traverse the six division methods, and determine the final division method by comparing the rate distortion of each method.

If the texture feature of a coding unit is a horizontal texture, the three division modes of no division, horizontally extended quadtree division and horizontal binary tree division are determined as the candidate division modes of the coding unit; if the texture feature of a coding unit is vertical texture, three division modes of no division, vertically extended quadtree division, and vertical binary tree division are determined as candidate division modes of the coding unit.

By performing this step, the six division methods provided by the original standard audio and video coding protocol are preliminarily screened according to the texture characteristics of the coding unit, which reduces the number of traversal times of the coding unit division methods and reduces the coding time complexity of the image data to be coded. Spend.

Step S5: For each coding unit, traverse the candidate division modes corresponding to the coding units in sequence, and determine the division mode corresponding to each coding unit.

In an optional embodiment, by traversing the determined candidate division modes, calculating the rate-distortion value under each division mode, comparing the rate-distortion values under each division mode, and determining the division mode corresponding to the smallest rate-distortion value. Determines the division method of the coding unit.

Step S6: Encoding the image data to be encoded in combination with the division manner of each encoding unit to obtain an encoding result.

In an optional embodiment, the encoding part in the standard audio and video encoding protocol is used to encode the image data to be encoded in combination with the division method of each encoding unit.

In the embodiment of the present invention, the coding matrix of each coding unit is obtained by performing frequency domain conversion on the coding unit, the texture feature of each coding unit is determined by the coding matrix, and the division method of each coding unit is divided according to the texture feature of each coding unit The limitation is carried out to reduce the number of division modes of each coding unit, and the final division mode is determined for each coding unit according to the defined division mode, which reduces the number of traversal times for the division modes, thereby shortening the time for encoding image data.

In an optional embodiment, the texture features of the coding units are respectively determined according to the coding matrix, including:

First, determine the horizontal element array and vertical element array in the encoding matrix.

In an optional embodiment, the values at different positions in the coding matrix correspond to energy values at different frequencies, the element arrays belonging to the same row in the coding matrix can reflect the horizontal texture of the coding unit, and the element arrays belonging to the same column in the coding matrix can be Reflecting the vertical texture of the coding unit, for example, the elements at the three positions (1, 0), (2, 0), and (3, 0) in the coding matrix may be determined as a horizontal element array, and the coding matrix The elements at the three positions (0, 1), (0, 2), (0, 3) are determined as a vertical element array.

Then, the texture feature of the coding unit is determined according to the ratio of the absolute value sum of each element in the horizontal element array to the absolute value sum of each element in the vertical element array.

In an optional embodiment, calculate the absolute value sum of each element of the horizontal element array in an encoding matrix and the ratio of the absolute value sum of each element of the vertical element array, set the horizontal threshold value and the vertical threshold value, and the horizontal threshold value and the vertical threshold value can be based on The instance needs to be set. If the ratio is greater than the horizontal threshold, the image texture of the coding unit corresponding to the coding matrix is determined as the horizontal texture.

If the ratio is smaller than the vertical threshold, the image texture of the coding unit corresponding to the coding matrix is determined as a vertical texture.

If the ratio is greater than or equal to the horizontal threshold and less than or equal to the vertical threshold, no division, quadtree division, horizontally extended quadtree division, vertically extended quadtree division, horizontal binary tree division, and vertical binary tree division are determined as coding units. For the candidate division mode, the above step S5 is executed, for example, the horizontal threshold may be set to 5, and the vertical threshold may be set to 3.

In an optional embodiment, after the above step S1 and before the above step S2, the method further includes:

First, coding unit information is determined.

In an optional embodiment, the coding tree unit information includes coding unit information, and in the process of encoding the image data by a standard audio and video protocol, the coding tree unit information can be obtained, and the coding unit information can be determined by the coding tree unit information. .

Then, the size of the coding unit is determined according to the coding unit information, and if the size of the coding unit is equal to the first preset value, the foregoing step S2 is performed.

In an optional embodiment, the first preset value may be set according to actual requirements. Exemplarily, the first preset value may be set to 64×64, and the coding unit information includes the size of the coding unit. If the size of the coding unit is equal to 64×64, the above step S2 is performed.

If the size of the coding unit is larger or smaller than 64×64, no division, quadtree division, horizontally extended quadtree division, vertically extended quadtree division, horizontal binary tree division, and vertical binary tree division are determined as the candidate division methods of the coding unit , and execute the above step S5.

In an optional embodiment, after the above step S2 and before the above step S3, the method further includes:

First, the complexity coefficient matrix is extracted from the coding matrix.

In an optional embodiment, the number of rows and columns of the coding matrix is consistent with the size of the coding unit corresponding to the coding matrix. If the size of a coding unit is 64×64, then the coding matrix corresponding to the coding unit is that a row and column are all 64. The matrix of The 8×8 matrix can reflect the image complexity of the coding unit, and the 8×8 matrix is determined as the complexity coefficient matrix.

Then, if the sum of the absolute values of the elements in the complexity coefficient matrix is smaller than the second preset value, the above-mentioned step S3 is performed.

In an optional embodiment, the second preset value is set according to actual requirements. Exemplarily, the second preset value can be set to 1. If the sum of the absolute values of the elements in the complexity coefficient matrix is less than 1, then Perform the above step S3.

If the sum of the absolute values of the elements in the complexity coefficient matrix is greater than or equal to 1, no division, quadtree division, horizontally extended quadtree division, vertically extended quadtree division, horizontal binary tree division and vertical binary tree division are determined as For the candidate division mode of the coding unit, perform the above step S5.

In an optional embodiment, the image data encoding method provided by the embodiment of the present invention is applied to the official reference software HPM6.0 of the AVS3 standard, which conforms to the AVS3 encoding specification and can encode and decode video data in different formats.

In an optional embodiment, an image data encoding method is provided. The specific process is shown in FIG. 2 . The steps of the method are:

(1) Obtain the information of the coding unit (CU) in the coding tree unit (LCU), including the size information of the coding unit. For details of obtaining the coding unit information in the coding tree unit, refer to the description of step S1 in the above-mentioned embodiment. This will not be repeated here.

(2) Determine whether the size of the coding unit is 64×64. If the size of the coding unit is 64×64, execute step (3). If the size of the coding unit is not 64×64, use the division part in the standard audio and video coding protocol. The coding unit is divided, and step (7) is performed after the division is completed.

(3) Discrete cosine transform (DCT) is performed on the coding unit to obtain DCT coefficients corresponding to the coding unit. For details, refer to the description of the coding matrix in the above embodiment, and details are not repeated here.

(4) Judging the complexity of the coding unit, the steps of judging the complexity of the coding unit refer to the description in the above-mentioned embodiment, and will not repeat them here, if the complexity of the judging coding unit is simple, then execute step (5); The complexity of the unit is complex, and the coding unit is divided by using the division part in the standard audio and video coding protocol, and step (7) is performed after the division is completed.

(5) Judging whether the coding unit satisfies the horizontal and vertical stripe characteristics, refer to the description of the step of determining the texture feature of the coding unit in the above-mentioned embodiment for details, and will not repeat them here. If the texture feature of the coding unit can be determined, the coding unit satisfies the horizontal and vertical stripe characteristics, Then perform step (6); if the texture feature of the coding unit cannot be determined, the coding unit does not meet the horizontal and vertical stripe characteristics, use the division part in the standard audio and video coding protocol to divide the coding unit, and perform step (7) after the division is completed.

(6) Judgment of a specific mode is carried out according to the horizontal and vertical stripe characteristics of the coding unit, the specific mode is traversed to determine the final division mode, and the details of determining the final division mode according to the horizontal and vertical stripe characteristics refer to the description of step S4 and step S5 in the above-mentioned embodiment, It is not repeated here.

(7) judge whether there are coding units in the coding tree unit that have not obtained the final division mode, if there are still coding units that have not obtained the final division mode, return to step (1) to carry out; if all coding units in the coding tree unit have obtained the final division The method uses the encoding part in the standard audio and video encoding protocol, combined with the final division method to encode the image data to be encoded.

An embodiment of the present invention provides an image data encoding apparatus. As shown in FIG. 3 , the apparatus includes:

The information obtaining module 31 is configured to obtain each coding unit of the image data to be coded. For details, refer to the description of step S1 in the above embodiment, which is not repeated here.

The conversion module 32 is configured to perform frequency domain conversion on each coding unit to obtain a coding matrix of each coding unit. For details, refer to the description of step S2 in the above embodiment, which will not be repeated here.

The texture determination module 33 is configured to respectively determine the texture features of each coding unit according to the coding matrix. For details, refer to the description of step S3 in the above embodiment, which will not be repeated here.

The candidate determination module 34 is configured to respectively determine the candidate division modes of each coding unit according to the texture feature. For details, please refer to the description of step S4 in the above embodiment, which will not be repeated here.

The division determination module 35 is configured to traverse the candidate division modes corresponding to the coding units in sequence for each coding unit, and determine the division mode corresponding to each coding unit. For details, refer to the description of step S5 in the above embodiment, which will not be repeated here.

The encoding module 36 is configured to encode the to-be-encoded image data in combination with the division manner of each encoding unit to obtain an encoding result. For details, refer to the description of step S6 in the above embodiment, which is not repeated here.

For the specific limitations and beneficial effects of an image data encoding apparatus, reference may be made to the above limitations on the image data encoding method, which will not be repeated here. Each module in the above-mentioned image data encoding apparatus may be implemented in whole or in part by software, hardware, or a combination thereof. The above modules can be embedded in or independent of the processor in the electronic device in the form of hardware, or stored in the memory in the electronic device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

Embodiments of the present invention further provide a non-transitory computer storage medium, where the computer storage medium stores computer-executable instructions, and the computer-executable instructions can execute the image data encoding method in any of the foregoing method embodiments. Wherein, the storage medium may be a magnetic disk, an optical disk, a read-only memory (Read-Only Memory, ROM), a random access memory (Random Access Memory, RAM), a flash memory (Flash Memory), a hard disk (Hard) DiskDrive, abbreviation: HDD) or solid-state drive (Solid-State Drive, SSD), etc.; the storage medium may also include a combination of the above-mentioned types of memories.

An embodiment of the present invention further provides a computer device. As shown in FIG. 4 , the computer device may include at least one processor 41 , at least one communication interface 42 , at least one communication bus 43 and at least one memory 44 , wherein the communication interface 42 It may include a display screen (Display) and a keyboard (Keyboard), and the optional communication interface 42 may also include a standard wired interface and a wireless interface. The memory 44 may be a high-speed RAM memory (Random Access Memory, volatile random access memory), or may be a non-volatile memory (non-volatile memory), such as at least one disk memory. The memory 44 can optionally also be at least one storage device located away from the aforementioned processor 41 . An application program is stored in the memory 44, and the processor 41 invokes the program code stored in the memory 44 for performing the steps of any of the above-described inventive embodiments.

The communication bus 43 may be a peripheral component interconnect (PCI for short) bus or an extended industry standard architecture (EISA for short) bus or the like. The communication bus 43 can be divided into an address bus, a data bus, a control bus, and the like. For ease of presentation, only one thick line is used in FIG. 4, but it does not mean that there is only one bus or one type of bus.

The memory 44 may include volatile memory (English: volatile memory), such as random-access memory (English: random-access memory, abbreviation: RAM); the memory may also include non-volatile memory (English: non-volatile memory) memory), such as flash memory (English: flash memory), hard disk (English: hard diskdrive, abbreviation: HDD) or solid-state drive (English: solid-state drive, abbreviation: SSD); the memory 34 may also include the above-mentioned types of memory The combination.

The processor 41 may be a central processing unit (English: central processing unit, abbreviation: CPU), a network processor (English: network processor, abbreviation: NP), or a combination of CPU and NP.

The processor 41 may further include a hardware chip. The above-mentioned hardware chip may be an application-specific integrated circuit (English: application-specific integrated circuit, abbreviation: ASIC), a programmable logic device (English: programmable logic device, abbreviation: PLD) or a combination thereof. The above-mentioned PLD may be a complex programmable logic device (English: complex programmable logic device, abbreviation: CPLD), a field programmable gate array (English: field-programmable gate array, abbreviation: FPGA), a general array logic (English: generic arraylogic , abbreviation: GAL) or any combination thereof.

Optionally, memory 44 is also used to store program instructions. The processor 41 may invoke program instructions to implement the image data encoding method shown in the embodiment of FIG. 1 of the present invention.

Claims (10)

1. An image data encoding method, comprising:

acquiring each coding unit of image data to be coded;

performing frequency domain conversion on each coding unit to obtain a coding matrix of each coding unit;

respectively determining the texture characteristics of each coding unit according to the coding matrix;

respectively determining the candidate partition mode of each coding unit according to the texture features;

for each coding unit, sequentially traversing the candidate partition modes corresponding to the coding units, and determining the partition mode corresponding to each coding unit;

and coding the image data to be coded by combining the dividing mode of each coding unit to obtain a coding result.

2. The image data encoding method according to claim 1, wherein determining texture features of the encoding units respectively according to the encoding matrices comprises:

determining a transverse element array and a longitudinal element array in the coding matrix;

and determining the texture features of the coding unit according to the ratio of the absolute value sum of each element in the transverse element array to the absolute value sum of each element in the longitudinal element array.

3. The image data encoding method according to claim 1 or 2, wherein the texture feature includes a horizontal texture, and the determining the candidate partition modes of the encoding unit according to the texture feature includes:

and if the texture features are horizontal textures, determining non-division, horizontal expansion quad-tree division and horizontal binary tree division as candidate division modes of the coding unit.

4. The image data encoding method according to claim 1 or 2, wherein the texture feature includes a vertical texture, and the determining the candidate partition modes of the encoding unit according to the texture feature includes:

and if the texture features are vertical textures, determining non-partition, vertical extended quadtree partition and vertical binary tree partition as candidate partition modes of the coding unit.

5. The image data encoding method according to claim 1, wherein after the step of acquiring the encoding unit of the image to be encoded and before the step of frequency domain converting the encoding unit, further comprising:

determining coding unit information;

and determining the size of the coding unit according to the coding unit information, and if the size of the coding unit is equal to a first preset value, performing frequency domain conversion on the coding unit.

6. The image data encoding method according to claim 5, further comprising:

if the size of the coding unit is greater than or less than a first preset value,

determining non-division, quadtree division, horizontal extended quadtree division, vertical extended quadtree division, horizontal binary tree division and vertical binary tree division as candidate division modes of the coding unit;

and traversing the candidate division modes corresponding to the coding units and determining the division mode corresponding to each coding unit.

7. The image data encoding method according to claim 1, wherein after the step of performing frequency domain conversion on the encoding unit to obtain the encoding matrix of the encoding unit and before the step of determining the texture feature of the encoding unit based on the encoding matrix, the method further comprises:

extracting a complexity coefficient matrix according to the coding matrix;

and if the sum of the absolute values of all the elements in the complexity coefficient matrix is smaller than a second preset value, executing the step of determining the texture characteristics of the coding unit by the coding matrix.

8. The image data encoding method according to claim 7, further comprising:

if the sum of the absolute values of the elements in the complexity coefficient matrix is greater than or equal to a second preset value,

determining non-division, quadtree division, horizontal extended quadtree division, vertical extended quadtree division, horizontal binary tree division and vertical binary tree division as candidate division modes of the coding unit;

and executing the step of sequentially traversing the candidate division modes corresponding to the coding units and determining the division mode corresponding to each coding unit.

9. A computer-readable storage medium, characterized in that the computer-readable storage medium stores computer instructions which, when executed by a processor, implement the image data encoding method according to any one of claims 1 to 8.

10. A computer device, comprising: at least one processor; and a memory communicatively coupled to the at least one processor; wherein the memory stores instructions executable by the at least one processor to perform the image data encoding method of any of claims 1-8.

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