WO2021128277A1

WO2021128277A1 - Cross component adaptive loop filtering method and apparatus, and video coding and decoding device

Info

Publication number: WO2021128277A1
Application number: PCT/CN2019/129168
Authority: WO
Inventors: 姚杰; 朱建清; 数井君彦
Original assignee: 富士通株式会社; 姚杰; 朱建清
Priority date: 2019-12-27
Filing date: 2019-12-27
Publication date: 2021-07-01

Abstract

Provided are a cross component adaptive loop filtering method and apparatus, and a video coding and decoding device. The method comprises: performing adaptive loop filtering on a luminance component of a current sample, and taking an obtained filtered output as a residual correction of a chrominance component of the current sample, wherein a luminance difference value between the current sample and an adjacent sample is limited within a preset range; and correcting the chrominance component of the current sample on the basis of the residual correction to obtain a filtered chrominance component.

Description

Cross-component adaptive loop filtering method, device and video coding and decoding equipment

Technical field

The embodiments of the present application relate to the technical field of video coding and decoding.

Background technique

In the High Efficiency Video Coding (HEVC, High Efficiency Video Coding) standard, deblocking filtering (DF, Deblocking Filtering), sample adaptive offset (SAO, Sample Adaptive Offset) filtering, and adaptive loop filtering (ALF) have been proposed. , Adaptive Loop Filtering), etc. At the encoding end, the loop filtering information from DF, SAO, and ALF can be provided to the entropy encoder and encoded into the bit stream. After the information is correctly restored at the decoding end, the quality of the video image can be improved.

In the new generation of video coding standards (VVC, Versatile Video Coding), cross-component adaptive loop filtering (CC-ALF, Cross Component Adaptive Loop Filtering) is proposed and studied. CC-ALF can use luminance sample values to correct chrominance components.

It should be noted that the above introduction to the technical background is only for the convenience of a clear and complete description of the technical solutions of the present application, and to facilitate the understanding of those skilled in the art. It should not be considered that the above technical solutions are well-known to those skilled in the art just because these solutions are described in the background art part of this application.

Summary of the invention

However, the inventor found that if there are large differences between adjacent sample values in CC-ALF, the efficiency of CC-ALF will be affected, and the coding and decoding performance of chrominance components cannot be further improved.

In response to at least one of the foregoing problems, embodiments of the present application provide a cross-component adaptive loop filtering method, device, and video encoding and decoding equipment.

According to an aspect of the embodiments of the present application, there is provided a cross-component adaptive loop filtering method, the method including:

Perform adaptive loop filtering on the luminance component of the current sample, and use the obtained filter output as the residual correction of the chrominance component of the current sample; wherein the luminance difference between the current sample and adjacent samples is Restricted within the preset range;

Correcting the chrominance component of the current sample based on the residual correction to obtain a filtered chrominance component.

According to another aspect of the embodiments of the present application, there is provided a cross-component adaptive loop filtering device, the device including:

The filtering part performs adaptive loop filtering on the luminance component of the current sample, and uses the obtained filter output as the residual correction of the chrominance component of the current sample; wherein the difference between the current sample and the adjacent sample The brightness difference is limited to a preset range; and

A correction part that corrects the chrominance component of the current sample based on the residual correction to obtain a filtered chrominance component.

According to another aspect of the embodiments of the present application, a video encoding and decoding device is provided, including a memory and a processor, the memory stores a computer program, and the processor is configured to execute the computer program to implement the following operations:

Perform adaptive loop filtering on the luminance component of the current sample, and use the obtained filter output as the residual correction of the chrominance component of the current sample; wherein the luminance difference between the current sample and adjacent samples is Restricted within the preset range; and

One of the beneficial effects of the embodiments of the present application is: adaptive loop filtering is performed on the luminance component of the current sample, and the obtained filter output is used as the residual correction of the chrominance component of the current sample; The brightness difference between adjacent samples is limited to a preset range. As a result, the efficiency of CC-ALF can be improved, and the coding and decoding performance of chrominance components can be further improved.

With reference to the following description and drawings, specific implementations of the present application are disclosed in detail, and the ways in which the principles of the present application can be adopted are indicated. It should be understood that the scope of the embodiments of the present application is not limited thereby. Within the spirit and scope of the terms of the appended claims, the implementation of the present application includes many changes, modifications and equivalents.

Features described and/or shown for one embodiment can be used in one or more other embodiments in the same or similar manner, combined with features in other embodiments, or substituted for features in other embodiments .

It should be emphasized that the term "comprising/comprising" when used herein refers to the existence of a feature, a whole, a step or a component, but does not exclude the existence or addition of one or more other features, a whole, a step or a component.

Description of the drawings

The elements and features described in one drawing or one embodiment of the embodiment of the present application may be combined with the elements and features shown in one or more other drawings or embodiments. In addition, in the drawings, similar reference numerals indicate corresponding parts in several drawings, and may be used to indicate corresponding parts used in more than one embodiment.

Figure 1 is a schematic diagram of SAO, ALF and CC-ALF;

Figure 2 is an example diagram of CC-ALF using diamond filtering;

Fig. 3 is a schematic diagram of a cross-component adaptive loop filtering method according to an embodiment of the present application;

FIG. 4 is a schematic diagram of a cross-component adaptive loop filtering device according to an embodiment of the present application;

FIG. 5 is another schematic diagram of a cross-component adaptive loop filtering device according to an embodiment of the present application;

Fig. 6 is another schematic diagram of a video coding and decoding device according to an embodiment of the present application.

Detailed ways

With reference to the drawings, the foregoing and other features of this application will become apparent through the following description. In the specification and drawings, specific implementations of the application are specifically disclosed, which indicate some implementations in which the principles of the application can be adopted. It should be understood that the application is not limited to the described implementations. On the contrary, the present application is not limited to the described implementations. The application includes all modifications, variations and equivalents falling within the scope of the appended claims.

In the embodiments of this application, the terms "first", "second", etc. are used to distinguish different elements from the terms, but they do not indicate the spatial arrangement or chronological order of these elements. These elements should not be used by these terms. Limited. The term "and/or" includes any and all combinations of one or more of the associated listed terms. The terms "comprising", "including", "having" and the like refer to the existence of the stated features, elements, elements or components, but do not exclude the presence or addition of one or more other features, elements, elements or components.

In the embodiments of this application, the singular forms "a", "the", etc. include plural forms, which should be broadly understood as "a" or "a type" rather than being limited to the meaning of "a"; in addition, the term "so" "Said" should be understood to include both singular and plural forms, unless the context clearly indicates otherwise. In addition, the term "based on" should be understood as "based at least in part on...", and the term "based on" should be understood as "based at least in part on...", unless the context clearly dictates otherwise.

Figure 1 is a schematic diagram of SAO, ALF and CC-ALF. As shown in Figure 1, the luminance component filtered by SAO (represented by the luminance channel y below) is ALF (represented by ALF luminance in Fig. 1) and output The filtered luminance sample value.

As shown in Figure 1, the chrominance components filtered by SAO (indicated by chrominance channels Cb and Cr below) are ALF (indicated by ALF chrominance in Figure 1), and the filtered chrominance sample value I _{1 is output} And I ₂ . The output of the chroma channel can be expressed by the following formula:

O(x,y)=I(x,y)+ΔI _i (x,y); (1)

Among them, O(x,y) represents the chroma sample value output by the chroma channel, I(x,y) represents the chroma sample value output by the ALF, and ΔI _i (x,y) represents the chroma channel output by the CC-ALF The residual correction of i.

Thus, the filtered chrominance sample value can be output through loop filtering.

As shown in Figure 1, CC-ALF uses the luminance component to correct the chrominance component. For example, CC-ALF uses a diamond filter on the luminance sample value, and outputs information from the filter at the same location to generate residual corrections ΔI ₁ and ΔI _{2 for the} chrominance channel.

FIG 2 is a CC-ALF using an example of FIG rhombic filter, shown in Figure 2, e.g., CC-ALF may filter the 3 × 4 sample values, it may represent chrominance channels i of CC-ALF using the S _i range. 2, the S _i can comprise 8 sample values, where (x _{_C,} y _C) denotes the present sample. The residual correction of the chroma channel can be expressed by the following formula:

Among them, ΔI _i (x,y) represents the residual correction of chroma channel i, S _i represents the CC-ALF range of chroma channel i, and I ₀ (x _C +x ₀ ,y _C +y ₀ ) represents the sample (x _C +x ₀ ,y _C +y ₀ ) brightness value, c _i (x ₀ ,y ₀ ) represents the weighting coefficient of CC-ALF for chroma channel i.

The inventor found that if there is a large difference between adjacent sample values in CC-ALF, the efficiency of CC-ALF will be affected, and the coding and decoding performance of chrominance components cannot be further improved. In response to this problem, the embodiments of the present application propose the following technical solutions.

In the embodiments of the present application, yCbCr is taken as an example for description, but the present application is not limited to this, for example, it can also be applied to other luminance channels and chrominance channels. In addition, CC-ALF takes 3×4 diamond filtering as an example for description, but the application is not limited to this, for example, other filtering methods may also be used.

Embodiments of the first aspect

The embodiment of the present application provides a cross-component adaptive loop filtering method. Fig. 3 is a schematic diagram of a cross-component adaptive loop filtering method according to an embodiment of the present application. As shown in Figure 3, the method includes:

301. Perform adaptive loop filtering on the luminance component of the current sample, and use the obtained filter output as the residual correction of the chrominance component of the current sample; wherein the luminance difference between the current sample and adjacent samples The value is limited to a preset range;

302. Correct the chrominance component of the current sample based on the residual correction to obtain a filtered chrominance component.

In the embodiment of the present application, the luminance component input in 301 may be a sample value after SAO filtering. Regarding how to perform SAO filtering and ALF on the luminance component and the chrominance component, please refer to the related technologies of SAO and ALF for details. In addition, for details on how to perform CC-ALF, please refer to Figure 2 and related technologies.

It is worth noting that Figure 3 above only schematically illustrates part of the relevant content of the embodiments of the present application, but the present application is not limited thereto. For example, the order of execution among various operations can be appropriately adjusted, and some other operations can be added or some operations can be reduced. Those skilled in the art can make appropriate modifications based on the above content, and are not limited to the description of FIG. 3 above.

In some embodiments, the above formula (2) can be modified as:

Among them, ΔI _i (x, y) represents the residual correction of chroma channel i, (x _C , y _C ) represents the current sample, S _i represents the CC-ALF range of chroma channel i; I ₀ (x _C , y _C) represents the luminance value of the current _{_{sample; (x C + x 0,}} y C + y 0) S _i indicates the sample in addition to the current neighboring _{_{samples, I 0 (x C + x}} 0, y C + y 0) Represents the luminance value of adjacent samples (x _C + x ₀ , y _C + y ₀ _{); c i} (x ₀ , y ₀ ) represents the weight coefficient of CC-ALF for chrominance channel i.

In some embodiments, a limiting function may be used to limit the brightness difference between the current sample and the adjacent sample within a preset range, and the filtering performed in this way may be referred to as non-linear CC-ALF. For the sake of simplicity, in this paper, the operation of limiting the brightness difference between the current sample and the adjacent sample in the CC-ALF to a preset range is simply referred to as limiting the CC-ALF.

It is worth noting that the present application is not limited to the limiting function, and other implementation manners that limit the brightness difference between the current sample and the adjacent sample can be applied to the present application.

Taking the limiting function as an example, for example, the limiting function is expressed as follows:

K(d,b)=min(b,max(-b,d));

Where K is the limiting function, d is the input parameter, and b is the preset limiting range. However, this application is not limited to this, and other limiting functions can also be used.

In some embodiments, the formula (3) can be transformed based on the limiting function. For example, the following formula is used to obtain the residual correction of the chrominance channel:

Among them, ΔI _i (x,y) represents the residual correction of the chrominance channel i, I ₀ (x _C ,y _C ) represents the brightness value of the current sample (x _C ,y _C _{), I 0} (x _C + x ₀ , y _C + y ₀ ) represents the luminance value of the adjacent samples (x _C + x ₀ , y _C + y ₀ _{), S i} represents the CC-ALF range of the chrominance channel i, c _i (x ₀ , y ₀ ) represents the weight coefficient of the CC-ALF of the chrominance channel i, K represents the limiting function, and k(x ₀ , y ₀ ) represents the preset range.

In some embodiments, k(x ₀ , y ₀ ) is a clipping parameter related to position (x ₀ , y _{0 ).} In addition, for each filter coefficient, a limiting parameter can be specified. Through this adaptive limiting, the difference between the input sample value to be filtered and the adjacent input sample of the filter can be limited. In addition, the encoder can perform optimization to find the best k(x ₀ , y ₀ ) related to the weight of each filter.

As a result, ALF is performed on the luminance component of the current sample, and the obtained filtered output is used as the residual correction of the chrominance component of the current sample; wherein the luminance difference between the current sample and adjacent samples is limited to the preset range Inside. It can improve the efficiency of CC-ALF and further improve the coding and decoding performance of chrominance components.

The above cross-component adaptive loop filtering method can be performed on the encoding end and/or the decoding end. In addition, the encoding end can also encode the CC-ALF limiting information into the bit stream, so that the decoding end can perform better decoding based on the information, thereby further improving the encoding and decoding performance.

In some embodiments, the limit value corresponding to the preset range may be preset. For example, only 4 fixed values may be used, and the limit value includes 1023, 201, 39, and 8. And these limit values can be correlated with the limit index, as shown in Table 1.

Table 1

限幅索引Clipping Index	限幅值Limit value
00	10231023
11	201201
22	3939
33	88

It is worth noting that the above description only takes 4 limiter values as an example, but the application is not limited to this, for example, other values can also be used, or more than 4 limiter values can also be used, or Use less than 4 limit values.

In some embodiments, a diamond filter as an example of 3 × 4, S _i may include eight sample values; thus each chrominance channel may correspond to up to seven limit value. However, the present application is not limited to this. For example, each chroma channel may correspond to more than 7 clipping values, or may also correspond to less than 7 clipping values.

In some embodiments, indication information indicating whether to limit the CC-ALF (which may be referred to as non-linear CC-ALF) may be incorporated into the bitstream. For example, the indication information may be represented by ccalf_cb_clip_flag or ccalf_cr_clip_flag. The default value of ccalf_cb_clip_flag or ccalf_cr_clip_flag is, for example, 0 (false).

For example, for the Cb channel, ccalf_cb_clip_flag is 0, which means that CC-ALF is not clipped, and ccalf_cb_clip_flag is 1, which means that CC-ALF is clipped. For the Cr channel, ccalf_cr_clip_flag is 0, which means that CC-ALF is not clipped, and ccalf_cr_clip_flag is 1, which means that CC-ALF is clipped.

In some embodiments, when the CC-ALF is clipped, the clip index corresponding to the clip value of the preset range may be encoded into the bitstream. For example, the clip index may be represented by ccalf_cb_clip_idx or ccalf_cr_clip_idx. The default value of ccalf_cb_clip_idx or ccalf_cr_clip_idx is 0, for example.

For example, corresponding to Table 1, if CC-ALF uses 1023 for clipping, the index "0" (for example, using two-bit 00) can be programmed into the bitstream; if CC-ALF uses 201 for clipping, Then the index "1" (for example, using two bits of 01) can be incorporated into the bit stream; if CC-ALF uses 39 for clipping, then the index "2" (for example, using two bits of 10) can be incorporated into the bit stream. In the stream; if CC-ALF uses 8 for clipping, the index "3" (for example, using two bits of 11) can be encoded into the bit stream.

Table 2 exemplarily shows the syntax of the nonlinear CC-ALF of the embodiment of the present application.

Table 2

Table 2 exemplarily describes the embodiments of the present application, but the present application is not limited thereto.

It is worth noting that the above only describes the relevant content of the application, but the application is not limited to this. For image coding and/or loop filtering, other operations or processes, such as entropy coding, quantization, and transformation, may also be included. For the specific content of these operations or processes, you can refer to related technologies.

The encoding end has been schematically described above. In addition, the decoding end can receive the bit stream accordingly and decode it accordingly.

In some embodiments, the indication information indicating whether to limit the CC-ALF can be decoded from the bitstream.

For example, at the decoder, if the indication information (ccalf_cb_clip_flag and/or ccalf_cr_clip_flag) and the index (ccalf_cb_clip_idx and/or ccalf_cr_clip_idx) in the bitstream are received, the CC-ALF can be clipped according to the indication information and the index, So as to better perform loop filtering at the decoding end.

In some embodiments, in a case where the indication information indicates that the CC-ALF is clipped, the index corresponding to the clip value of the preset range may be decoded from the bitstream.

For example, if the indication information ccalf_cb_clip_flag in the bitstream is 1, then the clip index ccalf_cb_clip_idx in the bitstream can be further obtained. Corresponding to Table 1, if the index is "0" (for example, using two-bit 00), then CC-ALF is limited by 1023; if the index is "1" (for example, using two-bit 01), then CC-ALF uses 201 for clipping; if the index is “2” (for example, using two-bit 10), then CC-ALF uses 39 for clipping; if the index is “3” (for example, using two-bit 11 ), then use 8 for CC-ALF to limit the amplitude.

It is worth noting that the above only describes the relevant content of the application, but the application is not limited to this. For image decoding and/or loop filtering, other operations or processes, such as entropy decoding, inverse quantization, and inverse transformation, may also be included. For the specific content of these operations or processes, you can refer to related technologies.

The above embodiments only exemplify the embodiments of the present application, but the present application is not limited thereto, and appropriate modifications may also be made on the basis of the above various embodiments. For example, each of the above embodiments may be used alone, or one or more of the above embodiments may be combined.

It can be seen from the above-mentioned embodiment that adaptive loop filtering is performed on the luminance component of the current sample, and the obtained filter output is used as the residual correction of the chrominance component of the current sample; the difference between the current sample and the adjacent sample is The brightness difference is limited within the preset range. As a result, the efficiency of CC-ALF can be improved, and the coding and decoding performance of chrominance components can be further improved.

Embodiment of the second aspect

The embodiment of the present application also provides a cross-component adaptive loop filtering device, and the same content as in the embodiment of the first aspect will not be repeated. FIG. 4 is a schematic diagram of a cross-component adaptive loop filter device according to an embodiment of the present application. As shown in FIG. 4, the cross-component adaptive loop filter device 400 includes:

The filtering unit 401, which performs adaptive loop filtering on the luminance component of the current sample, and uses the obtained filter output as the residual correction of the chrominance component of the current sample; wherein the current sample is between the adjacent samples The brightness difference of is limited to a preset range; and

The correction unit 402 corrects the chrominance component of the current sample based on the residual correction to obtain the filtered chrominance component.

In some embodiments, a limiting function is used to limit the brightness difference between the current sample and the adjacent sample within a preset range.

In some embodiments, the limiting function is expressed as follows:

K(d,b)=min(b,max(-b,d));

Where K is the limiting function, d is the input parameter, and b is the preset limiting range.

In some embodiments, the following formula is used to obtain the residual correction of the chrominance channel:

Among them, ΔI _i (x,y) represents the residual correction of chroma channel i, I ₀ (x _C ,y _C ) represents the brightness value of the current sample (x _C ,y _C _{), I 0} (x _C + x ₀ , y _C + y ₀ ) represents the luminance value of the adjacent samples (x _C + x ₀ , y _C + y ₀ ), and S _i represents that the chrominance channel i performs the cross-component adaptive loop The filtering range, c _i (x ₀ , y ₀ ) represents the weight coefficient of the cross-component adaptive loop filtering performed by the chrominance channel i, K represents the limiting function, k(x ₀ , y ₀ ) Indicates the preset range.

In some embodiments, as shown in FIG. 4, the cross-component adaptive loop filtering device 400 further includes:

The encoding unit 403 encodes the instruction information indicating whether to limit the cross-component adaptive loop filtering into the bit stream.

In some embodiments, the encoding unit 403 also encodes the index corresponding to the clip value of the preset range into the bitstream in the case of clipping the cross-component adaptive loop filtering.

FIG. 5 is another schematic diagram of the cross-component adaptive loop filtering device according to an embodiment of the present application. As shown in FIG. 5, the cross-component adaptive loop filtering device 500 includes: a filtering unit 501 and a correction unit 502; as described above.

In some embodiments, as shown in FIG. 5, the cross-component adaptive loop filtering device 500 further includes:

The decoding unit 503 decodes the instruction information indicating whether to limit the cross-component adaptive loop filter from the bit stream.

In some embodiments, the decoding unit 503 also decodes the clip corresponding to the preset range from the bit stream when the indication information indicates that the cross-component adaptive loop filtering is to be clipped. The index of the value.

In some embodiments, the cross-component adaptive loop filtering uses a diamond filter, the chrominance channel includes Cb and Cr channels, and the luminance channel includes a y channel.

In some embodiments, each of the chrominance channels corresponds to a maximum of 7 clipping values; the clipping values include 1023, 201, 39, and 8.

It is worth noting that the above only describes the components or modules related to the application, but the application is not limited thereto. The cross-component adaptive

loop filtering device

400 or 500 may also include other components or modules. For the specific content of these components or modules, reference may be made to related technologies.

In addition, for the sake of simplicity, FIG. 4 or 5 only exemplarily shows the connection relationship or signal direction between the various components or modules, but it should be clear to those skilled in the art that various related technologies such as bus connection can be used. The above-mentioned various components or modules may be implemented by hardware facilities such as a processor and a memory; the implementation of this application does not limit this.

The above embodiments only exemplify the embodiments of the present application, but the present application is not limited to this, and appropriate modifications can also be made on the basis of the above embodiments. For example, each of the above embodiments may be used alone, or one or more of the above embodiments may be combined.

Embodiments of the third aspect

The embodiments of the present application also provide a video encoding and decoding device, which performs image processing or video processing, and may be an encoder on the encoding end, a decoder on the decoding end, or a device including an encoder and a decoder. equipment.

Fig. 6 is a schematic diagram of a video encoding and decoding device according to an embodiment of the present application. As shown in FIG. 6, a video encoding and decoding device 600 may include: a processor 601 and a memory 602; the memory 602 is coupled to the processor 601. The memory 602 can store various data; in addition, it also stores an information processing program 603, and the program 603 is executed under the control of the processor 601.

In some embodiments, the functions of the cross-component adaptive

loop filtering device

400 or 500 may be integrated into the processor 601. The processor 601 may be configured to implement the cross-component adaptive loop filtering method as described in the embodiment of the first aspect.

For example, the processor 601 may be configured to perform the following control: perform adaptive loop filtering on the luminance component of the current sample, and use the obtained filtered output as the residual correction of the chrominance component of the current sample; The luminance difference between the current sample and the adjacent sample is limited within a preset range; and the chrominance component of the current sample is corrected based on the residual correction to obtain a filtered chrominance component.

In addition, as shown in FIG. 6, the video codec device 600 may further include: an input/output (I/O) device 604, a display 605, etc.; wherein the functions of the above-mentioned components are similar to those in the prior art, and will not be repeated here. It is worth noting that the video codec device 600 does not necessarily include all the components shown in FIG. 6; in addition, the video codec device 600 may also include components not shown in FIG. 6, such as a camera, Hard Disk Drive (HDD, Hard Disk Driver), etc.; refer to related technologies.

The embodiments of the present application provide a computer-readable program, wherein when the program is executed in a video coding/decoding device or an electronic device, the program causes the electronic device to execute the cross-component autonomy described in the embodiment of the first aspect. Adapt to loop filtering method.

An embodiment of the present application provides a storage medium storing a computer-readable program, wherein the computer-readable program enables a video codec device or an electronic device to perform the cross-component adaptive loop filtering as described in the embodiment of the first aspect method.

The above devices and methods of this application can be implemented by hardware, or can be implemented by hardware combined with software. This application relates to such a computer-readable program, when the program is executed by a logic component, the logic component can realize the above-mentioned device or constituent component, or the logic component can realize the above-mentioned various methods Or steps. This application also relates to storage media used to store the above programs, such as hard disks, magnetic disks, optical disks, DVDs, flash memory, etc.

The method/device described in conjunction with the embodiments of the present application may be directly embodied as hardware, a software module executed by a processor, or a combination of the two. For example, one or more of the functional block diagrams and/or one or more combinations of the functional block diagrams shown in the figure may correspond to each software module of the computer program flow or each hardware module. These software modules can respectively correspond to the steps shown in the figure. These hardware modules can be implemented by solidifying these software modules by using a field programmable gate array (FPGA), for example.

The software module can be located in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM or any other form of storage medium known in the art. A storage medium may be coupled to the processor, so that the processor can read information from the storage medium and write information to the storage medium; or the storage medium may be a component of the processor. The processor and the storage medium may be located in the ASIC. The software module can be stored in the memory of the mobile terminal, or can be stored in a memory card that can be inserted into the mobile terminal. For example, if the device (such as a mobile terminal) uses a larger-capacity MEGA-SIM card or a large-capacity flash memory device, the software module can be stored in the MEGA-SIM card or a large-capacity flash memory device.

One or more of the functional blocks and/or one or more combinations of the functional blocks described in the drawings can be implemented as general-purpose processors, digital signal processors (DSPs) for performing the functions described in this application. ), application specific integrated circuit (ASIC), field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, or any appropriate combination thereof. One or more of the functional blocks described in the drawings and/or one or more combinations of the functional blocks can also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, or multiple micro-processing Processor, one or more microprocessors in communication with the DSP, or any other such configuration.

The application is described above in conjunction with specific implementations, but it should be clear to those skilled in the art that these descriptions are all exemplary and do not limit the scope of protection of the application. Those skilled in the art can make various variations and modifications to the application according to the spirit and principle of the application, and these variations and modifications are also within the scope of the application.

Claims

A cross-component adaptive loop filtering method, the method includes:

Perform adaptive loop filtering on the luminance component of the current sample, and use the obtained filter output as the residual correction of the chrominance component of the current sample; wherein the luminance difference between the current sample and adjacent samples is Restricted within the preset range; and

Correcting the chrominance component of the current sample based on the residual correction to obtain a filtered chrominance component.
The cross-component adaptive loop filtering method according to claim 1, wherein a limiting function is used to limit the brightness difference between the current sample and the adjacent sample within a preset range.
The cross-component adaptive loop filtering method according to claim 2, wherein the limiting function is expressed as follows:

K(d,b)=min(b,max(-b,d));

Where K is the limiting function, d is the input parameter, and b is the preset limiting range.
The cross-component adaptive loop filtering method according to claim 2, wherein the residual correction of the chrominance component is obtained using the following formula:

Among them, ΔI i (x,y) represents the residual correction of chroma channel i, I 0 (x C ,y C ) represents the brightness value of the current sample (x C ,y C ), I 0 (x C + x 0 , y C + y 0 ) represents the luminance value of the adjacent samples (x C + x 0 , y C + y 0 ), and S i represents that the chrominance channel i performs the cross-component adaptive loop The filtering range, c i (x 0 , y 0 ) represents the weight coefficient of the cross-component adaptive loop filtering performed by the chrominance channel i, K represents the limiting function, k(x 0 , y 0 ) Indicates the preset range.
The cross-component adaptive loop filtering method according to claim 1, wherein the method further comprises:

The instruction information indicating whether to limit the cross-component adaptive loop filtering is encoded into the bitstream.
The cross-component adaptive loop filtering method according to claim 5, wherein the method further comprises:

In the case of clipping the cross-component adaptive loop filtering, the index corresponding to the clipping value of the preset range is incorporated into the bitstream.
The cross-component adaptive loop filtering method according to claim 1, wherein the method further comprises:

Decode the indication information from the bitstream that indicates whether to limit the cross-component adaptive loop filtering.
The cross-component adaptive loop filtering method according to claim 7, wherein the method further comprises:

In a case where the indication information indicates that the cross-component adaptive loop filtering is to be clipped, the index corresponding to the clip value of the preset range is decoded from the bit stream.
The cross-component adaptive loop filtering method according to claim 1, wherein the cross-component adaptive loop filtering uses a diamond filter, the chrominance channel includes Cb and Cr, and the luminance channel includes y.
The cross-component adaptive loop filtering method according to claim 9, wherein each of the chrominance channels corresponds to a maximum of 7 clipping values; the clipping values include 1023, 201, 39, and 8.
A cross-component adaptive loop filtering device, the device comprising:

The filtering part performs adaptive loop filtering on the luminance component of the current sample, and uses the obtained filter output as the residual correction of the chrominance component of the current sample; wherein the difference between the current sample and the adjacent sample The brightness difference is limited to a preset range; and

A correction part that corrects the chrominance component of the current sample based on the residual correction to obtain a filtered chrominance component.
11. The cross-component adaptive loop filtering device according to claim 11, wherein a limiting function is used to limit the luminance difference between the current sample and the adjacent sample within a preset range.
The cross-component adaptive loop filtering device according to claim 12, wherein the limiting function is expressed as follows:

K(d,b)=min(b,max(-b,d));

Where K is the limiting function, d is the input parameter, and b is the preset limiting range.
The cross-component adaptive loop filtering device according to claim 12, wherein the residual correction of the chrominance component is obtained using the following formula:

Among them, ΔI i (x,y) represents the residual correction of chroma channel i, I 0 (x C ,y C ) represents the brightness value of the current sample (x C ,y C ), I 0 (x C + x 0 , y C + y 0 ) represents the luminance value of the adjacent samples (x C + x 0 , y C + y 0 ), and S i represents that the chrominance channel i performs the cross-component adaptive loop The filtering range, c i (x 0 , y 0 ) represents the weight coefficient of the cross-component adaptive loop filtering performed by the chrominance channel i, K represents the limiting function, k(x 0 , y 0 ) Indicates the preset range.
The cross-component adaptive loop filtering device according to claim 11, wherein the device further comprises:

The encoding unit encodes the instruction information indicating whether to limit the cross-component adaptive loop filtering into the bit stream.
The cross-component adaptive loop filter device according to claim 15, wherein the encoding unit also performs clipping on the cross-component adaptive loop filter, and cuts the value corresponding to the preset range The index of the clipping value is coded into the bit stream.
The cross-component adaptive loop filtering device according to claim 11, wherein the device further comprises:

The decoding unit decodes the instruction information indicating whether to limit the cross-component adaptive loop filter from the bit stream.
The cross-component adaptive loop filter device according to claim 17, wherein the decoding unit further extracts from the bit when the instruction information indicates that the cross-component adaptive loop filter should be clipped. The decoded index in the stream corresponds to the clip value of the preset range.
The cross-component adaptive loop filtering device according to claim 11, wherein the cross-component adaptive loop filtering uses a diamond filter, the chrominance channel includes Cb and Cr channels, and the luminance channel includes a y channel. Wherein, each of the chrominance channels corresponds to a maximum of 7 amplitude limiting values; the limiting amplitude values include 1023, 201, 39, and 8.
A video encoding and decoding device includes a memory and a processor, the memory stores a computer program, and the processor is configured to execute the computer program to implement the following operations:

Perform adaptive loop filtering on the luminance component of the current sample, and use the obtained filter output as the residual correction of the chrominance component of the current sample; wherein the luminance difference between the current sample and adjacent samples is Restricted within the preset range; and

Correcting the chrominance component of the current sample based on the residual correction to obtain a filtered chrominance component.