STRONG INTRA SMOOTHING FOR IN REXT
Based on conditions or restrictions, Strong Intra Smoothing (SIS) is enabled or disabled. SIS is not allowed for chroma when the chroma format is 444, and SIS is not allowed for chroma when the chroma format is 422 or 444.
This application is a continuation of U.S. Ser. No. 16/246,651, filed Jan. 14, 2019, which is a continuation of U.S. Ser. No. 14/635,176, filed Mar. 2, 2015, now U.S. Pat. No. 10,230,992, and also claims priority under 35 U.S.C. § 119(e) of U.S. Provisional Application Ser. No. 61/971,140, filed Mar. 27, 2014; U.S. Provisional Application Ser. No. 61/954,248, filed Mar. 17, 2014; and U.S. Provisional Patent Application Ser. No. 61/947,207, filed Mar. 3, 2014, each of which are hereby incorporated by reference in their entireties for all purposes.
FIELD OF THE INVENTIONThe present invention relates to video coding. More specifically, the present invention relates to high efficiency video coding.
BACKGROUND OF THE INVENTIONIn JCTVC-P1005_v1, Strong Intra Smoothing (SIS) is allowed to apply to chroma when chroma format is 4:4:4. When intra_smoothing_disabled_flag is equal to 0 and either cldx is equal to 0 or ChromaArrayType is equal to 3, the filtering process of neighboring samples specified is invoked with the sample array p and the transform block size nTbS as inputs, and the output is reassigned to the sample array p. In RExt6.0 SIS is only allowed for luma. Thus, there is a mismatch on how to deal with SIS for the chroma in 444 chroma format.
SUMMARY OF THE INVENTIONBased on conditions or restrictions, Strong Intra Smoothing (SIS) is enabled or disabled. SIS is not allowed for chroma when the chroma format is 444, and SIS is not allowed for chroma when the chroma format is 422 or 444.
In one aspect, a method programmed in a non-transitory memory of a device comprises acquiring video content and encoding the video content without implementing strong intra smoothing depending on the chroma format of the video content. The method further comprises determining the chroma format is 444; and not enabling strong intra smoothing. The method further comprises determining the chroma format is 422 or 444; and not enabling strong intra smoothing. A strong intra smoothing flag is equal to 1 and a image component index is equal to 0. The device is selected from the group consisting of a personal computer, a laptop computer, a computer workstation, a server, a mainframe computer, a handheld computer, a personal digital assistant, a cellular/mobile telephone, a smart appliance, a gaming console, a digital camera, a digital camcorder, a camera phone, a smart phone, a portable music player, a tablet computer, a mobile device, a video player, a video disc writer/player, a television, a home entertainment system and smart jewelry.
In another aspect, a system programmed in a non-transitory memory of a device comprises a receiving device configured for receiving encoded video content, wherein the encoded video content was encoded without using strong intra smoothing depending on the chroma format of the video content and a display device configured for displaying the encoded video content. Encoding the encoded video content included determining the chroma format is 444; and not enabling strong intra smoothing. Encoding the encoded video content included determining the chroma format is 422 or 444 and not enabling strong intra smoothing. A strong intra smoothing flag is equal to 1 and a image component index is equal to 0. The device is selected from the group consisting of a personal computer, a laptop computer, a computer workstation, a server, a mainframe computer, a handheld computer, a personal digital assistant, a cellular/mobile telephone, a smart appliance, a gaming console, a digital camera, a digital camcorder, a camera phone, a smart phone, a portable music player, a tablet computer, a mobile device, a video player, a video disc writer/player, a television, a home entertainment system and smart jewelry.
In another aspect, an apparatus comprises a display device, a non-transitory memory for storing an application, the application for receiving video content, wherein the video content was encoded without using strong intra smoothing depending on the chroma format of the video content and displaying the video content on the display device and a processing component coupled to the memory, the processing component configured for processing the application. Encoding the encoded video content included determining the chroma format is 444; and not enabling strong intra smoothing. Encoding the encoded video content included determining the chroma format is 422 or 444; and not enabling strong intra smoothing. A strong intra smoothing flag is equal to 1 and a image component index is equal to 0. The apparatus is selected from the group consisting of a personal computer, a laptop computer, a computer workstation, a server, a mainframe computer, a handheld computer, a personal digital assistant, a cellular/mobile telephone, a smart appliance, a gaming console, a digital camera, a digital camcorder, a camera phone, a smart phone, a portable music player, a tablet computer, a mobile device, a video player, a video disc writer/player, a television, a home entertainment system and smart jewelry.
In High Efficiency Video Coding (HEVC) version 1, strong intra smoothing (SIS) is applied to luma (420 format) to reduce (e.g. smooth) some visual artifacts in intra prediction. In Range Extension (RExt) of HEVC, more chroma formats (monochrome, 4:2:2 and 4:4:4) and higher bitdepths (12, 14, 16) are supported. Implementations to extend the SIS in RExt to address SIS for 444 chroma format. Restrictions on applying SIS are also described.
SIS introduces blocking artifacts and coding efficiency loss although SIS improves contouring artifacts. If the disabling SIS conditions are not satisfied, then the appropriate flag is set to a value other than 0 such as 1.
Filtering Process of Neighboring Samples
- When filterFlag is equal to 1, the following applies:
- The variable bilntFlag is derived as follows:
If all of the following conditions are true, bilntFlag is set equal to 1: - strong_intra_smoothing_enabled_flag is equal to 1
- nTbS is equal to 32
- cldx is equal to 0 //cldx is the image component index
- Abs(p[−1][−1]+p[nTbS*2−1][−1]−2*p[nTbS−1][−1]<(1<<(BitDepth
Y −5)) - Abs(p[−1][−1]+p[−1][nTbS*2−1]−2*p[−1][nTbS−1])<(1<<(BitDepth
Y −5))
Otherwise, bilntFlag is set equal to 0.
Shown herein is a comparison between SIS “on” and “off” for chroma, based on both AHGS and AHG8 test sequences. The reference software used is HM13.0+RExt6.0.
More specifically, SIS “on” means that SIS is allowed for chroma when the chroma format is 4:4:4 and SIS is applied because intra_smoothing_disabled_flag is set to 0 (false) in default settings. Anchor: SIS “off” is exactly the HM13.0+RExt6.0.
In the simulation, AHGS test sequences and conditions apply. Because the simulation is run in a cluster, encoding and decoding times are not accurate. The results are summarized in Table 1. Results show that allowing SIS for chroma when chroma format is 4:4:4 will degrade the coding performance of current reference software under common test conditions.
In the simulation, AHG8 test sequences and conditions apply. Because the simulation is run in a cluster, encoding and decoding times are not accurate. The results are summarized in Table 2. Results show that allowing SIS for chroma when the chroma format is 4:4:4 will degrade the coding performance of current reference software under common test conditions.
In some embodiments, the SIS decision method application(s) 230 include several applications and/or modules. In some embodiments, modules include one or more sub-modules as well. In some embodiments, fewer or additional modules are able to be included.
Examples of suitable computing devices include a personal computer, a laptop computer, a computer workstation, a server, a mainframe computer, a handheld computer, a personal digital assistant, a cellular/mobile telephone, a smart appliance, a gaming console, a digital camera, a digital camcorder, a camera phone, a smart phone, a portable music player, a tablet computer, a mobile device, a video player, a video disc writer/player (e.g., DVD writer/player, high definition disc writer/player, ultra high definition disc writer/player), a television, a home entertainment system, smart jewelry (e.g., smart watch) or any other suitable computing device.
To utilize the SIS decision method described herein, a device such as a digital camera/camcorder is used to acquire image/video content or a device such as a television is used to display video content. The SIS decision method is automatically used during the encoding process of the acquired or displayed video content such as when the video content is transmitted. The SIS decision method is able to be implemented with user assistance or automatically without user involvement.
In operation, the SIS decision method determines when SIS is implemented to ensure proper and efficient encoding of content.
Some Embodiments of Strong Intra Smoothing for in RExt
- 1. A method programmed in a non-transitory memory of a device comprising:
- a. acquiring video content; and
- b. encoding the video content without implementing strong intra smoothing depending on the chroma format of the video content.
- 2. The method of clause 1 further comprising determining the chroma format is 444; and not enabling strong intra smoothing.
- 3. The method of clause 1 further comprising determining the chroma format is 422 or 444; and not enabling strong intra smoothing.
- 4. The method of clause 1 wherein a strong intra smoothing flag is equal to 1 and a image component index is equal to 0.
- 5. The method of clause 1 wherein the device is selected from the group consisting of a personal computer, a laptop computer, a computer workstation, a server, a mainframe computer, a handheld computer, a personal digital assistant, a cellular/mobile telephone, a smart appliance, a gaming console, a digital camera, a digital camcorder, a camera phone, a smart phone, a portable music player, a tablet computer, a mobile device, a video player, a video disc writer/player, a television, a home entertainment system and smart jewelry.
- 6. A system programmed in a non-transitory memory of a device comprising:
- a. a receiving device configured for receiving encoded video content, wherein the encoded video content was encoded without using strong intra smoothing depending on the chroma format of the video content; and
- b. a display device configured for displaying the encoded video content.
- 7. The system of clause 6 wherein encoding the encoded video content included determining the chroma format is 444; and not enabling strong intra smoothing.
- 8. The system of clause 6 wherein encoding the encoded video content included determining the chroma format is 422 or 444; and not enabling strong intra smoothing.
- 9. The system of clause 6 wherein a strong intra smoothing flag is equal to 1 and a image component index is equal to 0.
- 10. The system of clause 6 wherein the device is selected from the group consisting of a personal computer, a laptop computer, a computer workstation, a server, a mainframe computer, a handheld computer, a personal digital assistant, a cellular/mobile telephone, a smart appliance, a gaming console, a digital camera, a digital camcorder, a camera phone, a smart phone, a portable music player, a tablet computer, a mobile device, a video player, a video disc writer/player, a television, a home entertainment system and smart jewelry.
- 11. An apparatus comprising:
- a. a display device;
- b. a non-transitory memory for storing an application, the application for:
- i. receiving video content, wherein the video content was encoded without using strong intra smoothing depending on the chroma format of the video content; and
- ii. displaying the video content on the display device; and
- c. a processing component coupled to the memory, the processing component configured for processing the application.
- 12. The apparatus of clause 11 wherein encoding the encoded video content included determining the chroma format is 444; and not enabling strong intra smoothing.
- 13. The apparatus of clause 11 encoding the encoded video content included determining the chroma format is 422 or 444; and not enabling strong intra smoothing.
- 14. The apparatus of clause 11 wherein a strong intra smoothing flag is equal to 1 and a image component index is equal to 0.
- 15. The apparatus of clause 11 wherein the apparatus is selected from the group consisting of a personal computer, a laptop computer, a computer workstation, a server, a mainframe computer, a handheld computer, a personal digital assistant, a cellular/mobile telephone, a smart appliance, a gaming console, a digital camera, a digital camcorder, a camera phone, a smart phone, a portable music player, a tablet computer, a mobile device, a video player, a video disc writer/player, a television, a home entertainment system and smart jewelry.
The present invention has been described in terms of specific embodiments incorporating details to facilitate the understanding of principles of construction and operation of the invention. Such reference herein to specific embodiments and details thereof is not intended to limit the scope of the claims appended hereto. It will be readily apparent to one skilled in the art that other various modifications may be made in the embodiment chosen for illustration without departing from the spirit and scope of the invention as defined by the claims.
Claims
1. An image processing device, comprising:
- a processor configured to: encode an image such that non-application of strong intra smoothing to chroma in a case that chroma format is 444; and encode the image such that application of the strong intra smoothing to the chroma in a case that all of the following conditions are true:
- strong_intra_smoothing_enabled_flag is equal to 1,
- nTbS is equal to 32,
- cldx is equal to 0,
- Abs(p[−1][−1]+p[nTbS*2−1][−1]−2*p[nTbS−1][−1]<(1<<(BitDepthY−5)),
- Abs(p[−1][−1]+p[−1][nTbS*2−1]−2*p[−1][nTbS−1])<(1<<(BitDepthY−5)).
2. An image processing method, comprising:
- in an image processing device:
- encoding an image such that non-application of strong intra smoothing to chroma in a case that chroma format is 444; and
- encoding the image such that application of the strong intra smoothing to the chroma in a case that all of the following conditions are true:
- strong_intra_smoothing_enabled_flag is equal to 1,
- nTbS is equal to 32,
- cldx is equal to 0,
- Abs(p[−1][−1]+p[nTbS*2−1][−1]−2*p[nTbS−1][−1]<(1<<(BitDepthY−5)),
- Abs(p[−1][−1]+p[−1][nTbS*2−1]−2*p[−1][nTbS−1])<(1<<(BitDepthY−5)).
3. An image processing device, comprising:
- a processor configured to: decode a bitstream in a state that strong intra smoothing is disable in a case that chroma format is 444; and decode the bitstream in a state that the strong intra smoothing is enable in a case that all of the following conditions are true:
- strong_intra_smoothing_enabled_flag is equal to 1,
- nTbS is equal to 32,
- cldx is equal to 0,
- Abs(p[−1][−1]+p[nTbS*2−1][−1]−2*p[nTbS−1][−1]<(1<<(BitDepthY−5)),
- Abs(p[−1][−1]+p[−1][nTbS*2−1]−2*p[−1][nTbS−1])<(1<<(BitDepthY−5)).
4. An image processing method, comprising:
- in an image processing device: decoding a bitstream in a state that strong intra smoothing is disable in a case that chroma format is 444; and decoding the bitstream in a state that the strong intra smoothing is enable in a case that all of the following conditions are true:
- strong_intra_smoothing_enabled_flag is equal to 1,
- nTbS is equal to 32,
- cldx is equal to 0,
- Abs(p[−1][−1]+p[nTbS*2−1][−1]−2*p[nTbS−1][−1]<(1<<(BitDepthY−5)),
- Abs(p[−1][−1]+p[−1][nTbS*2−1]−2*p[−1][nTbS−1])<(1<<(BitDepthY−5)).
Type: Application
Filed: Mar 17, 2020
Publication Date: Jul 9, 2020
Inventors: OHJI NAKAGAMI (TOKYO), TERUHIKO SUZUKI (TOKYO), ALI J. TABATABAI (CUPERTINO, CA), JUN XU (SUNNYVALE, CA)
Application Number: 16/821,764