DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Amendment
Applicant’s Amendments filed on February 18, 2026, has been entered and made of record.
Currently pending Claim(s) 1-15
Independent Claim(s) 1 and 14-15
Amended Claim(s) 1, 7-12, and 14-15
Response to Arguments
This office action is responsive to Applicant’s Arguments/Remarks Made in an Amendment received on February 18, 2026.
In view of amendments filed on February 18, 2026, to the claims, the Applicant has amended claims 7-12 in response to the Examiner’s previous 35 U.S.C. § 112(b) rejection. The claims now use the language “coordinate shift” instead of “changing a location,” and claims 11-12 now further clarify the coordinate shift of a luma sample. Thus, any ambiguity is removed from claims 7-12 and the 35 U.S.C. § 112(b) rejections are overcome. The Applicant has also amended the independent claims 1 and 14-15 to now include new limitations which further explain the determination of the offset. This determination now includes classifying sample values of the collocated luma sample and collocated chroma samples into three different bands and deriving a joint index, and the offset is determined based on the joint index.
In view of Applicant Arguments/Remarks filed February 18, 2026, with respect to the claims, the Applicant argued (Remarks pages 7-9) that Kuo fails to teach the newly amended content of independent claims 1 and 14-15 regarding the integrated 3-band classification mechanism and the joint indexing, and Kuo instead teaches conventional SAO and CC-SAO methods based on hierarchical class indexing. The Examiner finds this argument to be persuasive. Kuo teaches many classification examples throughout [Col. 17, line 46 – Col. 20, line 51] but does not specifically teach a joint index based on three different bands. Also, the Applicant argued (Remarks page 8) that both Chen (US 10,419,757 B2) and Zhang (US 11,477,449 B2) fail to make up for the deficiencies of Kuo regarding the new limitations, and the Examiner finds this argument to be persuasive as well.
However, the Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action, and the Examiner presents a rejection utilizing the art of Kotra (US 2022/0400292 A1), which includes priority to a provisional application filed on June 14, 2021. Kotra teaches the new limitations presented in the new amendments and includes the same equations presented in the Applicant’s arguments for determining a joint index for band offset. In 0076 (paragraph 0069 of the provisional application), Kotra teaches:
[Equation 1]
bandY=(Y col ·N Y)>>BD
bandU=(U col ·N U)>>BD
bandY=(V col ·N V)>>BD
i=bandY·(N U ·N V)+bandU ·N V+bandV
C′ rec=Clip1(C rec+σCCSAO[i])
Furthermore, Kotra provides direct motivation for utilizing this equation for deriving a joint index for determining the offset to be applied to the reconstructed samples ([0076] “In one example of the CCSAO design, to achieve a better complexity/performance trade-off, only band offset (BO) is used to enhance the quality of the reconstructed samples. For a given luma/chroma sample, three candidate samples are selected to classify the given sample into different categories: one collocated Y sample, one collocated U sample, and one collocated V sample. Video encoder 200 and video decoder 300 may classify the sample values of these three selected samples into three different bands {bandY, bandU, bandV}, and may use a joint index i to indicate the category of the given sample. One offset is determined and added to the reconstructed samples that fall into that category”). Here, Kotra discloses that a better tradeoff between design and complexity can be achieved through using only band offset in the CCSAO design, which is the same motivation provided for the present invention (Remarks page 8; Specification [0148-0149]). Therefore, the independent claims are rejected under 35 U.S.C. § 103 using Kuo in view of Kotra.
Additionally, Yin et al. (US 12,542,899 B2, foreign application priority to July 1, 2021), hereafter Yin, also teaches the same equation and motivation in [Col. 8, lines 45-67] as taught by the present invention’s Specification [0148-0149] and Kotra [0076] regarding the newly amended limitations. Although Yin is included in the Conclusion of this office action and not used in the 35 U.S.C. § 103 rejections, the Examiner strongly suggests consideration of Yin’s teachings when making future amendments.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-6 and 14-15 are rejected under 35 U.S.C. 103 as being unpatentable over Kuo et al. (US 12,149,687 B2), hereafter Kuo, in view of Kotra et al. (US 2022/0400292 A1), hereafter Kotra.
Regarding claim 1, Kuo teaches an image decoding method performed by an image decoding apparatus ([Col. 2, lines 43-48] “The present application describes implementations related to video data encoding and decoding and, more particularly, to methods and apparatus on improving the coding efficiency of chroma coding, including improving the coding efficiency by exploring cross-component relationship between luma and chroma components.”), comprising:
determining whether a cross component sample adaptive offset (CC-SAO) is activated based on a value of a first syntax element (Table 2 shows CCSAO syntax. The flags cc_sao_enabled_flag, ph_cc_sao_cb_flag, etc. are used to determine is CCSAO is enabled for the sequence, for the Cb channel, etc. [Col. 6, lines 26-32] “The encoded video data communicated over link 16, or provided on storage device 32, may include a variety of syntax elements generated by video encoder 20 for use by video decoder 30 in decoding the video data. Such syntax elements may be included within the encoded video data transmitted on a communication medium, stored on a storage medium, or stored a file server.”);
deriving a collocated luma sample and collocated chroma samples corresponding to each other from reconstructed samples based on a chroma format of the reconstructed samples, based on the value of the first syntax element specifying that the CC-SAO is activated ([Col. 4, lines 8-12] “FIG. 11 is a block diagram of a sample process illustrating that besides luma, the other cross-component collocated (1102) and neighboring (white) chroma samples are also fed into CCSAO classification in accordance with some implementations of the present disclosure. FIG. 6A, 6B and FIG. 11 show the input of CCSAO classification. In FIG. 11, current chroma sample is 1104, the cross-component collocated chroma sample is 1102, and the collocated luma sample is 1106.” Additionally, Col. 22, lines 34-37, shows that the methods are dependent on the chroma format.); and
determining an offset to be applied to the reconstructed samples based on the collocated luma sample and the collocated chroma samples ([Col. 17, lines 46-55] “FIG. 6A is a block diagram illustrating the system and process of CCSAO according to some implementations of the present disclosure. The luma samples after luma deblocking filter (DBF Y) is used to determine additional offsets for chroma Cb and Cr after SAO Cb and SAO Cr. For example, the current chroma sample 602 is first classified using collocated 604 and neighboring (white) luma samples 606, and the corresponding CCSAO offset value of the corresponding class is added to the current chroma sample value.” Later implementations, such as the implementation shown in Fig. 11, use collocated chroma samples along with luma samples.).
Kuo fails to teach wherein the determining the offset includes classifying sample values of the collocated luma sample and the collocated chroma samples into three different bands and deriving a joint index used to indicate a band offset category based on the three different bands, and wherein the offset to be applied to the reconstructed samples is determined based on the joint index.
However, Kotra teaches wherein the determining the offset includes classifying sample values of the collocated luma sample and the collocated chroma samples into three different bands and deriving a joint index used to indicate a band offset category based on the three different bands, and wherein the offset to be applied to the reconstructed samples is determined based on the joint index ([0076-0077] “For a given luma/chroma sample, three candidate samples are selected to classify the given sample into different categories: one collocated Y sample, one collocated U sample, and one collocated V sample. Video encoder 200 and video decoder 300 may classify the sample values of these three selected samples into three different bands {bandY, bandU, bandV}, and may use a joint index i to indicate the category of the given sample. One offset is determined and added to the reconstructed samples that fall into that category, which can be formulated as:
bandY=(Y col ·N Y)>>BD
bandU=(U col ·N U)>>BD
bandY=(V col ·N V)>>BD
i=bandY·(N U ·N V)+bandU ·N V+bandV
C′ rec=Clip1(C rec+σCCSAO[i]) (1)
In equation (1), {Ycol, Ucol, Vcol} are the three selected collocated samples that are used to classify the current sample; {NY, NU, NV} are the numbers of equally divided bands applied to {Ycol, Ucol, Vcol} full range, respectively;”).
Kuo and Kotra are analogous in the art to the claimed invention, because both teach methods of video encoding/decoding for reconstructing video data, and both utilize a CC-SAO filter operation. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kuo’s invention by using a joint index for determining an offset to be applied to reconstructed samples of a category. This modification would achieve a better tradeoff between complexity and performance ([Kotra 0076] “In one example of the CCSAO design, to achieve a better complexity/performance trade-off, only band offset (BO) is used to enhance the quality of the reconstructed samples.”).
Regarding claim 2, Kuo teaches wherein based on the chroma format of the reconstructed samples being a 4:4:4 chroma format, a luma sample located at the same location as the collocated chroma samples is derived as the collocated luma sample ([Col. 22, lines 34-37] “In some embodiments, different Yp is applied on different chroma format. For example, in FIG. 12, the Yp of (a) is used for the 420 chroma format, the Yp of (b) is used for the 422 chroma format, and Y0 is used for the 444 chroma format.” Y0 is the same location as the collated chroma sample.).
Regarding claim 3, Kuo teaches wherein based on the chroma format of the reconstructed samples being a predetermined chroma format, a luma sample located at a predetermined location among luma samples located nearby from locations of the collocated chroma samples is derived as the collocated luma sample (Fig. 10 shows deriving a luma sample (located at 7) neighboring the chroma sample (located at 0) for input to the CCSAO classifier. [Col. 21, lines 53-59] “In some embodiments, a classifier (or class index) uses different luma sample position for C0 classification. FIG. 10 is a block diagram showing a classifier using different luma sample position for C0 classification in accordance with some implementations of the present disclosure, for example, using the neighboring Y7 but not Y0 for C0 classification.”).
Regarding claim 4, Kuo teaches wherein the predetermined chroma format is a 4:2:2 chroma format or a 4:2:0 chroma format ([Col. 22, lines 34-37] “The collocated luma sample value (Y0) can be replaced by a phase corrected value (Yp) obtained by weighing neighboring luma samples. Different Yp can be a different classifier. In some embodiments, different Yp is applied on different chroma format. For example, in FIG. 12 , the Yp of (a) is used for the 420 chroma format, the Yp of (b) is used for the 422 chroma format, and Y0 is used for the 444 chroma format.”).
Regarding claim 5, Kuo teaches wherein based on the chroma format of the reconstructed samples being a predetermined chroma format, the collocated luma sample is derived from less than 9 luma samples among luma samples located nearby from locations of the collocated chroma samples (Fig. 12 shows how a collocated luma sample value is derived using the 8 neighboring luma samples. [Col. 22, lines 24-33] “In some embodiments, the collocated luma sample value (Y0) is replaced by a value (Yp) obtained by weighing collocated and neighboring luma samples… The collocated luma sample value (Y0) can be replaced by a phase corrected value (Yp) obtained by weighing neighboring luma samples. Different Yp can be a different classifier.”).
Regarding claim 6, Kuo teaches the image decoding method of claim 5, wherein the predetermined chroma format is any one of a 4:4:4 chroma format, a 4:2:2 chroma format or a 4:2:0 chroma format ([Col. 22, lines 34-37] “In some embodiments, different Yp is applied on different chroma format. For example, in FIG. 12, the Yp of (a) is used for the 420 chroma format, the Yp of (b) is used for the 422 chroma format, and Y0 is used for the 444 chroma format.”).
Regarding claim 14, Kuo teaches an image encoding method performed by an image encoding apparatus ([Col. 2, lines 43-48] “The present application describes implementations related to video data encoding and decoding and, more particularly, to methods and apparatus on improving the coding efficiency of chroma coding, including improving the coding efficiency by exploring cross-component relationship between luma and chroma components.”), comprising:
deriving a collocated luma sample and collocated chroma samples corresponding to each other from reconstructed samples based on a chroma format of the reconstructed samples ([Col. 4, lines 8-12] “FIG. 11 is a block diagram of a sample process illustrating that besides luma, the other cross-component collocated (1102) and neighboring (white) chroma samples are also fed into CCSAO classification in accordance with some implementations of the present disclosure. FIG. 6A, 6B and FIG. 11 show the input of CCSAO classification. In FIG. 11, current chroma sample is 1104, the cross-component collocated chroma sample is 1102, and the collocated luma sample is 1106.” Additionally, Col. 22, lines 34-37, shows that the methods are dependent on the chroma format.);
determining a cross component sample adaptive offset (CC-SAO) to be applied to the reconstructed samples based on the collocated luma sample and the collocated chroma samples ([Col. 17, lines 46-55] “FIG. 6A is a block diagram illustrating the system and process of CCSAO according to some implementations of the present disclosure. The luma samples after luma deblocking filter (DBF Y) is used to determine additional offsets for chroma Cb and Cr after SAO Cb and SAO Cr. For example, the current chroma sample 602 is first classified using collocated 604 and neighboring (white) luma samples 606, and the corresponding CCSAO offset value of the corresponding class is added to the current chroma sample value.” Later implementations, such as the implementation shown in Fig. 11, use collocated chroma samples along with luma samples.); and
encoding a first syntax element specifying whether the CC-SAO is activated (Table 2 shows CCSAO syntax. The flags cc_sao_enabled_flag, ph_cc_sao_cb_flag, etc. are used to determine is CCSAO is enabled for the sequence, for the Cb channel, etc. [Col. 6, lines 26-32] “The encoded video data communicated over link 16, or provided on storage device 32, may include a variety of syntax elements generated by video encoder 20 for use by video decoder 30 in decoding the video data. Such syntax elements may be included within the encoded video data transmitted on a communication medium, stored on a storage medium, or stored a file server.”).
Kuo fails to teach wherein the determining the offset includes classifying sample values of the collocated luma sample and the collocated chroma samples into three different bands and deriving a joint index used to indicate a band offset category based on the three different bands, and wherein the offset to be applied to the reconstructed samples is determined based on the joint index.
However, Kotra teaches wherein the determining the offset includes classifying sample values of the collocated luma sample and the collocated chroma samples into three different bands and deriving a joint index used to indicate a band offset category based on the three different bands, andwherein the offset to be applied to the reconstructed samples is determined based on the joint index ([0076-0077] “For a given luma/chroma sample, three candidate samples are selected to classify the given sample into different categories: one collocated Y sample, one collocated U sample, and one collocated V sample. Video encoder 200 and video decoder 300 may classify the sample values of these three selected samples into three different bands {bandY, bandU, bandV}, and may use a joint index i to indicate the category of the given sample. One offset is determined and added to the reconstructed samples that fall into that category, which can be formulated as:
bandY=(Y col ·N Y)>>BD
bandU=(U col ·N U)>>BD
bandY=(V col ·N V)>>BD
i=bandY·(N U ·N V)+bandU ·N V+bandV
C′ rec=Clip1(C rec+σCCSAO[i]) (1)
In equation (1), {Ycol, Ucol, Vcol} are the three selected collocated samples that are used to classify the current sample; {NY, NU, NV} are the numbers of equally divided bands applied to {Ycol, Ucol, Vcol} full range, respectively;”).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kuo’s invention by using a joint index for determining an offset to be applied to reconstructed samples of a category. This modification would achieve a better tradeoff between complexity and performance ([Kotra 0076] “In one example of the CCSAO design, to achieve a better complexity/performance trade-off, only band offset (BO) is used to enhance the quality of the reconstructed samples.”).
Regarding claim 15, Kuo teaches a method of transmitting a bitstream by an image encoding method ([Col. 2, lines 43-48] “The present application describes implementations related to video data encoding and decoding and, more particularly, to methods and apparatus on improving the coding efficiency of chroma coding, including improving the coding efficiency by exploring cross-component relationship between luma and chroma components.”), the image encoding method comprising:
deriving a collocated luma sample and collocated chroma samples corresponding to each other from reconstructed samples based on a chroma format of the reconstructed samples ([Col. 4, lines 8-12] “FIG. 11 is a block diagram of a sample process illustrating that besides luma, the other cross-component collocated (1102) and neighboring (white) chroma samples are also fed into CCSAO classification in accordance with some implementations of the present disclosure. FIG. 6A, 6B and FIG. 11 show the input of CCSAO classification. In FIG. 11, current chroma sample is 1104, the cross-component collocated chroma sample is 1102, and the collocated luma sample is 1106.” Additionally, Col. 22, lines 34-37, shows that the methods are dependent on the chroma format.);
determining a cross component sample adaptive offset (CC-SAO) to be applied to the reconstructed samples based on the collocated luma sample and the collocated chroma samples ([Col. 17, lines 46-55] “FIG. 6A is a block diagram illustrating the system and process of CCSAO according to some implementations of the present disclosure. The luma samples after luma deblocking filter (DBF Y) is used to determine additional offsets for chroma Cb and Cr after SAO Cb and SAO Cr. For example, the current chroma sample 602 is first classified using collocated 604 and neighboring (white) luma samples 606, and the corresponding CCSAO offset value of the corresponding class is added to the current chroma sample value.” Later implementations, such as the implementation shown in Fig. 11, use collocated chroma samples along with luma samples.); and
encoding a first syntax element specifying whether the CC-SAO is activated (Table 2 shows CCSAO syntax. The flags cc_sao_enabled_flag, ph_cc_sao_cb_flag, etc. are used to determine is CCSAO is enabled for the sequence, for the Cb channel, etc. [Col. 6, lines 26-32] “The encoded video data communicated over link 16, or provided on storage device 32, may include a variety of syntax elements generated by video encoder 20 for use by video decoder 30 in decoding the video data. Such syntax elements may be included within the encoded video data transmitted on a communication medium, stored on a storage medium, or stored a file server.”).
Kuo fails to teach wherein the determining the offset includes classifying sample values of the collocated luma sample and the collocated chroma samples into three different bands and deriving a joint index used to indicate a band offset category based on the three different bands, and wherein the offset to be applied to the reconstructed samples is determined based on the joint index.
However, Kotra teaches wherein the determining the offset includes classifying sample values of the collocated luma sample and the collocated chroma samples into three different bands and deriving a joint index used to indicate a band offset category based on the three different bands, and wherein the offset to be applied to the reconstructed samples is determined based on the joint index.([0076-0077] “For a given luma/chroma sample, three candidate samples are selected to classify the given sample into different categories: one collocated Y sample, one collocated U sample, and one collocated V sample. Video encoder 200 and video decoder 300 may classify the sample values of these three selected samples into three different bands {bandY, bandU, bandV}, and may use a joint index i to indicate the category of the given sample. One offset is determined and added to the reconstructed samples that fall into that category, which can be formulated as:
bandY=(Y col ·N Y)>>BD
bandU=(U col ·N U)>>BD
bandY=(V col ·N V)>>BD
i=bandY·(N U ·N V)+bandU ·N V+bandV
C′ rec=Clip1(C rec+σCCSAO[i]) (1)
In equation (1), {Ycol, Ucol, Vcol} are the three selected collocated samples that are used to classify the current sample; {NY, NU, NV} are the numbers of equally divided bands applied to {Ycol, Ucol, Vcol} full range, respectively;”).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kuo’s invention by using a joint index for determining an offset to be applied to reconstructed samples of a category. This modification would achieve a better tradeoff between complexity and performance ([Kotra 0076] “In one example of the CCSAO design, to achieve a better complexity/performance trade-off, only band offset (BO) is used to enhance the quality of the reconstructed samples.”).
Claims 7-12 are rejected under 35 U.S.C. 103 as being unpatentable over Kuo (US 12,149,687 B2) in view of Kotra (US 2022/0400292 A1), and further in view of Chen et al. (US 10,419,757 B2), hereafter Chen.
Regarding claim 7, Kuo teaches methods of selecting collocated chroma and luma samples using cross-component filtering, and these methods are typically implemented in various ways to be applied to different chroma formats as shown by Col. 22, lines 34-37. Additionally, Fig. 11 shows an example of selecting a collocated chroma sample in what appears to be 4:2:0 format, but Kuo does not teach the specific details of selecting of a collocated chroma sample across different formats. Similarly, Kotra teaches CC-SAO applied to different formats but does not provide the specific details of selecting collocated samples based on the format. Thus, Kuo and Kotra fail to teach wherein the collocated chroma samples are derived based on a coordinate shift of chroma samples among the reconstructed samples based on the chroma format of the reconstructed samples.
However, Chen teaches wherein the collocated chroma samples are derived based on a coordinate shift of chroma samples among the reconstructed samples based on the chroma format of the reconstructed samples (Fig. 4A shows an example of using a cross-component filter for the 4:2:0 chroma format. In 4:2:0 format, each 4x2 block of luma samples contains only 2 chroma samples. Thus, the collocated chroma sample is determined by obtaining the chroma sample (Denoted as “X”) that is above or below the current location (Denoted as “O” for luma samples. There is a luma sample at every location in the 4:2:0 format.). Locations on the top row of a 4x2 block would obtain the chroma directly below, and locations on the bottom row would obtain the chroma directly above. This is shown by the dotted line in Fig. 4A and discussed starting at Col. 15, line 42.).
Kuo, Kotra, and Chen are analogous in the art to the claimed invention, because all teach methods of selecting chroma and luma samples using cross-component filtering. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kuo’s invention by implementing the cross-component filtering so that collocated chroma samples are selected based on the chroma format. This modification would allow for the filtering and selection of samples across different formats when the position of luma and chroma pixels are not aligned (Chen [Col. 15, lines 45-51] “The corresponding pixels in the other components are those pixels at the same sampling position. However, for some color formats, such as 4:2:0, the sampling position of luma and chroma pixels may not be aligned, as shown in FIG. 4A. Therefore, the present disclosure describes different methods to derive the corresponding cross-component pixels.”).
Regarding claim 8, Kuo and Kotra fail to teach wherein the collocated chroma samples are derived based on a horizontal shift of the chroma samples to a horizontal location of the collocated luma sample, based on the chroma format of the reconstructed samples not being a 4:4:4 chroma format.
However, Chen teaches wherein the collocated chroma samples are derived based on a horizontal coordinate shift of the chroma samples to a horizontal location of the collocated luma sample ([Col. 16, lines 38-45] “Thus, in the example of FIG. 5A, a current sample 500 is a chroma sample at a position between an upper luma sample 502 above the chroma sample and a lower luma sample 504 below the chroma sample. Upper luma sample 502 and lower luma sample 504 are luma samples. A video coding device may use a weighted average of upper luma sample 502 and lower luma sample 504 to determine a virtual luma sample 506.”),
based on the chroma format of the reconstructed samples not being a 4:4:4 chroma format (The method shown in Fig. 5A is taught for 4:2:0 format).
Therefore, it would have been obvious to one of ordinary skill in the art to determine collocated chroma samples by selecting a chroma samples with the same horizontal position as a collocated luma sample. This modification allows for the cross-component filter to select collocated luma and chroma samples in the 4:2:0 format, which includes less chroma information than luma information ([Col. 15, lines 45-52] “The corresponding pixels in the other components are those pixels at the same sampling position. However, for some color formats, such as 4:2:0, the sampling position of luma and chroma pixels may not be aligned, as shown in FIG. 4A. Therefore, the present disclosure describes different methods to derive the corresponding cross-component pixels.”).
Regarding claim 9, Kuo and Kotra fail to teach wherein the collocated chroma samples are derived based on a vertical coordinate shift of the chroma samples to a vertical location of the collocated luma sample, based on the chroma format of the reconstructed samples being a 4:2:0 chroma format.
However, Chen teaches wherein the collocated chroma samples are derived based on a vertical coordinate shift of the chroma samples to a vertical location of the collocated luma sample, based on the chroma format of the reconstructed samples being a 4:2:0 chroma format (Chen teaches that collocated a collocated chroma sample is derived when it is vertically directly under or above the current position, which includes a luma sample. [Col. 15, lines 60-67 – Col. 16, lines 1-9] “For the 4:2:0 color format, shown in FIG. 4A, several methods of selecting corresponding cross-component pixels may be utilized. In one example, the correspondence between luma and chroma samples may be set up as indicated by dotted circles in FIG. 4A. One correspondence is to relate the luma samples located immediately upper to the chroma samples. Another correspondence is to relate the luma samples located immediately bottom to the chroma samples. Thus, in the example of FIG. 4A, a current sample 50 is located between an upper sample 52 and a lower sample 54. As part of applying the cross component filter, a video coder may determine the filtered value of current sample 50 based on α, β, and either the upper luma sample 52 or lower luma sample 54. For instance, the video coder may use upper luma sample 52 or lower luma sample 54 as Pcc or pi cc in the example formulas for applying the cross-component filter described elsewhere in this disclosure.”).
Therefore, it would have been obvious to one of ordinary skill in the art to determine collocated chroma samples by selecting a chroma samples with the same vertical position as a collocated luma sample. This modification allows for the cross-component filter to select collocated luma and chroma samples in the 4:2:0 format, which includes less chroma information than luma information ([Col. 15, lines 45-52] “The corresponding pixels in the other components are those pixels at the same sampling position. However, for some color formats, such as 4:2:0, the sampling position of luma and chroma pixels may not be aligned, as shown in FIG. 4A. Therefore, the present disclosure describes different methods to derive the corresponding cross-component pixels.”).
Regarding claim 10, Kuo and Kotra teach the image decoding method of claim 1. Kuo further teaches wherein the collocated luma sample is derived based on a coordinate shift of a luma sample among the reconstructed samples, based on the chroma format of the reconstructed samples (Fig. 10 shows deriving a luma sample (located at 7) neighboring the chroma sample (located at 0) for input to the CCSAO classifier. [Col. 21, lines 53-59] “In some embodiments, a classifier (or class index) uses different luma sample position for C0 classification. FIG. 10 is a block diagram showing a classifier using different luma sample position for C0 classification in accordance with some implementations of the present disclosure, for example, using the neighboring Y7 but not Y0 for C0 classification.”).
Regarding claim 11, Kuo and Kotra fail to teach wherein the collocated luma sample is derived based on a horizontal coordinate shift of the luma sample to a horizontal location of the collocated chroma sample.
However, Chen teaches wherein the collocated luma sample is derived based on a horizontal coordinate shift of the luma sample to a horizontal location of the collocated chroma samples ([Col. 16, lines 38-45] “Thus, in the example of FIG. 5A, a current sample 500 is a chroma sample at a position between an upper luma sample 502 above the chroma sample and a lower luma sample 504 below the chroma sample. Upper luma sample 502 and lower luma sample 504 are luma samples. A video coding device may use a weighted average of upper luma sample 502 and lower luma sample 504 to determine a virtual luma sample 506.”),
based on the chroma format of the reconstructed samples not being a 4:4:4 chroma format (The method shown in Fig. 5A is taught for 4:2:0 format).
Therefore, it would have been obvious to one of ordinary skill in the art to determine a collocated luma sample by selecting a luma sample with the same horizontal position as the collocated chroma samples. This modification allows for the cross-component filter to select collocated luma and chroma samples in the 4:2:0 format, which includes less chroma information than luma information ([Col. 15, lines 45-52] “The corresponding pixels in the other components are those pixels at the same sampling position. However, for some color formats, such as 4:2:0, the sampling position of luma and chroma pixels may not be aligned, as shown in FIG. 4A. Therefore, the present disclosure describes different methods to derive the corresponding cross-component pixels.”).
Regarding claim 12, Kuo and Kotra fail to teach wherein the collocated luma sample is derived based on a vertical coordinate shift of the luma sample to a vertical location of one of the collocated chroma samples, based on the chroma format of the reconstructed samples being a 4:2:0 chroma format.
However, Chen teaches wherein the collocated luma sample is derived based on a vertical coordinate shift of the luma sample to a vertical location of one of the collocated chroma samples, based on the chroma format of the reconstructed samples being a 4:2:0 chroma format (Chen teaches that collocated a collocated chroma sample is derived when it is vertically directly under or above the current position, which includes a luma sample. [Col. 15, lines 60-67 – Col. 16, lines 1-9] “For the 4:2:0 color format, shown in FIG. 4A, several methods of selecting corresponding cross-component pixels may be utilized. In one example, the correspondence between luma and chroma samples may be set up as indicated by dotted circles in FIG. 4A. One correspondence is to relate the luma samples located immediately upper to the chroma samples. Another correspondence is to relate the luma samples located immediately bottom to the chroma samples. Thus, in the example of FIG. 4A, a current sample 50 is located between an upper sample 52 and a lower sample 54. As part of applying the cross-component filter, a video coder may determine the filtered value of current sample 50 based on α, β, and either the upper luma sample 52 or lower luma sample 54. For instance, the video coder may use upper luma sample 52 or lower luma sample 54 as Pcc or pi cc in the example formulas for applying the cross-component filter described elsewhere in this disclosure.”).
Therefore, it would have been obvious to one of ordinary skill in the art to determine a collocated luma sample by selecting a luma sample with the same vertical position as the collocated chroma samples. This modification allows for the cross-component filter to select collocated luma and chroma samples in the 4:2:0 format, which includes less chroma information than luma information ([Col. 15, lines 45-52] “The corresponding pixels in the other components are those pixels at the same sampling position. However, for some color formats, such as 4:2:0, the sampling position of luma and chroma pixels may not be aligned, as shown in FIG. 4A. Therefore, the present disclosure describes different methods to derive the corresponding cross-component pixels.”).
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Kuo (US 12,149,687 B2) in view of Kotra (US 2022/0400292 A1), and further in view of Zhang et al. (US 11,477,449 B2), hereafter Zhang.
Regarding claim 13, Kuo teaches that when higher level flags are off, then lower-level syntax flags are inferred to be off ([Col. 27, lines 35-37] “If a higher-level flag is off, the lower level flags can be inferred from the off state of the flag and do not need to be signaled.”), and Kuo teaches using flags to determine if CCSAO is activated for enabled for the chroma channels (See ph_cc_sao_cb_flag and ph_cc_sao_cr_flag in Table 18). However, Kuo and Kotra both fail to teach wherein the first syntax element is obtained from a bitstream based on the chroma format of the reconstructed samples not being a monochrome chroma format and is inferred to be a value specifying that the CC-SAO is not activated based on the chroma format of the reconstructed samples being a monochrome chroma format.
However, Zhang teaches wherein the first syntax element is obtained from a bitstream based on the chroma format of the reconstructed samples not being a monochrome chroma format (Zhang teaches the chroma_format_idc flag, which represents the chroma format and shows that the bitstream is not monochrome. chroma_format_idc is a well-documented and well-known flag of the high efficiency video coding standard. [Col. 37, lines 52-56] “FIG. 12 illustrates the indicated relative position of the top-left chroma sample when chroma_format_idc is equal to 1 (4:2:0 chroma format), and chroma_sample_loc_type is equal to the value of a variable ChromaLocType.” [Col. 37, lines 64-67] “The relative spatial positioning of the chroma samples, as illustrated in FIG. 13, can be expressed by defining two variables HorizontalOffsetC and VerticalOffsetC as a function of chroma_format_idc and the variable ChromaLocType.”), and
is inferred to be a value specifying that the CC-SAO is not activated based on the chroma format of the reconstructed samples being a monochrome chroma format ([Col. 85, lines 1-8] “In some embodiments, temporal prediction of the adaptive loop filtering operation is disabled based on the condition. In some embodiments, the syntax element indicates a temporal prediction of the adaptive loop filtering operation, and the syntax element is omitted in the coded representation in case the condition is satisfied. The condition specifies that a color format of the video is 4:0:0 or color components of the video are coded separately.” Here, Zhang teaches that adaptive loop filtering (ALF) is disabled since the syntax value shows a chroma format of 4:0:0. Although, adaptive loop filtering is not the same as SAO, both are in-loop filters used in video compression and could be disabled for a 4:0:0 chroma format.)
Kuo, Kotra, and Zhang are analogous in the art, because all teach methods of using syntax flags for filtering methods. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to infer that CC-SAO is not activated when a higher-level flag is received from the bitstream which indicates that chroma information is being used. This modification would implement the logic already discussed by Kuo in Col. 27, lines 35-37, and it would allow for flags from the bitstream to provide color format information for in-loop filters (Zhang [Col. 85, lines 1-8] “In some embodiments, temporal prediction of the adaptive loop filtering operation is disabled based on the condition… The condition specifies that a color format of the video is 4:0:0 or color components of the video are coded separately.”). Additionally, Zhang teaches that the methods could be adapted for use with VVC, which is the standard for CC-SAO ([Col. 1, lines 34-36] “The described methods may be applied to existing video coding standards (e.g., High Efficiency Video Coding (HEVC) or Versatile Video Coding) and future video coding standards or video codecs.”).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Yin et al. (US 12,542,899 B2) teaches a method using a bilateral filter and a CC-SAO filter to samples in each block of a video stream. Additionally, Yin et al. [Col. 8, lines 45-67] teaches the use of a joint index to indicate the category for a sample using the same method as the newly amended independent claims 1 and 14-15 of the present application.
Li et al. (US 11,431,985 B2) teaches a method for image decoding wherein a received bitstream includes prediction information for each block, and reconstructed samples for each block are derived using the prediction information.
Kuo et al. (US 2024/0430439 A1) teaches a method for decoding video data which includes classifying received samples and determining offsets based on the classification category.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/Eric Shoemaker/
Patent Examiner
/XIAO LIU/Primary Examiner, Art Unit 2664
Prosecution Insights