Court Opinion

ID: 6495291
Source: CourtListenerOpinion
Date Created: 2022-06-27 14:00:38.716919+00
Date Added: 2024-06-11T08:46:19.368454
License: Public Domain

Case: 21-1931     Document: 40    Page: 1   Filed: 06/27/2022

        NOTE: This disposition is nonprecedential.

   United States Court of Appeals
       for the Federal Circuit
                   ______________________

                NETFLIX, INC., HULU, LLC,
                       Appellants

                             v.

                        DIVX, LLC,
                          Appellee
                   ______________________

                         2021-1931
                   ______________________

     Appeal from the United States Patent and Trademark
 Office, Patent Trial and Appeal Board in No. IPR2020-
 00052.
                  ______________________

                   Decided: June 27, 2022
                   ______________________

     HARPER BATTS, Sheppard Mullin Richter & Hampton
 LLP, Menlo Park, CA, argued for appellants. Also repre-
 sented by JEFFREY LIANG, CHRISTOPHER SCOTT PONDER;
 MATTHEW G. HALGREN, San Diego, CA.

     KENNETH J. WEATHERWAX, Lowenstein & Weatherwax
 LLP, Santa Monica, CA, argued for appellee. Also
 represented by PARHAM HENDIFAR, NATHAN NOBU
 LOWENSTEIN.
                 ______________________
Case: 21-1931     Document: 40      Page: 2    Filed: 06/27/2022

 2                                    NETFLIX, INC.   v. DIVX, LLC

     Before LOURIE, BRYSON, and HUGHES, Circuit Judges.
 BRYSON, Circuit Judge.
     Appellants Netflix, Inc., and Hulu, LLC, (collectively,
 “petitioners”) petitioned for inter partes review of U.S. Pa-
 tent No. 8,139,651 (“the ’651 patent”), which is owned by
 appellee DivX, LLC. The Patent Trial and Appeal Board
 instituted an inter partes review, and in its Final Written
 Decision, the Board held that none of the challenged claims
 were unpatentable based on the grounds asserted in the
 petition. We affirm in part, vacate in part, and remand.
                               I
                               A
     The ’651 patent is directed to “methods of deblocking
 compressed video.” ’651 patent, col. 1, ll. 15–16. In gen-
 eral, digital videos consist of a series of frames, each of
 which contains numerous pixels. Id. at col. 1, ll. 17–19.
 Although digital video files in their native form are typi-
 cally very large, the file size of a video can be reduced using
 “compression schemes” that “achieve significant reductions
 in the amount of digital data required to encode a video se-
 quence.” Id. at col. 1, ll. 19–24.
     Some compression schemes, such as that used by the
 well-known “MPEG-4” encoding standard, divide each
 frame of a video into separately encoded blocks of pixels.
 Id. at col. 1, ll. 25–29. When a video frame is reconstructed
 from the separately encoded blocks, however, “artifacts”
 that reduce the overall quality of the image can appear at
 the boundaries between the blocks. Id. at col. 1, ll. 29–34.
 In their opening brief, petitioners illustrate that phenome-
 non with a photograph made up of a large number of blocks
 of pixels, each block consisting of a small square with de-
 fined edges. See Appellants’ Br. 5. Those edges are the
 “artifacts” described in the specification of the ’651 patent.
 The ’651 patent discloses that a deblocking filter can be
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 NETFLIX, INC.   v. DIVX, LLC                               3

 applied to “smooth out [the] edges” created by the squares
 in the photograph. Id. at 5–6.
     Claim 1 is the only independent claim of the ’651 pa-
 tent. It recites:
     1. A method of deblocking a reconstructed video
     frame, comprising:
         identifying a boundary between two blocks
         of the reconstructed video frame;
         determining the level of detail of the recon-
         structed video frame across a region in
         which the block boundary is located,
         wherein the region includes pixels from
         multiple rows and multiple columns of the
         reconstructed video frame that encompass
         pixels immediately adjacent to at least two
         sides of the block boundary and includes at
         least one pixel that is not immediately ad-
         jacent to the block boundary;
         selecting a filter to apply to predetermined
         pixels on either side of the block boundary
         based upon the determined level of detail.
 ’651 patent, claim 1.
     The dispute in this appeal relates to the second method
 step, which requires “determining the level of detail of the
 reconstructed video frame.” Id. The specification discloses
 the following formula for calculating the level of detail in
 several of the embodiments of the ’651 patent:

 where i is the number of rows in the region and j is the
 number of columns in the region. Id. at col. 3, ll. 46–57.
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 4                                    NETFLIX, INC.   v. DIVX, LLC

 That calculation is commonly referred to as the “sum of ab-
 solute differences” or “SAD” calculation. See id. at col. 8,
 ll. 61–63. As applied to a particular region having a hori-
 zontal block boundary, the SAD calculation would require
 determining the absolute difference between each pair of
 vertically adjacent pixels and summing those differences. 1
 Id. at col. 9, ll. 6–10. What results is a measure that ap-
 proximates the level of variation among pairs of adjacent
 pixels within the region of interest.
     The SAD calculation is explicitly recited in dependent
 claims 2 and 4 of the ’651 patent. Those claims recite:
     2. The method of claim 1, wherein the determina-
     tion of the level of detail of the reconstructed video
     frame in a region in which the block boundary is
     located further comprises taking the sum of the ab-
     solute difference of at least some of the pixels
     within a set of pixels surrounding the block bound-
     ary.
     4. The method of claim 2, wherein the set of pixels
     is an 8x8 block that is evenly divided by the hori-
     zontal block boundary.
                               B
      The petition for inter partes review of the ’651 patent
 raised three grounds of invalidity. First, petitioners as-
 serted that claims 1, 17, and 18 of the ’651 patent were an-
 ticipated by U.S. Patent No. 6,504,873 (“Vehviläinen”) and
 were therefore unpatentable under 35 U.S.C. § 102. Sec-
 ond, petitioners asserted that claims 1 and 17–19 of the
 ’651 patent would have been obvious in view of Vehviläinen

     1     The numerical value that corresponds to each pixel
 typically represents either the “chrominance” or the “lumi-
 nance” of the pixel. See ’651 patent, col. 3, line 56; id. at
 col. 4, line 1.
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 NETFLIX, INC.   v. DIVX, LLC                                 5

 and were therefore unpatentable under 35 U.S.C. § 103.
 Third, petitioners asserted that claims 1, 2, 4, and 17–19 of
 the ’651 patent would have been obvious in view of the com-
 bination of Vehviläinen and U.S. Patent Pub. No.
 2004/0076237 (“Kadono”) and were therefore unpatentable
 under section 103.
     Like the ’651 patent, the Vehviläinen reference dis-
 closes methods for deblocking compressed video files. The
 specification of Vehviläinen teaches that the choice of filter
 to be applied at a particular block boundary should be
 “based on the measurement of both edge variance [i.e., var-
 iance among a set of pixels closest to the block boundary]
 and variance inside the block [i.e., variance among a larger
 region of pixels within the block]. ” Vehviläinen, col. 9, ll.
 8–10.
     Vehviläinen discloses two methods for calculating the
 variance across a region of pixels. First, Vehviläinen dis-
 closes a traditional formula for calculating variance:

 Id. at col. 10, line 35. In that equation, N refers to the num-
 ber of pixels in the region, 𝑥𝑥𝑖𝑖 refers to the numerical value
 of a given pixel in the region, and 𝑥𝑥̅ refers to the mean nu-
 merical value of all the pixels in the region. Id. at col. 10,
 ll. 40–43. The variance calculation compares the value of
 each individual pixel in the region with the average value
 of all the pixels in the region.
     Vehviläinen notes that performing the “[n]ormal vari-
 ance calculation is an exhausting operation,” and therefore
 as an alternative it discloses the “min-max approximation,”
 which it asserts is a simpler method for estimating the var-
 iance. Id. at col. 10, ll. 32, 43–45. The min-max approxi-
 mation is defined by the following equation:
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 6                                       NETFLIX, INC.   v. DIVX, LLC

 Id. at col. 10, line 47. In that calculation, 𝑥𝑥𝑚𝑚𝑚𝑚𝑚𝑚 refers to the
 highest numerical value of all the pixels in the given re-
 gion, and 𝑥𝑥𝑚𝑚𝑚𝑚𝑚𝑚 refers to the lowest numerical value of all
 the pixels in the region. Id. at col. 10, ll. 52–55. That ver-
 sion of the variance calculation thus compares only the two
 pixels in the region that have the largest and smallest nu-
 merical values.
     Kadono also discloses methods for deblocking com-
 pressed video files. In one embodiment, Kadono discloses
 comparing a series of pixels using “the sum of the absolute
 values of the difference[s]” between the pixels to determine
 whether to apply a “deblocking operation,” and if so, which
 deblocking operation to apply. Kadono, ¶¶ 203–07.
     In addition to disclosing the use of the SAD calculation,
 Kadono discloses an “omega threshold,” which is a thresh-
 old that is used to determine whether a stronger filter can
 be applied once it is determined that a region is smooth.
 Id. at ¶ 125 (“[I]f the pixel difference is small . . . Ω is there-
 fore preferably set so that a stronger filter . . . is applied
 based on whether the pixel difference is extremely low (less
 than Ω) . . . .”).
                                  C
     In its Institution Decision, the Board construed the
 claim term “level of detail” to mean “level of variation in
 visual elements across adjacent pixels”; the Board reaf-
 firmed that construction in its Final Written Decision. Net-
 flix Inc. v. DivX, LLC, No. IPR2020-00052, 2021 WL
 1582150, at *5 (P.T.A.B. Apr. 22, 2021). In adopting that
 construction, the Board relied upon a statement in the
 specification of the ’651 patent indicating that that the
 term “detail” refers to “visual elements of a video frame
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 NETFLIX, INC.   v. DIVX, LLC                                7

 that vary significantly across adjacent pixels.” Id. (quoting
 ’651 patent, col. 1, ll. 55–57).
      Applying that construction, the Board found that Ve-
 hviläinen did not anticipate claim 1 of the ’651 patent be-
 cause Vehviläinen did not disclose the “determining the
 level of detail” step of the claim. The Board reasoned that
 the variance calculation disclosed in Vehviläinen does not
 determine “the level of variation in visual elements across
 adjacent pixels.” Id. at *9. In the Board’s view, to conclude
 that Vehviläinen discloses that limitation would “elimi-
 nate[] the requirement that detail be calculated across ad-
 jacent pixels, improperly broadening the limitation to a
 determination of variation in visual elements across the en-
 tire claimed region.” Id.
      The Board also found that there was no motivation to
 combine Vehviläinen with Kadono. The Board noted that
 “select[ing] a filter based on the differences between adja-
 cent pixels [as in Kadono] rather than variance across the
 region would have been understood by an ordinarily skilled
 artisan as changing the basic principle of Vehviläinen’s op-
 eration.” Id. at *14. The Board reached that conclusion by
 relying upon language in the specification of Vehviläinen
 stating that “adjacent video pixels as such are not filtered
 in comparison with each other.” Id. (quoting Vehviläinen,
 col. 2, ll. 41–45) (emphasis omitted). The Board did not ad-
 dress petitioners’ separate argument that the omega
 threshold disclosed in Kadono could be combined with Ve-
 hviläinen. See J.A. 129–36.
                                II
     On appeal, petitioners raise three issues: (1) whether
 the Board properly construed the term “level of detail”; (2)
 whether substantial evidence supports the Board’s finding
 that Vehviläinen does not disclose the “determining the
 level of detail” step of claim 1; and (3) whether the Board
 erred in finding that a skilled artisan would not have been
 motivated to combine Vehviläinen with Kadono.
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 8                                   NETFLIX, INC.   v. DIVX, LLC

     We review the Board’s claim construction de novo and
 the Board’s factual findings regarding anticipation and
 motivation to combine for substantial evidence. See Accel-
 eration Bay, LLC v. Activision Blizzard Inc., 908 F.3d 765,
 769 (Fed. Cir. 2018).
     With regard to the claim construction issue, petitioners
 argue that the Board applied an unduly narrow construc-
 tion of the claim term “level of detail.” Specifically, peti-
 tioners allege that in its analysis of Vehviläinen the Board
 construed “level of detail” to require calculation of the var-
 iation between adjacent pixels rather than across adjacent
 pixels. According to petitioners, the Board’s construction
 had the effect of narrowing the method of determining
 “level of detail” to include only calculations based on the
 sum of absolute differences in the values between adjacent
 pixels.
     We agree with petitioners that in construing the claim
 limitation “determining the level of detail . . . across a re-
 gion in which the block boundary is located” the Board held
 that the method of claim 1 of the ’651 patent required com-
 parison of values between pairs of adjacent pixels. The
 Board’s construction excluded Vehviläinen’s calculation
 method because that method does not directly compare the
 value of any particular pixel to the value of an adjacent
 pixel. An examination of the language of claim 1 and the
 specification of the ’651 patent leads us to conclude that
 claim 1 is not limited in that fashion.
      By its terms, claim 1 is quite broad. The language of
 the claim is not specific as to the methodology to be used in
 the level-of-detail calculation, nor does it specify what type
 of filter should be applied based upon the determined level
 of detail. See ’651 patent, claim 1. Rather, claim 1 simply
 provides that the level of detail is calculated “across a re-
 gion in which the block boundary is located.” Id.
     Principles of claim differentiation indicate that the
 term “level of detail,” as used in claim 1, encompasses more
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 NETFLIX, INC.   v. DIVX, LLC                                 9

 than just the SAD calculation. The SAD calculation is re-
 cited in dependent claim 2 (and, by extension, in several
 other claims that depend from claim 2), which is strong ev-
 idence that claim 1 necessarily encompasses more subject
 matter than claim 2. See Littelfuse, Inc. v. Mersen USA EP
 Corp., 29 F.4th 1376, 1380 (Fed. Cir. 2022) (“By definition,
 an independent claim is broader than a claim that depends
 from it . . . .”); Intamin Ltd. v. Magnetar Techs., Corp., 483
 F.3d 1328, 1335 (Fed. Cir. 2007) (“An independent claim
 impliedly embraces more subject matter than its narrower
 dependent claim.”).
     DivX suggested to the Board that claim differentiation
 does not apply in this case because there could be other
 methods for determining the level of variation between
 pairs of immediately adjacent pixels that do not use the
 SAD calculation. J.A. 3423. For instance, one might sum
 the squares of the differences between adjacent pixels or
 compute the sum of differences without taking the absolute
 value of those differences (as the SAD calculation requires).
 See id.
      Both of those alternative calculation methods would
 appear to fall within the scope of claim 1 even under the
 Board’s narrow interpretation of the scope of that claim.
 For that reason, DivX’s argument demonstrates that claim
 differentiation does not fully resolve the claim construction
 issue. Nevertheless, the difference between claims 1 and 2
 provides guidance as to the scope of claim 1 because claim
 2 prescribes a specific methodology for determining the
 level of detail across a region of a video frame, while claim
 1 does not.
     The specification provides further insight into the
 meaning of the term “level of detail” as used in claim 1 of
 the ’651 patent. It explains that “detail” refers to “visual
 elements of a video frame that vary significantly across ad-
 jacent pixels.” Id. at col. 1, ll. 55–57. The specification of-
 fers that description in contrast to the term “smooth,”
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 10                                    NETFLIX, INC.   v. DIVX, LLC

 which refers to “a region of a video frame where the [pixel
 values] either do not vary or vary gradually across adjacent
 pixels.” Id. at col. 1, ll. 53–55.
     Nothing in the specification indicates that the term
 “detail” was intended to require that the level-of-detail cal-
 culation involve a direct comparison between the values of
 immediately adjacent pixels. In light of the reference in
 claim 1 to determining the level of detail “across a region,”
 the use of the phrase “across adjacent pixels” in the speci-
 fication is best understood to refer to the degree of varia-
 tion in pixel values across a region of contiguous pixels (i.e.,
 a region in which each pixel is adjacent to at least one other
 pixel in the region), rather than being limited to a determi-
 nation of variation based on direct comparisons of value be-
 tween adjacent pairs of pixels.
     The specification’s use of the phrase “vary gradually
 across adjacent pixels” is instructive in this regard, as it
 suggests that determining whether a region is “smooth” or
 “detailed” depends on the degree of variation across a re-
 gion of contiguous pixels. There is no reason that a system
 that does not rely on direct comparison of individual adja-
 cent pixels, but instead compares the pixels in the region
 to some other reference point (e.g., the mean pixel value),
 would not be at least as capable of determining whether
 pixel values vary gradually across a region of contiguous
 pixels as a system that relies on an aggregation of the dif-
 ferences in value between individual adjacent pixels.
     In light of the breadth of claim 1 and the discussion of
 the terms “detail” and “smooth” in the specification, we con-
 strue the claim term “level of detail” to mean “level of var-
 iation in visual elements across a region of pixels.” Because
 the Board’s construction of claim 1 was limited to a method
 that depended on determining the differences in value be-
 tween pairs of adjacent pixels, we hold that the Board’s in-
 terpretation of claim 1 was too narrow. We therefore
 vacate the Board’s ruling on the validity of claim 1 and
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 NETFLIX, INC.   v. DIVX, LLC                                11

 remand this case for the Board to consider whether Ve-
 hviläinen discloses the “determining the level of detail”
 step of claim 1 under the proper construction of that step.
                                III
      Petitioners also challenge the Board’s finding that a
 skilled artisan would not have been motivated to combine
 Vehviläinen with the SAD calculation disclosed in Kadono.
 We hold that the Board’s finding is supported by substan-
 tial evidence, and we therefore affirm the Board’s decision
 on that issue.
      Petitioners raise several objections to the Board’s rul-
 ing on the motivation-to-combine issue. First, petitioners
 argue that the Board violated the Administrative Proce-
 dure Act (“APA”) by relying on an argument not raised in
 the briefs. Second, they argue that the Board’s finding that
 applying Kadono’s SAD calculation would change the prin-
 ciple of operation of Vehviläinen is unsupported by sub-
 stantial evidence. Third, they argue that the Board erred
 in excluding its arguments regarding “SIMD instructions.”
 Fourth, they argue that the Board failed to address the pe-
 titioners’ argument regarding Kadono’s omega threshold.
                                A
      In their APA argument, petitioners object to the
 Board’s statement that using Kadono’s SAD calculation
 would “chang[e] the basic principle of Vehviläinen’s opera-
 tion.” Netflix, 2021 WL 1582150, at *14. Petitioners argue
 that the principle-of-operation line of reasoning was raised
 for the first time in the Board’s Final Written Decision, and
 that they were denied an opportunity to respond to it. See
 Appellants’ Br. 52–54.
     Petitioners’ argument focuses too narrowly on the
 Board’s choice of language, and in particular the Board’s
 use of the phrase “principle of operation.” In its Patent
 Owner Response, DivX argued that there would be no mo-
 tivation to combine Kadono with Vehviläinen, in part
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 12                                   NETFLIX, INC.   v. DIVX, LLC

 because “Vehviläinen expressly seeks to avoid even the
 general type of filtering (low pass filtering) that both the
 [’651] Patent and Kadono utilize.” J.A. 1779. DivX’s ex-
 pert, Dr. Chandrajit Bajaj, echoed that argument in his re-
 port, in which he noted that “Vehviläinen’s filter
 application decision process matches its filter application
 process, and also does not analyze adjacent pixels in com-
 parison with their adjacent pixels.” J.A. 2100, ¶ 62. Those
 arguments are consistent with the Board’s reasoning; the
 only difference is that they do not use the phrase “principle
 of operation.” Accordingly, we reject petitioners’ argument
 that the Board’s conclusions represent a new argument to
 which they were denied an opportunity to respond.
                               B
     Petitioners next argue that the Board’s finding that
 Kadono would change Vehviläinen’s principle of operation
 is unsupported by substantial evidence. Petitioners argue
 that “the only portion of the evidentiary record that even
 discusses or references the principle of operation for the
 ‘level of detail’” is the testimony of their expert, Dr. Victor
 Michael Bove, in which he stated that replacing Ve-
 hviläinen’s variance calculation with Kadono’s SAD calcu-
 lation “would not have changed the principle of operation
 for either reference.” Appellants’ Br. 54–55 (quoting J.A.
 1131–32, ¶ 144). The Board, however, found that testi-
 mony “unpersuasive” due to “the inconsistencies between
 Dr. Bove’s testimony and the teachings of Vehviläinen.”
 Netflix, 2021 WL 1582150, at *15.
     More generally, petitioners’ argument suffers from the
 same flaw as their APA argument, which is that it focuses
 too narrowly on the specific phrase “principle of operation.”
 Dr. Bajaj’s report provides support for the Board’s finding,
 as he notes that the filter selection approach in Ve-
 hviläinen (which relies on the variance calculation) is “ex-
 actly contrary” to the SAD calculation. J.A. 2100–2101, ¶
 62. We therefore hold that the Board’s finding that
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 NETFLIX, INC.   v. DIVX, LLC                                 13

 Kadono’s SAD calculation would have changed the princi-
 ple of operation of Vehviläinen is supported by substantial
 evidence.
                                C
       Petitioners next argue that the Board improperly
 deemed their arguments regarding “single instruction mul-
 tiple data” (“SIMD”) instructions to be forfeited. Petition-
 ers argued in their petition that “Kadono teaches
 performance optimizations to accelerate SAD calculations
 . . . on SIMD . . . processors.” J.A. 128. In petitioners’ view,
 a skilled artisan therefore “would have been motivated to
 apply Kadono’s teaching to improve Vehviläinen[] . . . par-
 ticularly for use on SIMD computer platforms.” Id. Peti-
 tioners added in their reply brief before the Board that
 “[t]here are certain SIMD instruction sets that explicitly
 can calculate [SAD] in parallel on multiple pixels at on[c]e.”
 J.A. 2670.
     In its Final Written Decision, the Board held that
 DivX’s arguments regarding SIMD instruction sets were
 forfeited because they were raised for the first time in re-
 ply. Netflix, 2021 WL 1582150, at *15 n.11. The Board did
 not hold that petitioners’ arguments regarding SIMD pro-
 cessors in general were forfeited, as those arguments were
 raised in the petition. See id. at *15. We therefore do not
 agree with petitioners that the Board improperly excluded
 their specific arguments regarding SIMD instructions.
      In any event, the Board held that “[e]ven if not for-
 feited, we are not persuaded that the use of [SIMD] instruc-
 tions support a motivation to combine given our
 determination that use of Kadono’s SAD calculation would
 change Vehviläinen’s basic principle of operation.” Id. at
 *15 n.11. As noted above, the Board’s finding regarding
 Vehviläinen’s principle of operation is supported by sub-
 stantial evidence. In their briefing on appeal, petitioners
 have offered no reason to believe that the use of SIMD pro-
 cessors or instructions is enough to overcome the fact that
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 14                                  NETFLIX, INC.   v. DIVX, LLC

 Kadono’s SAD calculation method would significantly
 change the operation of Vehviläinen. See Appellants’ Br.
 61–62 (offering no argument other than that the Board’s
 conclusion relies on the principle-of-operation analysis that
 petitioners allege was erroneous). Accordingly, the Board
 did not err in its treatment of petitioners’ arguments re-
 garding SIMD instructions.
                               D
      Petitioners’ final argument is that the Board failed to
 consider their alternative argument regarding the omega
 threshold disclosed in Kadono. In addition to their argu-
 ments regarding Kadono’s SAD calculation, petitioners ar-
 gue that Kadono’s omega threshold could be used to
 provide additional filtering in very smooth regions as part
 of Vehviläinen’s filter selection process. Petitioners cor-
 rectly point out that the Board did not address their omega-
 threshold argument in its Final Written Decision. See Net-
 flix, 2021 WL 1582150, at *14–16. The Board mentioned
 Kadono’s omega threshold argument in its Final Written
 Decision, but only as part of its summary of petitioners’ ar-
 guments. Id. at *12.
      Petitioners’ argument regarding Kadono’s omega
 threshold, however, is different on appeal from the argu-
 ment they raised before the Board. In their opening brief
 on appeal, petitioners argue that a skilled artisan could ap-
 ply “Kadono’s omega threshold, paired with Kadono’s filter,
 to Vehviläinen Step 80 [of Figure 6] without altering Ve-
 hviläinen’s other filters or detail calculations.” Appellants’
 Br. 65. That argument is different from the argument pe-
 titioners made before the Board, where they argued that
 the proposed combination of Kadono and Vehviläinen “does
 not use Kadono’s filters; it applies Kadono’s selection teach-
 ings ([omega] threshold and SAD).” J.A. 2672. That dis-
 tinction is important given the Board’s reliance on the fact
 that Vehviläinen’s variance calculation is closely tied to its
 choice of filter. Netflix, 2021 WL 1582150, at *14. The
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 NETFLIX, INC.   v. DIVX, LLC                                15

 suggestion that Kadono’s filter might be used in a way that
 maintains Vehviläinen’s primary principle of operation
 could change the motivation-to-combine analysis, but that
 argument was raised for the first time on appeal and is
 therefore forfeited.
     Petitioners’ arguments regarding the motivation to
 combine Kadono with Vehviläinen are unpersuasive. Be-
 cause the petition challenged claims 2 and 4 only on the
 ground of obviousness in view of Vehviläinen and Kadono,
 we uphold the Board’s decision rejecting petitioners’ argu-
 ment that those two claims are unpatentable.
                                 IV
     In summary, because the Board applied an improperly
 narrow construction of the term “level of detail” in claim 1
 of the ’651 patent, we vacate the Board’s construction of
 that term along with its findings regarding whether Ve-
 hviläinen discloses the level-of-detail step of claim 1. Be-
 cause the Board’s finding that a skilled artisan would not
 be motivated to combine Vehviläinen with Kadono is sup-
 ported by substantial evidence, we affirm the Board’s deci-
 sion as to dependent claims 2 and 4.
     On remand, should the Board find that Vehviläinen
 discloses the level-of-detail step of claim 1 under the proper
 construction, it should address DivX’s remaining argu-
 ments for finding that claim 1 is not unpatentable. See Ap-
 pellee’s Br. 65–66.
   AFFIRMED-IN-PART, VACATED-IN-PART, AND
                 REMANDED
                                COSTS
 No costs.