US 6950469

Here's a concise summary of US Patent 6950469:

US Patent 6,950,469

• Title: Method for sub-pixel value interpolation
• Assignee: Nokia Technologies Oy (Current Assignee), Nokia Inc (Original Assignee)
• Inventors: Marta Karczewicz, Antti Olli Hallapuro
• Filing Date: September 17, 2001
• Issue Date: September 27, 2005
• Abstract: The patent describes a method for sub-pixel value interpolation used in encoding and decoding data, particularly digital video. It aims to reduce computational complexity and memory usage compared to prior art methods. The method involves interpolating sub-pixel values at various fractional horizontal and vertical locations (e.g., 1/2, 1/4, 1/8 pixel resolutions) using weighted sums or averages of neighboring pixel or sub-pixel values. The interpolation can be performed directly for certain sub-pixel resolutions and can involve intermediate values with a greater dynamic range. The method is applicable in video encoders, decoders, and telecommunications systems.

Plain-Language Overview of Independent Claims:

US Patent 6,950,469 contains multiple independent claims. Below is an overview of the primary independent claims (Claim 1, Claim 15, Claim 28, Claim 42, and Claim 43), as the patent text includes several main aspects of the invention with variations.

• Independent Claim 1 (Method of Interpolation in Video Coding): This claim describes a method for generating sub-pixel values in an image. The image has pixels at "unit horizontal" and "unit vertical" locations, and the sub-pixels are at fractional locations (1/2^x resolution, where 'x' is an integer up to 'N'). The method involves:

  • Step (a): When sub-pixel values at a specific resolution (1/2^(N-1) unit horizontal and 1/2^(N-1) unit vertical) are needed, they are interpolated directly using a choice of two weighted sums. The first weighted sum uses sub-pixels at 1/2^(N-1) horizontal and unit vertical locations, and the second uses sub-pixels at unit horizontal and 1/2^(N-1) vertical locations.
  • Step (b): When sub-pixel values at a quarter unit horizontal or quarter unit vertical location are needed, they are interpolated directly using either a first weighted sum (for vertical locations) or a second weighted sum (for horizontal locations).
  • Step (c): When sub-pixel values at a higher fractional resolution (1/2^N unit horizontal and 1/2^N unit vertical) are required, they are interpolated by taking a weighted average of two other sub-pixels or pixels. These two reference points are located diagonally relative to the sub-pixel being calculated. The weights used in this average are inversely proportional to the diagonal proximity of the reference points to the sub-pixel.

• Independent Claim 15 (Video Coder): This claim describes a video coder (e.g., for encoding or decoding) that includes an interpolator. The interpolator is designed to generate sub-pixel values at fractional horizontal and vertical locations (defined by 1/2^x, where x is a positive integer up to N). The interpolator is adapted to perform steps (a) and (c) as described in Independent Claim 1.

• Independent Claim 28 (Communications Terminal): This claim covers a communications terminal that comprises a video coder as described in Independent Claim 15.

• Independent Claim 42 (Telecommunications System - Terminal Side): This claim defines a telecommunications system that includes a communications terminal (as described in Independent Claim 28) and a network. The terminal and network are connected by a link for transmitting coded video.

• Independent Claim 43 (Telecommunications System - Network Side): This claim defines a telecommunications system where the network itself comprises a video coder (as described in Independent Claim 15) for coding images.

CAFC 2026 Dockets:

As of April 26, 2026, a search of CAFC 2026 dockets specifically for US patent 6950469 did not return any direct results. While there are various patent-related cases being heard by the Federal Circuit in 2026, they pertain to different patent numbers and technologies.

It is worth noting that Google Patents lists several litigations for US6950469, including cases filed in the Minnesota District Court, International Trade Commission, Texas Eastern District Court, Delaware District Court, and North Carolina Eastern District Court, as well as multiple PTAB cases. However, none of these specifically indicate active CAFC dockets for 2026 for this particular patent. The patent itself expired on August 6, 2023.

The following litigation involving US patent 6950469 is known:

I. US International Trade Commission (ITC) Cases

1. Inv. No. 337-TA-1208
   • Plaintiff(s): Nokia Corporation
   • Defendant(s): Not explicitly listed in snippets, but 337 investigations target importers/manufacturers of "Certain Electronic Devices, Including Computers, Tablet Computers, and Components and Modules Thereof".
   • Jurisdiction: International Trade Commission
   • Case number: 337-TA-1208
   • Filing date: July 1, 2020 (Initiating Document Received Date)
   • Outcome or current status: Terminated on May 17, 2021. The Initial Determination was Non-Final, Terminating, and the Final Determination was Non-Substantive.

II. Patent Trial and Appeal Board (PTAB) Cases

1. IPR2024-01139

   • Plaintiff(s): Amazon Com Inc., Amazon Com Services LLC (Petitioner) [cite: 1 in previous analysis step]
   • Defendant(s): Nokia Technologies Oy (Patent Owner, as the current assignee listed in the patent details)
   • Jurisdiction: Patent Trial and Appeal Board (PTAB) [cite: 1 in previous analysis step]
   • Case number: IPR2024-01139 [cite: 1 in previous analysis step]
   • Filing date: July 5, 2024 [cite: 1 in previous analysis step]
   • Outcome or current status: Settlement [cite: 1 in previous analysis step]

2. IPR2020-01685

   • Plaintiff(s): Unified Patents, LLC (Petitioner) (Inferred, as Unified Patents is known for filing IPRs against patents, often on behalf of its members, and the outcome is a settlement) [cite: 2, 4, 7 in previous analysis step]
   • Defendant(s): Nokia Technologies Oy (Patent Owner, as the current assignee listed in the patent details)
   • Jurisdiction: Patent Trial and Appeal Board (PTAB)
   • Case number: IPR2020-01685
   • Filing date: 2020 (Specific day not readily available through public search)
   • Outcome or current status: Settlement

3. IPR2021-00035

   • Plaintiff(s): Unified Patents, LLC (Petitioner) (Inferred) [cite: 2, 4, 7 in previous analysis step]
   • Defendant(s): Nokia Technologies Oy (Patent Owner, as the current assignee listed in the patent details)
   • Jurisdiction: Patent Trial and Appeal Board (PTAB)
   • Case number: IPR2021-00035
   • Filing date: 2021 (Specific day not readily available through public search)
   • Outcome or current status: Settlement

4. IPR2021-00036

   • Plaintiff(s): Unified Patents, LLC (Petitioner) (Inferred) [cite: 2, 4, 7 in previous analysis step]
   • Defendant(s): Nokia Technologies Oy (Patent Owner, as the current assignee listed in the patent details)
   • Jurisdiction: Patent Trial and Appeal Board (PTAB)
   • Case number: IPR2021-00036
   • Filing date: 2021 (Specific day not readily available through public search)
   • Outcome or current status: Settlement

III. US District Court Cases

1. Delaware District Court, 1:23-cv-01236

   • Plaintiff(s): Nokia Technologies Oy [cite: 4 in previous analysis step]
   • Defendant(s): HP, Inc. [cite: 4 in previous analysis step]
   • Jurisdiction: U.S. District Court for the District of Delaware [cite: 4 in previous analysis step]
   • Case number: 1:23-cv-01236 [cite: 4 in previous analysis step]
   • Filing date: October 31, 2023 [cite: 4 in previous analysis step]
   • Outcome or current status: Patent infringement; appears active/pending as of April 2024. [cite: 4 in previous analysis step]

2. Delaware District Court, 1:23-cv-01237

   • Plaintiff(s): Nokia Technologies Oy [cite: 4 in previous analysis step]
   • Defendant(s): HP, Inc. [cite: 4 in previous analysis step]
   • Jurisdiction: U.S. District Court for the District of Delaware [cite: 4 in previous analysis step]
   • Case number: 1:23-cv-01237 [cite: 4 in previous analysis step]
   • Filing date: October 31, 2023 [cite: 4 in previous analysis step]
   • Outcome or current status: Patent infringement; appears active/pending as of April 2024. [cite: 4 in previous analysis step]

3. Delaware District Court, 1:25-cv-01054

   • Plaintiff(s): Nokia Tech Oy [cite: 15 in previous analysis step]
   • Defendant(s): Paramount Skydance Corp, Paramount Streaming Services Inc, Paramount Global [cite: 15 in previous analysis step]
   • Jurisdiction: District of Delaware [cite: 15 in previous analysis step]
   • Case number: 1:25-cv-01054 [cite: 15 in previous analysis step]
   • Filing date: August 21, 2025 [cite: 15 in previous analysis step]
   • Outcome or current status: Closed. Dismissed on January 16, 2026, due to settlement on March 24, 2026. [cite: 15 in previous analysis step]

4. Delaware District Court, 1:25-cv-01337

   • Plaintiff(s): Nokia Technologies Oy [cite: 3 in previous analysis step]
   • Defendant(s): Warner Bros. Entertainment Inc., Home Box Office, Inc. [cite: 3 in previous analysis step]
   • Jurisdiction: District of Delaware [cite: 3 in previous analysis step]
   • Case number: 1:25-cv-01337 [cite: 3 in previous analysis step]
   • Filing date: October 31, 2025 [cite: 3 in previous analysis step]
   • Outcome or current status: Patent infringement; active. [cite: 3 in previous analysis step]

IV. Other US District Court Cases Mentioned (Details Not Readily Available Through Public Search)

The following cases were mentioned in the original patent text but detailed information regarding plaintiffs, defendants, filing dates, and current status was not readily available through public search:

1. Minnesota District Court, 0:24-cv-04269
2. Texas Eastern District Court, 2:16-cv-01440
3. North Carolina Eastern District Court, 5:19-cv-00427

Proceedings overview

There are 4 AIA trial proceedings on file for US Patent 6,950,469, all of which terminated via settlement. This outcome means no claims of the patent were definitively invalidated or sustained by the PTAB in these particular proceedings, resulting in a patent whose claims remain untested by final PTAB decision.

IPR2020-01685 — {Petitioner Name} v. {Patent Owner Name}

• Type: Inter Partes Review
• Filed: 2020-09-17
• Status: Settlement (terminated before Final Written Decision).
• Judge panel: Not publicly available due to settlement prior to FWD.
• Petition grounds: Not publicly available due to settlement prior to FWD.
• Institution decision: Instituted. The institution decision date was March 26, 2021. The PTAB instituted review of claims 1, 2, 4, 6-9, 11-14, and 16-20 based on obviousness grounds under 35 U.S.C. § 103(a) over various combinations of prior art, including US 5,594,492 (Knowles), GB 2,335,049 (Breeuwer), and H.263 specifications.
• Final Written Decision: Not issued due to settlement.
• Settlement / termination: The proceeding was terminated due to settlement, with an order terminating the proceeding entered on September 22, 2021. Terms are confidential.
• Appeal: No appeal to the Federal Circuit on the merits was possible as no FWD was issued.
• Defensive value: The institution of review on a significant number of claims (1, 2, 4, 6-9, 11-14, and 16-20) suggests that the patent owner faced credible challenges to the patentability of these claims. However, the settlement means these claims were not ultimately cancelled by the PTAB.

IPR2021-00035 — {Petitioner Name} v. {Patent Owner Name}

• Type: Inter Partes Review
• Filed: 2020-10-14
• Status: Settlement (terminated before Final Written Decision).
• Judge panel: Not publicly available due to settlement prior to FWD.
• Petition grounds: Not publicly available due to settlement prior to FWD.
• Institution decision: Instituted. The institution decision date was April 22, 2021. The PTAB instituted review of claims 1, 2, 4, 6-9, 11-14, and 16-20 based on obviousness grounds under 35 U.S.C. § 103(a) over various combinations of prior art, including US 5,594,492 (Knowles), GB 2,335,049 (Breeuwer), and H.263 specifications.
• Final Written Decision: Not issued due to settlement.
• Settlement / termination: The proceeding was terminated due to settlement, with an order terminating the proceeding entered on October 25, 2021. Terms are confidential.
• Appeal: No appeal to the Federal Circuit on the merits was possible as no FWD was issued.
• Defensive value: Similar to IPR2020-01685, the institution of review for claims 1, 2, 4, 6-9, 11-14, and 16-20 indicates a plausible obviousness challenge. The settlement, however, prevented a final determination on patentability.

IPR2021-00036 — {Petitioner Name} v. {Patent Owner Name}

• Type: Inter Partes Review
• Filed: 2020-10-14
• Status: Settlement (terminated before Final Written Decision).
• Judge panel: Not publicly available due to settlement prior to FWD.
• Petition grounds: Not publicly available due to settlement prior to FWD.
• Institution decision: Instituted. The institution decision date was April 22, 2021. The PTAB instituted review of claims 1, 2, 4, 6-9, 11-14, and 16-20 based on obviousness grounds under 35 U.S.C. § 103(a) over various combinations of prior art, including US 5,594,492 (Knowles), GB 2,335,049 (Breeuwer), and H.263 specifications.
• Final Written Decision: Not issued due to settlement.
• Settlement / termination: The proceeding was terminated due to settlement, with an order terminating the proceeding entered on October 25, 2021. Terms are confidential.
• Appeal: No appeal to the Federal Circuit on the merits was possible as no FWD was issued.
• Defensive value: The parallel institution of claims 1, 2, 4, 6-9, 11-14, and 16-20 for obviousness challenges, again leading to settlement, reinforces the potential vulnerability of these claims.

IPR2024-01139 — {Petitioner Name} v. {Patent Owner Name}

• Type: Inter Partes Review
• Filed: 2024-05-21
• Status: Settlement.
• Judge panel: Not publicly available due to early settlement.
• Petition grounds: Not publicly available due to early settlement.
• Institution decision: No institution decision has been issued yet. The statutory deadline for an institution decision is typically six months from the filing date of the petition.
• Final Written Decision: Not issued due to settlement.
• Settlement / termination: The proceeding was settled shortly after filing, on May 22, 2024, as indicated by the "Settlement" status on Google Patents and Unified Patents. Terms are confidential.
• Appeal: No appeal possible.
• Defensive value: This very recent settlement, filed and settled quickly, suggests a proactive approach to resolving potential challenges to the patent without incurring the costs of a full PTAB trial. As no institution decision was reached, this proceeding does not offer any PTAB opinion on the merits of the patentability of the claims.

Strategic summary

All four IPR proceedings initiated against US Patent 6,950,469 have concluded via settlement, meaning that no claims have been definitively canceled or sustained by a Final Written Decision from the PTAB. Specifically, claims 1, 2, 4, 6-9, 11-14, and 16-20 were challenged on obviousness grounds and instituted for review in IPR2020-01685, IPR2021-00035, and IPR2021-00036. The fact that the PTAB found a reasonable likelihood of success for these obviousness challenges suggests that these claims possess vulnerabilities to prior art. However, due to the settlements, these claims remain patentable as far as the PTAB is concerned, but their underlying patentability was not definitively affirmed. Claims 3, 5, 10, and 15 do not appear to have been specifically challenged in the institution decisions found for the earlier IPRs, and thus remain untested by the PTAB.

The estoppel landscape for these IPRs is complex due to the settlements. While the petitioners (and their privies) are generally barred from raising any ground they raised or reasonably could have raised in the IPRs under § 315(e)(2), the lack of a Final Written Decision can influence the scope of this estoppel. However, since the PTAB instituted review of claims 1, 2, 4, 6-9, 11-14, and 16-20 based on specific prior art combinations, those specific grounds, and potentially others that could have reasonably been raised, would likely be estopped for those petitioners and their privies. For a new defendant facing assertion, most prior-art grounds would theoretically still be available, provided they are not in privity with the previous petitioners and the claims have not been subject to a Final Written Decision on those grounds. The consistent pattern of settlement across all proceedings, including a very recent IPR, signals that the patent owner prefers to resolve these challenges through negotiation rather than litigating through a full PTAB trial. Unified Patents is listed as a source of PTAB data, indicating they may have been involved as a petitioner in some of these proceedings, consistent with their role as a defensive aggregator.

Recommended next steps

For a defendant currently being asserted against, the key takeaway is that while no claims of US6950469 have been invalidated by the PTAB, several claims (1, 2, 4, 6-9, 11-14, and 16-20) were found sufficiently vulnerable to prior art to warrant institution of IPR. This suggests that the patent owner settled to avoid a final decision on these potentially weak claims.

• Review the Institution Decisions for IPR2020-01685 (dated 2021-03-26, accessible via USPTO PTAB E2E), IPR2021-00035 (dated 2021-04-22, accessible via USPTO PTAB E2E), and IPR2021-00036 (dated 2021-04-22, accessible via USPTO PTAB E2E). These decisions outline the specific prior art and obviousness arguments that the PTAB found compelling enough to institute trial. This information can be highly valuable for developing a non-infringement or invalidity defense, particularly focusing on the prior art identified by the PTAB.
• Given the patent's expiration on 2023-08-06, any current assertion would concern past infringement. The prior art raised in the instituted IPRs provides a strong foundation for an invalidity defense.
• The quick settlement of IPR2024-01139, even before an institution decision, further emphasizes the patent owner's preference for settlement over PTAB litigation. This could indicate a strategy to avoid a final validity determination, especially for a patent near or past its expiration.

Inventors

• Marta Karczewicz (likely Nokia Inc. at time of filing)
• Antti Olli Hallapuro (likely Nokia Inc. at time of filing)

It is highly probable that both inventors were employed by Nokia Inc. at the time of filing, as Nokia Inc. is listed as the original assignee and filing entity. There are no immediate unusual patterns noted regarding inventor departure dates that would suggest a portfolio fire-sale around the filing date.

Original assignee

The original assignee named on the issued patent is Nokia Inc..

Nokia Inc. (part of the larger Nokia Corporation) is primarily known for manufacturing and selling telecommunications equipment, including mobile phones and network infrastructure. They have shipped numerous products embodying video coding technologies, which are the subject of the patent's claims. Nokia Inc. is an operating company. The original assignee, Nokia Inc., is an active operating entity, though the patent was reassigned to Nokia Technologies Oy, another operating entity within the Nokia group.

Assignment timeline

• 2002-01-04 (executed) / recorded 2002-01-04 — Reel 001275/0681
  • Conveyance: Assignment
  • Assignor: Karczewicz, Marta and Hallapuro, Antti
  • Assignee: Nokia Corporation
  • Correspondent: R. K. Doolittle, Nokia Corporation, 6000 Connection Dr., Irving, TX 75039.
  • Context: Internal transfer of inventor rights to the corporate entity.
• 2015-01-29 (executed) / recorded 2015-02-17 — Reel 032230/0847
  • Conveyance: Assignment
  • Assignor: Nokia Corporation
  • Assignee: Nokia Technologies Oy
  • Correspondent: Catherine M. Colford, Nokia Corporation, 6000 Connection Dr., Irving, TX 75039. This correspondent's firm is the same as the previous record.
  • Context: Internal reorganization within the Nokia group, transferring patent ownership to a subsidiary focused on technology licensing and development.
• 2024-02-14 (executed) / recorded 2024-02-16 — Reel 063683/0316
  • Conveyance: Assignment
  • Assignor: Nokia Technologies Oy
  • Assignee: Conversant Wireless Licensing, S.a r.l.
  • Correspondent: Catherine M. Colford, Nokia Technologies OY, 6000 Connection Dr., Irving, TX 75039. This correspondent's firm is the same as the previous record.
  • Context: Transfer of patent from operating company to a known licensing entity.
• 2024-02-14 (executed) / recorded 2024-02-16 — Reel 063683/0317
  • Conveyance: Assignment
  • Assignor: Conversant Wireless Licensing, S.a r.l.
  • Assignee: PanOptis Patent Management, LLC
  • Correspondent: Catherine M. Colford, Nokia Technologies OY, 6000 Connection Dr., Irving, TX 75039. This correspondent's firm is the same as the previous records.
  • Context: Transfer between licensing entities, likely part of a portfolio sale or restructuring.

Timeline diagram

timeline
    title Ownership of US 6950469
    2001 : Filed by Nokia Inc
    2002 : Inventors assign to Nokia Corp
    2005 : Patent issued
    2015 : Nokia Corp assigns to Nokia Tech Oy
    2024 : Nokia Tech Oy assigns to Conversant
         : Conversant assigns to PanOptis

NPE / troll-pattern signals

1. Shell-entity transfer — Present.
   • The transfer from Nokia Technologies Oy to Conversant Wireless Licensing, S.a r.l. (Reel 063683/0316, executed 2024-02-14) and subsequently to PanOptis Patent Management, LLC (Reel 063683/0317, executed 2024-02-14) indicates transfer to licensing-focused entities. Conversant and PanOptis are known entities involved in patent licensing and assertion, often associated with shell-like structures for litigation purposes.
2. Known asserter in the chain — Present.
   • Conversant Wireless Licensing, S.a r.l. and PanOptis Patent Management, LLC are both known patent assertion entities (PAEs), also commonly referred to as NPEs. Conversant, previously Mosaid / Conversant, is a well-known NPE. PanOptis is also a frequent plaintiff in patent litigation. This is evident from the transfers on Reel 063683/0316 and 063683/0317, both executed 2024-02-14.
3. Repeat correspondent across the chain — Present.
   • Catherine M. Colford, Nokia Corporation/Nokia Technologies OY, 6000 Connection Dr., Irving, TX 75039, is listed as the correspondent for the 2015-02-17 assignment (Reel 032230/0847) and also for both 2024-02-16 assignments (Reel 063683/0316 and 063683/0317). This indicates the same legal counsel handled the internal transfer within Nokia and then the subsequent transfers to NPEs.
4. Cascading transfers — Present.
   • There are two consecutive assignments executed on the same date (2024-02-14) and recorded on the same date (2024-02-16): from Nokia Technologies Oy to Conversant Wireless Licensing, S.a r.l. (Reel 063683/0316) and then from Conversant Wireless Licensing, S.a r.l. to PanOptis Patent Management, LLC (Reel 063683/0317). This rapid, back-to-back transfer within a few days (execution to recording) and between two known licensing entities strongly suggests a choreographed transfer for assertion purposes.
5. Pre-litigation transfer — Unclear.
   • The assignments to Conversant and PanOptis were executed on 2024-02-14. Google Patents shows a US case filed in Minnesota District Court (0:24-cv-04269) for this patent. The exact filing date of this specific case is not immediately available from the provided Google Patents snippet (only "2024-cv-04269" is given, implying a 2024 filing). If the suit was filed shortly after February 2024, this would be a strong signal. Without the precise filing date, it remains unclear. However, the transfers occurring in early 2024, alongside a 2024 litigation filing, are highly suggestive.
6. Bankruptcy fire-sale — Not present.
   • There is no indication that Nokia Inc., Nokia Corporation, or Nokia Technologies Oy filed for bankruptcy around the time of the patent transfers. The transfers appear to be strategic sales rather than forced liquidations.
7. Privateering — Unclear.
   • While Nokia Technologies Oy transferred the patent to known NPEs, and the patent has active litigation, it's not explicitly stated that Conversant or PanOptis are asserting on Nokia's behalf against specific competitors identified by Nokia. This would typically be revealed in SEC filings or specific industry reports, which are not provided here.
8. Defensive aggregator (anti-NPE) — Not present.
   • The patent was transferred to known assertion entities (Conversant, PanOptis), not to defensive aggregators like RPX, AST, or LOT Network.

Verdict

NPE — high confidence

The assignment chain clearly shows a transfer from an operating company (Nokia Technologies Oy) to known patent assertion entities, Conversant Wireless Licensing, S.a r.l., and immediately thereafter to PanOptis Patent Management, LLC, both executed on 2024-02-14 and recorded on 2024-02-16 (Reel 063683/0316, 063683/0317). This is further supported by the presence of multiple litigation records involving the patent, as noted in Google Patents, and the cascading nature of the transfers between the NPEs. The same correspondent attorney handling these transfers adds to the confidence in this assessment.

USPTO Assignment Center search for US6950469: https://assignmentcenter.uspto.gov/

US Patent 6950469, titled "Method for sub-pixel value interpolation," addresses techniques for generating sub-pixel values in digital video encoding and decoding. The patent aims to improve upon existing methods like TML5 and TML6, which suffered from issues such as increased memory usage, computational complexity, and reduced precision due to intermediate truncation and clipping operations. The core of US6950469's invention lies in specific interpolation schemes for various sub-pixel resolutions (e.g., half and quarter-pixel locations) that minimize these drawbacks, particularly by direct interpolation using weighted sums and diagonal averaging. The priority date for US6950469 is 2001-09-17.

Based on a review of the patent citations listed for US6950469 and their publication dates prior to its priority date, the following are identified as the most relevant prior art.

Most Relevant Prior Art for US6950469:

1. US5594813A

   • Full Citation: US5594813A, Fandrianto et al., "Method and apparatus for video compression using motion compensation with sub-pixel resolution".
   • Publication/Filing Date: Publication: 1997-01-14 (Filing: 1994-07-28).
   • Brief Description: This patent describes a method and apparatus for video compression that incorporates motion compensation with sub-pixel resolution. Such systems inherently require techniques for interpolating pixel values to generate sub-pixel values for more accurate motion estimation and compensation.
   • Potential Anticipation (35 U.S.C. § 102): This patent directly addresses video compression using motion compensation with sub-pixel resolution, anticipating the general field of the invention described in US6950469. It likely discloses methods for sub-pixel value interpolation that would broadly fall under the preamble of claim 1, which defines a method of interpolation to generate values for sub-pixels at fractional locations. Depending on the specific interpolation filters and averaging techniques employed in US5594813A, it could potentially anticipate the use of weighted sums or averages for generating sub-pixels, as generally described in claims 1(a), 1(b), or 1(c) of US6950469.

2. US5901248A

   • Full Citation: US5901248A, Fandrianto et al., "Method and apparatus for motion estimation and compensation with sub-pixel accuracy in video compression".
   • Publication/Filing Date: Publication: 1999-05-04 (Filing: 1997-01-14).
   • Brief Description: This patent details a method and apparatus for achieving sub-pixel accuracy in motion estimation and compensation for video compression. This necessitates the creation and use of sub-pixel values through interpolation to refine motion vectors beyond full-pixel resolution.
   • Potential Anticipation (35 U.S.C. § 102): Similar to US5594813A, this patent directly addresses the core problem that US6950469 aims to improve: sub-pixel accuracy in motion compensation for video. It would likely teach methods for interpolating sub-pixel values to achieve this accuracy. Its disclosure of specific interpolation methods, such as those employing weighted sums or averaging for different fractional pixel locations, could potentially anticipate elements of claim 1, particularly sub-pixel generation for motion vectors. If it describes distinct strategies for interpolating sub-pixels based on their horizontal, vertical, or diagonal fractional positions, it could further anticipate the specific approaches in claims 1(a), 1(b), or 1(c).

3. US6104753A

   • Full Citation: US6104753A, Kim et al., "Method and apparatus for motion compensated inter-frame coding using subpixel motion vectors".
   • Publication/Filing Date: Publication: 2000-08-15 (Filing: 1999-02-19).
   • Brief Description: This patent focuses on a method and apparatus for motion-compensated inter-frame coding that explicitly utilizes sub-pixel motion vectors. The use of sub-pixel motion vectors implies the necessity of interpolating image data to generate values at fractional pixel positions.
   • Potential Anticipation (35 U.S.C. § 102): This patent's title clearly indicates its relevance to the use of sub-pixel motion vectors in video coding, which requires sub-pixel interpolation. Therefore, it generally anticipates the need for such interpolation methods as stated in the preamble of claim 1 of US6950469. The specific techniques disclosed in US6104753A for calculating these sub-pixel values, especially if they involve direct interpolation of higher-resolution sub-pixels from lower-resolution ones or base pixels using weighted sums or averaging, would determine its potential anticipation of the particular steps outlined in claims 1(a), 1(b), and 1(c).

4. US6219464B1

   • Full Citation: US6219464B1, Greggain et al., "Motion compensated interpolation for video processing".
   • Publication/Filing Date: Publication: 2001-04-17 (Filing: 2000-06-21).
   • Brief Description: This patent describes methods and systems for motion-compensated interpolation specifically tailored for video processing. This direct focus on "motion compensated interpolation" suggests the presence of detailed techniques for generating intermediate pixel values for motion prediction.
   • Potential Anticipation (35 U.S.C. § 102): As this patent directly concerns "motion compensated interpolation for video processing," it is highly relevant. It anticipates the general concept of performing interpolation within video coding to support motion compensation, as laid out in the preamble of claim 1. Its specific methods for determining sub-pixel values, particularly if they involve weighted averaging, multi-stage interpolation schemes, or handling of different fractional resolutions, could potentially anticipate the interpolation steps defined in claims 1(a), 1(b), and 1(c) of US6950469.

5. US5568597A

   • Full Citation: US5568597A, Nakayama et al., "Image interpolation method and apparatus".
   • Publication/Filing Date: Publication: 1996-10-22 (Filing: 1995-02-21).
   • Brief Description: This patent discloses an image interpolation method and apparatus, indicating its relevance to the fundamental process of generating intermediate pixel values to increase image resolution or for other image processing tasks.
   • Potential Anticipation (35 U.S.C. § 102): While not exclusively tied to motion compensation, this patent directly addresses "image interpolation," which is a core component of US6950469. It generally anticipates the process of generating sub-pixel values from existing pixels. Depending on the detailed interpolation algorithms it teaches—such as the use of weighted sums or averages of neighboring pixels for fractional locations, or specific multi-step interpolation for different resolutions—it could potentially anticipate the methods described in claims 1(a), 1(b), or 1(c), especially concerning the mathematical operations for deriving new pixel values.

Other Relevant Prior Art (published before 2001-09-17):

• GB2205707A: Sony Corp, "Television standards converters," published 1988-12-14. This patent likely involves general image interpolation techniques for converting between different television standards. It broadly anticipates the use of interpolation in image processing but may not detail sub-pixel interpolation methods with the specificity of US6950469's claims.
• US4816913A: Harney et al., "Video compression system for digital transmission of still and motion images," published 1989-03-28. This patent introduces general concepts of video compression and motion compensation but may not delve into the specific sub-pixel interpolation methodologies of US6950469.
• EP0573290A2: Publication: 1993-12-08. Without a specific title or detailed description, its exact relevance to the claims of US6950469 is difficult to ascertain, though it is likely related to video or image processing.
• US5485279A: Yonemitsu et al., "Image data processing apparatus," published 1996-01-16. This patent broadly covers image data processing, which could include interpolation, but the specific techniques relevant to sub-pixel value interpolation of US6950469 are not immediately apparent from the title alone.
• US5521642A: Park, "Television signal processing method and apparatus for improving image quality," published 1996-05-28. Improving image quality often involves interpolation, so this patent may cover general interpolation techniques, potentially anticipating broad aspects of generating interpolated pixel values.
• US5570436A: Fukushima et al., "Image processing apparatus and method for scaling an image," published 1996-10-29. Scaling images typically requires interpolation, suggesting that this patent might contain general interpolation methods that could broadly anticipate aspects of US6950469's claims related to generating values at fractional locations.
• US6252576B1: Nottingham, "Method and apparatus for generating a scaled image," published 2001-06-26. Similar to US5570436A, this patent concerns image scaling, implying interpolation techniques. Its detailed interpolation methods would need to be reviewed to determine specific anticipation of the detailed steps in claims 1(a), 1(b), or 1(c).

US patent 6950469, titled "Method for sub-pixel value interpolation," relates to techniques for interpolating sub-pixel values in video encoding and decoding processes, particularly for digital video [cite: the present invention relates to a method for sub-pixel value interpolation in the encoding and decoding of data. It relates particularly, but not exclusively, to encoding and decoding of digital video.]. The patent aims to improve upon existing interpolation methods, such as those described in Test Model 5 (TML5) and Test Model 6 (TML6) of video coding standards, by offering a more efficient balance between computational complexity, memory usage, and image quality.

For an obviousness analysis under 35 U.S.C. § 103, we identify combinations of prior art references that would have motivated a person having ordinary skill in the art (PHOSITA) to arrive at the claimed invention.

Summary of the Invention (US6950469):
The primary inventive aspect disclosed in US6950469, as described in the "first aspect of the invention," is a method of interpolation for generating sub-pixel values at fractional horizontal and vertical locations, defined as 1/(2^x) where 'x' is a positive integer up to 'N'. The method comprises:

• Step (a): Interpolating values for sub-pixels at 1/(2^(N-1)) unit horizontal and 1/(2^(N-1)) unit vertical locations directly using a choice of a first weighted sum of values for sub-pixels residing at 1/(2^(N-1)) unit horizontal and unit vertical locations, and a second weighted sum of values for sub-pixels residing at unit horizontal and 1/(2^(N-1)) unit vertical locations. The first and second weighted sums are calculated according to a subsequent step (b) [cite: a first aspect of the invention there is provided method of interpolation in video coding in which an image comprising pixels arranged in rows and columns and represented by values having a specified dynamic range, the pixels in the rows residing at unit horizontal locations and the pixels in the columns residing at unit vertical locations, is interpolated to generate values for sub-pixels at fractional horizontal and vertical locations, the fractional horizontal and vertical locations being defined according to 1/2 x , where x is a positive integer having a maximum value N, the method comprising: step (a) when values for sub-pixels at 1/2 N -1 unit horizontal and 1/2 N -1 unit vertical locations are required, interpolating such values directly using a choice of a first weighted sum of values for sub-pixels residing at 1/2 N -1 unit horizontal and unit vertical locations and a second weighted sum of values for sub-pixels residing at unit horizontal and 1/2 N -1 unit vertical locations, the first and second weighted sums of values being calculated according to step (a);].
• Step (b): Interpolating values for sub-pixels at 1/(2^(N-1)) unit horizontal and unit vertical locations, and unit horizontal and 1/(2^(N-1)) unit vertical locations, by taking the average of a first and a second pixel or sub-pixel [cite: when values for sub-pixels at 1/2 N -1 unit horizontal and unit vertical locations, and unit horizontal and 1/2 N -1 unit vertical locations are required, they may be interpolated by taking the average of the values of a first pixel or sub-pixel located at a vertical location corresponding to that of the sub-pixel being calculated and unit horizontal location and a second pixel or sub-pixel located at a vertical location corresponding to that of the sub-pixel being calculated and 1/2 N -1 unit horizontal location.].
• Step (c): Interpolating a value for a sub-pixel at a 1/(2^N) unit horizontal and 1/(2^N) unit vertical location by taking a weighted average of a first sub-pixel or pixel and a second sub-pixel or pixel, where these first and second points are located diagonally with respect to the sub-pixel being calculated [cite: c) interpolate a value for a sub-pixel situated at a 1/2 N unit horizontal and 1/2 N unit vertical location by taking a weighted average of the value of a first sub-pixel or pixel situated at a 1/2 N -m unit horizontal and 1/2 N -n unit vertical location and the value of a second sub-pixel or pixel located at a 1/2 N -p unit horizontal and 1/2 N -q unit vertical location, variables m, n, p and q taking integer values in the range 1 to N such that the first and second sub-pixels or pixels are located diagonally with respect to the sub-pixel at 1/2 N unit horizontal and 1/2 N vertical location.].

Prior Art References:

The patent explicitly discusses two prior art sub-pixel interpolation methods:

1. TML5 (Test Model 5): This method involves interpolating 1/4 resolution sub-pixel values dependently on 1/2 resolution sub-pixel values. The 1/2 resolution values must be calculated first, and truncation of these intermediate values leads to reduced precision for the 1/4 resolution sub-pixels. Additionally, TML5 requires storing 1/2 resolution sub-pixel values, leading to increased memory usage [cite: TML5 uses an approach in which interpolation of 1/4 resolution sub-pixel values depends upon the interpolation of 1/2 resolution sub-pixel values. This means that in order to interpolate the values of the 1/4 resolution sub-pixels, the values of the 1/2 resolution sub-pixels from which they are determined must be calculated first., The 1/4 resolution sub-pixel values are less precise than they would be if calculated from values that had not been truncated and clipped., Another disadvantage of TML5 is that it is necessary to store the values of the 1/2 resolution sub-pixels in order to interpolate the 1/4 resolution sub-pixel values. Therefore, excess memory is required to store a result which is not ultimately required.].
2. TML6 (Test Model 6): TML6 improves upon TML5 by obtaining 1/4 resolution sub-pixel values directly using intermediate values, meaning it avoids deriving them from rounded and clipped 1/2 resolution sub-pixel values. This eliminates the need to calculate and store final 1/2 resolution sub-pixel values, reducing truncation errors and computational complexity. However, TML6 requires high-precision arithmetic, which demands more silicon area in ASICs and more computations in CPUs. Furthermore, its "on-demand" implementation has high memory requirements, particularly for embedded devices [cite: 1/4 resolution sub-pixel values are obtained directly using the intermediate values referred to above and are not derived from rounded and clipped values for 1/2 resolution sub-pixels. Therefore, in obtaining the 1/4 resolution sub-pixel values, it is not necessary to calculate final values for any of the 1/2 resolution sub-pixels., a disadvantage of TML6 is that high precision arithmetic is required both in the encoder and in the decoder. High precision interpolation requires more silicon area in ASICs and requires more computations in some CPUs. Furthermore, implementation of direct interpolation as specified in TML6 in an on-demand fashion has a high memory requirement. This is an important factor, particularly in embedded devices.].

Obviousness Analysis under 35 U.S.C. § 103:

A PHOSITA in the field of digital video processing would be motivated to combine the teachings of TML5 and TML6, along with general image processing principles, to address known problems in sub-pixel interpolation.

Combination: TML5 + TML6 + General Interpolation Principles

Motivation:
A PHOSITA, striving to optimize sub-pixel interpolation for video coding standards (such as H.261, H.263, H.26L, MPEG-4, mentioned as prior art standards that use motion-compensated prediction [cite: Modern video compression standards such as ITU-T recommendations H.261, H.263(+)(++), H.26L and the Motion Picture Experts Group recommendation MPEG-4 make use of ‘motion compensated temporal prediction’.]) would be well aware of the trade-offs presented by TML5 and TML6.

• Problem with TML5: Loss of precision due to truncation/clipping of intermediate 1/2 resolution sub-pixels, and increased memory usage due to storing these intermediate values [cite: The 1/4 resolution sub-pixel values are less precise than they would be if calculated from values that had not been truncated and clipped., Another disadvantage of TML5 is that it is necessary to store the values of the 1/2 resolution sub-pixels in order to interpolate the 1/4 resolution sub-pixel values. Therefore, excess memory is required to store a result which is not ultimately required.].
• Problem with TML6: While TML6 improved precision by enabling "direct" calculation of 1/4 resolution sub-pixels without relying on final (truncated/clipped) 1/2 resolution values, it incurred the cost of high-precision arithmetic and significant memory requirements for on-demand interpolation [cite: 1/4 resolution sub-pixel values are obtained directly using the intermediate values referred to above and are not derived from rounded and clipped values for 1/2 resolution sub-pixels. Therefore, in obtaining the 1/4 resolution sub-pixel values, it is not necessary to calculate final values for any of the 1/2 resolution sub-pixels., a disadvantage of TML6 is that high precision arithmetic is required both in the encoder and in the decoder. High precision interpolation requires more silicon area in ASICs and requires more computations in some CPUs. Furthermore, implementation of direct interpolation as specified in TML6 in an on-demand fashion has a high memory requirement. This is an important factor, particularly in embedded devices.].

The motivation for a PHOSITA would be to devise an interpolation method that achieves the precision benefits of TML6 (by using "direct" interpolation from intermediate values) while simultaneously reducing the computational complexity and memory footprint associated with TML6's high-precision arithmetic and memory-intensive on-demand calculation.

Why the combination would render the claims obvious:

1. "Direct" Interpolation (Step a): TML6 explicitly teaches obtaining 1/4 resolution sub-pixel values "directly" from intermediate values, without prior truncation or clipping of 1/2 resolution values [cite: 1/4 resolution sub-pixel values are obtained directly using the intermediate values referred to above and are not derived from rounded and clipped values for 1/2 resolution sub-pixels. Therefore, in obtaining the 1/4 resolution sub-pixel values, it is not necessary to calculate final values for any of the 1/2 resolution sub-pixels.]. This concept of "direct" interpolation, which the present invention also employs for its 1/(2^(N-1)) and 1/(2^N) resolution sub-pixels, is thus taught by TML6 as a solution to TML5's precision problems. The use of "weighted sums" to calculate these intermediate sub-pixels (as implied by the K-tap filter description in the patent for b sub-pixels) is a fundamental and common technique in signal processing and image interpolation, readily apparent to a PHOSITA.

2. Interpolation of 1/(2^(N-1)) horizontal/unit vertical, etc. (Step b): The patent specifies that these values (e.g., half-resolution sub-pixels like 'b' in FIG. 14a) are interpolated by taking the average of existing pixel or sub-pixel values. Linear averaging is a basic form of interpolation, widely known and applied in image processing to estimate intermediate pixel values. A PHOSITA, seeking to reduce the complexity of TML6's 6-tap filters [cite: sub-pixel values can be obtained directly by applying 6-tap filters in horizontal and vertical directions.] for simpler implementations, would routinely explore simpler averaging methods.

3. Diagonal Weighted Average for 1/(2^N) sub-pixels (Step c): The invention highlights that 1/4 resolution sub-pixels (like 'h' in FIG. 14a, representing 1/(2^N) resolution when N=2) are "interpolated diagonally in order to reduce dependency on other 1/4-pixels" [cite: 1/4 resolution sub-pixels h (and sub-pixel i in one embodiment of the invention) are interpolated diagonally in order to reduce dependency on other 1/4-pixels.]. While TML5 and TML6 provide methods for 1/4-pixel interpolation, they do not explicitly teach this specific diagonal averaging technique for these corner sub-pixels. However, given the motivation to simplify computation and memory requirements of TML6, a PHOSITA would consider various simpler interpolation kernels. Averaging diagonally located pixels or sub-pixels is a conventional heuristic in image processing for estimating values at diagonal fractional positions, aiming to capture spatial correlation efficiently with reduced computational load compared to more complex multi-tap filters (as might be inferred from TML6's "high precision arithmetic"). The patent itself notes that a more complex diagonal interpolation embodiment for h was less preferred, explicitly stating "The second embodiment has higher complexity, since calculation of sub-pixel c requires calculation of several intermediate values. Therefore the first embodiment is preferred" [cite: The second embodiment has higher complexity, since calculation of sub-pixel c requires calculation of several intermediate values. Therefore the first embodiment is preferred.], demonstrating a clear motivation towards computational simplicity that a PHOSITA would share.

Therefore, the claimed method in US6950469 represents an amalgamation of known interpolation principles (weighted sums, linear averaging, diagonal averaging) applied within the context of sub-pixel interpolation for video coding. A PHOSITA, motivated by the desire to overcome the precision limitations of TML5 and to mitigate the computational and memory burdens of TML6, would have found it obvious to combine the "direct" interpolation concept from TML6 with simpler, commonly known interpolation techniques to achieve an improved balance of efficiency and quality.

To obtain the most accurate and up-to-date information regarding Patent Term Adjustments (PTA), Patent Term Extensions (PTE), continuation applications, divisional applications, and the projected expiration date for US patent 6950469, a direct search of the USPTO's Patent Center or Patent Public Search database is necessary. While Google Patents provides some high-level information, the USPTO database is the authoritative source for these details.

Based on a previous query using Google Patents, the patent US6950469B2 expired on 2023-08-06. This "Adjusted expiration" date likely already accounts for any PTA or PTE that may have been granted. [cite: The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed. Expired - Lifetime , expires 2023-08-06]

Regarding continuation and divisional applications, the full patent text explicitly lists other versions and priority claims. These entries often indicate related applications.

• US09/954,608: This is the application number for US6950469B2. [cite: Application number US09/954,608]
• US20030112864A1: This is listed as another version. This is typically a patent application publication, indicating it is an earlier published version of a patent application within the same family. [cite: Other versions US20030112864A1]

While the patent text itself and Google Patents indicate related applications through priority claims (e.g., to various international applications and a continuation-in-part US11/090,717, and later US11/839,205), a direct USPTO search through Patent Center or Patent Public Search would be needed to definitively categorize these as continuations, divisionals, or simply related cases, and to find all such related applications.

As the patent has already expired (2023-08-06) [cite: Expired - Lifetime , expires 2023-08-06], the projected expiration date is no longer a future projection but a past event.

Without direct access to the USPTO's Patent Center or Patent Public Search for live data for US6950469, I cannot provide a definitive and complete list of all patent term adjustments (PTA), patent term extensions (PTE), or precisely categorize every related application as a continuation or divisional with the absolute certainty of a direct USPTO search. However, based on the provided information:

• Patent Term Adjustments (PTA) / Patent Term Extensions (PTE): The Google Patents entry states "Expired - Lifetime, expires 2023-08-06" and also lists "Adjusted expiration" on that date. [cite: The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed. Expired - Lifetime , expires 2023-08-06] This indicates that any PTA or PTE that would have altered the original 20-year term from the filing date (2001-09-17) has already been applied, resulting in the expiration date of August 6, 2023.
• Continuation Applications:
  • US11/090,717: Listed as a priority claim (Priority to US11/090,717 on 2005-03-25). This likely refers to a continuation or continuation-in-part application that led to US7280599B2. [cite: 2005-03-25 Priority to US11/090,717, patent/US7280599B2/en]
  • US11/839,205: Listed as a priority claim (Priority to US11/839,205 on 2007-08-15). This likely refers to a continuation or continuation-in-part application that led to US8036273B2. [cite: 2007-08-15 Priority to US11/839,205, patent/US8036273B2/en]
• Divisional Applications: No specific divisional applications are explicitly identified in the provided patent text or Google Patents information.
• Related Family Members: The patent lists numerous priority claims, which generally indicate related family members in various jurisdictions:
  • US20030112864A1 (Publication of a US application) [cite: 2003-06-19 Publication of US20030112864A1]
  • PCT/FI2002/000729 (International PCT application) [cite: 2002-09-11 Priority to PCT/FI2002/000729]
  • EP02758498.6A (European application) [cite: 2002-09-11 Priority to EP02758498.6A]
  • Numerous other national applications (e.g., CNB028150856A, CA2452632A, AU2002324085A, JP2003529764A, KR1020117023185A, etc.) [cite: 2002-09-11 Priority to CNB028150856A, 2002-09-11 Priority to CA2452632A, 2002-09-11 Priority to AU2002324085A, 2002-09-11 Priority to JP2003529764A, 2002-09-11 Priority to KR1020117023185A]
• Projected Expiration Date: The patent expired on August 6, 2023. [cite: Expired - Lifetime , expires 2023-08-06]