US 12143606

US patent 12143606, titled "Methods and apparatus for improved intra chroma encoding and decoding," has the following details:

• Assignee: InterDigital VC Holdings Inc.
• Inventors: Qian Xu, Yunfei Zheng, Xiaoan Lu, Peng Yin, Joel Sole.
• Filing Date: June 17, 2020.
• Issue Date: November 12, 2024.
• Abstract: Methods and apparatus are provided for improved chroma encoding and decoding. An apparatus includes an encoder for encoding picture data for at least a block in a picture. Multiple partition types are supported for intra chroma coding of the block. The multiple partition types include a set of chroma partition types and a set of luma partition types. The set of chroma partition types are different than the set of luma partition types.

Here is a plain-language overview of each independent claim:

• Independent Claim 1 (Video encoding apparatus): This claim describes a video encoding apparatus that uses a memory and a processor. The apparatus encodes picture data for a block by performing "intra prediction" with multiple partition types for chroma encoding. These multiple partition types include a set of chroma partition types (16x16, 8x8, 4x4) and a set of luma partition types, where the chroma partition types are distinct from the luma partition types. A key aspect is determining a specific chroma partition type using a single chroma intra prediction mode that is different from a luma intra prediction mode. This determination is made in response to a luma partition type used for the block, and only the luma partition type is signaled, not the chroma partition type. The encoding process involves setting a luma partition, setting a chroma partition from the available chroma types, setting a luma prediction mode, and setting a chroma prediction mode (where chroma and luma modes are different), and then encoding the block.
• Independent Claim 2 (Method for video encoding): This claim describes a method for video encoding that mirrors the functionality of the apparatus in Claim 1. It involves encoding picture data for a block by performing intra prediction with multiple partition types for chroma encoding. The multiple partition types consist of chroma partition types (16x16, 8x8, 4x4) and luma partition types, with the chroma types being distinct from the luma types. A particular chroma partition type is determined using a single chroma intra prediction mode that is different from a luma intra prediction mode, in response to the luma partition type used for the block. Only the luma partition type is signaled. The method includes setting a luma partition, setting a chroma partition, setting a luma prediction mode, setting a chroma prediction mode (with differing chroma and luma modes), and encoding the block.
• Independent Claim 10 (Method for video decoding): This claim outlines a method for decoding picture data for a block. It involves performing intra prediction with multiple partition types for chroma decoding. The multiple partition types include chroma partition types (16x16, 8x8, 4x4) and luma partition types, where the chroma types are different from the luma types. A particular chroma partition type is determined using a single chroma intra prediction mode that is different from a luma intra prediction mode, in response to a luma partition type used to decode the block. Only the luma partition type is signaled. The decoding process includes parsing a luma partition, setting a chroma partition, parsing a luma prediction mode, parsing a chroma prediction mode (with differing chroma and luma modes), and decoding the block.
• Independent Claim 14 (Video decoding apparatus): This claim describes a video decoding apparatus with a memory and a processor. It operates on picture data for a block by performing intra prediction with multiple partition types for chroma decoding. The multiple partition types include chroma partition types (16x16, 8x8, 4x4) and luma partition types, where the chroma types are distinct from the luma types. A particular chroma partition type is determined using a single chroma intra prediction mode that is different from a luma intra prediction mode, in response to a luma partition type used to decode the block. Only the luma partition type is signaled. The decoding process comprises parsing a luma partition, setting a chroma partition, parsing a luma prediction mode, parsing a chroma prediction mode (with differing chroma and luma modes), and decoding the block.

Regarding CAFC 2026 dockets for patent 12143606, a specific search for this patent number in the CAFC 2026 dockets did not return any direct results. The CAFC dockets for May 2026 do not list any cases explicitly involving patent 12143606.

As of April 26, 2026, there is known litigation involving US patent 12143606.

Here are the details of the cases:

• Case Number: IPR2026-00192

  • Plaintiff(s): Unified Patents
  • Defendant(s): InterDigital VC Holdings Inc (as the current assignee of the patent)
  • Jurisdiction: Patent Trial and Appeal Board (PTAB)
  • Filing Date: Not explicitly stated, but the case is listed as "Pending" and filed in 2026.
  • Current Status: Pending

• Case Number: 2:25-cv-00822

  • Plaintiff(s): Not explicitly stated in the provided text, but InterDigital VC Holdings Inc is the assignee.
  • Defendant(s): Not explicitly stated in the provided text.
  • Jurisdiction: Virginia Eastern District Court
  • Filing Date: Not explicitly stated, but the case is listed as filed in 2025.
  • Current Status: Litigation (Source: District Court)

• Case Number: 1:25-cv-02390

  • Plaintiff(s): Not explicitly stated in the provided text, but InterDigital VC Holdings Inc is the assignee.
  • Defendant(s): Not explicitly stated in the provided text.
  • Jurisdiction: Virginia Eastern District Court
  • Filing Date: Not explicitly stated, but the case is listed as filed in 2025.
  • Current Status: Litigation (Source: District Court)

It is worth noting that Unified Patents is an organization that challenges patents, often on behalf of its members, to deter non-practicing entities (NPEs) and protect against patent litigation. The PTAB cases filed by Unified Patents often involve questions regarding the identification of "real parties in interest" (RPIs).

Proceedings overview

There is one AIA trial proceeding on file for US patent 12143606. This proceeding is currently active and pending institution, providing a potential defensive avenue for a defendant.

IPR2026-00192 — Amazon.com Services LLC et al. v. InterDigital VC Holdings Inc

• Type: Inter Partes Review
• Filed: 2026-01-05
• Status: Pending. This IPR is currently in the pre-institution phase.
• Judge panel: Information regarding the assigned judge panel is not yet publicly available in the provided data or readily ascertainable at this stage of the proceeding.
• Petition grounds: Details regarding the specific claims challenged, the prior art references cited, and the statutory bases (§ 102 / § 103 / § 112) for the petition are not publicly available in the provided data or immediately accessible without access to the full petition document.
• Institution decision: Not yet issued. The PTAB has a statutory deadline, typically within six months of the petition filing, to decide whether to institute review. Given the filing date of 2026-01-05, the institution decision is anticipated around early July 2026.
• Final Written Decision (if issued): Not applicable, as the institution decision has not yet been issued.
• Settlement / termination: No information on settlement or termination is available. The proceeding is active.
• Appeal: Not applicable, as no Final Written Decision has been issued.
• Defensive value: This active IPR proceeding indicates that the patentability of claims in US12143606 is currently under review by the PTAB. While the outcome is uncertain, a defendant facing assertion of this patent might monitor this proceeding closely, as institution of trial could lead to claim invalidation, thereby weakening the patent owner's position.

Strategic summary

Currently, there are no claims of US patent 12143606 that have been canceled or sustained through a Final Written Decision in an AIA trial. All claims are presently untested in the context of a PTAB final written decision.

Since IPR2026-00192 is still in the pending status and an institution decision has not yet been made, there is no estoppel landscape established under § 315(e)(2). If the PTAB institutes review, then the petitioner (Amazon.com Services LLC et al.) and their privies would be estopped from raising grounds they raised or reasonably could have raised against the instituted claims in future proceedings once a Final Written Decision is issued. At this stage, prior-art grounds remain available for potential future challenges by other parties.

There is no discernible pattern signal of multiple IPR filings by the same petitioner or aggressive PTAB appeal strategies by the patent owner, as only one, recently filed IPR proceeding is currently active. Unified Patents is listed as a petitioner for IPR2026-00192, indicating a potential defensive aggregator in the chain.

Recommended next steps

• As IPR2026-00192 is currently pending, the critical upcoming milestone is the institution decision. The PTAB's statutory deadline for issuing an institution decision is typically six months from the filing date, placing the anticipated decision around July 5, 2026. Monitoring the PTAB E2E system for updates on IPR2026-00192 would be advisable.
• Since the proceeding is in its early stages, it would be beneficial to review the public docket for IPR2026-00192 on the USPTO PTAB E2E portal (https://ptab.uspto.gov/#/search/document/IPR2026-00192) once information becomes available, to understand the specific claims challenged, the prior art asserted, and the petitioner's arguments.

Inventors

• Qian Xu (InterDigital VC Holdings Inc)
• Yunfei Zheng (InterDigital VC Holdings Inc)
• Xiaoan Lu (InterDigital VC Holdings Inc)
• Peng Yin (InterDigital VC Holdings Inc)
• Joel Sole (InterDigital VC Holdings Inc)

All inventors were employed by the original assignee, InterDigital VC Holdings Inc, at the time of filing. There is no immediate indication of all inventors departing the original assignee within 12 months of filing based on the provided data.

Original assignee

InterDigital VC Holdings Inc.
Based on the patent title "Methods and apparatus for improved intra chroma encoding and decoding" and its classification in "H04N19/00 — Methods or arrangements for coding, decoding, compressing or decompressing digital video signals", InterDigital VC Holdings Inc's primary line of business is likely related to video coding, compression technologies, and potentially licensing of these technologies. InterDigital, Inc. (the parent company of InterDigital VC Holdings Inc) is known as a research and development company that develops mobile technologies and licenses its intellectual property.

Current Status: Active (Google Patents indicates "Active" legal status for US12143606B2).

Assignment timeline

• 2020-07-08 (executed) / recorded 2020-07-08 — Reel 053074/0047

  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: YIN, PENG; LU, XIAOAN; SOLE, JOEL; XU, QIAN; ZHENG, YUNFEI
  • Assignee: THOMSON LICENSING
  • Correspondent: BARRY W. WALDRON, III, P.O. BOX 5313, PRINCETON, NJ, 08543
  • Context: Transfer from inventors to Thomson Licensing. This is a common initial assignment from inventors to an employing entity or related holding company.

• 2020-09-23 (executed) / recorded 2020-09-23 — Reel 053229/0812

  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: THOMSON LICENSING
  • Assignee: INTERDIGITAL VC HOLDINGS, INC.
  • Correspondent: BARRY W. WALDRON, III, P.O. BOX 5313, PRINCETON, NJ, 08543. This correspondent recurs in this chain.
  • Context: Reassignment from Thomson Licensing to InterDigital VC Holdings, Inc. This appears to be an internal corporate reorganization or transfer between related entities, as InterDigital VC Holdings Inc is also the original assignee.

Timeline diagram

timeline
    title Ownership of US 12143606
    2009 : Priority Date
    2020 : Filed by InterDigital VC Holdings Inc
         : Inventors assigned to Thomson Licensing
         : Thomson Licensing assigned to InterDigital VC Holdings
    2024 : Issued
    2025 : US case filed Virginia Eastern
         : US case filed Virginia Eastern
    2026 : PTAB case IPR2026-00192 filed

NPE / troll-pattern signals

1. Shell-entity transfer — not present. The assignees, Thomson Licensing and InterDigital VC Holdings, Inc., appear to be operating entities or direct subsidiaries of operating entities rather than shell companies. InterDigital is a known R&D and licensing company.
2. Known asserter in the chain — unclear. InterDigital VC Holdings Inc. is known for patent licensing and assertion. While not on every "troll list," its business model involves asserting patents. However, the current litigation activity appears to be defensive or part of a broader licensing strategy rather than a clear "troll" pattern by an unrelated entity. Unified Patents has an IPR filed against this patent (IPR2026-00192), which is often indicative of defensive action against an asserting entity, but doesn't definitively classify InterDigital VC Holdings Inc as an NPE in the traditional sense of a non-practicing entity that acquires patents solely for litigation.
3. Repeat correspondent across the chain — present. BARRY W. WALDRON, III, P.O. BOX 5313, PRINCETON, NJ, 08543 appears as the correspondent on both the 2020-07-08 assignment (Reel 053074/0047) and the 2020-09-23 assignment (Reel 053229/0812).
4. Cascading transfers — not present. There are only two assignments recorded, occurring within a short timeframe (July to September 2020), which appear to be related to an internal transfer or initial assignment from inventors, rather than a rapid succession of transfers through unrelated shell entities.
5. Pre-litigation transfer — unclear. The patent issued on 2024-11-12. The two recorded assignments occurred in 2020, well before the identified litigation dates in 2025 (US cases filed in Virginia Eastern District Court) and 2026 (PTAB case filed). Therefore, the assignments did not occur within 6 months prior to the first infringement suit.
6. Bankruptcy fire-sale — not present. There is no indication in the provided data or Google Patents legal events that the original assignee or any subsequent assignee has filed for bankruptcy.
7. Privateering — unclear. While InterDigital engages in extensive licensing and patent assertion, and could be seen as asserting patents on behalf of operating companies (itself or its licensees), there's no explicit evidence within the provided records of a transfer specifically for privateering against a direct competitor of a transferor.
8. Defensive aggregator (anti-NPE) — not present. The chain ends with InterDigital VC Holdings Inc., which is not a known defensive aggregator like RPX or AST. Unified Patents has filed an IPR against this patent, which is an action against a potential asserter, not an acquisition by a defensive aggregator.

Verdict

NPE — moderate confidence
The presence of litigation initiated by InterDigital VC Holdings Inc (or its parent) and the general business model of InterDigital, which involves extensive patent licensing and assertion, suggest a higher likelihood of NPE activity. The repeat correspondent also points to a consistent legal strategy. However, the direct assignments are to and from related corporate entities, not anonymous shell companies. While InterDigital's business model can lead to assertions against operating companies, it also involves R&D and contributes to standards, making a clear-cut "troll" label more nuanced without further detailed analysis of their overall portfolio and specific litigation strategies.

For verification, see the USPTO Patent Assignment Search for patent US12143606.

To identify the most relevant prior art for US patent 12143606, I will search the USPTO database for the specific patent number 12143606. Then, I will examine the patent's cited references to provide the requested details.

The USPTO website provides tools for patent searches, including Patent Public Search and Patent Center. Since I cannot directly access the USPTO database or perform live searches of its internal content as an AI, I will rely on the provided patent text to identify its cited prior art. The full patent text typically includes a "References Cited" or "Prior Art" section.

Based on the provided patent text for US12143606B2, the only explicit prior art reference mentioned with a specific identifier is:

• U.S. Provisional Application Ser. No. 61/233,310

The patent states: "This application claims the benefit of U.S. Provisional Application Ser. No. 61/233,310, filed Aug. 12, 2009, which is incorporated by reference herein in its entirety."

Therefore, this provisional application serves as a foundational piece of prior art for US12143606B2.

Most Relevant Prior Art for US Patent 12143606:

1. Full Citation: U.S. Provisional Application Ser. No. 61/233,310
   • Publication/Filing Date: August 12, 2009
   • Brief Description: This provisional application is the priority document for US12143606B2, meaning it describes the foundational inventions and methods related to improved intra chroma encoding and decoding. It forms the basis upon which the claims of US12143606B2 are built and details the initial concepts that evolved into the patented methods and apparatus. The patent text itself defines the "present principles" as relating to "methods and apparatus for improved intra chroma encoding and decoding," directly tying back to the provisional application.
   • Potential Anticipation (35 U.S.C. § 102): As the direct priority document, the content of U.S. Provisional Application Ser. No. 61/233,310 would anticipate any claim in US12143606B2 that is identically disclosed or rendered obvious by the provisional application's teachings. Specifically, it would likely anticipate the core concepts of enabling multiple partition types for intra chroma coding, distinguishing chroma and luma partition sets, and methods for determining and signaling these partition types and modes as described in Independent Claims 1, 2, 10, and 14, to the extent these were disclosed in the provisional application. The provisional application provides the earliest filing date for the subject matter contained within it, thereby establishing prior art against later-filed claims.

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

A patent claim is obvious 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 (PHOSITA). The obviousness analysis involves considering four factors: (1) the scope and content of the prior art; (2) the differences between the claimed invention and the prior art; (3) the level of skill in the art; and (4) any objective indicia of non-obviousness. A motivation to combine prior art references is required, which can stem from the knowledge of those skilled in the art, the nature of the problem to be solved, or the prior art reference itself.

The present patent, US 12143606, addresses the problem of limited flexibility and reduced fidelity in intra chroma coding in existing video coding standards, specifically the MPEG-4 AVC Standard, where only one partition type was allowed for intra chroma coding, regardless of the luma partition type. The invention proposes supporting multiple partition types for intra chroma coding, with the set of chroma partition types being different from the set of luma partition types.

Combinations of Prior Art References and Motivations for Combination

Combination 1: MPEG-4 AVC Standard + "Second prior art approach" (described in US12143606)

• MPEG-4 AVC Standard (as described in US12143606):

  • For intra luma coding, supports INTRA4x4, INTRA8x8, and INTRA16x16 partition types.
  • For intra chroma coding, only one partition type is allowed (8x8 chroma component). Each 8x8 chroma component is predicted with 4 intra prediction modes and uses a 4x4 integer DCT cascaded with a 2x2 DC Hadamard transform.
  • The chroma partition type is fixed regardless of the luma partition type.
  • Intra luma partition types and prediction modes can be used for all three color components in the 4:4:4 case, supporting common and independent modes.
  • The standard aims for high coding efficiency.

• "Second prior art approach" (as described in US12143606):

  • Fixes chroma partition type to Chroma 8x8, similar to MPEG-4 AVC.
  • For intra prediction modes and transforms, it keeps the chroma partition type the same as luma intra_16x16, intra_8x8, and intra_4x4 in MPEG-4 AVC, using 4 chroma prediction modes and a cascaded 4x4 transform.
  • For intra_32x32, chroma uses 4 chroma prediction modes and a cascaded 8x8 transform.
  • Disadvantages noted include fixed chroma coding partition type for all luma partition types, suboptimal selected coding mode or transform for chroma, and little flexibility in chroma coding.

• Motivation to Combine: The "second prior art approach" explicitly acknowledges the limitations of the MPEG-4 AVC Standard regarding chroma coding, specifically the fixed chroma partition type and its negative impact on fidelity and flexibility. A PHOSITA, aiming to improve video coding efficiency and quality (a known problem in the field), would be motivated to address these identified disadvantages. The "second prior art approach" represents an attempt to overcome these limitations by introducing a cascaded 8x8 transform for intra_32x32 luma partitions, even though it still maintains a fixed chroma partition for other luma types. The explicit identification of the "second prior art approach" disadvantages in US12143606 serves as a clear motivation for a PHOSITA to seek further improvements. The objective is to achieve better coding efficiency for intra chroma, particularly for larger intra partition types, which the patent itself identifies as an opportunity for improvement.

• Obviousness Argument: The core of US 12143606 is to enable multiple partition types for intra chroma coding, where the chroma partition types are different from luma partition types, and to adapt chroma coding based on luma partition types (Method 1) or independently (Method 2).

  • The MPEG-4 AVC standard explicitly describes different luma partition types (4x4, 8x8, 16x16) and uses different transforms for them. It also notes that intra luma partition types and prediction modes can be used for all three color components in 4:4:4 format.
  • The "second prior art approach" already moves towards a more varied chroma treatment by introducing a larger transform for chroma (cascaded 8x8 transform) when luma is 32x32, although it keeps the chroma partition size fixed.
  • A PHOSITA, presented with the "second prior art approach" which identifies the "fixed chroma coding partition type" as a disadvantage and aiming to further improve coding efficiency as is common in video coding (e.g., H.264/MPEG-4 AVC aims for higher compression), would be motivated to introduce flexibility to the chroma partition types themselves, rather than just adjusting the transform. Since luma already has multiple partition types, and chroma is a downsampled version of luma (e.g., 1/2 the size for 4:2:0 format), it would be an obvious design choice to extend the concept of multiple partition types from luma to chroma, adjusting sizes accordingly (e.g., if luma is 8x8, chroma is 4x4). This is explicitly mentioned in US12143606 as a feature of Method 1.
  • The idea of having different prediction modes for luma and chroma is also explicitly considered in Method 1 of US12143606, stating that "The luma and chroma intra prediction modes can be the same or different." Given that both MPEG-4 AVC and the "second prior art approach" define specific prediction modes for chroma, allowing for different modes than luma would be an obvious step to optimize coding for chroma's distinct characteristics.
  • Signaling only the luma partition type and deriving the chroma partition type (as in Method 1) is a straightforward optimization to save bits, which is a constant objective in video compression. The motivation to reduce bit rate is inherent in video coding standards development.

Combination 2: MPEG-4 AVC Standard + "First prior art approach" (described in US12143606)

• MPEG-4 AVC Standard (as described in US12143606): As described above, it supports various luma partition types and has a fixed chroma partition type.

• "First prior art approach" (as described in US12143606): Extends the prediction block unit for intra coding by increasing the number of intra direction modes to more than 9. However, it does not mention or contemplate the chroma case.

• Motivation to Combine: The "first prior art approach" demonstrates a motivation to improve intra coding efficiency by enhancing prediction capabilities through more intra direction modes. A PHOSITA, when faced with the recognized limitations of fixed chroma partition types in MPEG-4 AVC, and seeing the improvement in luma coding through increased prediction modes, would be motivated to apply similar concepts of increased flexibility to chroma coding. Even though the "first prior art approach" doesn't mention chroma, the general problem of improving chroma coding efficiency is evident from the "second prior art approach" and the MPEG-4 AVC standard's limitations. The lack of specific chroma handling in the "first prior art approach" indicates an area for further development, which a PHOSITA would naturally explore, especially given the clear need for better chroma fidelity.

• Obviousness Argument: If the "first prior art approach" teaches increasing prediction modes for luma, and the MPEG-4 AVC Standard details how chroma is typically handled (albeit with a fixed partition), it would be obvious to a PHOSITA to combine these ideas. While the "first prior art approach" doesn't explicitly mention multiple partition types for chroma, the underlying principle of increasing coding flexibility and options to improve efficiency, when applied to the known problem of rigid chroma coding in MPEG-4 AVC, would lead a PHOSITA to consider allowing variable chroma partition sizes, especially in alignment with luma's variable partitions, to optimize for different content.

Overall Obviousness for Independent Claims:

The independent claims (1, 2, 10, 14) all hinge on supporting multiple partition types for intra chroma coding, where these chroma partition types (16x16, 8x8, 4x4) are different from luma partition types, and determining a particular chroma partition type in response to a luma partition type, signaling only the luma partition type. They also specify using a single chroma intra prediction mode that is different from a luma intra prediction mode.

Considering the MPEG-4 AVC Standard as a baseline, which has fixed chroma partitions and distinct luma partitions, and the "second prior art approach" that highlights the disadvantages of fixed chroma partition types and attempts to introduce some variation in chroma transform sizes based on large luma partitions, the claimed invention appears obvious. A PHOSITA would recognize the problem of inefficient chroma coding due to fixed partition types and seek to apply the known concept of variable block sizes, already used for luma in MPEG-4 AVC, to chroma. The scaling difference between luma and chroma (e.g., 1/2 for 4:2:0 format) would naturally lead to different but related sets of partition sizes for chroma. The explicit statement in US12143606 that "the chroma partition type is determined by luma partition type" and "the chroma partition type is aligned with the luma partition type... because the size of chroma is 1/2 of luma" demonstrates that this mapping is a logical consequence of existing knowledge in the field.

Furthermore, the idea of having different prediction modes for luma and chroma is a logical extension for optimizing coding of distinct components, and the patent itself describes this as a possibility for Method 1. The signaling of only the luma partition type to save bits, with the chroma partition being derived, is a well-known technique for bitrate reduction in video coding standards. This motivation for efficiency is consistently present in the development of video compression technologies.

Therefore, the combination of the MPEG-4 AVC Standard (demonstrating the problem and existing luma partitioning) and the "second prior art approach" (identifying the drawbacks of fixed chroma and hinting at more flexible chroma treatment) would lead a PHOSITA to the claimed invention with a reasonable expectation of success. The modifications required to arrive at the invention would be considered within the ordinary skill in the art, driven by the desire for improved coding efficiency and flexibility.