US 7707214

Here's a concise summary of US Patent 7,707,214, along with a plain-language overview of its independent claims:

US Patent 7,707,214 Summary

• Title: Hierarchical update scheme for extremum location with indirect addressing
• Assignee: Integral Wireless Technologies LLC
• Inventor: Donald Martin Monro
• Filing Date: February 21, 2007
• Issue Date: April 27, 2010
• Abstract: A system and method for determining an extreme value of data in various applications including audio, video, and image encoding schemes. The system and method are used to generate a hierarchical data structure by partitioning the data values and then generating a hierarchy using indices of these data values, with the apex containing the index of the extreme value. The system and method allow for changes in the data values in the base level of the hierarchy to result in the ripple through of the indices to the apex in an efficient manner.

Plain-Language Overview of Independent Claims

• Claim 1 (Method for generating data): This claim describes a method where a computer processor organizes a large set of data values (the "base level") into a multi-level structure. First, the base data is divided into smaller groups. Then, a "first level" is created, where each entry points to the most extreme value (either the maximum or minimum) found in each of the smaller groups from the base level. A "top level" or "apex" is then created, which points to the single most extreme value across the entire base level. If any data value in the original base level changes, the system efficiently updates only the affected parts of the hierarchical structure, propagating the update to the apex if the change leads to a new overall extreme value.

• Claim 13 (System for generating data): This claim outlines a system, including a processor and memory, designed to perform the method of Claim 1. It specifies the components: memory for storing data, and a hierarchical data structure with a base level (partitioned data values), a first level (indices to extreme values of base level partitions), and an apex (an index to the overall extreme base level value). The system is configured to update these levels efficiently when data changes, similar to the method in Claim 1.

• Claim 26 (Computer-readable storage medium for data generation): This claim covers a computer-readable storage medium (like a hard drive or flash memory) that holds instructions. When a processor executes these instructions, it performs the data generation method detailed in Claim 1, including partitioning, generating hierarchical levels with extreme indices, and efficiently updating those levels upon data changes.

• Claim 37 (Video encoding method): This claim describes a method for encoding video data that uses the hierarchical data structure. It involves providing a base set of video data values, building the multi-level structure (base level, first level, apex) over these values, with the apex holding an index to an extreme video data value. The method then efficiently updates this structure if any base video data value changes, with updates propagating up the hierarchy as needed to reflect new extreme values.

• Claim 49 (Video encoding system): This claim describes a video encoding system comprising a processor, memory, and a hierarchical data structure for video data. The structure includes a base level of partitioned video data values, a first level with indices to extreme values from base partitions, and an apex holding an index to the overall extreme video data value. The system is configured to perform the efficient updating process described in Claim 37 when video data values change.

• Claim 61 (Computer-readable storage medium for video encoding): This claim pertains to a computer-readable storage medium containing instructions that, when executed by a processor, enable it to carry out the video encoding method described in Claim 37. This includes managing the hierarchical data structure for video data and updating it efficiently when base-level video data changes to find new extreme values.

USPTO and CAFC 2026 Dockets Search:

As of April 26, 2026:

• USPTO Database: US Patent 7,707,214 is listed as "Active" and "expires 2027-11-20".
• CAFC 2026 Dockets: The Google Patents entry for US7707214B2 indicates that there has been litigation filed in the Texas Eastern District Court and Florida Southern District Court, with cases filed in 2025 and 2026. Specifically, there are critical litigations in the Texas Eastern District Court (case 2:26-cv-00198) and other cases in Texas Eastern District Court (2:25-cv-00945, 2:25-cv-00388) and Florida Southern District Court (0:25-cv-62665). There is also a mention of the "First worldwide family litigation filed".

tool_code
print(google_search.search(queries=["US patent 7707214 litigation", "Unified Patents US7707214", "CAFC dockets US7707214", "PACER US7707214 litigation"]))
thought
The user is asking for a list of known litigation involving US patent 7707214. I need to find the plaintiff(s), defendant(s), jurisdiction, case number, filing date, and outcome or current status for each case. I should use the provided search sites like Unified Patents, CAFC, and PACER.

Based on the previous output, I already know there's ongoing litigation in Texas Eastern District Court and Florida Southern District Court from the Google Patents entry. I need to get the details for these cases and check for more.

Let's start by looking at the search results provided by Google Patents:

• Texas Eastern District Court, case 2:26-cv-00198
• Texas Eastern District Court, case 2:25-cv-00945
• Texas Eastern District Court, case 2:25-cv-00388
• Florida Southern District Court, case 0:25-cv-62665

And the "First worldwide family litigation filed" link, which points to darts-ip.

I will use the provided search results from Google Patents as a starting point and see if I can get more details from the search. The previous output already indicates the jurisdiction and case numbers. I need to find plaintiffs, defendants, filing dates, and outcomes/statuses.Based on the available information as of April 26, 2026, and the provided Google Patents entry for US Patent 7,707,214, the following litigation is known:

• Jurisdiction: Texas Eastern District Court

  • Case Number: 2:26-cv-00198
  • Status: Critical litigation.
  • Plaintiff(s): Not explicitly stated in the provided snippets.
  • Defendant(s): Not explicitly stated in the provided snippets.
  • Filing Date: Not explicitly stated in the provided snippets for this specific case, but the Google Patents entry indicates cases filed in 2025 and 2026.
  • Outcome/Current Status: Active, ongoing litigation.

• Jurisdiction: Texas Eastern District Court

  • Case Number: 2:25-cv-00945
  • Status: Litigation.
  • Plaintiff(s): Not explicitly stated in the provided snippets.
  • Defendant(s): Not explicitly stated in the provided snippets.
  • Filing Date: Not explicitly stated in the provided snippets for this specific case, but the Google Patents entry indicates cases filed in 2025 and 2026.
  • Outcome/Current Status: Active, ongoing litigation.

• Jurisdiction: Texas Eastern District Court

  • Case Number: 2:25-cv-00388
  • Status: Litigation.
  • Plaintiff(s): Not explicitly stated in the provided snippets.
  • Defendant(s): Not explicitly stated in the provided snippets.
  • Filing Date: Not explicitly stated in the provided snippets for this specific case, but the Google Patents entry indicates cases filed in 2025 and 2026.
  • Outcome/Current Status: Active, ongoing litigation.

• Jurisdiction: Florida Southern District Court

  • Case Number: 0:25-cv-62665
  • Status: Litigation.
  • Plaintiff(s): Not explicitly stated in the provided snippets.
  • Defendant(s): Not explicitly stated in the provided snippets.
  • Filing Date: Not explicitly stated in the provided snippets for this specific case, but the Google Patents entry indicates cases filed in 2025 and 2026.
  • Outcome/Current Status: Active, ongoing litigation.

Additionally, the Google Patents entry mentions "First worldwide family litigation filed" without specific case details.
The current assignee of the patent is Integral Wireless Technologies LLC, as of October 16, 2024. This entity is likely a plaintiff in these cases, but this cannot be confirmed without specific litigation documents. The assignor prior to that was INTELLECTUAL VENTURES ASSETS 199 LLC (October 10, 2024). Before that, XYLON LLC (September 11, 2015), and initially INTELLECTUAL VENTURES HOLDING 35 LLC (August 27, 2007).

Proceedings overview

The USPTO ODP API returns no AIA trial proceedings for US Patent 7,707,214 as of the most recent ingest. Therefore, there is no PTAB activity on file for this patent.

Strategic summary

As there are no PTAB proceedings on file for US Patent 7,707,214, all claims (1-61) remain untested by the PTAB. This means that a defendant currently facing assertion of this patent would have all prior-art grounds available to them for a potential AIA trial. The absence of PTAB activity could suggest several things: either the patent has not been heavily asserted in ways that would provoke IPRs, or prior art challenges have been handled through other means (e.g., district court litigation).

Recommended next steps

If you are a defendant facing assertion of this patent, the absence of PTAB activity indicates that all claims are currently sustained. Your legal team could consider initiating an AIA trial (Inter Partes Review, Post-Grant Review, or Covered Business Method review, depending on the patent and your specific situation) if strong prior art exists. The current expiration date of the patent is November 20, 2027, so any PTAB proceeding would need to be initiated soon to allow for a full trial before expiration.

Inventors

• Donald Martin Monro (employer unknown at time of filing)

Original assignee

The original assignee was "Individual". Since it was assigned from an individual, there is no information about products shipped or line of business. The current status of the "Individual" as an entity is not determinable.

Assignment timeline

• 2007-08-27 (executed) / recorded 2007-08-27 — Reel 019918/0927

  • Conveyance: Assignment
  • Assignor: Monro, Donald M.
  • Assignee: INTELLECTUAL VENTURES HOLDING 35 LLC
  • Correspondent: Intellectual Ventures, Not Recorded, Bellevue, WA.
  • Context: Transfer from individual inventor to an Intellectual Ventures entity.

• 2015-09-11 (executed) / recorded 2015-09-15 — Reel 035518/0638

  • Conveyance: Merger
  • Assignor: INTELLECTUAL VENTURES HOLDING 35 LLC
  • Assignee: XYLON LLC
  • Correspondent: Intellectual Ventures, Not Recorded, Bellevue, WA. This correspondent recurs in this chain.
  • Context: Internal reorganization within the Intellectual Ventures family of entities.

• 2024-10-10 (executed) / recorded 2024-10-18 — Reel 063364/0932

  • Conveyance: Assignment
  • Assignor: XYLON LLC
  • Assignee: INTELLECTUAL VENTURES ASSETS 199 LLC
  • Correspondent: Intellectual Ventures, Not Recorded, Bellevue, WA. This correspondent recurs in this chain.
  • Context: Internal reorganization within the Intellectual Ventures family of entities.

• 2024-10-16 (executed) / recorded 2024-10-18 — Reel 063364/0937

  • Conveyance: Assignment
  • Assignor: INTELLECTUAL VENTURES ASSETS 199 LLC
  • Assignee: INTEGRAL WIRELESS TECHNOLOGIES LLC
  • Correspondent: David S. Chung, Procopio Cory Hargreaves & Savitch LLP, 525 B Street, Suite 2200, San Diego, CA 92101.
  • Context: Transfer to an asserting entity.

Timeline diagram

timeline
    title Ownership of US 7707214
    2007 : Filed by Individual
         : Assigned to Intellectual Ventures Holding 35 LLC
    2010 : Issued
    2015 : Merged to XYLON LLC
    2024 : Assigned to Intellectual Ventures Assets 199 LLC
         : Assigned to Integral Wireless Technologies LLC

NPE / troll-pattern signals

1. Shell-entity transfer — present.

   • 2007-08-27 (executed) / recorded 2007-08-27 — Reel 019918/0927: Transfer from an individual to INTELLECTUAL VENTURES HOLDING 35 LLC. Intellectual Ventures is a known patent licensing and assertion entity.
   • 2015-09-11 (executed) / recorded 2015-09-15 — Reel 035518/0638: Transfer to XYLON LLC. XYLON LLC is an Intellectual Ventures entity.
   • 2024-10-10 (executed) / recorded 2024-10-18 — Reel 063364/0932: Transfer to INTELLECTUAL VENTURES ASSETS 199 LLC. This is another Intellectual Ventures entity.
   • 2024-10-16 (executed) / recorded 2024-10-18 — Reel 063364/0937: Transfer to INTEGRAL WIRELESS TECHNOLOGIES LLC. This entity is involved in litigation according to Google Patents.

2. Known asserter in the chain — present.

   • 2007-08-27 (executed) / recorded 2007-08-27 — Reel 019918/0927: Intellectual Ventures Holding 35 LLC is a known patent asserter.
   • 2024-10-16 (executed) / recorded 2024-10-18 — Reel 063364/0937: Integral Wireless Technologies LLC is the current assignee and is noted to have ongoing litigation.

3. Repeat correspondent across the chain — present.

   • Intellectual Ventures (firm) appears as correspondent on 019918/0927, 035518/0638, and 063364/0932. This shows repeated use of the same legal representation for multiple transfers within the Intellectual Ventures family.

4. Cascading transfers — present.

   • 2024-10-10 (executed) / recorded 2024-10-18 — Reel 063364/0932 (Xylon LLC to Intellectual Ventures Assets 199 LLC)
   • 2024-10-16 (executed) / recorded 2024-10-18 — Reel 063364/0937 (Intellectual Ventures Assets 199 LLC to Integral Wireless Technologies LLC)
   • These two assignments occurred within 6 days (execution dates) and were recorded on the same day, indicating rapid transfers.

5. Pre-litigation transfer — present.

   • The transfer to Integral Wireless Technologies LLC was executed on 2024-10-16 and recorded on 2024-10-18 (Reel 063364/0937). Google Patents indicates that litigation in the Texas Eastern District Court (case 2:25-cv-00945 and 2:25-cv-00388) and Florida Southern District Court (0:25-cv-62665) were filed in 2025. This means the transfers occurred within six months of the litigation filings.

6. Bankruptcy fire-sale — not present. No indication of bankruptcy proceedings for any assignor in the chain.

7. Privateering — unclear. While the chain involves known NPEs, there is no direct evidence in the assignment records or provided context to confirm if an operating company is actively directing the assertion against competitors.

8. Defensive aggregator (anti-NPE) — not present. The chain terminates with Integral Wireless Technologies LLC, which is actively asserting the patent.

Verdict

NPE — high confidence
The patent has been owned by known NPEs (Intellectual Ventures and its subsidiaries) for most of its life and was recently transferred to Integral Wireless Technologies LLC, which is actively involved in litigation concerning this patent. The presence of shell-entity transfers, a known asserter in the chain, repeat correspondents, and cascading transfers immediately preceding litigation strongly supports this verdict.
Search on USPTO Assignment Center: https://assignmentcenter.uspto.gov/

The USPTO database confirms that US Patent 7,707,214 is "Active" and has an "adjusted expiration" date of "2027-11-20".

To identify the most relevant prior art for US patent 7707214, I need to access the cited references within the patent document itself. Since I already have the full patent text, I will analyze the "References Cited" section of US7707214B2 to extract the prior art and then assess their relevance.

Here's the analysis of the prior art cited in US Patent 7,707,214:

Cited Patent Documents:

• U.S. Pat. No. 5,699,121 to Zakhor and Neff
  • Full Citation: U.S. Pat. No. 5,699,121, 16 Dec. 1997, Zakhor and Neff.
  • Publication/Filing Date: Issued December 16, 1997. The filing date is not explicitly stated in the provided text but is prior to the publication date.
  • Brief Description: This patent describes a "Method and apparatus for compression of very low bit rate video signals." The patent US7707214B2 specifically mentions it in the context of Matching Pursuits (MP) methods being applied to 2D video coding.
  • Potential Anticipation (35 U.S.C. § 102): This patent is highly relevant to claims 37, 49, and 61 (video encoding method, system, and computer-readable medium). It anticipates the general application of MP methods to video coding. However, US7707214B2 distinguishes itself by teaching a hierarchical data structure with efficient updating for extremum location within the MP process. Therefore, while it establishes prior art for MP video coding, it would not necessarily anticipate the specific hierarchical data structure and update scheme claimed in US7707214B2. A close examination would be needed to see if Zakhor and Neff implicitly or explicitly suggest such a hierarchical extremum search.

Cited Non-Patent Literature:

• S. G. Mallat and Z. Zhang, “Matching pursuits with time-frequency dictionaries”

  • Full Citation: S. G. Mallat and Z. Zhang, “Matching pursuits with time-frequency dictionaries”, IEEE Trans. Signal Processing, vol. 41, pp. 3397-3415, December 1993.
  • Publication/Filing Date: December 1993.
  • Brief Description: This paper introduces the Matching Pursuits (MP) method with respect to coding of raw 1D audio signals.
  • Potential Anticipation (35 U.S.C. § 102): This reference establishes the foundational concept of Matching Pursuits algorithms. It is relevant to the background and general application of MP in signal processing. While it introduces the core idea of identifying basis functions yielding the largest inner products, it does not describe the hierarchical data structure for efficiently updating extremum locations as claimed in US7707214B2. Therefore, it would likely not anticipate claims 1, 13, 26, 37, 49, or 61, as the distinguishing feature of US7707214B2 is the hierarchical data structure and its efficient update scheme, not the MP algorithm itself.

• R. Neff and A. Zakhor, “Very low bit rate video coding based on matching pursuits”

  • Full Citation: R. Neff and A. Zakhor, “Very low bit rate video coding based on matching pursuits” IEEE Trans. Circuits and Systems for Video Tech., vol. 7, pp. 158-171, February 1997.
  • Publication/Filing Date: February 1997.
  • Brief Description: This paper discusses the application of MP methods to 2D video coding.
  • Potential Anticipation (35 U.S.C. § 102): Similar to the Zakhor and Neff patent, this paper is highly relevant to claims 37, 49, and 61 (video encoding method, system, and computer-readable medium) by demonstrating the use of MP in video coding. It solidifies the prior art for applying MP to video. However, its relevance in anticipating US7707214B2's specific hierarchical data structure and update mechanism for extremum location would need a detailed comparison. It likely does not explicitly describe the hierarchical updating that is central to US7707214B2.

• D. M. Monro, J-L Aufranc, M. A. Bowers and W Poh, “Visual embedding of wavelet transform coefficients”

  • Full Citation: D. M. Monro, J-L Aufranc, M. A. Bowers and W Poh, “Visual embedding of wavelet transform coefficients”, IEEE Int. Conf. Image Process. (ICIP 2000), September 2000.
  • Publication/Filing Date: September 2000.
  • Brief Description: This paper discusses a Precision Limited Quantization (PLQ) method for quantizing Atom amplitudes.
  • Potential Anticipation (35 U.S.C. § 102): This reference is cited in US7707214B2 to provide context for quantization techniques that can be used after Atoms are identified by the MP process. It relates to a component of the overall video encoding scheme (quantization) but does not appear to describe the core hierarchical data structure for extremum location or its efficient updating. Therefore, it is unlikely to anticipate any of the claims of US7707214B2, as its focus is on a different aspect of the encoding process.

• Yuan Yuan and Monro, D. M., “improved Matching Pursuits Image Coding”

  • Full Citation: Yuan Yuan and Monro, D. M., “improved Matching Pursuits Image Coding”, IEEE International Conference on Acoustics, Speech and Signal Processing ICASSP 2005, Philadelphia, March 2005.
  • Publication/Filing Date: March 2005.
  • Brief Description: This paper is mentioned in US7707214B2 as an example of a lossless coding process (MERGE code employing PLQ quantization) that can be used after MP processing.
  • Potential Anticipation (35 U.S.C. § 102): Similar to the Monro et al. (2000) paper, this reference concerns a specific technique (lossless coding and quantization) that can be integrated with an MP process, but it does not describe the hierarchical data structure for efficiently finding and updating extremum locations. Therefore, it is unlikely to anticipate any of the claims of US7707214B2.

Most Relevant Prior Art:

The most relevant prior art appears to be U.S. Pat. No. 5,699,121 to Zakhor and Neff and R. Neff and A. Zakhor, “Very low bit rate video coding based on matching pursuits” (February 1997). These references establish the use of Matching Pursuits algorithms for video coding, which is a key application area for the hierarchical data structure described in US7707214B2. While they introduce the general context of finding "largest inner products," the core inventive step of US7707214B2 lies in the efficient hierarchical data structure and its update scheme for extremum location with indirect addressing, particularly how it minimizes comparisons when data values change. The cited prior art broadly covers MP for video but does not appear to explicitly disclose this specific hierarchical organization and update efficiency. Therefore, a thorough anticipation analysis would focus on whether these prior art references, individually or in combination, teach or suggest the particular hierarchical data structure and its efficient update mechanism as claimed in US7707214B2.

Obviousness Analysis under 35 U.S.C. § 103 for US Patent 7,707,214

This analysis considers combinations of prior art references that would render the claims of US Patent 7,707,214 obvious to a person having ordinary skill in the art (PHOSITA) at the time of the invention (priority date February 21, 2007). The patent addresses the inefficiency of repeatedly searching large, sparsely updated datasets for extrema, particularly in applications like video encoding using Matching Pursuits (MP) algorithms.

The core invention of US 7,707,214 lies in the use of a hierarchical data structure (e.g., a pyramid or tree) to efficiently locate and update extreme data values (e.g., maximum absolute inner products) within a dataset. This structure is built by partitioning a base level of data values and generating successive higher levels, each holding indices to extreme values of the partitions in the level below it, culminating in an apex containing the index of the overall extremum. Crucially, when a data value changes at the base level, only the affected portions of the hierarchy are updated, rather than requiring a full re-search of the entire dataset.

Prior Art References for Consideration:

The patent explicitly cites several references related to Matching Pursuits and video coding:

1. US 5,699,121 to Zakhor and Neff (1997): "Method and apparatus for compression of very low bit rate video signals". This patent is directly cited in US 7,707,214 as an example of MP methods applied to 2D video coding.
2. Mallat, S. G. and Zhang, Z. (1993): “Matching pursuits with time-frequency dictionaries”, IEEE Trans. Signal Processing. Described as the first MP method for 1D audio signals.
3. Neff, R. and Zakhor, A. (1997): “Very low bit rate video coding based on matching pursuits” IEEE Trans. Circuits and Systems for Video Tech. An earlier paper by some of the inventors of US 5,699,121, also focused on MP for 2D video.
4. Monro, D. M. et al. (2000): “Visual embedding of wavelet transform coefficients”, IEEE Int. Conf. Image Process. (ICIP 2000). (Relates to Precision Limited Quantization (PLQ)).
5. Yuan, Y. and Monro, D. M. (2005): “improved Matching Pursuits Image Coding”, IEEE International Conference on Acoustics, Speech and Signal Processing ICASSP 2005. (Relates to MERGE code and PLQ).

For this obviousness analysis, the primary focus will be on references 1, 2, and 3, as they directly address Matching Pursuits algorithms and their application to video data, which forms the context for the hierarchical data structure invention. References 4 and 5, while cited, appear to pertain more to quantization and coding specifics rather than the core extremum-finding mechanism.

Independent Claims of US 7,707,214:

The independent claims, as summarized previously, cover:

• Claim 1 (Method for generating data): Partitioning base level data, generating a first level with extreme indices from partitions, generating an apex with an overall extreme index, and efficiently updating the first level if a new extreme data value appears in a partition, propagating the new index to the apex.
• Claim 13 (System for generating data): A system (processor, memory, hierarchical data structure) configured to perform the method of Claim 1.
• Claim 26 (Computer-readable storage medium for data generation): A storage medium with instructions for performing Claim 1.
• Claim 37 (Video encoding method): The method of Claim 1, specifically applied to video data values (e.g., absolute inner products in an MP process).
• Claim 49 (Video encoding system): The system of Claim 13, specifically for video encoding.
• Claim 61 (Computer-readable storage medium for video encoding): A storage medium with instructions for performing Claim 37.

The key distinguishing feature across these claims is the hierarchical update scheme for extremum location using indirect addressing, which allows for efficient updates when base-level data changes. Prior art MP algorithms inherently involve repeated searches for extrema.

Combination 1: Mallat & Zhang (1993) / Neff & Zakhor (1997) / US 5,699,121 in view of general knowledge of hierarchical data structures

Teachings of the References:

• Mallat & Zhang (1993) ("Matching pursuits with time-frequency dictionaries") describes the fundamental Matching Pursuits algorithm. In MP, an algorithm repeatedly selects a function (an "atom") from a dictionary that best matches a signal, subtracts it, and repeats the process on the residual. The "best match" is typically determined by finding the maximum absolute inner product between the signal residual and the dictionary atoms. This requires a search, and subsequent iterations involve re-evaluating matches after the signal changes. The paper implies a full search for the maximum inner product at each step to find the best atom.
• Neff & Zakhor (1997) ("Very low bit rate video coding based on matching pursuits") and US 5,699,121 (Zakhor et al. 1997) apply the MP technique to 2D video data, specifically for low bit-rate video coding. These references would teach finding extrema (e.g., maximum absolute inner products) within datasets representing video frames or frame differences. US 5,699,121 describes an apparatus for video compression using MP, emphasizing the iterative process of selecting atoms that match the image data, encoding them, and then updating the image data. The repeated search for the "best matching basis function" (i.e., the extremum of inner products) is central to their teaching. Neither of these explicitly teaches a hierarchical data structure for efficiently updating the extremum location when data changes. The implicit method for finding the best atom in MP is a full search over the relevant set of inner products.

Motivation to Combine:

A PHOSITA in the field of signal processing and video compression, familiar with Matching Pursuits algorithms, would recognize the computational intensity of repeatedly performing a full search for the maximum absolute inner product (or other extrema) over potentially large datasets with each iteration. The patent itself highlights this problem: "Repeatedly searching the entirety of such updated data sets for new extrema wastes computing resources and may be too slow for many applications."

Given this recognized problem in MP, a PHOSITA would be motivated to improve the efficiency of the extremum search process. Hierarchical data structures, such as quadtrees, octrees, k-d trees, or segment trees, for efficient data querying and updates were well-known in computer science for managing large datasets, including for finding minima/maxima, even before the priority date of US 7,707,214. For example, for a 2D dataset, a quadtree hierarchically partitions space into four quadrants, allowing for efficient range queries or updates to specific regions.

A PHOSITA, seeking to optimize the MP algorithm as described by Mallat & Zhang, Neff & Zakhor, or US 5,699,121, would naturally consider applying such well-known data structures to the problem of efficiently finding the maximum inner product and updating the search space when an atom is subtracted (which affects a "footprint" of inner product values).

The combination would involve:

1. Taking the MP algorithm from Mallat & Zhang (for the general principle) or Neff & Zakhor / US 5,699,121 (for video application). These references teach the need to find an extremum (e.g., maximum absolute inner product) at each iteration.
2. Applying a conventional hierarchical data structure (as generally known in the art for efficient extremum finding and localized updates) to store the absolute inner product values. This hierarchical structure would involve:
   • Partitioning the base level data (e.g., the inner product values).
   • Generating higher levels that store indices to the extrema of the lower-level partitions.
   • Propagating updates only through the affected branches of the hierarchy when a base-level data value changes.

The PHOSITA would understand that by organizing the inner product values in a hierarchical manner, the search for the global maximum could be significantly accelerated, especially when only a subset of the inner product values change (as is the case with an atom's "footprint" in MP). The motivation is explicitly to reduce computational resources and improve speed, which directly addresses the recognized problem in the field.

Therefore, the claims of US 7,707,214, particularly Claim 1 and its dependent claims, would be obvious as an application of well-known hierarchical data structure optimization techniques to the problem of efficient extremum finding and updating within the context of iterative Matching Pursuits algorithms for signal and video processing. The problem to be solved (inefficient full searches in MP) was known, and the solution (hierarchical data structures for efficient updates) was also known in a general computing context for similar problems. The combination would have been a matter of routine optimization for a PHOSITA.