US 7769238

US Patent 7769238, titled "Picture coding method and picture decoding method," was issued to Panasonic Holdings Corp (current assignee: VIDEOLABS Inc, Panasonic Holdings Corp). The inventors are Kiyofumi Abe, Shinya Kadono, Satoshi Kondo, and Makoto Hagai. The filing date for this patent was October 26, 2007, and it was granted on August 3, 2010. The priority date is April 15, 2002.

Abstract:
The patent describes a picture coding method and a picture decoding method designed to improve coding efficiency for the number of non-zero coefficients in a block, regardless of the quality of the current picture. This is achieved by predicting the number of non-zero coefficients in a current block based on neighboring coded blocks, then selecting variable length coding (VLC) tables (including code tables and VLC tables) according to this predictive value for encoding. The decoding method mirrors this process, using the predictive value to select the appropriate VLC tables for decoding.

Plain-Language Overview of Independent Claims:

• Independent Claim 1: This claim describes a picture coding method. It involves coding an image block by block, where the image is transformed into coefficients representing spatial frequency components. The method calculates a predictive value for the number of non-zero coefficients in a current block based on the number of non-zero coefficients in previously coded neighboring blocks. It then selects variable length coding (VLC) tables based on this predictive value and uses these selected tables to perform variable length coding for the number of non-zero coefficients in the current block.

• Independent Claim 13: This claim describes a picture decoding method. It involves decoding an image block by block that was coded using the method of claim 1. The method calculates a predictive value for the number of non-zero coefficients in a current block to be decoded, based on the number of non-zero coefficients in previously decoded neighboring blocks. It then selects variable length decoding (VLD) tables based on this predictive value and uses these selected tables to perform variable length decoding to obtain the number of non-zero coefficients for the current block.

Regarding CAFC 2026 dockets for patent number 7769238, a search reveals that the patent family has been involved in litigation, including multiple US cases filed in the Texas Western District Court, Texas Eastern District Court, Delaware District Court, and International Trade Commission, as well as PTAB cases. One PTAB case, IPR2025-01329, was filed and is marked as "Settlement." Other PTAB cases (IPR2022-00628 and IPR2018-00658) were "Not Instituted - Merits." The current legal status of the patent is "Expired - Lifetime," with an adjusted expiration date of August 16, 2024. Therefore, as of April 26, 2026, the patent is expired.## US Patent 7769238: Picture Coding and Decoding with Adaptive VLC Table Selection

US Patent 7769238, titled "Picture coding method and picture decoding method," was granted on August 3, 2010, from an application filed on October 26, 2007. The inventors listed are Kiyofumi Abe, Shinya Kadono, Satoshi Kondo, and Makoto Hagai. Originally assigned to Panasonic Corp, the current assignees include VIDEOLABS Inc and Panasonic Holdings Corp. The patent's priority date is April 15, 2002.

Abstract

The patent describes a picture coding and decoding method designed to enhance coding efficiency for the number of non-zero coefficients within image blocks, irrespective of the current picture's quality. This is achieved by predicting the count of non-zero coefficients in a current block using data from already coded neighboring blocks. Subsequently, variable length coding (VLC) tables, which may include both code tables and VLC tables, are dynamically selected based on this predictive value for the encoding process. The decoding method mirrors this process, employing the predictive value to select appropriate VLC tables for accurate decoding.

Independent Claim Overview

Independent Claim 1: Picture Coding Method
This claim outlines a method for encoding images on a block-by-block basis. The core steps involve:

1. Transforming the image: Converting image data into coefficients that represent spatial frequency components.
2. Predicting non-zero coefficients: Calculating an estimated number of non-zero coefficients for a "current block" (the block being processed) by analyzing the actual number of non-zero coefficients in already coded blocks located around its periphery.
3. Selecting VLC tables: Choosing specific variable length coding tables (which can include both code tables and VLC tables) based on the predictive value determined in the previous step.
4. Variable length coding: Applying variable length coding to the actual number of non-zero coefficients in the current block, using the tables that were selected.

Independent Claim 13: Picture Decoding Method
This claim describes a corresponding method for decoding images that were encoded using a technique similar to Claim 1. The key steps include:

1. Predicting non-zero coefficients: Calculating an estimated number of non-zero coefficients for a "current block" (the block being decoded) by analyzing the actual number of non-zero coefficients in already decoded blocks located around its periphery.
2. Selecting VLD tables: Choosing specific variable length decoding tables based on the predictive value determined in the previous step.
3. Variable length decoding: Performing variable length decoding to determine the actual number of non-zero coefficients for the current block, using the tables that were selected.

Legal Status and Litigation

As of the current date (April 26, 2026), US Patent 7769238 is expired, having reached its adjusted expiration date of August 16, 2024.

Despite its expired status, the patent family has been involved in significant litigation. Records show multiple cases filed in US District Courts, specifically the Texas Western District Court, Texas Eastern District Court, and Delaware District Court. Additionally, cases were brought before the International Trade Commission. The patent also faced challenges at the Patent Trial and Appeal Board (PTAB), with IPR2025-01329 reaching a settlement. Two other PTAB cases, IPR2022-00628 and IPR2018-00658, were not instituted on the merits.