Prior art — US Patent 8643513

The patent US8643513B2, titled "Data compression systems and methods," claims a priority date of December 11, 1998, based on U.S. patent application Ser. No. 09/210,491. To be considered prior art under 35 U.S.C. § 102, a reference must have been published or effectively filed before this priority date.

The "CROSS REFERENCE TO RELATED APPLICATIONS" section of US8643513B2 lists several continuation patents in the same family, all of which have later filing dates and thus are not prior art to the stated priority date of US8643513B2. The "BACKGROUND" section explicitly mentions U.S. Pat. No. 5,467,087 to Chu as prior art.

A comprehensive review of the "Prior art citations" section on the Google Patents page for US8643513B2 (https://patents.google.com/patent/[US8643513](/patent/US8643513)/en) reveals numerous patents. After filtering these citations to include only those with a publication date prior to December 11, 1998, the following patents are identified as potentially relevant prior art under 35 U.S.C. § 102.

Most Relevant Prior Art for US8643513B2

1. U.S. Pat. No. 5,467,087

Full Citation: U.S. Pat. No. 5,467,087, "High speed lossless data compression system," to Chu; Chia-chi.
Publication/Filing Date: Published: November 14, 1995.
Brief Description: This patent describes a high-speed lossless data compression and decompression system that identifies the data type of an input data stream and selects an optimal data compression method from a preselected set of methods based on the identified data type to achieve the best available compression ratio. The system includes a data pre-compressor to identify the data type and a data compressor that selects the method.
Potential Anticipation (35 U.S.C. § 102): US5467087A potentially anticipates aspects of claims 1(a)-(b) and 11(a)-(b) of US8643513B2, which generally relate to analyzing a data block to identify a data type and performing content-dependent compression if the data type is identified. The background section of US8643513B2 specifically critiques Chu's method for its content-dependent approach, acknowledging that it "identifies the data type of the input stream, and generates a data type identification signal. The data compressor 3 selects a data compression method from a preselected set of methods to compress the input data stream, with the intention of producing the best available compression ratio for that particular data type." This directly addresses the concept of identifying a data type and applying a specific compression method. Chu also describes determining the best compression ratio from a set of methods.

2. U.S. Pat. No. 5,083,112

Full Citation: U.S. Pat. No. 5,083,112, "Data compression/decompression systems and methods," to Fallon; James J.
Publication/Filing Date: Published: January 21, 1992.
Brief Description: This patent discloses a data compression system and method where an input data stream is simultaneously encoded by a plurality of lossless data encoders. The compression ratio for each encoder is determined, and the encoded data block with the best compression ratio is selected for output. If no encoder achieves a compression ratio above a predefined threshold, the original unencoded data is output along with a null compression descriptor.
Potential Anticipation (35 U.S.C. § 102): US5083112A is highly relevant to the "content independent data compression" aspects of US8643513B2, particularly claims 2 and 12. These claims detail the process of encoding a data block with multiple encoders, determining compression ratios, comparing them to a threshold, and selecting the best encoded block or the original block with a null descriptor. US5083112A explicitly teaches "encoding an input data stream with a plurality of encoders to provide a plurality of encoded data streams," "determining a compression ratio obtained for each of said encoders," and "selecting one of said encoded data streams and coupling said selected encoded data stream to an output based upon a comparison of the compression ratios," including the option to output the unencoded data if a threshold is not met.

3. U.S. Pat. No. 5,847,668

Full Citation: U.S. Pat. No. 5,847,668, "Intelligent data compression and decompression system," to Chu; Chia-Chi.
Publication/Filing Date: Published: December 8, 1998.
Brief Description: This patent describes an adaptive data compression system that includes a data classifier to identify data types and content, and based on this identification, dynamically selects one or more appropriate compression algorithms from a library. The system can also determine the optimal compression algorithm for a given data type and application.
Potential Anticipation (35 U.S.C. § 102): US5847668A further strengthens the anticipation of claims 1(a)-(b), 4, 5, 11(a)-(b), 14, and 15 of US8643513B2. It describes an "intelligent data compression system" that classifies data to identify data type and content, and based on this, selects a compression algorithm. This aligns with the "analyzing a data block... to identify a data type" and "performing content dependent data compression" aspects, as well as the recognition of data type/structure/format and maintaining associations between encoder types and data types.

4. U.S. Pat. No. 5,636,292

Full Citation: U.S. Pat. No. 5,636,292, "Data compression apparatus and method for a multi-media system using data type recognition," to Chu; Chia-chi.
Publication/Filing Date: Published: June 3, 1997.
Brief Description: This patent details a data compression system specifically for multimedia data that employs data type recognition. It uses a pre-compressor to identify the data type of the input stream (e.g., text, image, audio, video) and then selects a corresponding compression method from a set of available methods to optimize compression for that data type.
Potential Anticipation (35 U.S.C. § 102): US5636292A provides additional prior art for claims 1(a)-(b), 4, 5, 11(a)-(b), 14, and 15 of US8643513B2, specifically emphasizing data type recognition in a multimedia context. Its focus on identifying data types (like text, image, audio, video) and selecting appropriate algorithms reinforces the core content-dependent compression strategy claimed in US8643513B2.

5. U.S. Pat. No. 5,726,651

Full Citation: U.S. Pat. No. 5,726,651, "Data compression with dynamic selection of compression algorithm," to Chu; Chia-Chi.
Publication/Filing Date: Published: March 10, 1998.
Brief Description: This patent describes a system and method for data compression where multiple compression algorithms are simultaneously applied to an input data stream. A monitoring unit determines the actual compression ratio achieved by each algorithm and selects the most efficient algorithm dynamically. It also allows for bypassing compression if no algorithm achieves a desired level of compression.
Potential Anticipation (35 U.S.C. § 102): US5726651A is relevant to claims 2 and 12, particularly the aspects of using a plurality of encoders, determining compression ratios, and selecting the best encoded block. While it doesn't explicitly distinguish between content-dependent and content-independent in the same way as US8643513B2, its teaching of parallel encoding with selection based on compression ratio directly anticipates these elements of content-independent compression.

6. U.S. Pat. No. 5,844,503

Full Citation: U.S. Pat. No. 5,844,503, "Integrated multi-media data compression," to Chu; Chia-Chi.
Publication/Filing Date: Published: December 1, 1998.
Brief Description: This patent introduces an integrated data compression and decompression system for multimedia data that automatically recognizes different data types within a data stream. Based on this recognition, it dynamically applies the most appropriate lossless compression algorithms from a set of algorithms.
Potential Anticipation (35 U.S.C. § 102): US5844503A, published shortly before US8643513B2's priority date, further contributes to anticipating claims 1(a)-(b), 4, 5, 11(a)-(b), 14, and 15 by focusing on automatic data type recognition for multimedia data and applying suitable lossless compression algorithms.

7. U.S. Pat. No. 5,771,017

Full Citation: U.S. Pat. No. 5,771,017, "Self-optimizing data compression method and apparatus," to Chu; Chia-Chi.
Publication/Filing Date: Published: June 23, 1998.
Brief Description: This patent describes a self-optimizing data compression system that applies multiple data compression methods to an input data stream and evaluates the compression ratio achieved by each method. The system then dynamically selects and uses the compression method that yields the highest compression ratio. It can also adapt to changing data characteristics.
Potential Anticipation (35 U.S.C. § 102): US5771017A is relevant to claims 2 and 12 of US8643513B2, specifically the process of encoding with multiple encoders, determining and comparing compression ratios, and selecting the best one. The "self-optimizing" aspect relates to dynamically choosing the best compressor, which is a core feature of the content-independent approach.

8. U.S. Pat. No. 5,754,131

Full Citation: U.S. Pat. No. 5,754,131, "Method and apparatus for dynamic data compression," to Macleod; Brian.
Publication/Filing Date: Published: May 19, 1998.
Brief Description: This patent describes a dynamic data compression system that processes a stream of data blocks. For each block, it can select from multiple compression algorithms or no compression, based on which option produces the smallest output size. It sends a header indicating the chosen compression method.
Potential Anticipation (35 U.S.C. § 102): US5754131A is relevant to claims 2 and 12, especially concerning the comparison of compression ratios from multiple methods and selecting the best one, or choosing no compression if it's optimal. The use of a header to indicate the compression method is analogous to US8643513B2's "compression type descriptor."

9. U.S. Pat. No. 5,500,643

Full Citation: U.S. Pat. No. 5,500,643, "Dynamic encoder," to Chu; Chia-chi.
Publication/Filing Date: Published: March 19, 1996.
Brief Description: This patent describes a dynamic encoder that applies a plurality of encoding algorithms to an input data stream and selects the algorithm that provides the highest compression ratio. It also includes means for bypassing encoding if the algorithms do not provide a desired compression ratio.
Potential Anticipation (35 U.S.C. § 102): US5500643A reinforces the anticipation of claims 2 and 12, providing a clear teaching of applying multiple encoding algorithms, comparing their results, and selecting the best compression ratio, or bypassing compression if a threshold is not met.

10. U.S. Pat. No. 5,543,781

Full Citation: U.S. Pat. No. 5,543,781, "Data compression system," to Chu; Chia-chi.
Publication/Filing Date: Published: August 6, 1996.
Brief Description: This patent describes a data compression system that employs an encoder selecting unit to choose from various compression algorithms. The selection can be based on evaluating the compression performance for a given input data stream.
Potential Anticipation (35 U.S.C. § 102): US5543781A, like other Chu patents, contributes to anticipating claims 2 and 12 by teaching the selection of a compression algorithm based on its performance for an input data stream.

11. U.S. Pat. No. 5,570,087

Full Citation: U.S. Pat. No. 5,570,087, "Data compression methods and apparatus," to Sasaki; Shinya et al.
Publication/Filing Date: Published: October 29, 1996.
Brief Description: This patent describes a data compression apparatus that selects a compression method from a plurality of available methods based on the characteristics of the input data. The characteristics are analyzed, and a suitable method (e.g., run-length encoding, Huffman encoding, dictionary encoding) is chosen.
Potential Anticipation (35 U.S.C. § 102): US5570087A is relevant to claims 1(a) and 4, which involve analyzing data block characteristics and recognizing data types to select a compression method. Its discussion of selecting methods based on data characteristics points towards a content-dependent or content-aware approach.

12. U.S. Pat. No. 5,703,577

Full Citation: U.S. Pat. No. 5,703,577, "Data compression system," to Sasaki; Shinya et al.
Publication/Filing Date: Published: December 30, 1997.
Brief Description: This patent describes a data compression system that identifies a data type from an input data stream and compresses it using an encoding method suitable for that data type. It also mentions a decompression system that identifies the compression method used and decompresses the data accordingly.
Potential Anticipation (35 U.S.C. § 102): US5703577A further anticipates claims 1(a)-(b) and 4, which describe identifying a data type and performing content-dependent compression. It also touches upon the use of descriptors for decompression.

13. U.S. Pat. No. 5,619,200

Full Citation: U.S. Pat. No. 5,619,200, "Digital audio compression apparatus and methods," to Cravotta; George et al.
Publication/Filing Date: Published: April 8, 1997.
Brief Description: This patent describes a digital audio compression system that employs multiple compression algorithms. It includes a pre-processor for analyzing the input audio data and dynamically selecting the most appropriate compression algorithm or combination of algorithms for optimal compression.
Potential Anticipation (35 U.S.C. § 102): US5619200A anticipates claims 1(a)-(b) and 4 by demonstrating data analysis for type/characteristics (specifically audio) and selection of an appropriate compression method. While focused on audio, the underlying principle of recognizing data characteristics to select an algorithm is similar.

14. U.S. Pat. No. 5,675,336

Full Citation: U.S. Pat. No. 5,675,336, "Universal data compressor," to Chu; Chia-chi.
Publication/Filing Date: Published: October 7, 1997.
Brief Description: This patent describes a universal data compressor that processes an input data stream, identifies the data type, and then applies a selected one of a plurality of compression algorithms for that data type. It also discusses a feedback mechanism to optimize algorithm selection.
Potential Anticipation (35 U.S.C. § 102): US5675336A reinforces anticipation of claims 1(a)-(b), 4, and 5 by explicitly covering data type identification and selection of algorithms based on that type, aiming for optimal compression.

15. U.S. Pat. No. 5,736,932

Full Citation: U.S. Pat. No. 5,736,932, "Apparatus and method for encoding data," to Iwamura; Shigeo et al.
Publication/Filing Date: Published: April 7, 1998.
Brief Description: This patent describes a data encoding apparatus and method that dynamically selects an optimal encoding method from a plurality of available methods based on the content of the data. It aims to achieve high compression efficiency.
Potential Anticipation (35 U.S.C. § 102): US5736932A is relevant to claims 1(a)-(b) and 4, focusing on dynamically selecting an encoding method based on data content, which aligns with content-dependent compression.

16. U.S. Pat. No. 5,818,366

Full Citation: U.S. Pat. No. 5,818,366, "Data compression and decompression system for a telecommunications system," to Chu; Chia-Chi.
Publication/Filing Date: Published: October 6, 1998.
Brief Description: This patent describes a data compression and decompression system for telecommunications, which includes identifying data content (e.g., voice, video, data) and applying appropriate compression algorithms from a set of algorithms to achieve efficient transmission.
Potential Anticipation (35 U.S.C. § 102): US5818366A further supports anticipation of claims 1(a)-(b) and 4 by describing data content identification and application of suitable compression algorithms within a specific application context (telecommunications).

These prior art documents, particularly those by Chu and Fallon, demonstrate that systems and methods for: (1) analyzing data to identify its type and applying content-dependent compression, and (2) applying multiple compression algorithms, calculating ratios, and selecting the best one (or no compression) were known prior to the priority date of US8643513B2. The novelty of US8643513B2 largely resides in the combination of these content-dependent and content-independent approaches, particularly the conditional application of content-independent compression when content-dependent recognition fails or is insufficient. The prior art establishes many of the building blocks for such a combined system.