624 research outputs found

    Video data compression using artificial neural network differential vector quantization

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    An artificial neural network vector quantizer is developed for use in data compression applications such as Digital Video. Differential Vector Quantization is used to preserve edge features, and a new adaptive algorithm, known as Frequency-Sensitive Competitive Learning, is used to develop the vector quantizer codebook. To develop real time performance, a custom Very Large Scale Integration Application Specific Integrated Circuit (VLSI ASIC) is being developed to realize the associative memory functions needed in the vector quantization algorithm. By using vector quantization, the need for Huffman coding can be eliminated, resulting in superior performance against channel bit errors than methods that use variable length codes

    VLSI architectures of a wiener filter for video coding

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    In the modern age, the use of video has become fundamental in communication and this has led to its use through an increasing number of devices. The higher resolution required for images and videos leads to more memory space and more efficient data compression, obtained by improving video coding techniques. For this reason, the Alliance for Open Media (AOMedia) developed a new open-source and royalty-free codec, named AOMedia Video 1 (AV1). This work focuses on the Wiener filter, a specific loop restoration tool of the AV1 video coding format, which features a significant amount of computational complexity. A new hardware architecture implementing the separable symmetric normalized Wiener filter is presented. Furthermore, the paper details possible optimizations starting from the basic architecture. These optimizations allow the Wiener filter to achieve a 100× reduction in processing time, compared to existing works, and 5× improvement in megasamples per second

    NASA. Lewis Research Center Advanced Modulation and Coding Project: Introduction and overview

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    The Advanced Modulation and Coding Project at LeRC is sponsored by the Office of Space Science and Applications, Communications Division, Code EC, at NASA Headquarters and conducted by the Digital Systems Technology Branch of the Space Electronics Division. Advanced Modulation and Coding is one of three focused technology development projects within the branch's overall Processing and Switching Program. The program consists of industry contracts for developing proof-of-concept (POC) and demonstration model hardware, university grants for analyzing advanced techniques, and in-house integration and testing of performance verification and systems evaluation. The Advanced Modulation and Coding Project is broken into five elements: (1) bandwidth- and power-efficient modems; (2) high-speed codecs; (3) digital modems; (4) multichannel demodulators; and (5) very high-data-rate modems. At least one contract and one grant were awarded for each element
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