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Akcelerator transformacji DCT do kompresji obrazu w sensorach wizyjnych

Kłosowski M., Pankiewicz B., Wójcikowski M.

Przegląd Elektrotechniczny

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2015

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R. 91, nr 9

97-100

PL

W komunikacie przedstawiono konfigurowalny cyfrowy akcelerator transformacji DCT przeznaczony dla enkodera wideo standardu H.264. Akcelerator realizuje także odwrotną transformację DCT oraz kwantyzację i dekwantyzację. Akcelerator początkowo zaimplementowano w układzie FPGA. Został on pomyślnie zweryfikowany, a następnie zaimplementowany w układzie ASIC w technologii UMC 90 nm. Szczegółowe wyniki testów akceleratora ASIC zostały porównane z innymi dostępnymi w literaturze. Funkcjonalność akceleratora została szczegółowo opisana w komunikacie. System testujący został zoptymalizowany do współpracy z programem x.264 pracującym pod kontrolą systemu Linux i jest przeznaczony do sprzętowego wspierania kompresji wideo w standardzie HD. Ze względu na niewielki pobór mocy oraz małą powierzchnię rdzenia opisany akcelerator może łatwo zostać zintegrowany z sensorem wizyjnym.

EN

In the paper a customizable digital Discrete Cosine Transform accelerator for the H.264 video compression standard has been described. The accelerator also performs the inverse DCT, quantization and dequantization. The accelerator was initially implemented in the FPGA. It has been successfully verified, then implemented in an ASIC using the 90 nm UMC technology. Detailed test results of the accelerator ASIC were compared to other results available in the literature. Functionality of the accelerator has been described in detail in the paper. The testing system has been optimized for easy integration with the x.264 encoder software running under Linux OS and is devoted to accelerate HD video compression. Due to the low power consumption and a small area of the core described accelerator can be easily integrated with the video sensor.

2

Decentralized design of interconnected H infinity feedback control systems with quantized signals

Zhai G., Chen N., Gui W.

International Journal of Applied Mathematics and Computer Science

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2013

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Vol. 23, no. 2

317--325

EN

In this paper, we consider the design of interconnected H infinity feedback control systems with quantized signals. We assume that a decentralized dynamic output feedback has been designed for an interconnected continuous-time LTI system so that the closed-loop system is stable and a desired H infinity disturbance attenuation level is achieved, and that the subsystem measurement outputs are quantized before they are passed to the local controllers. We propose a local-output-dependent strategy for updating the parameters of the quantizers, so that the overall closed-loop system is asymptotically stable and achieves the same H infinity disturbance attenuation level. Both the pre-designed controllers and the parameters of the quantizers are constructed in a decentralized manner, depending on local measurement outputs.

3

Hybrid stabilization of discrete-time LTI systems with two quantized signals

Zhai G., Matsumoto Y., Chen X., Imae J., Kobayashi T.

International Journal of Applied Mathematics and Computer Science

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2005

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Vol. 15, no 4

509-516

EN

We consider stabilizing a discrete-time LTI (linear time-invariant) system via state feedback where both the quantized state and control input signals are involved. The system under consideration is stabilizable and stabilizing state feedback has been designed without considering quantization, but the system’s stability is not guaranteed due to the quantization effect. For this reason, we propose a hybrid quantized state feedback strategy asymptotically stabilizing the system, where the values of the quantizer parameters are updated at discrete time instants. We also extend the result to the case of static output feedback.