【正文】 中北大學(xué) 2020 屆畢業(yè)設(shè)計(jì)說明書 第 1 頁 共 15 頁 英文原文 Mixed DSP /FPGA implementation of an errorresilient image transmission system based on JPEG2020 Marco Grangetto,Enrico Magli, Maurizio Martina, Fabrizio Vacca Abstract This paper describes a demonstrator of an errorresilient image munication system over wireless packet works, based on the novel JPEG2020 standard. In particular, the decoder implementation is addressed, which is the most critical task in terms of plexity and power consumption, in view of use on a wireless portable terminal for cellular applications. The system implementation is based on a mixed DSP/FPGA architecture, which allows to parallelize some putational tasks, thus leading to efficient system operation. 1 Introduction Nowadays, there is a growing interest in the endtoend transmission of images, especially motivated by the shortterm deployment of next generation mobile munication services (UMTSIMT2020). However, transmission in a worked, tetherless environment provides both opportunities and challenges. The wireless context implies that the data may undergo bit errors and packet losses, making it necessary to foresee error recovery modalities. It is thereby necessary that image munication techniques are provided with the ability to recover, or at least conceal, the effect of such losses. The forthing JPEG2020 image pression standard has been designed to match these requirements, and embeds some error detection and concealment tools. This paper addresses the development of a demonstrator of an errorresilient JPEG2020 decoder implementation for image munication over a lossy packet work. The robustness to packet erasures is achieved by bining the flexibility of the JPEG2020 framework with the powerfulness of sourcechannel adaptive, optimized ReedSolomon codes. The decoder implementation is particularly significant in the context of wireless 中北大學(xué) 2020 屆畢業(yè)設(shè)計(jì)說明書 第 2 頁 共 15 頁 portable terminals for nextgeneration cellular systems, where the limited power budget and available dimensions impose severe constraints on the design of a multimedia processing system. 2 System overview In the following we provide a brief description of the functional units of the implemented system. JPEG2020 image pression JPEG2020 is the novel ISO standard for still image coding, and is intended to provide innovative solutions according to the new trends in multimedia technologies. At the time of this writing, the standard is in advanced publication stage。 the Final Committee Draft is the most recent JPEG2020 description publicly available, which our implementation conforms to. JPEG2020 not only yields superior performance with respect to existing standards in terms of pression capability and subjective quality, but also numerous additional functionalities, such as loss less and lossy pression, progressive transmission, and error resilience. The architecture of the JPEG2020 is based on the transform coding approach. An image may be divided into several subimages (tiles), to reduce memory and puting requirements. A biorthogonal discrete wavelet transform (DWT) is first applied to each tile, whose output is a series of versions of the tile at different resolution levels (subbands)。 then, the transform coefficients are quantized, independently for each subband, with an embedded deadzone quantizer. Each subband of the wavelet deposition is divided into rectangular blocks (codeblocks), which are in dependently encoded with EBCOT (Embedded Block Coding with Optimized Truncation) 。 this latter is based on a bitplane approach (. the most significant bits of the subband coefficients are transmitted first), context modeling and arithmetic coding. The bit stream output by EBCOT is organized by the rate allocator into a sequence of layers, each layer containing contributions from each codeblock。 the truncation points associated with each layer are optimized in the rate distortion sense. The final JPEG2020 bit stream consists of a main header, followed by one or more sections corresponding to individual tiles. Each tile prises a tile header and a layered 中北大學(xué) 2020 屆畢業(yè)設(shè)計(jì)說明書 第 3 頁 共 15 頁 representation of the included codeblocks, organized into packets. In order to form a progressive bitstream, . one that can be only partially decoded with minimal penalty, the layers are formed and ordered in such a way that the most important information is placed at the beginning of the bitstream. The JPEG2020 decoder performs exactly the same steps (except for rate allocation), in reverse order: syntax pars