The paper presents a new architecture composed of bit plane-parallel coder for Embedded Block Coding with Optimized Truncation (EBCOT) entropy encoder used in JPEG2000. In the architecture, the coding information of e...The paper presents a new architecture composed of bit plane-parallel coder for Embedded Block Coding with Optimized Truncation (EBCOT) entropy encoder used in JPEG2000. In the architecture, the coding information of each bit plane can be obtained simultaneously and processed parallel. Compared with other architectures, it has advantages of high parallelism, and no waste clock cycles for a single point. The experimental results show that it reduces the processing time about 86% than that of bit plane sequential scheme. A Field Programmable Gate Array (FPGA) prototype chip is designed and simulation results show that it can process 512×512 gray-scaled images with more than 30 frames per second at 52MHz.展开更多
Broadband satellite networks are capable of providing global coverage and support various services. The networks constructed by Low Earth Orbit （LEO） satellite constellations have attracted great interests because o...Broadband satellite networks are capable of providing global coverage and support various services. The networks constructed by Low Earth Orbit （LEO） satellite constellations have attracted great interests because of their short round-trip delays and wide bandwidths. A challenging problem is to develop a simple and efficient packet routing algorithm for the LEO satellite constellation network. This paper presents a SpiderWeb Topological Network （SWTN） and a distributed packet routing algorithm for the LEO satellite constellation network based on the SWTN. The algorithm gives the minimum propagation delay paths with low computational complexity and requires no routing tables, which is practical for on-board processing. The performance of the algorithm is demon- strated through simulations.展开更多
This paper proposes a method of error detection based on macroblock （MB） types for video transmission. For decoded inter MBs, the absolute values of received residues are accumulated. At the same time, the intra tex...This paper proposes a method of error detection based on macroblock （MB） types for video transmission. For decoded inter MBs, the absolute values of received residues are accumulated. At the same time, the intra textural complexity of the current MB is estimated by that of the motion compensated reference block. We compare the inter residue with the intra textural complexity. If the inter residue is larger than the intra textural complexity by a predefined threshold, the MB is considered to be erroneous and errors are concealed. For decoded intra MBs, the connective smoothness of the current MB with neighboring MBs is tested to find erroneous MBs. Simulation results show that the new method can remove those seriously-corrupted MBs efficiently. Combined with error concealment, the new method improves the recovered quality at the decoder by about 0.5--1 dB.展开更多
In order to satisfy the need of diagnoses,based on the characteristic of medical images that a sequence of frames are formed in one body inspection,a new strategy for medical images compression is proposed.The 3-D wav...In order to satisfy the need of diagnoses,based on the characteristic of medical images that a sequence of frames are formed in one body inspection,a new strategy for medical images compression is proposed.The 3-D wavelet is adopted and the planar zerotree is extended to the 3-D zerotree.By making use of the 3-D zerotree structure,a simple method for region of interest(ROI)mask generation is put forward.Medical images are compressed by three-dimensional embedded coding with the compression of regions of interest.Simulation results have shown that it can efficiently improve the compression ratio without affecting the diagnoses.展开更多
基金Supported in part by the "863" Program (No.2003 AA1ZB10)
文摘The paper presents a new architecture composed of bit plane-parallel coder for Embedded Block Coding with Optimized Truncation (EBCOT) entropy encoder used in JPEG2000. In the architecture, the coding information of each bit plane can be obtained simultaneously and processed parallel. Compared with other architectures, it has advantages of high parallelism, and no waste clock cycles for a single point. The experimental results show that it reduces the processing time about 86% than that of bit plane sequential scheme. A Field Programmable Gate Array (FPGA) prototype chip is designed and simulation results show that it can process 512×512 gray-scaled images with more than 30 frames per second at 52MHz.
基金supported by the National Natural Science Foundation of China(Grant No.60532060)the National Key Lab.of Space Microwave Technique Foundation(Grant No.514730201).
文摘Broadband satellite networks are capable of providing global coverage and support various services. The networks constructed by Low Earth Orbit （LEO） satellite constellations have attracted great interests because of their short round-trip delays and wide bandwidths. A challenging problem is to develop a simple and efficient packet routing algorithm for the LEO satellite constellation network. This paper presents a SpiderWeb Topological Network （SWTN） and a distributed packet routing algorithm for the LEO satellite constellation network based on the SWTN. The algorithm gives the minimum propagation delay paths with low computational complexity and requires no routing tables, which is practical for on-board processing. The performance of the algorithm is demon- strated through simulations.
基金the BK21 Foundation of Korea and the National Natural Science Foundation of China (Grant Nos. 60532060, 60672117 and 60607010)
文摘This paper proposes a method of error detection based on macroblock （MB） types for video transmission. For decoded inter MBs, the absolute values of received residues are accumulated. At the same time, the intra textural complexity of the current MB is estimated by that of the motion compensated reference block. We compare the inter residue with the intra textural complexity. If the inter residue is larger than the intra textural complexity by a predefined threshold, the MB is considered to be erroneous and errors are concealed. For decoded intra MBs, the connective smoothness of the current MB with neighboring MBs is tested to find erroneous MBs. Simulation results show that the new method can remove those seriously-corrupted MBs efficiently. Combined with error concealment, the new method improves the recovered quality at the decoder by about 0.5--1 dB.
基金supported by the National Natural Science Foundation of China(Grant No.60272050).
文摘In order to satisfy the need of diagnoses,based on the characteristic of medical images that a sequence of frames are formed in one body inspection,a new strategy for medical images compression is proposed.The 3-D wavelet is adopted and the planar zerotree is extended to the 3-D zerotree.By making use of the 3-D zerotree structure,a simple method for region of interest(ROI)mask generation is put forward.Medical images are compressed by three-dimensional embedded coding with the compression of regions of interest.Simulation results have shown that it can efficiently improve the compression ratio without affecting the diagnoses.
