Cardiovascular diseases are the origin of many causes of death worldwide. They impose on practitioners optimal diagnostic methods such as telemedicine in order to be able to quickly detect anomalies for daily care and...Cardiovascular diseases are the origin of many causes of death worldwide. They impose on practitioners optimal diagnostic methods such as telemedicine in order to be able to quickly detect anomalies for daily care and monitoring of patients. The Electrocardiogram (ECG) is an examination that can detect abnormal functioning of the heart and generates a large number of digital data which can be stored or transmitted for further analysis. For storage or transmission purposes, one of the challenges is to reduce the space occupied by ECG signal and for that, it is important to offer more and more efficient algorithms capable of achieving high compression rates, while offering a good quality of reconstruction in a relatively short time. We propose in this paper a new ECG compression scheme that is based on a subset of signal splitting and 2D processing, the wavelet transform (DWT) and SPIHT coding which has proved their worth in the field of signal processing and compression. They are exploited for decorrelation and coding of the signal. The results obtained are significant and offer many perspectives.展开更多
该文提出一种基于非负张量分解的高光谱图像压缩算法。首先将高光谱图像的每个谱段进行2维离散5／3小波变换，消除高光谱图像的空间冗余。然后将所有谱段的每级小波变换的4个小波子带看作为4个张量。对每个小波子带张量采用改进HALS（Hi...该文提出一种基于非负张量分解的高光谱图像压缩算法。首先将高光谱图像的每个谱段进行2维离散5／3小波变换，消除高光谱图像的空间冗余。然后将所有谱段的每级小波变换的4个小波子带看作为4个张量。对每个小波子带张量采用改进HALS（Hierarchical Alternating Least Squares）算法进行非负分解，来消除光谱冗余和空间残余冗余，同时保护了光谱信息。最后，将分解的因子矩阵进行熵编码。实验结果表明，该文提出的压缩算法具有良好压缩性能，在压缩比32：1-4：1范围内，平均信噪比高于40dB，与传统高光谱图像压缩算法比较，平均峰值信噪比提高了1．499dB。有效地提高了高光谱图像压缩算法的压缩性能和保护了光谱信息。展开更多
To achieve high parallel computation of discrete wavelet transform （DWT） in JPEG2000, a high-throughput two-dimensional （2D） 9/7 DWT very large scale integration （VLSI） design is proposed, in which the row proce...To achieve high parallel computation of discrete wavelet transform （DWT） in JPEG2000, a high-throughput two-dimensional （2D） 9/7 DWT very large scale integration （VLSI） design is proposed, in which the row processor is based on flipping structure. Due to the difference of the input data flow, the column processor is obtained by adding the input selector and data buffer to the row processor. Normalization steps in row and column DWT are combined to reduce the number of multipliers, and the rationality is verified. By rearranging the output of four-line row DWT with a multiplexer （MUX）, the amount of data processed by each column processor becomes half, and the four-input/four- output architecture is implemented. For an image with the size of N x N, the computing time of one-level 2D 9/7 DWT is 0.25N2 ＋ 1.5N clock cycles. The critical path delay is one multiplier delay, and only 5N internal memory is required. The results of post-route simulation on FPGA show that clock frequency reaches 136 MHz, and the throughput is 544 Msample/s, which satisfies the requirements of high-speed applications.展开更多
文摘Cardiovascular diseases are the origin of many causes of death worldwide. They impose on practitioners optimal diagnostic methods such as telemedicine in order to be able to quickly detect anomalies for daily care and monitoring of patients. The Electrocardiogram (ECG) is an examination that can detect abnormal functioning of the heart and generates a large number of digital data which can be stored or transmitted for further analysis. For storage or transmission purposes, one of the challenges is to reduce the space occupied by ECG signal and for that, it is important to offer more and more efficient algorithms capable of achieving high compression rates, while offering a good quality of reconstruction in a relatively short time. We propose in this paper a new ECG compression scheme that is based on a subset of signal splitting and 2D processing, the wavelet transform (DWT) and SPIHT coding which has proved their worth in the field of signal processing and compression. They are exploited for decorrelation and coding of the signal. The results obtained are significant and offer many perspectives.
文摘该文提出一种基于非负张量分解的高光谱图像压缩算法。首先将高光谱图像的每个谱段进行2维离散5／3小波变换，消除高光谱图像的空间冗余。然后将所有谱段的每级小波变换的4个小波子带看作为4个张量。对每个小波子带张量采用改进HALS（Hierarchical Alternating Least Squares）算法进行非负分解，来消除光谱冗余和空间残余冗余，同时保护了光谱信息。最后，将分解的因子矩阵进行熵编码。实验结果表明，该文提出的压缩算法具有良好压缩性能，在压缩比32：1-4：1范围内，平均信噪比高于40dB，与传统高光谱图像压缩算法比较，平均峰值信噪比提高了1．499dB。有效地提高了高光谱图像压缩算法的压缩性能和保护了光谱信息。
基金国家教育部新世纪人才支持计划( the New Century Excellent Talent Foundation from MOE of China under Grant No.NCET- 05- 0897)新疆维吾尔自治区高校自然科学研究计划项目( the Natural Science Research Project of Higher Education of Xinjiang+1 种基金 China under Grant No.XJEDU2004E02 No.XJEDU2006I10) 。
基金The National Science and Technology M ajor Project of the M inistry of Science and Technology of China(No.2014ZX03003007-009)
文摘To achieve high parallel computation of discrete wavelet transform （DWT） in JPEG2000, a high-throughput two-dimensional （2D） 9/7 DWT very large scale integration （VLSI） design is proposed, in which the row processor is based on flipping structure. Due to the difference of the input data flow, the column processor is obtained by adding the input selector and data buffer to the row processor. Normalization steps in row and column DWT are combined to reduce the number of multipliers, and the rationality is verified. By rearranging the output of four-line row DWT with a multiplexer （MUX）, the amount of data processed by each column processor becomes half, and the four-input/four- output architecture is implemented. For an image with the size of N x N, the computing time of one-level 2D 9/7 DWT is 0.25N2 ＋ 1.5N clock cycles. The critical path delay is one multiplier delay, and only 5N internal memory is required. The results of post-route simulation on FPGA show that clock frequency reaches 136 MHz, and the throughput is 544 Msample/s, which satisfies the requirements of high-speed applications.
