In clinical diagnoses systems , a large number of ecg data are acquired during sampling . so storage and transmission of ecg data have become the problem under settlement . therefore efficient data compression algorithm is necessary to reduce the quantity of data 临床诊断过程中,心电信号的存储与传输是一个有待解决的问题,由于采集到的原始信号的数据量巨大,为了便于对大量的心电数据进行存储、分析和传输,对于这些数据的压缩处理是十分必要的。
In the paper , chapter 1 gives a comprehensive introduction of digital image compressing including its recent status , technical standards , classification in the world . chapter 2 introduces briefly the thought and ii procedure of vector quantization , describes lgb algorithm and vector quantization based on sofm neural network . chapter 3 discusses predictable coding in lossy and lossless aspects , analyzes adaptive predictable coding based on bp neural network , introduces the evaluation of algorithm on neural network in image compression . chapter 4 discusses the applications of mathematical transformation in image compression and does experiments related , analyzes the strategies of image coding in transformed domain . in chapter 5 images are decomposed and represented by wavelet transform , then discusses the characteristics and effects of wavelet functions in image compression , analyzes the wavelet coefficients after images are decomposed ; based on the theories and analyses in the prior chapters , the paper presents an image compression scheme and gives results . the test results shows that the image compression scheme is practical and helpful to map into the local content of images to get rid off redundancy , so that , it can require satisfactory results of image compression 方案首先利用小波多分辨分析性质，对图像进行小波分解，对分解后各子图的小波系数进行了统计分析，针对各子图的小波系数特点，对不同的子图分别采用不同的压缩方法，低频子图采用基于神经网络的自适应预测编码，高频子图采用基于神经网络的矢量量化编码，从而实现对图像数据的压缩处理。本论文第一章介绍了数字图像压缩处理的国内外当前的概况以及其技术标准和分类。在第二章，介绍了数字图像的矢量量化技术的数学思想和过程，对lbg算法和基于sofm神经网络的矢量量化进行了阐述、分析。
After analyzing the characters windows system in graphic platform , at the same time describing how to use mirror driver in core mode realiz the screen sample . therefore , this paper introduce the character of usb controller chip cy7c68013 . the system is a facility image processing system , which can direct link to usb interface and get the digital signal of various images from the computer . the outer device finish the image process 并在此基础之上对阐述了如何通过内核模式下的镜像驱动实现屏幕采样,并介绍镜像驱动实现的方法以及如何使用镜像驱动来实现屏幕的高效采样,对采样得到的图像系统进行了压缩处理以适应usb的传输要求,压缩程序将采集到的一帧帧图像压缩成为mpeg4的流数据。
In the digital ultrasonic flaw detectors , backward - wave signal is sampled and changed through the highspeed a / d converter , and we ' ll get a large number of datas . because datas are not all be used to draw testing curve , they must be compacted . lt is necessary to compress so much datas , so data - compaction instrument must be designed and used . here introduces the principle of data - compaction instrument , and designs a exclusive instrument using isp which may change compression point and automatically provide 1024 consecutive addresses of outside data storage unit 在数字化超声波探伤中，回波信号经高速a d采样变换后，会得到大量的采集数据。但在探伤曲线的描绘中并不是用到所有数据，因此要对这些数据进行压缩处理，这就需要用到数据压缩器，这里介绍了一种应用在线可编程技术及器件实现对大量采样数据进行快速压缩的方法，并设计了一种新型的专用isp数据压缩器，该压缩器具有压缩点数可调，可自动提供1024个连续的外部数据存储单元的地址等特点。
The main content of this thesis includes : ( 1 ) the introduction of theory of digitalization if receiver , including the theories on signal sampling , multi - velocity signal processing , pulse compress , and so on ; ( 2 ) design of system scheme based on system requirements , including confirm the sampling rate , design the decimation filters in digital down converter , and design the matching filters ; ( 3 ) analysis and discussion about the software and hardware implement schemes of digitalization if receiver and the pulse compression system , including the introduction and choice of chips , the realization of system module in fpga , design hardware circuit ; ( 4 ) presentation on the test results about our system based on fpga 本文的主要工作包括: ( 1 )介绍线性调频信号的数字中频接收的原理,主要包括信号采样理论,多速率信号处理理论,脉冲压缩理论等。 ( 2 )结合系统指标进行系统总体方案的设计和论证,包括采样率的确定,数字下变频各级抽取滤波的设计,以及匹配滤波的设计。 ( 3 )分析讨论并给出具有实用价值的线性调频脉冲雷达中频信号数字化接收及脉冲压缩处理系统的软硬件实现方案,包括芯片的选择和简介,系统各个模块在fpga中的实现,以及硬件电路的设计。
For this kind of xml , this article discusses a feasible approach to improve the performance by a big margin without any changing of its original logical structure . we also develop a compression model on this kind of xml , and try to do some mining work taking the xml as the data object according to its large - scale information feature 本文针对一类大信息量的xml ，探讨了在不改变逻辑结构的前提下，大幅度提高其访问性能的可能方案；探讨了对这类xml实施压缩处理的方案；并根据xml持有大量信息的特点，提出了将其作为数据挖掘对象的方案。
The g . 729 speech - compressing algorithm , written in c language , produces a huge amount of program codes , which cannot be stored in the chip - memory of dsp because of its 16k storing space . therefore , g . 729 speech - compressing algorithm written in c language is faced with the problems of low processing speed , and synthesis ( or real time ) . the main goal of this paper is to accomplish g . 729 speech signal compressing algorithm programmed in c54x general assembly language , and to overcome the problems above 在利用tms320vc5402进行语音信号压缩处理时，其开发软件提供了支持c等高级语言编译器，但该dsp的片上存储空间仅有16k ，如果选用c语言编程实现g . 729语音压缩算法，程序代码量过大很难都存放在片内存储器，这样运算速度降低，很难解决实时(或同步)问题。
So , image has now become the most important data type in the filed of multimedia technology , and image process and analysis technology has now become the specialty in the field of modern signal process . because of the great amount of data and information in image , it is necessary to compress the image data in order to adapt to the practical application demand . the redundancy of statistic , structure and vision in image provides the possibility to image compress 由于图像信息丰富、数据量大，因此，为满足实际应用需要，有必要对图像数据进行压缩处理，而图像数据中存在着大量的冗余信息，包括统计冗余、结构冗余以及视觉冗余等，所以为压缩提供了可能，目前已发展成为专门的研究领域? ?图像编码。
In the second chapter , some relative basic theories in wavelet analyse is first proposed in brief , involving the cause of develop - ment of wavelet theory ( that means its good ) , the definition of continuous wavelet , discrete wavelet and dyadic wavelet and the multiresolution analysis for constructing orthogonal wavelet . then the biorthogonal wavelet and method of its application for image compression is discussed . based on the research of genetic algorithm for the constructing method of wavelet filters , the method of con - structing optimal wavelet filters for the specific image compression is put forward , so the problem about image optimal compression is solved successfully with the combination of genetic algorithm and wavelet used in image compression 在第二章首先简述与图像压缩相关的小波分析基础理论知识，涉及到小波得到发展的原因及其优点，连续小波，离散小波，二进小波具体形式定义，以及构造在正交小波的多分辨分析。然后阐述了紧支撑双正交小波及其在图像压缩具体应用方法之后，基于遗传算法对小波滤波器的构造方法进行的研究，提出了解决对任意特定图像进行压缩处理所需要的最优小波滤波器的构造问题，从而将遗传算法与小波压缩有机结合起来实现了图像的最优压缩。
This thesis mainly studies the digital pulse compression technique and analyses the pulse compression performance of lfm signal with high compression ration . it also simply describes the basic theories of sar imaging and signal processing . based on these theories and high performance digital signal processing chip adsp21160 , we successfully design and realize a frequency domain digital pulse compression system on hhpc board with four adsp21160 embedded 本文主要研究了合成孔径雷达成像技术中距离和方位频域数字脉冲压缩技术，着重分析了高压缩比下lfm信号的脉压性能，简述了合成孔径雷达成像的基本原理和信号处理，在此基础上结合高性能数字信号处理芯片adsp21160研制成功了基于hhpc板的二维频域数字脉冲压缩处理系统。
