基于小波变换的信号奇异性检测及去噪例程

在matlab环境下，实现ECG信号R波的检测，使用的方法是小波变换。(Matlab environment, the realization of the R wave of the ECG signal detection, the methods used wavelet transform.)

Wavelet compression algorithm. Start by computing a complete wavelet-transform using the cohen-daubechies-fevereau (2,2) biorthogonal wavelet (which incidentally seems to be the same as used for lossless JPEG2000, but they call it a (5,3)?).

一维向量的离散短时Fourier变换函数。函数名：stft，输入：要处理的一维数组，加窗：矩形窗，窗口宽度：20。(One-dimensional vector of discrete short-time Fourier transform function. Function name: stft, enter: To deal with the one-dimensional array, plus a window: rectangular windows, window width: 20.)

小波分解，得到低频系数并求特征熵，可用来对信号进行分选识别(Wavelet decomposition, low coefficient and entropy, which can be used for signal sorting and recognition)

说明：  针对不同采样频率和输入信噪比的心磁信号进行滤波操作，呈现出对同一输入信号采取不同滤波算法的去噪结果。(The filtering operation is performed on the magnetic heart signals of different sampling frequencies and input signal-to-noise ratios, showing the denoising results of different filtering algorithms for the same input signal.)

实现小波变换，小波滤波器，小波除噪等功能。(To achieve wavelet transform, wavelet filters, wavelet denoising function)

说明：  使用小波变换和神经网络的混合图像压缩，希望对大家有所帮助(Using wavelet transform and neural network hybrid image compression, I hope all of you to help)

说明：  实现k-l变换，代码短，效率高，适合初学者进行上机练习，原理简单，比较容易懂和实现。(Achieve kl transformation, the code short, high efficiency, suitable for beginners to practice on the machine, simple in principle, relatively easy to understand and achieve.)

数字基带传输基带信号，指未经调制的信号。这些信号的特征是其频谱从零频或很低频率开始，占据较宽的频带。 基带信号在传输前，必须经过一些处理或者某些变换（如码型变换、波形和频谱变换）才能送入信道中传输。处理或变换的目的是使信号的特性与信道的传输特性相匹配。 数字基带信号是消息代码的波形表示。表示形式有多种，有单极性、双极性波形，归零和非归零波形，差分波形、多电平波形之分，各自有不同的特点。 研究数字基带信号通过加性高斯白噪声信道的传输，并且假设信道除了叠加高斯噪声外，不会对信号产生其他失真。(matlabSimulation(pulse amplitude modulation) modulation signal in AWGN (additive white Gaussian noise AWGN (Additive White Gaussian Noise)) under the channel bit error rate and bit error rate performance, and compared with the theoretical value.)

基于Matlab的JPEG2000图像压缩实现，离散小波变换DWT，程序中图片的位置修改下可以自己运行程序看到效果(Matlab-based implementation of the JPEG2000 image compression, discrete wavelet transform DWT, where the image changes the program may be run its own program to see results)