wavelet1d/new1DSWTDemo.md

1D Stationary Wavelet Transform Demo

Notes

1. dwt and dwt_sym functions are interchangeable in the following code as they take the same arguments.

2. Please make sure that right header file is included. Following sample program links to wavelet2d.h which is the header for shared libraries. wavelet2s.h must be included for static libraries.

Sample Code

//============================================================================
// Name        : swtdemo.cpp
// Author      : Rafat Hussain
// Version     :
// Copyright   : 
// Description : 1D Stationary Wavelet Transform Demo
//============================================================================

#include <iostream>
#include <fstream>
#include "wavelet2d.h"
#include <vector>
#include <string>
#include <cmath>
using namespace std;

int main() {
	cout << "********J- LEVEL DISCRETE WAVELET TRANSFORM IMPLEMENTATION*********" << endl; // prints
	    cout << "This program accepts signal from the user in a file format " << endl;
	    cout << "and performs Discrete Wavelet Transform with specified   " << endl;
	    cout << "wavelet. "                                               << endl;
	    cout << "                                                             " << endl;
	    cout << " The Following Wavelets are in the Database:                 " << endl;
	    cout << " haar, db1, db2, db3, db4, db5, db6, db7, db8, db9, db10,  "   << endl;
	    cout << " db11, db12, db13, db14, db15.                               "  << endl;
	    cout << " bior1.1, bio1.3, bior1.5, bior2.2, bior2.4,bior2.6,bior2.8, " << endl;
	    cout << " bior3.1, bior3.3, bior3.5, bior3.7, bior3.9, bior4.4,"        << endl;
	    cout << " bior5.5, bior6.8."                                            << endl;
	    cout << " coif1, coif2, coif3, coif4, coif5."                           << endl;
	    cout << "Please Enter the Wavelet Name at the Prompt( No quotes)     :" << endl;

	    string nm; // nm will store the name of Wavelet Family
	    cin >> nm;
	    cout << "Enter the name of signal file at the Prompt eg., signal.txt :" << endl;
	    char inp[50];
	    cin >> inp;
	    vector<double> sig;
	    ifstream sig_inp(inp);
        if ( !sig_inp.good()){
        	cout << "The File doesn't exist"<< endl;
        }
	    while (sig_inp) {
	    	double temp;
	    	sig_inp >> temp;
	    	sig.push_back(temp);
	    }
	    sig.pop_back();
	    vector<double> original;
	    original = sig; // Make a copy of the signal if you want to use original signal
       // later on. The other option is to use IDWT output as the SWt/ISWT system is
       // Perefect Reconstruction system.
	    cout << "Please Enter the Number of DWT Stages J             :" << endl;

	    int J;
	    cin >> J ;

        vector<double> swt_output;

        // perform J-Level DWT
        int length;// All coefficients are of same length. Variable "length" returns length
        // of coefficients. It is not required for ISWT computations.



	    swt(sig, J, nm, swt_output, length);

            ofstream swtcoeff("swtcoeff.txt");
            for (unsigned int i=0; i < swt_output.size(); i++) {
              swtcoeff << swt_output[i] << endl;
             } 
	    vector<double> iswt_output;
	    iswt(swt_output,J, nm,iswt_output);
            ofstream sig1("recon.txt");
            ofstream diff("diff.txt");

            cout <<" Recon signal size" << iswt_output.size() << endl;
            for (unsigned int i = 0; i < iswt_output.size(); i++){
                sig1 << iswt_output[i] << endl;
                diff << iswt_output[i] - original[i] << endl;

            }


	    return 0;
}

Console Running swt demo

Input Signal(Length-256)

SWT Coefficients for two level of Decomposition(Length 3 X 256)

Reconstructed Signal