Isis 3.0 Application Source Code Reference

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butterworth.cpp

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#include "Isis.h"

#include <float.h>
#include <cmath>

#include "ProcessByLine.h"
#include "LineManager.h"

using namespace std; 
using namespace Isis;

void lowpass (Buffer &in, Buffer &out);
void highpass (Buffer &in, Buffer &out);
void bandpass (Buffer &in, Buffer &out);
void bandstop (Buffer &in, Buffer &out);
double radius (int x1, int y1, int x2, int y2);

int x, y, g;
double d, dw;

void IsisMain()
{
  ProcessByLine p;

  UserInterface &ui = Application::GetUserInterface();

  //  Initialize the input and output cubes
  Isis::Cube *icube = p.SetInputCube ("FROM");

  // get the center pixels coordinates
  x = (icube->Samples()+1)/2;
  y = (icube->Lines()+1)/2;

  p.SetOutputCube ("TO");

  // Get the input values
  d = ui.GetDouble ("CUTOFF");
  dw = ui.GetDouble("BANDWIDTH");
  g = ui.GetInteger ("ORDER");

  // checks the type and runs the appropriate filter
  if (ui.GetString("TYPE") == "LOWPASS") {
      p.StartProcess(lowpass);
  }
  else if (ui.GetString("TYPE") == "HIGHPASS") {
      p.StartProcess(highpass);
  }
  else if (ui.GetString("TYPE") == "BANDPASS") {
      p.StartProcess(bandpass);
  }
  else if (ui.GetString("TYPE") == "BANDSTOP") {
      p.StartProcess(bandstop);
  }
  else {
    string msg = "Unknow value for TYPE [" +
                 ui.GetString("TYPE") + "]";
    throw iException::Message(iException::Programmer,msg,_FILEINFO_);
  }

  p.EndProcess();
}

// Applies a lowpass filter to an image in the frequency domain.
void lowpass (Buffer &in, Buffer &out)
{
    double dist = 0.0;
    double B = 0.0;

    for (int i=0; i<in.size(); i++)
    {
        dist = radius(in.Sample(i), in.Line(i), x, y);
        B = 1/(1+pow(dist/d, 2*g));

        out[i] = B*in[i];
    }
}

// Applies a highpass filter to an image in the frequency domain.
void highpass (Buffer &in, Buffer &out)
{
    double dist = 0.0;
    double B = 0.0;

    for (int i=0; i<in.size(); i++)
    {
        dist = radius(in.Sample(i), in.Line(i), x, y);
        B = 1/(1+pow(d/dist, 2*g));

        out[i] = B*in[i];
    }
}

// Applies a bandpass filter to an image in the frequency domain.
void bandpass (Buffer &in, Buffer &out)
{
    double dist = 0.0;
    double B = 0.0;

    for (int i=0; i<in.size(); i++)
    {
        dist = radius(in.Sample(i), in.Line(i), x, y);
        B = 1-1/(1+pow(dw*dist/(dist*dist-d*d), 2*g));

        out[i] = B*in[i];
    }
}

// Applies a bandstop filter to an image in the frequency domain.
void bandstop (Buffer &in, Buffer &out)
{
    double dist = 0.0;
    double B = 0.0;

    for (int i=0; i<in.size(); i++)
    {
        dist = radius(in.Sample(i), in.Line(i), x, y);
        B = 1/(1+pow(dw*dist/(dist*dist-d*d), 2*g));

        out[i] = B*in[i];
    }
}

// measures the distance (or radius lenght) between the
// point (x1, y1) and (x2,y2)
double radius (int x1, int y1, int x2, int y2)
{
    return sqrt((double)((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2)));
}