[ VIGRA Homepage | Function Index | Class Index | Namespaces | File List | Main Page ]

total_variation.cxx VIGRA

Smooth an image with Total Variation (TV) regularization (standard ROF model, anisotropic, second order)
Usage: example_total_variation reads a given parameter file (see tv.par, aniso_tv.par, secondo_oder_tv.par in the examples subfolder) and performes a smoothing with TV regularization with the parameters given in this file.

/************************************************************************/
/*                                                                      */
/*                 Copyright 2012 by Frank Lenzen &                     */
/*                                           Ullrich Koethe             */
/*                                                                      */
/*    This file is part of the VIGRA computer vision library.           */
/*    The VIGRA Website is                                              */
/*        http://hci.iwr.uni-heidelberg.de/vigra/                       */
/*    Please direct questions, bug reports, and contributions to        */
/*        ullrich.koethe@iwr.uni-heidelberg.de    or                    */
/*        vigra@informatik.uni-hamburg.de                               */
/*                                                                      */
/*    Permission is hereby granted, free of charge, to any person       */
/*    obtaining a copy of this software and associated documentation    */
/*    files (the "Software"), to deal in the Software without           */
/*    restriction, including without limitation the rights to use,      */
/*    copy, modify, merge, publish, distribute, sublicense, and/or      */
/*    sell copies of the Software, and to permit persons to whom the    */
/*    Software is furnished to do so, subject to the following          */
/*    conditions:                                                       */
/*                                                                      */
/*    The above copyright notice and this permission notice shall be    */
/*    included in all copies or substantial portions of the             */
/*    Software.                                                         */
/*                                                                      */
/*    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND    */
/*    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES   */
/*    OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND          */
/*    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT       */
/*    HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,      */
/*    WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING      */
/*    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR     */
/*    OTHER DEALINGS IN THE SOFTWARE.                                   */                
/*                                                                      */
/************************************************************************/

#include <iostream>
#include <stdio.h>
#include <string.h>
#include <vigra/stdimage.hxx>
#include <vigra/stdimagefunctions.hxx>
#include <vigra/impex.hxx>
#include <vigra/multi_array.hxx>
#include <vigra/tv_filter.hxx>

#ifdef _MSC_VER
#define strcasecmp _stricmp
#endif

using namespace vigra; 


// Read a string from file <file>.
void read_string(FILE *file,const char *name, char* out){
  char dummy[80];
  int s=fscanf(file,"%s %s ",dummy,out);
  if (s==EOF || s<2){
    std::cout<<"Could not read from file.\n";
    exit(0); 
  }
  else if (strcasecmp(name,dummy)!=0){
    std::cout<<"Found parameter "<<dummy<<" instead of "<<name<<"\n";
    exit(0);
  }
  else
    std::cout<<"Parameter "<<name<<" = "<<out<<std::endl;
}

// read a flota-value from file <file>
float read_value(FILE *file,const char *name){
  char dummy[80];
  char dummy2[80];
  float f=0;
  
  int s=fscanf(file,"%s %s ",dummy,dummy2); 
  
  
  if (s==EOF || s<2){
    std::cout<<"Could not read from file.\n";
    exit(0); 
  }
  else if (strcasecmp(name,dummy)!=0){
    std::cout<<"Found parameter "<<dummy<<" instead of "<<name<<"\n";
    exit(0);
  }
  else{
    f=atof(dummy2);
    std::cout<<"Parameter "<<name<<" = "<<f<<std::endl;
  }
  return f;
}


int main(int argc, char ** argv)
{
  
  using namespace multi_math;
  
  if(argc <2)
  {
    std::cout << "Usage: " << argv[0] << " parameterfile" << std::endl;
    std::cout << "(supported formats for images: " << vigra::impexListFormats() << ")" << std::endl;
    
    return 1;
  }
  
  try
  {   
    char infile[80],outfile[80];
    double alpha0=0.01*sqrt(255.0),beta0=0.1*sqrt(255.0),sigma=0.1,rho=.5,K=10,eps=0,gamma0=0;
    int mode,inner_steps=200,outer_steps=5,write_steps=0;
    
    FILE *file=fopen(argv[1],"r");         // open parameter file 
    if (!file){
      std::cout<<"Cannot open file "<<argv[1]<<std::endl;
      return 1;
    }
    read_string(file,"input_file",infile);    // read name of input file (an image)
    read_string(file,"output_file",outfile);  // read name of output file (an image)
    mode=(int)read_value(file,"mode");        // read mode:  1- standard Total Variation
                                              //             2- Anisotropic Total Variation
                                              //             3- Anisotropic Total Variation with Higher Order term
                          
    // further parameters depend on mode                          
    switch(mode){
      case 1:
      case 2:
    inner_steps=1000;                 // read number of iteration steps
    alpha0=read_value(file,"alpha");  // read alpha
    eps=read_value(file,"epsilon");   // read eps
    break;
      case 3:
    outer_steps=(int)read_value(file,"outer_steps"); // read number of outer iteration steps
    inner_steps=(int)read_value(file,"inner_steps"); // read number of inner iteration steps
    alpha0=read_value(file,"alpha");  // read alpha
    beta0=read_value(file,"beta");    // read beta 
    sigma=read_value(file,"sigma");   // read sigma
    rho=read_value(file,"rho");       // read rho
    K=read_value(file,"edge_factor"); // read parameter K (edge sensitivity)
    write_steps=(int)read_value(file,"write_outer_steps"); //read flag for writing intermediate result after each outer iteration
    break;  
      
      case 4:
    outer_steps=(int)read_value(file,"outer_steps"); // read number of outer iteration steps
    inner_steps=(int)read_value(file,"inner_steps"); // read number of inner iteration steps
    alpha0=read_value(file,"alpha"); // read alpha
    beta0=read_value(file,"beta");   // read beta 
    gamma0=read_value(file,"gamma"); // read gamma
    sigma=read_value(file,"sigma");  // read sigma
    rho=read_value(file,"rho");      // read rho
    K=read_value(file,"edge_factor");// read parameter K (edge sensitivity)
    write_steps=(int)read_value(file,"write_outer_steps");//read flag for writing intermediate result after each outer iteration
    break;
      default:
    std::cout<<"Unknown mode "<<mode<<std::endl;
    }
    int stretch=(int)read_value(file,"histogram_stretch");        // flag for histogram stretching: 0 -no, 1 -yes
    
    
    
    vigra::ImageImportInfo info(infile); // get information about input image
    
    
    
    if(info.isGrayscale())
    {
      MultiArray<2,double> data(Shape2(info.width(),info.height()));
      MultiArray<2,double> out(Shape2(info.width(),info.height())); 
      MultiArray<2,double> weight(Shape2(info.width(),info.height()));  
    
      
      for (int y=0;y<data.shape(1);y++){
    for (int x=0;x<data.shape(0);x++){
      weight(x,y)=1;                         // set weight to 1 (needed for anisotropicTotalVariationFilter and
                                             // higherOrderTotalVariationFilter
    }
      }
      importImage(info, destImage(data));        // read image data
      data=data*(1/255.);                        // scale to [0,1] (smoothing parameters are tuned to this scaling)
      
      //------------------------------------
      //     Choose specific TV Filter
      //------------------------------------
      switch(mode){
    case 1:
    std::cout<<"Standard TV filter"<<std::endl;
    totalVariationFilter(data,out,alpha0,inner_steps,eps);
       break;
    case 2: 
    std::cout<<"Weighted TV filter"<<std::endl;
    totalVariationFilter(data,out,weight,alpha0,inner_steps,eps);
       break;
       case 3:{
    std::cout<<"Anisotropic TV filter"<<std::endl;
    
    MultiArray<2,double> phi(Shape2(info.width(),info.height()));
    MultiArray<2,double> alpha(Shape2(info.width(),info.height()));
    MultiArray<2,double> beta(Shape2(info.width(),info.height())); 
    
    out=data;   //'data' serves as initial value
    
    for (int i=0;i<outer_steps;i++){   // Outer loop to update anisotropic data 
      std::cout<<"outer step "<<i<<"\n";
      
      getAnisotropy(out,phi,alpha,beta,alpha0,beta0,sigma,rho,K);  // get anisotropic data
      anisotropicTotalVariationFilter(data,weight,phi,alpha,beta,out,inner_steps); //perform smoothing 
      
      if(write_steps){
        char dummy[80];
        sprintf(dummy,"output_step_%03d.png",i);
        std::cout<<"Writing temp file\n";
        if (stretch)
           exportImage(srcImageRange(out), vigra::ImageExportInfo(dummy)); //exportImage performes histogramm stretching
        else{
          MultiArray<2,unsigned char>  buffer(Shape2(info.width(),info.height()));
          buffer=max(min(out*255+0.5,0.),255.);                              //scaling back to [0,255], clipping, cast to uint8
          exportImage(srcImageRange(buffer), vigra::ImageExportInfo(dummy));
        }  
      }
    }
       break;
       }
       
       case 4:{
     std::cout<<"Second order TV filter"<<std::endl;
     
     MultiArray<2,double> phi(Shape2(info.width(),info.height()));
     MultiArray<2,double> alpha(Shape2(info.width(),info.height()));
     MultiArray<2,double> beta(Shape2(info.width(),info.height()));  
     MultiArray<2,double> gamma(Shape2(info.width(),info.height())); 
     MultiArray<2,double> xedges(Shape2(info.width(),info.height())); 
     MultiArray<2,double> yedges(Shape2(info.width(),info.height())); 
     
     for (int y=0;y<data.shape(1);y++){  // set data needed for second order term
       for (int x=0;x<data.shape(0);x++){
         gamma(x,y)=gamma0;
         xedges(x,y)=1;
         yedges(x,y)=1;
       }
     }
     
     out=data;  //'data' serves as initial value
     
     for (int i=0;i<outer_steps;i++){// Outer loop to update anisotropic data 
       std::cout<<"outer step "<<i<<"\n";
       
       getAnisotropy(out,phi,alpha,beta,alpha0,beta0,sigma,rho,K); // get anisotropic data
       secondOrderTotalVariationFilter(data,weight,phi,alpha,beta,gamma,xedges,yedges,out,inner_steps);//perform smoothing 
       
       if(write_steps){
         char dummy[80];
         sprintf(dummy,"output_step_%03d.png",i);
         std::cout<<"Writing temp file\n"; 
         if (stretch)
            exportImage(srcImageRange(out), vigra::ImageExportInfo(dummy));
         else{
           MultiArray<2,unsigned char>  buffer(Shape2(info.width(),info.height()));
           buffer=max(min(out*255+0.5,0.),255.);                              //scaling back to [0,255], clipping, cast to uint8
           exportImage(srcImageRange(buffer), vigra::ImageExportInfo(dummy));
         }  
       }
     }
       }
      }
      //-------------------------------------
      if (stretch)
      exportImage(srcImageRange(out), vigra::ImageExportInfo(outfile));  //write result to file
      else{
    MultiArray<2,unsigned char>  buffer(Shape2(info.width(),info.height()));
    buffer=min(max(out*255.+0.5,0.),255.);                              //scaling back to [0,255], clipping, cast to uint8
    exportImage(srcImageRange(buffer), vigra::ImageExportInfo(outfile));
      }
    }
    else
    {
      std::cout<<"Color images are currently not supported !\n";
    }
  }
  catch (vigra::StdException & e)
  {
    std::cout << e.what() << std::endl;
    return 1;
  }
  
  return 0;
}

© Ullrich Köthe (ullrich.koethe@iwr.uni-heidelberg.de)
Heidelberg Collaboratory for Image Processing, University of Heidelberg, Germany

html generated using doxygen and Python
vigra 1.9.0 (Tue Nov 6 2012)