ExampleUpsampleBy2Grey.cpp

Example for upsampling images by factor of 2 on grey images , ImageConvert

Author

MIP

/* 
This file is part of the BIAS library (Basic ImageAlgorithmS).

Copyright (C) 2003-2009    (see file CONTACT for details)
  Multimediale Systeme der Informationsverarbeitung
  Institut fuer Informatik
  Christian-Albrechts-Universitaet Kiel


BIAS is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.

BIAS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License
along with BIAS; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

/** 
    @example ExampleUpsampleBy2Grey.cpp
    @brief Example for upsampling images by factor of 2 on grey images
  @relates Rescale, ImageConvert
    @ingroup g_examples 
    @author MIP
*/

#include <Base/Image/Image.hh>
#include <Base/Image/ImageIO.hh>
#include <Base/Image/ImageConvert.hh>
#include <Filter/Rescale.hh>
#include <Base/Debug/TimeMeasure.hh>

#include <Base/Common/BIASpragma.hh>

using namespace BIAS;
using namespace std;


int main(int argc, char *argv[])
{

  cout<<"This example compares different upsampling methods for factor 2"
      <<endl;

  if (argc<2){
    BIASERR(argv[0]<<" <image-file>");
    return -1;
  }
 
  Image<unsigned char> im;
  if (ImageIO::Load(argv[1], im)!=0){
    BIASERR("error loading "<<argv[1]);
    return -2;
  }
  if (im.GetColorModel() != ImageBase::CM_Grey) ImageConvert::IP_ToGrey(im);
  Image<unsigned char> imbicubic(im.GetWidth()*2,im.GetHeight()*2,1);
  Image<unsigned char> imbilinear(im.GetWidth()*2,im.GetHeight()*2,1);
  Image<unsigned char> imnn(im.GetWidth()*2,im.GetHeight()*2,1);
                             
  // automatic
  Rescale<unsigned char, unsigned char> Upsampler;
  Upsampler.UpsampleBy2Grey(im, imnn, NearestNeighbour);
  Upsampler.UpsampleBy2Grey(im, imbilinear, Bilinear);
  Upsampler.UpsampleBy2Grey(im, imbicubic, Bicubic);

  //if (ImageIO::Save("image_bicubic_auto.mip", imbicubic)!=0){
  if (ImageIO::Save("image_bicubic_auto.mip", imbicubic)!=0){
    BIASERR("error writing cubic image");
    return -3;
  }
  //if (ImageIO::Save("image_bilinear_auto.mip", imbilinear)!=0){
  if (ImageIO::Save("image_bilinear_auto.mip", imbilinear)!=0){
    BIASERR("error writing bilinear image");
    return -3;
  } 
  //if (ImageIO::Save("image_nearestneighbor_auto.mip", imnn)!=0){
  if (ImageIO::Save("image_nearestneighbor_auto.mip", imnn)!=0){
    BIASERR("error writing bilinear image");
    return -3;
  }

  imbicubic.SetZero();
  imbilinear.SetZero();
  // manual
  unsigned char **pDc = imbicubic.GetImageDataArray();
  unsigned char **pDb = imbilinear.GetImageDataArray();

  double CurValue = 0;
  const unsigned int channelcount = im.GetChannelCount();
  for (unsigned int x=2; x<imbicubic.GetWidth()-6; x++) {
    for (unsigned int y=2; y<imbicubic.GetHeight()-6; y++) {
      for (unsigned int c=0; c<channelcount; c++) {
        CurValue = rint(im.BicubicInterpolation(double(x)*0.5,
                                                double(y)*0.5, c));
        if (CurValue<0.0)CurValue = 0.0;
        if (CurValue>255.0)CurValue = 255.0;
        pDc[y][(x*channelcount)+c] = (unsigned char) CurValue; 
        CurValue = rint(im.BilinearInterpolation(double(x)*0.5,
                                                 double(y)*0.5,
                                                 c));
        if (CurValue<0.0)CurValue = 0.0;
        if (CurValue>255.0)CurValue = 255.0;
        pDb[y][(x*channelcount)+c] = (unsigned char) CurValue;
      }
    }
  }

  //if (ImageIO::Save("image_bicubic.mip", imbicubic)!=0){
  if (ImageIO::Save("image_bicubic.mip", imbicubic)!=0){
    BIASERR("error writing cubic image");
    return -3;
  }
  //if (ImageIO::Save("image_bilinear.mip", imbilinear)!=0){
  if (ImageIO::Save("image_bilinear.mip", imbilinear)!=0){
    BIASERR("error writing bilinear image");
    return -3;
  }

  cout<<"Performing time measurements"<<endl;
  TimeMeasure b1,b2,b3;
  // warming up
  Upsampler.UpsampleBy2Grey(im, imbilinear, Bilinear);
  Upsampler.UpsampleBy2Grey(im, imbicubic, Bicubic);
  Upsampler.UpsampleBy2Grey(im, imnn, NearestNeighbour);
  unsigned int numberruns = 10;
  for (unsigned int i=0; i<numberruns; i++) {
    b1.Start();
    Upsampler.UpsampleBy2Grey(im, imbilinear, Bilinear);
    b1.Stop();
    b2.Start();
    Upsampler.UpsampleBy2Grey(im, imbicubic, Bicubic);
    b2.Stop();
    b3.Start();
    Upsampler.UpsampleBy2Grey(im, imnn, NearestNeighbour);
    b3.Stop();
  }
  cout<<"time nearest neighbor (real/user):"
      <<b3.GetRealTime()/double(numberruns)
      <<" "<<b3.GetUserTime()/double(numberruns)<<endl;
  cout<<"time bilinear (real/user):"<<b1.GetRealTime()/double(numberruns)
      <<" "<<b1.GetUserTime()/double(numberruns)<<endl;
  cout<<"time bicubic  (real/user):"<<b2.GetRealTime()/double(numberruns)
      <<" "<<b2.GetUserTime()/double(numberruns)<<endl;
  

  return 0;
}