test-CVcontour.C

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/*!@file SeaBee/test-CVcontour.C test opencv contour function   */
// //////////////////////////////////////////////////////////////////// //
// The iLab Neuromorphic Vision C++ Toolkit - Copyright (C) 2001 by the //
// University of Southern California (USC) and the iLab at USC.         //
// See http://iLab.usc.edu for information about this project.          //
// //////////////////////////////////////////////////////////////////// //
// Major portions of the iLab Neuromorphic Vision Toolkit are protected //
// under the U.S. patent ``Computation of Intrinsic Perceptual Saliency //
// in Visual Environments, and Applications'' by Christof Koch and      //
// Laurent Itti, California Institute of Technology, 2001 (patent       //
// pending; application number 09/912,225 filed July 23, 2001; see      //
// http://pair.uspto.gov/cgi-bin/final/home.pl for current status).     //
// //////////////////////////////////////////////////////////////////// //
// This file is part of the iLab Neuromorphic Vision C++ Toolkit.       //
//                                                                      //
// The iLab Neuromorphic Vision C++ Toolkit is free software; you can   //
// redistribute it and/or modify it under the terms of the GNU General  //
// Public License as published by the Free Software Foundation; either  //
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// The iLab Neuromorphic Vision C++ Toolkit is distributed in the hope  //
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// Boston, MA 02111-1307 USA.                                           //
// //////////////////////////////////////////////////////////////////// //
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// Primary maintainer for this file: Michael Montalbo <montalbo@usc.edu>
// $HeadURL: svn://isvn.usc.edu/software/invt/trunk/saliency/src/SeaBee/test-CVcontour.C $
// $Id: test-CVcontour.C 10794 2009-02-08 06:21:09Z itti $

#include "Component/ModelManager.H"

#include "Media/FrameSeries.H"
#include "Transport/FrameIstream.H"
#include "Transport/FrameInfo.H"
#include "Media/MediaOpts.H"

#include "Image/Image.H"
#include "Image/Pixels.H"
#include "Raster/Raster.H"
#include "Image/CutPaste.H"
#include "Image/OpenCVUtil.H"

#include "BeoSub/IsolateColor.H"
#include "Image/DrawOps.H"
#include "Image/ColorOps.H"

#include "GUI/XWinManaged.H"

#ifndef HAVE_OPENCV
  LFATAL("OpenCV must be installed in order to use this function");
#else

int thresh = 50;

// helper function:
// finds a cosine of angle between vectors
// from pt0->pt1 and from pt0->pt2
double angle( CvPoint* pt1, CvPoint* pt2, CvPoint* pt0 )
{
    double dx1 = pt1->x - pt0->x;
    double dy1 = pt1->y - pt0->y;
    double dx2 = pt2->x - pt0->x;
    double dy2 = pt2->y - pt0->y;
    return (dx1*dx2 + dy1*dy2)/sqrt((dx1*dx1 + dy1*dy1)*(dx2*dx2 + dy2*dy2) + 1e-10);
}

// returns sequence of squares detected on the image.
// the sequence is stored in the specified memory storage
CvSeq* findSquares4( IplImage* img, CvMemStorage* storage )
{
    CvSeq* contours;
    int i, c, l, N = 11;
    CvSize sz = cvSize( img->width & -2, img->height & -2 );
    IplImage* timg = cvCloneImage( img ); // make a copy of input image
    IplImage* gray = cvCreateImage( sz, 8, 1 );
    IplImage* pyr = cvCreateImage( cvSize(sz.width/2, sz.height/2), 8, 3 );
    IplImage* tgray;
    CvSeq* result;
    double s, t;
    // create empty sequence that will contain points -
    // 4 points per square (the square's vertices)
    CvSeq* squares = cvCreateSeq( 0, sizeof(CvSeq), sizeof(CvPoint), storage );

    // select the maximum ROI in the image
    // with the width and height divisible by 2
    cvSetImageROI( timg, cvRect( 0, 0, sz.width, sz.height ));

    // down-scale and upscale the image to filter out the noise
    cvPyrDown( timg, pyr, 7 );
    cvPyrUp( pyr, timg, 7 );
    tgray = cvCreateImage( sz, 8, 1 );

    // find squares in every color plane of the image
    for( c = 0; c < 3; c++ )
    {
        // extract the c-th color plane
        cvSetImageCOI( timg, c+1 );
        cvCopy( timg, tgray, 0 );

        // try several threshold levels
        for( l = 0; l < N; l++ )
        {
            // hack: use Canny instead of zero threshold level.
            // Canny helps to catch squares with gradient shading
            if( l == 0 )
            {
                // apply Canny. Take the upper threshold from slider
                // and set the lower to 0 (which forces edges merging)
                cvCanny( tgray, gray, 0, thresh, 5 );
                // dilate canny output to remove potential
                // holes between edge segments
                cvDilate( gray, gray, 0, 1 );
            }
            else
            {
                // apply threshold if l!=0:
                //     tgray(x,y) = gray(x,y) < (l+1)*255/N ? 255 : 0
                cvThreshold( tgray, gray, (l+1)*255/N, 255, CV_THRESH_BINARY );
            }

            // find contours and store them all as a list
            cvFindContours( gray, storage, &contours, sizeof(CvContour),
                CV_RETR_LIST, CV_CHAIN_APPROX_SIMPLE, cvPoint(0,0) );

            // test each contour
            while( contours )
            {
                // approximate contour with accuracy proportional
                // to the contour perimeter
                result = cvApproxPoly( contours, sizeof(CvContour), storage,
                    CV_POLY_APPROX_DP, cvContourPerimeter(contours)*0.02, 0 );
                // square contours should have 4 vertices after approximation
                // relatively large area (to filter out noisy contours)
                // and be convex.
                // Note: absolute value of an area is used because
                // area may be positive or negative - in accordance with the
                // contour orientation
                if( result->total == 4 &&
                    fabs(cvContourArea(result,CV_WHOLE_SEQ)) > 1000 &&
                    cvCheckContourConvexity(result) )
                {
                    s = 0;

                    for( i = 0; i < 5; i++ )
                    {
                        // find minimum angle between joint
                        // edges (maximum of cosine)
                        if( i >= 2 )
                        {
                            t = fabs(angle(
                            (CvPoint*)cvGetSeqElem( result, i ),
                            (CvPoint*)cvGetSeqElem( result, i-2 ),
                            (CvPoint*)cvGetSeqElem( result, i-1 )));
                            s = s > t ? s : t;
                        }
                    }

                    // if cosines of all angles are small
                    // (all angles are ~90 degree) then write quandrange
                    // vertices to resultant sequence
                    if( s < 0.3 )
                        for( i = 0; i < 4; i++ )
                            cvSeqPush( squares,
                                (CvPoint*)cvGetSeqElem( result, i ));
                }

                // take the next contour
                contours = contours->h_next;
            }
        }
    }

    // release all the temporary images
    cvReleaseImage( &gray );
    cvReleaseImage( &pyr );
    cvReleaseImage( &tgray );
    cvReleaseImage( &timg );

    return squares;
}


// the function draws all the squares in the image
void drawSquares( IplImage* img, IplImage* out, CvSeq* squares )
{
    CvSeqReader reader;
    int i;

    // initialize reader of the sequence
    cvStartReadSeq( squares, &reader, 0 );

    // read 4 sequence elements at a time (all vertices of a square)
    for( i = 0; i < squares->total; i += 4 )
    {
        CvPoint pt[4], *rect = pt;
        int count = 4;

        // read 4 vertices
        CV_READ_SEQ_ELEM( pt[0], reader );
        CV_READ_SEQ_ELEM( pt[1], reader );
        CV_READ_SEQ_ELEM( pt[2], reader );
        CV_READ_SEQ_ELEM( pt[3], reader );

        // draw the square as a closed polyline
        cvPolyLine( out, &rect, &count, 1, 1, CV_RGB(0,255,0), 3, CV_AA, 0 );
    }

}

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

  MYLOGVERB = LOG_INFO;

  ModelManager manager("CVContour Tester");

  nub::soft_ref<InputFrameSeries> ifs(new InputFrameSeries(manager));
  manager.addSubComponent(ifs);

  nub::soft_ref<OutputFrameSeries> ofs(new OutputFrameSeries(manager));
  manager.addSubComponent(ofs);

  manager.exportOptions(MC_RECURSE);

  // Parse command-line:
  if (manager.parseCommandLine(argc, argv,
                               "[image {*.ppm}]",
                               0, 1)
      == false) return(1);

  int w = ifs->getWidth(),  h = ifs->getHeight();
  std::string dims = convertToString(Dims(w, h));
  LINFO("image size: [%dx%d]", w, h);
  manager.setOptionValString(&OPT_InputFrameDims, dims);

  manager.setModelParamVal("InputFrameDims", Dims(w, h),
                           MC_RECURSE | MC_IGNORE_MISSING);

  manager.start();

  bool goforever = true;

  rutz::shared_ptr<XWinManaged> dispWin;
  dispWin.reset(new XWinManaged(Dims(w*2,h*2), 0, 0, "Contour Display"));

  // input image
  Image< PixRGB<byte> > img(w,h, ZEROS);


  IplImage* iplImg = 0;
  IplImage* out = 0;
  CvMemStorage* storage = 0;

  bool createMovie = true;

  while(goforever)
    {
      Image< PixRGB<byte> > dispImg(w*2,h*2, ZEROS);

      ifs->updateNext(); img = ifs->readRGB();
      if(!img.initialized()) {Raster::waitForKey(); break; }

      // create memory storage that will contain all the dynamic data
      storage = cvCreateMemStorage(0);

      iplImg = cvCloneImage(  img2ipl(img) );
      out = cvCloneImage(  img2ipl(img) );

      // find and draw the squares
      drawSquares( iplImg, out, findSquares4( iplImg, storage ) );

      inplacePaste(dispImg, ipl2rgb(out), Point2D<int>(w,0));
      dispWin->drawImage(dispImg, 0, 0);


      if(createMovie)
        {
          ofs->writeRGB(ipl2rgb(out), "test-CVcontour_Display",
                        FrameInfo("test-CVcontour_Display", SRC_POS));
        }

      // wait for key.
      //      Raster::waitForKey();

      // release both images
      cvReleaseImage( &iplImg );
      cvReleaseImage( &out );

      // clear memory storage - reset free space position
      cvClearMemStorage( storage );
    }

  // get ready to terminate:
  manager.stop();
  return 0;
}
#endif // HAVE_OPENCV


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