OnlineHandwritingPicture.cpp

#include "OnlineHandwritingPicture.h"
#include "signature.h"

OnlineHandwritingPicture::OnlineHandwritingPicture(int renderSize, OnlineHandwritingEncoding enc, int label, float penSpeed3d) :
  enc(enc), renderSize(renderSize), Picture(label), offset3d(0), penSpeed3d(penSpeed3d) {
}
OnlineHandwritingPicture::~OnlineHandwritingPicture() {
}
void OnlineHandwritingPicture::normalize() { //Fit centrally in the cube [-renderSize/2,renderSize/2]^2
  arma::mat pointsm(ops.size(),2);
  arma::mat pointsM(ops.size(),2);
  for (int i=0;i<ops.size();++i) {
    pointsm.row(i)=arma::min(ops[i],0);
    pointsM.row(i)=arma::max(ops[i],0);
  }
  pointsm=arma::min(pointsm,0);
  pointsM=arma::max(pointsM,0);
  float scale = arma::mat(pointsM-pointsm).max();
  assert(scale>0);
  for (int i=0;i<ops.size();++i) {
    ops[i]=ops[i]-arma::repmat(0.5*(pointsm+pointsM),ops[i].n_rows,1);
    ops[i]*=renderSize/scale;
  }
}

arma::mat constantSpeed
(arma::mat &stroke,
 float density,
 int multiplier = 1) {
  std::vector<float> lengths(stroke.n_rows);
  lengths[0]=0;
  for (int i=1;i<stroke.n_rows;i++) {
    lengths[i]=lengths[i-1]+pow(pow(stroke(i,0)-stroke(i-1,0),2)+
                                pow(stroke(i,1)-stroke(i-1,1),2),0.5);
  }
  float lTotal=lengths[stroke.n_rows-1];
  int n=(int)(0.5+lTotal/density);
  n*=multiplier;
  arma::mat r(n+1,2);
  int j=0;
  float alpha;
  r(0,0)=stroke(0,0);
  r(0,1)=stroke(0,1);
  for (int i=1;i<=n;i++) {
    while(n*lengths[j+1]<i*lTotal) j++;
    alpha=(lengths[j+1]-i*lTotal/n)/(lengths[j+1]-lengths[j]);
    r(i,0)=stroke(j,0)*alpha+stroke(j+1,0)*(1-alpha);
    r(i,1)=stroke(j,1)*alpha+stroke(j+1,1)*(1-alpha);
  }
  return r;
}


int mapToGrid(float coord, int scale_N) {
  return std::max(0,std::min(scale_N-1,(int)(coord+0.5*scale_N)));
}
int maxLength=0;
void OnlineHandwritingPicture::codifyInputData(SparseGrid &grid, std::vector<float> &features, int &nSpatialSites, int spatialSize) {
  int nInputFeatures=OnlineHandwritingEncodingSize[enc];
  //Background feature
  grid.backgroundCol=nSpatialSites++;
  features.resize(nInputFeatures*nSpatialSites,0);
  //Render character
  switch(enc) {
  case Simple:
    for (int i=0; i<ops.size(); i++) {
      arma::mat csp=constantSpeed(ops[i],0.1);
      for (int j=0;j<csp.n_rows;++j) {
        int
          a0=csp(j,0)+spatialSize/2.0,
          a1=csp(j,1)+spatialSize/2.0;
        if (a0>=0 and a1>=0 and a0<spatialSize and a1<spatialSize) {
          int n= a0*spatialSize + a1;
          if (grid.mp.find(n)==grid.mp.end()) {
            grid.mp[n]=nSpatialSites++;
            features.resize(nInputFeatures*nSpatialSites,0);
          }
          ++features[grid.mp[n]];
          //          std::cout <<"."<<std::flush;
        } //else  std::cout <<"x"<<std::flush;
      }
    }
    break;
  case Octogram: {//todo: Test
    float piBy4=3.1415926536/4;
    for (int i=0; i<ops.size(); i++) {
      arma::mat csp=constantSpeed(ops[i],0.1);
      for (int j=0;j<csp.n_rows-1;++j) {
        int
          a0=csp(j,0)+spatialSize/2.0,
          a1=csp(j,1)+spatialSize/2.0;
        if (a0>=0 and a1>=0 and a0<spatialSize and a1<spatialSize) {
          int n= a0*spatialSize + a1;
          if (grid.mp.find(n)==grid.mp.end()) {
            grid.mp[n]=nSpatialSites++;
            features.resize(nInputFeatures*nSpatialSites,0);
          }
          int mpnnIF=nInputFeatures*grid.mp[n];
          features[mpnnIF]++;
          float dx=(csp(j+1,0)-csp(j,0));
          float dy=(csp(j+1,1)-csp(j,1));
          float m=powf(dx*dx+dy*dy,0.5);
          dx/=m;
          dy/=m;
          for (int k=0;k<8;k++) {
            float alpha=1-acosf(cosf(k*piBy4)*dx+sinf(k*piBy4)*dy)/piBy4;
            if (alpha>0)
              features[mpnnIF+k+1]+=alpha;
          }
        }
      }
    }
    break;
  }
  case LogSignature1:
    //Todo
    break;
  case LogSignature2:
    //Todo
    break;
  case LogSignature3:
    //Todo
    break;
  case LogSignature4:
    //Todo
    break;
  case SpaceTime3d: {
    std::vector<arma::mat> csp;
    int cspLengths=0;
    for (int i=0; i<ops.size(); i++) {
      csp.push_back(constantSpeed(ops[i],0.1));
      cspLengths+=csp[i].n_rows;
    }
    // if (cspLengths>maxLength) {
    //   std::cout <<cspLengths*penSpeed3d << " " << std::flush;
    //   maxLength=cspLengths;
    // }
    int z=0;
    for (int i=0; i<ops.size(); i++) {
      for (int j=0;j<csp[i].n_rows;++j) {
        int
          a0=csp[i](j,0)+spatialSize/2.0,
          a1=csp[i](j,1)+spatialSize/2.0,
          a2=renderSize*((z-cspLengths/2)*penSpeed3d+offset3d)+spatialSize/2;
        z++;
        if (a0>=0 and a1>=0 and a2>=0 and a0<spatialSize and a1<spatialSize and a2<spatialSize) {
          int n= a0*spatialSize*spatialSize + a1*spatialSize + a2;
          if (grid.mp.find(n)==grid.mp.end()) {
            grid.mp[n]=nSpatialSites++;
            features.resize(nInputFeatures*nSpatialSites,0);
          }
          ++features[grid.mp[n]];
        }
      }
    }
    break;
  }
  case VectorSpaceTime3d: {
    std::vector<arma::mat> csp;
    int cspLengths=0;
    for (int i=0; i<ops.size(); i++) {
      csp.push_back(constantSpeed(ops[i],0.1));
      cspLengths+=csp[i].n_rows;
    }
    // if (cspLengths>maxLength) {
    //   std::cout << cspLengths*penSpeed3d << " " << std::flush;
    //   maxLength=cspLengths;
    // }
    int z=0;
    for (int i=0; i<ops.size(); i++) {
      for (int j=0;j<csp[i].n_rows-1;++j) {
        int
          a0=csp[i](j,0)+spatialSize/2.0,
          a1=csp[i](j,1)+spatialSize/2.0,
          a2=renderSize*((z-cspLengths/2)*penSpeed3d+offset3d)+spatialSize/2;
        z++;
        if (a0>=0 and a1>=0 and a2>=0 and a0<spatialSize and a1<spatialSize and a2<spatialSize) {
          int n= a0*spatialSize*spatialSize + a1*spatialSize + a2;
          if (grid.mp.find(n)==grid.mp.end()) {
            grid.mp[n]=nSpatialSites++;
            features.resize(nInputFeatures*nSpatialSites,0);
          }
          int mpnnIF=nInputFeatures*grid.mp[n];
          features[mpnnIF]++;
          float dx=(csp[i](j+1,0)-csp[i](j,0));
          float dy=(csp[i](j+1,1)-csp[i](j,1));
          float m=powf(dx*dx+dy*dy,0.5);
          dx/=m;
          dy/=m;
          features[mpnnIF+1]+=dx;
          features[mpnnIF+2]+=dy;
        }
      }
    }
    break;
  }
  }
}