| void Impala::Core::KeyPoint::Sift::AssignOrientation | ( | ) | [inline] |
Definition at line 204 of file Sift.h.
References Impala::Core::Table::TableTem< Col1T, Col2T, Col3T, Col4T, Col5T, Col6T, Col7T, Col8T, Col9T >::Add(), Impala::Core::Table::TableTem< Col1T, Col2T, Col3T, Col4T, Col5T, Col6T, Col7T, Col8T, Col9T >::Get1(), Impala::Core::Table::TableTem< Col1T, Col2T, Col3T, Col4T, Col5T, Col6T, Col7T, Col8T, Col9T >::Get2(), Impala::Core::Table::TableTem< Col1T, Col2T, Col3T, Col4T, Col5T, Col6T, Col7T, Col8T, Col9T >::Get3(), Impala::Core::Table::TableTem< Col1T, Col2T, Col3T, Col4T, Col5T, Col6T, Col7T, Col8T, Col9T >::Get4(), Impala::Core::Table::TableTem< Col1T, Col2T, Col3T, Col4T, Col5T, Col6T, Col7T, Col8T, Col9T >::Get5(), Impala::Core::KeyPoint::Detector::GetKeyPoints(), ILOG_INFO, mDetector, mGaussians, mGradAng, mGradMag, mKeyPoints, mLevelCnt, PI, Impala::Core::Table::TableTem< Col1T, Col2T, Col3T, Col4T, Col5T, Col6T, Col7T, Col8T, Col9T >::Set6(), Impala::Application::DemoCamera2d::sigma, and Impala::Core::Table::Table::Size().
Referenced by ExtractDescriptors().
00205 { 00206 00207 double sigma; 00208 int range=0; 00209 int k=0; 00210 int o,l,i,j,index; 00211 Array2dScalarReal64 *GA, *GM; 00212 Array2dScalarReal64 *Gaussian; 00213 00214 mKeyPoints=mDetector->GetKeyPoints(); 00215 int OrigSize = mKeyPoints->Size(); 00216 while(k<OrigSize) 00217 { 00218 sigma= mKeyPoints->Get1(k); 00219 i = mKeyPoints->Get2(k); 00220 j = mKeyPoints->Get3(k); 00221 o = mKeyPoints->Get4(k); 00222 l = mKeyPoints->Get5(k); 00223 index=o*mLevelCnt+l; 00224 00225 GA=mGradAng[index]; 00226 GM=mGradMag[index]; 00227 Gaussian=mGaussians[index]; 00228 //Weight the gradient magnitudes with a gaussian, 00229 // with a sigma 1.5 times the original, 00230 // and centered around the keypoint 00231 range = Gaussian->CW()/2; 00232 00233 double histAng[36]; 00234 for(int h=0;h<36;h++) 00235 histAng[h]=0; 00236 double incr=PI/36; 00237 00238 for(int x=-range;x<range+1;x++) 00239 { 00240 for(int y=-range;y<range+1;y++) 00241 { 00242 if((i+x<0)||(i+x>GA->CW())|| 00243 (j+y<0)||(j+y>GA->CH())) 00244 continue; 00245 if((x+range>=Gaussian->CW()||y+range>=Gaussian->CH())) 00246 continue; 00247 int bin=floor(18+GA->Value(i+x,j+y)/incr); 00248 if(bin>36) 00249 continue; 00250 histAng[bin]+=Gaussian->Value(x+range,y+range) * 00251 GM->Value(i+x,j+y); 00252 } 00253 00254 } 00256 //Find the maximum in the histogram 00257 double max_val=0; 00258 int max_bin=0; 00259 for(int b=0;b<36;b++) 00260 { 00261 if(histAng[b]>max_val) 00262 { 00263 max_val = histAng[b]; 00264 max_bin=b; 00265 } 00266 } 00267 mKeyPoints->Set6(k,-PI/2+incr*(max_bin+.5)); 00269 //Update the Orientation of the keypoint to max_bin 00270 double low,high; 00271 low=-PI/2+incr*max_bin; 00272 high=-PI/2+incr*(max_bin+1); 00273 //ILOG_DEBUG("Orientation("<<max_bin<<"):"<<histAng[max_bin] 00274 // <<" Values btw "<<low<<"-"<<high); 00275 00277 //Find other values which are greater than 80% of highest peak 00278 double max80= .8 * max_val; 00279 for(int b=1;b<35;b++) 00280 { 00281 if(b==max_bin) 00282 continue; 00283 if(histAng[b]>max80) 00284 { 00286 //Check if it is a peak 00287 if((histAng[b]>histAng[b-1])&&(histAng[b]>histAng[b+1])){ 00288 //Create a new keypoint at the same location 00289 //with this orientation 00290 // 00291 //ILOG_DEBUG("Create New Keypoint With Orientation:"<<b<<"-"<<histAng[b]); 00292 mKeyPoints->Add(sigma,i,j,o,l,-PI/2+incr*(b+.5)); 00293 } 00294 } 00295 } 00297 //find 3 histogram values closest to each peak, and fit a parabola 00298 //for better accuracy 00299 00300 k++; 00301 } 00302 ILOG_INFO("Total "<<mKeyPoints->Size()-OrigSize 00303 <<" new orientations assigned!"); 00304 return; 00305 }
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