| void Impala::Core::KeyPoint::DoG::LocalizeKeypoints | ( | ) | [inline] |
Definition at line 245 of file DoG.h.
References 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::Array::Octaves::GetOctave(), ILOG_INFO, Impala::Core::Array::Octaves::IsResamplingEnabled(), mCancelled, Impala::Core::KeyPoint::Detector::mKeyPoints, mOctaves, Impala::Core::Table::TableTem< Col1T, Col2T, Col3T, Col4T, Col5T, Col6T, Col7T, Col8T, Col9T >::Set2(), Impala::Core::Table::TableTem< Col1T, Col2T, Col3T, Col4T, Col5T, Col6T, Col7T, Col8T, Col9T >::Set3(), Impala::Application::DemoCamera2d::sigma, and Impala::Core::Table::Table::Size().
Referenced by FindKeyPoints().
00246 { 00247 int k = 0 ; 00248 int OrigSize=mKeyPoints->Size(); 00249 ILOG_INFO("Localizing "<<OrigSize<<" Keypoints"); 00250 int new_i; 00251 int new_j; 00252 int last=0; 00253 int count=0; 00254 mCancelled=0; 00255 double H[4]; 00256 double G[2]; 00257 double S[2]; 00258 Real64 Dx=0; 00259 Array2dScalarReal64* Octave; 00261 //form the Hessian matrix &Gradient vector around each point, 00262 //and find the shift from 00263 // -inv((Hessian(A))*Grad(A)) : evaluated at the keypoint 00264 while(k<OrigSize) 00265 { 00266 Real64 sigma=mKeyPoints->Get1(k); 00267 int i = mKeyPoints->Get2(k); 00268 int j = mKeyPoints->Get3(k); 00269 int o = mKeyPoints->Get4(k); 00270 int l = mKeyPoints->Get5(k); 00271 00272 00273 Octave=mOctaves->GetOctave(o,l); 00274 00275 int Width=mOctaves->GetOctave(o,l)->CW(); 00276 int Height=mOctaves->GetOctave(o,l)->CH(); 00277 00278 00279 //dd stands for derivative distance..something I just made up now-) 00280 int dd; 00281 00283 // If resampling is enabled, we have already reduced 00284 // the scale by two at every octave(doubling of sigma). 00285 // Therefore the derivative is the immediate neighbors. 00286 // 00287 // Otherwise we have to jump as much as one sigma for a derivative, 00288 // since the images are not scaled down as well. 00289 if(mOctaves->IsResamplingEnabled()) 00290 dd=1; 00291 else 00292 dd=sigma; 00293 00294 //ILOG_DEBUG("Using "<<dd<<" as der.distance @ ("<<o<<","<<l<<")"); 00295 if((i+2*dd>=Width)||(j+2*dd>=Height)||(i-2*dd<0)||(j-2*dd<0)) 00296 { 00297 //ILOG_WARN("Should cancel the keypoint"); 00298 mCancelled++; 00299 mKeyPoints->Set2(k,0); 00300 mKeyPoints->Set3(k,0); 00301 count=0; 00302 k++; 00303 last=k; 00304 continue; 00305 } 00306 00307 00308 00309 //Second row of Hessian 00310 //this is the first derivative wrt. x 00311 //[ -1 0 1 ] 00312 G[0] = Octave->Value(i+dd,j) - Octave->Value(i-dd,j); 00313 00314 00315 //second derivative wrt. x 00316 //[ 1 0 -2 0 1 ] 00317 H[0]= -2*Octave->Value(i,j) + 00318 Octave->Value(i-2*dd,j) + 00319 Octave->Value(i+2*dd,j) ; 00320 /* Second Derivative 00321 [ 1 0 -1] 00322 [ 0 0 0] 00323 [-1 0 1]*/ 00324 //second derivative wrt. y 00325 H[1]= Octave->Value(i-dd,j-dd) + 00326 Octave->Value(i+dd,j+dd) - 00327 Octave->Value(i-dd,j+dd) - 00328 Octave->Value(i+dd,j-dd) ; 00329 00330 //Third row of Hessian 00331 //this is the first derivative wrt. y 00332 G[1] = Octave->Value(i,j+dd) - Octave->Value(i,j-dd); 00333 00334 //second derivative wrt. y 00335 //[ 1 0 -2 0 1 ] 00336 H[2]= -2*Octave->Value(i,j) + 00337 Octave->Value(i,j-2*dd) + 00338 Octave->Value(i,j+2*dd) ; 00339 00340 /* Second Derivative 00341 [ 1 0 -1] 00342 [ 0 0 0] 00343 [-1 0 1]*/ 00344 //second derivative wrt. y 00345 H[3]= Octave->Value(i-dd,j-dd) + Octave->Value(i+dd,j+dd) - 00346 Octave->Value(i-dd,j+dd) - Octave->Value(i+dd,j-dd) ; 00347 00348 Real64 div = H[0]*H[3]-H[1]*H[2]; 00349 S[0]=(-H[3]*G[0]+H[1]*G[1])/div; 00350 S[1]=(H[2]*G[0]-H[0]*G[1])/div; 00351 00352 Dx= Octave->Value(i,j)+.5*(S[0]*G[0]+S[1]+G[1]); 00353 if(Dx<.03){ 00354 //ILOG_WARN("Should cancel the keypoint"); 00355 mCancelled++; 00356 mKeyPoints->Set2(k,0); 00357 mKeyPoints->Set3(k,0); 00358 count=0; 00359 k++; 00360 last=k; 00361 continue; 00362 } 00363 //advance to the next keypoint 00364 if(!((S[0]> 0.5)||(S[1]> 0.5)||(S[0]<-.5)||(S[1]<-.5))){ 00365 k++; 00366 last=k; 00367 count=0; 00368 }else{ 00369 new_i=i+S[0]; 00370 new_j=j+S[1]; 00371 if((new_i>0)&&(new_i<Width)){ 00372 mKeyPoints->Set2(k,new_i); 00373 }else{ 00374 //ILOG_INFO("Keypoint "<<k<<" : Location out of border"); 00375 count=0; 00376 k++; 00377 last=k; 00378 continue; 00379 } 00380 00381 00382 if((new_j>0)&&(new_j<Height)){ 00383 mKeyPoints->Set3(k,new_j); 00384 }else{ 00385 //ILOG_INFO("Keypoint "<<k<<" : Location out of border"); 00386 count=0; 00387 k++; 00388 last=k; 00389 continue; 00390 } 00391 00392 if(last==k) 00393 count++; 00394 /* 00395 ILOG_DEBUG("Keypoint "<<k<<" : Location shifted!("<<count<<")"); 00396 ILOG_DEBUG("Estimated Shift : "<<S[0]<<"x"<<S[1]); 00397 */ 00398 00399 if(count>10){ 00400 k++; 00401 last=k; 00402 count=0; 00403 } 00404 } 00405 00406 } 00407 ILOG_INFO("Cancel count:"<<mCancelled<<"/"<<OrigSize); 00408 00409 }
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