void compute_sift_matches(
keypointslist& keys1, keypointslist& keys2,
matchingslist& matchings,siftPar &par)
{
int imatch=0;
float sqminratio = par.MatchRatio * par.MatchRatio,
sqratio;
// write the keypoint descriptors in char
keypointslist_short keys1_short(keys1.size());
for (int i=0; i< (int) keys1.size(); i++)
{
keys1_short[i].x = keys1[i].x;
keys1_short[i].y = keys1[i].y;
keys1_short[i].scale = keys1[i].scale;
keys1_short[i].angle = keys1[i].angle;
for (int k=0; k < VecLength; k++)
{
keys1_short[i].vec[k] = (unsigned short) (keys1[i].vec[k]);
}
}
keypointslist_short keys2_short(keys2.size());
for (int i=0; i< (int) keys2.size(); i++)
{
keys2_short[i].x = keys2[i].x;
keys2_short[i].y = keys2[i].y;
keys2_short[i].scale = keys2[i].scale;
keys2_short[i].angle = keys2[i].angle;
for (int k=0; k < VecLength; k++)
{
keys2_short[i].vec[k] = (unsigned short) (keys2[i].vec[k]);
}
}
for (int i=0; i< (int) keys1.size(); i++) {
// sqratio = CheckForMatch(keys1[i], keys2, imatch,par);
sqratio = CheckForMatch_short(keys1_short[i], keys2_short, imatch,par);
if (sqratio< sqminratio){
//std::cout << "ok:" << sqratio << " , " << std::endl;
matchings.push_back( matching(keys1[i],keys2[imatch] ));
}else{
//std::cout << "ng:" << sqratio << " , " << std::endl;
}
// matchings.push_back( matching_char(keys1_char[i],keys2_char[imatch] ));
}
}
void compute_sift_matches(
keypointslist& keys1, keypointslist& keys2,
matchingslist& matchings,siftPar &par)
{
float sqminratio = par.MatchRatio * par.MatchRatio;
for (keypointslist::size_type i=0; i< keys1.size(); i++) {
keypointslist::size_type imatch=0;
float sqratio = CheckForMatch(keys1[i], keys2, imatch,par);
if(sqratio < sqminratio)
matchings.push_back( Match(keys1[i].x,keys1[i].y,
keys2[imatch].x, keys2[imatch].y) );
}
}
/* Remove the repetitive matches that appear in different simulations and retain only one */
void unique_match1(matchingslist &seg_in, matchingslist &seg_out, vector< vector <float> > &Minfoall_in, vector< vector <float> > &Minfoall_out)
{
int i_in, i_out;
float x1_in, x2_in, y1_in, y2_in, x1_out, x2_out, y1_out, y2_out;
int flag_unique;
float d1, d2;
int Th2 = 2;
seg_out.push_back(seg_in[0]);
Minfoall_out.push_back(Minfoall_in[0]);
/* For other matches */
if ( seg_in.size() > 1 )
{
/* check if a match is unique. if yes, copy */
matchingslist::iterator ptr_in = seg_in.begin();
for ( i_in = 1; i_in < (int) seg_in.size(); i_in++, ptr_in++ )
{
x1_in = ptr_in->first.x;
y1_in = ptr_in->first.y;
x2_in = ptr_in->second.x;
y2_in = ptr_in->second.y;
flag_unique = 1;
matchingslist::iterator ptr_out = seg_out.begin();
for ( i_out = 0; i_out < (int) seg_out.size(); i_out++, ptr_out++ )
{
x1_out = ptr_out->first.x;
y1_out = ptr_out->first.y;
x2_out = ptr_out->second.x;
y2_out = ptr_out->second.y;
d1 = (x1_in - x1_out)*(x1_in - x1_out) + (y1_in - y1_out)*(y1_in - y1_out);
d2 = (x2_in - x2_out)*(x2_in - x2_out) + (y2_in - y2_out)*(y2_in - y2_out);
if ( ( d1 <= Th2) && ( d2 <= Th2) )
{
flag_unique = 0;
continue;
}
}
if ( flag_unique == 1 )
{
seg_out.push_back(seg_in[i_in]);
Minfoall_out.push_back(Minfoall_in[i_in]);
}
}
}
}
int compute_asift_matches(int num_of_tilts1, int num_of_tilts2, int w1, int h1, int w2, int h2, int verb, vector< vector< keypointslist > >& keys1, vector< vector< keypointslist > >& keys2, matchingslist &matchings, siftPar &siftparameters)
// Match the ASIFT keypoints.
// Input:
// num_of_tilts1, num_of_tilts2: number of tilts that have been simulated on the two images. (They can be different.)
// w1, h1, w2, h2: widht/height of image1/image2.
// verb: 1/0 --> show/don not show verbose messages. (1 for debugging)
// keys1, keys2: ASIFT keypoints of image1/image2. (They should be calculated with compute_asift_keypoints.)
// matchings (output): the coordinates (col1, row1, col2, row2) of all the matching points.
//
// Output: the number of matching points.
{
float t_min, t_k, t;
int num_tilt1, num_tilt2, tt, num_rot_t2, num_rot1, rr;
int cc;
int tt2, rr2, num_rot1_2;
float t_im2;
/* It stores the coordinates of ALL matches points of ALL affine simulations */
vector< vector <float> > Minfoall;
int Tmin = 8;
float nfa_max = -2;
num_rot_t2 = 10;
t_min = 1;
t_k = sqrt(2.);
num_tilt1 = num_of_tilts1;
num_tilt2 = num_of_tilts2;
if ( ( num_tilt1 < 1 ) || ( num_tilt2 < 1 ) )
{
printf("Number of tilts num_tilt should be equal or larger than 1. \n");
exit(-1);
}
/* Initialize the vector structure for the matching points */
std::vector< vector< vector < vector < matchingslist > > > > matchings_vec(num_tilt1);
std::vector< vector< vector< vector< vector< vector <float> > > > > > Minfoall_vec(num_tilt1);
for (tt = 1; tt <= num_tilt1; tt++)
{
t = t_min * pow(t_k, tt-1);
if ( t == 1 )
{
num_rot1 = 1;
}
else
{
num_rot1 = round(num_rot_t2*t/2);
if ( num_rot1%2 == 1 )
{
num_rot1 = num_rot1 + 1;
}
num_rot1 = num_rot1 / 2;
}
matchings_vec[tt-1].resize(num_rot1);
Minfoall_vec[tt-1].resize(num_rot1);
for ( rr = 1; rr <= num_rot1; rr++ )
{
matchings_vec[tt-1][rr-1].resize(num_tilt2);
Minfoall_vec[tt-1][rr-1].resize(num_tilt2);
for (tt2 = 1; tt2 <= num_tilt2; tt2++)
{
t_im2 = t_min * pow(t_k, tt2-1);
if ( t_im2 == 1 )
{
num_rot1_2 = 1;
}
else
{
num_rot1_2 = round(num_rot_t2*t_im2/2);
if ( num_rot1_2%2 == 1 )
{
num_rot1_2 = num_rot1_2 + 1;
}
num_rot1_2 = num_rot1_2 / 2;
}
matchings_vec[tt-1][rr-1][tt2-1].resize(num_rot1_2);
Minfoall_vec[tt-1][rr-1][tt2-1].resize(num_rot1_2);
}
}
}
///*
// * setup the tilt and rotation parameters
// * for all the loops, this vector will hold
// * the following parameters:
// * tt, num_rot1, rr, tt2, num_rot1_2, rr2
// */
//vector<int> tilt_rot;
///* loop on tilts for image 1 */
//for (int tt = 1; tt <= num_tilt1; tt++)
//{
// float t = t_min * pow(t_k, tt-1);
// int num_rot1;
// /* if tilt t = 1, do not simulate rotation. */
// if ( 1 == tt )
// num_rot1 = 1;
// else
// {
// /* number of rotations to simulate */
// num_rot1 = round(num_rot_t2 * t / 2);
// if ( num_rot1%2 == 1 )
// num_rot1 = num_rot1 + 1;
// num_rot1 = num_rot1 / 2;
// }
// /* loop on rotations for image 1 */
// for (int rr = 1; rr <= num_rot1; rr++ )
// {
// /* loop on tilts for image 2 */
// for (int tt2 = 1; tt2 <= num_tilt2; tt2++)
// {
// float t_im2 = t_min * pow(t_k, tt2-1);
// int num_rot1_2;
// if ( tt2 == 1 )
// num_rot1_2 = 1;
// else
// {
// num_rot1_2 = round(num_rot_t2 * t_im2 / 2);
// if ( num_rot1_2%2 == 1 )
// num_rot1_2 = num_rot1_2 + 1;
// num_rot1_2 = num_rot1_2 / 2;
// }
// /* loop on rotations for image 2 */
// for (int rr2 = 1; rr2 <= num_rot1_2; rr2++ )
// {
// tilt_rot.push_back(tt);
// tilt_rot.push_back(num_rot1);
// tilt_rot.push_back(rr);
// tilt_rot.push_back(tt2);
// tilt_rot.push_back(num_rot1_2);
// tilt_rot.push_back(rr2);
// }
// }
// }
//}
/* Calculate the number of simulations */
#ifdef _OPENMP
omp_set_nested(1);
#endif
// loop on tilts for image 1.
#pragma omp parallel for private(tt)
for (int tt = 1; tt <= num_tilt1; tt++)
{
float t = t_min * pow(t_k, tt-1);
/* Attention: the t1, t2 do not follow the same convention as in compute_asift_keypoints */
float t1 = t;
float t2 = 1;
int num_rot1;
// If tilt t = 1, do not simulate rotation.
if ( tt == 1 )
{
num_rot1 = 1;
}
else
{
// The number of rotations to simulate under the current tilt.
num_rot1 = round(num_rot_t2*t/2);
if ( num_rot1%2 == 1 )
{
num_rot1 = num_rot1 + 1;
}
num_rot1 = num_rot1 / 2;
}
float delta_theta = PI/num_rot1;
// Loop on rotations for image 1.
#pragma omp parallel for private(rr)
for ( int rr = 1; rr <= num_rot1; rr++ )
{
float theta = delta_theta * (rr-1);
theta = theta * 180 / PI;
/* Read the keypoints of image 1 */
keypointslist keypoints1 = keys1[tt-1][rr-1];
// loop on tilts for image 2.
#pragma omp parallel for private(tt2)
for (int tt2 = 1; tt2 <= num_tilt2; tt2++)
{
float t_im2 = t_min * pow(t_k, tt2-1);
/* Attention: the t1, t2 do not follow the same convention as in asift_v1.c */
float t_im2_1 = t_im2;
float t_im2_2 = 1;
int num_rot1_2;
if ( tt2 == 1 )
{
num_rot1_2 = 1;
}
else
{
num_rot1_2 = round(num_rot_t2*t_im2/2);
if ( num_rot1_2%2 == 1 )
{
num_rot1_2 = num_rot1_2 + 1;
}
num_rot1_2 = num_rot1_2 / 2;
}
float delta_theta2 = PI/num_rot1_2;
#pragma omp parallel for private(rr2)
// Loop on rotations for image 2.
for ( int rr2 = 1; rr2 <= num_rot1_2; rr2++ )
{
float theta2 = delta_theta2 * (rr2-1);
theta2 = theta2 * 180 / PI;
/* Read the keypoints of image2. */
keypointslist keypoints2 = keys2[tt2-1][rr2-1];
// Match the keypoints of image1 and image2.
matchingslist matchings1;
compute_sift_matches(keypoints1,keypoints2,matchings1,siftparameters);
if ( verb )
{
printf("t1=%.2f, theta1=%.2f, num keys1 = %d, t2=%.2f, theta2=%.2f, num keys2 = %d, num matches=%d\n", t, theta, (int) keypoints1.size(), t_im2, theta2, (int) keypoints2.size(), (int) matchings1.size());
}
/* Store the matches */
if ( matchings1.size() > 0 )
{
matchings_vec[tt-1][rr-1][tt2-1][rr2-1] = matchingslist(matchings1.size());
Minfoall_vec[tt-1][rr-1][tt2-1][rr2-1].resize(matchings1.size());
for ( int cc = 0; cc < (int) matchings1.size(); cc++ )
{
///// In the coordinates the affine transformations have been normalized already in compute_asift_keypoints. So no need to normalize here.
// Normalize the coordinates of the matched points by compensating the simulate affine transformations
// compensate_affine_coor(matchings1[cc], w1, h1, w2, h2, t1, t2, theta, t_im2_1, t_im2_2, theta2);
matchings_vec[tt-1][rr-1][tt2-1][rr2-1][cc] = matchings1[cc];
vector<float> Minfo_1match(6);
Minfo_1match[0] = t1;
Minfo_1match[1] = t2;
Minfo_1match[2] = theta;
Minfo_1match[3] = t_im2_1;
Minfo_1match[4] = t_im2_2;
Minfo_1match[5] = theta2;
Minfoall_vec[tt-1][rr-1][tt2-1][rr2-1][cc] = Minfo_1match;
}
}
}
}
}
}
// Move the matches to a 1D vector
for (tt = 1; tt <= num_tilt1; tt++)
{
t = t_min * pow(t_k, tt-1);
if ( t == 1 )
{
num_rot1 = 1;
}
else
{
num_rot1 = round(num_rot_t2*t/2);
if ( num_rot1%2 == 1 )
{
num_rot1 = num_rot1 + 1;
}
num_rot1 = num_rot1 / 2;
}
for ( rr = 1; rr <= num_rot1; rr++ )
{
for (tt2 = 1; tt2 <= num_tilt2; tt2++)
{
t_im2 = t_min * pow(t_k, tt2-1);
if ( t_im2 == 1 )
{
num_rot1_2 = 1;
}
else
{
num_rot1_2 = round(num_rot_t2*t_im2/2);
if ( num_rot1_2%2 == 1 )
{
num_rot1_2 = num_rot1_2 + 1;
}
num_rot1_2 = num_rot1_2 / 2;
}
for ( rr2 = 1; rr2 <= num_rot1_2; rr2++ )
{
for ( cc=0; cc < (int) matchings_vec[tt-1][rr-1][tt2-1][rr2-1].size(); cc++ )
{
matchings.push_back(matchings_vec[tt-1][rr-1][tt2-1][rr2-1][cc]);
Minfoall.push_back(Minfoall_vec[tt-1][rr-1][tt2-1][rr2-1][cc]);
}
}
}
}
}
if ( verb )
{
printf("The number of matches is %d \n", (int) matchings.size());
}
if ( matchings.size() > 0 )
{
/* Remove the repetitive matches that appear in different simulations and retain only one. */
// Since tilts are simuated on both image 1 and image 2, it is normal to have repetitive matches.
matchingslist matchings_unique;
vector< vector<float> > Minfoall_unique;
unique_match1(matchings, matchings_unique, Minfoall, Minfoall_unique);
matchings = matchings_unique;
Minfoall = Minfoall_unique;
if ( verb )
{
printf("The number of unique matches is %d \n", (int) matchings.size());
}
// There often appear to be some one-to-multiple/multiple-to-one matches (one point in image 1 matches with many points in image 2/vice versa).
// This is an artifact of SIFT on interpolated images, as the interpolation tends to create some auto-similar structures (steps for example).
// These matches need to be removed.
/* Separating the removal of multiple-to-one and one-to-multiple in two steps:
- first remove multiple-to-one
- then remove one-to-multiple
This allows to avoid removing some good matches: multiple-to-one matches is much more frequent than one-to-multiple. Sometimes some of the feature points in image 1 that take part in "multiple-to-one" bad matches have also correct matches in image 2. The modified scheme avoid removing these good matches. */
// Remove to multiple-to-one matches
matchings_unique.clear();
Minfoall_unique.clear();
clean_match2(matchings, matchings_unique, Minfoall, Minfoall_unique);
matchings = matchings_unique;
Minfoall = Minfoall_unique;
// Remove to one-to-multiple matches
matchings_unique.clear();
Minfoall_unique.clear();
clean_match1(matchings, matchings_unique, Minfoall, Minfoall_unique);
matchings = matchings_unique;
Minfoall = Minfoall_unique;
if ( verb )
{
printf("The number of final matches is %d \n", (int) matchings.size());
}
// If enough matches to do epipolar filtering
if ( (int) matchings.size() >= Tmin )
{
//////// Use ORSA to filter out the incorrect matches.
// store the coordinates of the matching points
vector<Match> match_coor;
for ( cc = 0; cc < (int) matchings.size(); cc++ )
{
Match match1_coor;
match1_coor.x1 = matchings[cc].first.x;
match1_coor.y1 = matchings[cc].first.y;
match1_coor.x2 = matchings[cc].second.x;
match1_coor.y2 = matchings[cc].second.y;
match_coor.push_back(match1_coor);
}
std::vector<float> index;
// Guoshen Yu, 2010.09.23
// index.clear();
int t_value_orsa=10000;
int verb_value_orsa=0;
int n_flag_value_orsa=0;
int mode_value_orsa=2;
int stop_value_orsa=0;
// epipolar filtering with the Moisan-Stival ORSA algorithm.
// float nfa = orsa(w1, h1, match_coor, index, t_value_orsa, verb_value_orsa, n_flag_value_orsa, mode_value_orsa, stop_value_orsa);
float nfa = orsa((w1+w2)/2, (h1+h2)/2, match_coor, index, t_value_orsa, verb_value_orsa, n_flag_value_orsa, mode_value_orsa, stop_value_orsa);
// if the matching is significant, register the good matches
if ( nfa < nfa_max )
{
// extract meaningful matches
matchings_unique.clear();
Minfoall_unique.clear();
for ( cc = 0; cc < (int) index.size(); cc++ )
{
matchings_unique.push_back(matchings[(int)index[cc]]);
Minfoall_unique.push_back(Minfoall[(int)index[cc]]);
}
matchings = matchings_unique;
Minfoall = Minfoall_unique;
cout << "The two images match! " << matchings.size() << " matchings are identified. log(nfa)=" << nfa << "." << endl;
}
else
{
matchings.clear();
Minfoall.clear();
cout << "The two images do not match. The matching is not significant: log(nfa)=" << nfa << "." << endl;
}
}
else
{
matchings.clear();
Minfoall.clear();
cout << "The two images do not match. Not enough matches to do epipolar filtering." << endl;
}
}
else
{
cout << "The two images do not match.\n" << endl;
}
return matchings.size();
}
/* Remove the ALL multiple-to-one matches */
void clean_match2(matchingslist &seg_in, matchingslist &seg_out, vector< vector <float> > &Minfoall_in, vector< vector <float> > &Minfoall_out)
{
int i1, i2;
float x1_in, x2_in, y1_in, y2_in, x1_out, x2_out, y1_out, y2_out;
// Guoshen Yu, 2010.09.22, Windows version
// int flag_unique[seg_in.size()];
int tmp_size = seg_in.size();
int *flag_unique = new int[tmp_size];
int sum_flag=0;
float d1, d2;
int Th1 = 1;
int Th2 = 4;
for ( i1 = 0; i1 < (int) seg_in.size(); i1++ )
{
flag_unique[i1] = 1;
}
/* Set the flag of redundant matches to 0. */
matchingslist::iterator ptr_in = seg_in.begin();
for ( i1 = 0; i1 < (int) seg_in.size() - 1; i1++, ptr_in++ )
{
x1_in = ptr_in->first.x;
y1_in = ptr_in->first.y;
x2_in = ptr_in->second.x;
y2_in = ptr_in->second.y;
matchingslist::iterator ptr_out = ptr_in+1;
for ( i2 = i1 + 1; i2 < (int) seg_in.size(); i2++, ptr_out++ )
{
x1_out = ptr_out->first.x;
y1_out = ptr_out->first.y;
x2_out = ptr_out->second.x;
y2_out = ptr_out->second.y;
d1 = (x1_in - x1_out)*(x1_in - x1_out) + (y1_in - y1_out)*(y1_in - y1_out);
d2 = (x2_in - x2_out)*(x2_in - x2_out) + (y2_in - y2_out)*(y2_in - y2_out);
/* If redundant, set flags of both elements to 0.*/
if ( ( d1 > Th2) && ( d2 <= Th1) )
{
flag_unique[i1] = 0;
flag_unique[i2] = 0;
}
}
}
for ( i1 = 0; i1 < (int) seg_in.size(); i1++ )
{
sum_flag += flag_unique[i1];
}
/* Copy the matches that are not redundant */
if ( sum_flag > 0 )
{
for ( i1 = 0; i1 < (int) seg_in.size(); i1++ )
{
if ( flag_unique[i1] == 1 )
{
seg_out.push_back(seg_in[i1]);
Minfoall_out.push_back(Minfoall_in[i1]);
}
}
}
else
{
printf("Warning: all matches are redundant and are thus removed! This step of match cleaning is short circuited. (Normally this should not happen...)\n");
}
// Guoshen Yu, 2010.09.22, Windows version
delete [] flag_unique;
}