void matchSurf(int dimDesc, std::vector<float>& desc0,
std::vector<float>& desc1, Matching& matches, float ratio,
float maxDist) {
int len0 = (int) desc0.size();
int len1 = (int) desc1.size();
assert(len0 % dimDesc == 0 && len1 %dimDesc == 0);
int npts0 = len0 / dimDesc;
int npts1 = len1 / dimDesc;
matches.clear();
matches.reserve(npts0 > npts1 ? npts0 : npts1);
float dist, d1, d2;
for (int i = 0; i < npts0; i++) {
d1 = d2 = FLT_MAX;
int jMin = -1;
for (int j = 0; j < npts1; j++) {
dist = computeSurfDescDist(&desc0[0] + i * dimDesc,
&desc1[0] + j * dimDesc, dimDesc);
if (dist < d1) {
d2 = d1;
d1 = dist;
jMin = j;
} else if (dist < d2)
d2 = dist;
}
if (d1 < maxDist && d1 / d2 < ratio) {
matches.add(i, jMin, d1);
}
}
}
void matchSurf(const Mat_f& kdesc0, const Mat_f& kdesc1, Matching& matches,
float ratio) {
assert(kdesc0.rows > 0);
assert(kdesc0.cols == kdesc1.cols);
int dimDesc = kdesc0.cols;
matches.clear();
matches.reserve(std::max(kdesc0.rows, kdesc1.rows));
float dist, d1, d2;
for (int i = 0; i < kdesc0.rows; i++) {
d1 = d2 = FLT_MAX;
int jMin = -1;
for (int j = 0; j < kdesc1.rows; j++) {
dist = computeSurfDescDist(kdesc0.data + i * dimDesc,
kdesc1.data + j * dimDesc, dimDesc);
if (dist < d1) // if this feature matches better than current best
{
d2 = d1;
d1 = dist;
jMin = j;
} else if (dist < d2) // this feature matches better than second best
{
d2 = dist;
}
}
// If match has a d1:d2 ratio < 0.65 ipoints are a match
if (d1 / d2 < ratio) {
matches.add(i, jMin, d1);
}
}
}
int refineMatchedPoints(const Mat_d& pts1, const Mat_d& pts2, Matching& matches,
Matching& newMatches, double ratio) {
double ud[2] = { 0, 0 };
Mat_d d(matches.num, 2);
int num = matches.num;
for (int i = 0; i < num; i++) {
int idx1 = matches[i].idx1;
int idx2 = matches[i].idx2;
d.data[2 * i] = pts2.data[2 * idx2] - pts1.data[2 * idx1];
d.data[2 * i + 1] = pts2.data[2 * idx2 + 1] - pts1.data[2 * idx1 + 1];
ud[0] += d.data[2 * i];
ud[1] += d.data[2 * i + 1];
}
ud[0] /= num;
ud[1] /= num;
double cov[4] = { 0, 0, 0, 0 };
for (int i = 0; i < num; i++) {
double dx = d.data[2 * i] - ud[0];
double dy = d.data[2 * i + 1] - ud[1];
cov[0] += dx * dx;
cov[1] += dx * dy;
cov[3] += dy * dy;
}
double s = ratio * ratio;
cov[0] /= num / s;
cov[1] /= num / s;
cov[3] /= num / s;
cov[2] = cov[1];
double icov[4];
mat22Inv(cov, icov);
newMatches.clear();
newMatches.reserve(num);
for (int i = 0; i < num; i++) {
double dx = d.data[2 * i] - ud[0];
double dy = d.data[2 * i + 1] - ud[1];
double dist = dx * dx * icov[0] + 2 * dx * dy * icov[1]
+ dy * dy * icov[2];
if (dist < 1.0) {
newMatches.add(matches[i].idx1, matches[i].idx2, 0);
}
}
return newMatches.num;
}
/** match SURF feature points between two views*/
int NewMapPtsSURF::matchBetween(int iCam, int jCam, Matching& matches) {
std::vector<float>& desc1 = surfDescs[iCam];
std::vector<float>& desc2 = surfDescs[jCam];
int dim = m_descDim;
std::vector<cv::DMatch> matches1, matches2;
cv::Mat matDesc1(desc1.size() / dim, dim, CV_32F, &desc1[0]);
cv::Mat matDesc2(desc2.size() / dim, dim, CV_32F, &desc2[0]);
cv::BruteForceMatcher<cv::L2<float> > matcher;
matcher.match(matDesc1, matDesc2, matches1);
matcher.match(matDesc2, matDesc1, matches2);
//test
cv::Mat img1(m_img[iCam].rows, m_img[iCam].cols, CV_8UC1, m_img[iCam].data);
cv::Mat img2(m_img[jCam].rows, m_img[jCam].cols, CV_8UC1, m_img[jCam].data);
cv::Mat outImg;
cv::drawMatches(img1, surfPoints[iCam], img2, surfPoints[jCam], matches1, outImg);
cv::imwrite("/home/tsou/test.bmp", outImg);
//cross validation
std::vector<int> ind1;
ind1.assign(surfPoints[iCam].size(), -1);
for (size_t j = 0; j < matches1.size(); j++) {
int idx1 = matches1[j].queryIdx;
int idx2 = matches1[j].trainIdx;
ind1[idx1] = idx2;
}
matches.clear();
matches.reserve(matches2.size());
for (size_t j = 0; j < matches2.size(); j++) {
int idx2 = matches2[j].queryIdx;
int idx1 = matches2[j].trainIdx;
if (ind1[idx1] == idx2) {
matches.add(idx1, idx2, matches2[j].distance);
}
}
return matches.num;
}
