/** \brief Checks if a patch at a specific image location is still within the reference image.
*
* @param img - Reference Image.
* @param c - Coordinates of the patch in the reference image.
* @param withBorder - Check, using either the patch-patchSize of Patch::patch_ (withBorder = false) or the patch-patchSize
* of the expanded patch Patch::patchWithBorder_ (withBorder = true).
* @return true, if the patch is completely located within the reference image.
*/
static bool isPatchInFrame(const cv::Mat& img,const FeatureCoordinates& c,const bool withBorder = false){
if(c.isInFront() && c.com_warp_c()){
const int halfpatch_size = patchSize/2+(int)withBorder;
if(c.isNearIdentityWarping()){
if(c.get_c().x < halfpatch_size || c.get_c().y < halfpatch_size || c.get_c().x > img.cols-halfpatch_size || c.get_c().y > img.rows-halfpatch_size){
return false;
} else {
return true;
}
} else {
for(int x = 0;x<2;x++){
for(int y = 0;y<2;y++){
const float dx = halfpatch_size*(2*x-1);
const float dy = halfpatch_size*(2*y-1);
const float wdx = c.get_warp_c()(0,0)*dx + c.get_warp_c()(0,1)*dy;
const float wdy = c.get_warp_c()(1,0)*dx + c.get_warp_c()(1,1)*dy;
const float c_x = c.get_c().x + wdx;
const float c_y = c.get_c().y + wdy;
if(c_x < 0 || c_y < 0 || c_x > img.cols || c_y > img.rows){
return false;
}
}
}
return true;
}
} else {
return false;
}
}
/** \brief Draws the patch borders into an image.
*
* @param drawImg - Image in which the patch borders should be drawn.
* @param s - Scaling factor.
* @param color - Line color.
*/
void drawMultilevelPatchBorder(cv::Mat& drawImg,const FeatureCoordinates& c,const float s, const cv::Scalar& color,const FeatureWarping* mpWarp = nullptr) const{
if(!c.isInFront()) return;
if(mpWarp == nullptr){
patches_[0].drawPatchBorder(drawImg,c.get_c(),s*pow(2.0,nLevels-1),color,Eigen::Matrix2f::Identity());
} else {
if(mpWarp->com_affineTransform(&c)){
patches_[0].drawPatchBorder(drawImg,c.get_c(),s*pow(2.0,nLevels-1),color,mpWarp->get_affineTransform(&c));
}
}
}
/** \brief Extracts a multilevel patch from a given image pyramid.
*
* @param pyr - Image pyramid from which the patch data should be extracted.
* @param l - Patches are extracted from pyramid level 0 to l.
* @param mpCoor - Coordinates of the patch in the reference image (subpixel coordinates possible).
* @param mpWarp - Affine warping matrix. If nullptr not warping is considered.
* @param withBorder - If true, both, the general patches and the corresponding expanded patches are extracted.
*/
void extractMultilevelPatchFromImage(const ImagePyramid<nLevels>& pyr,const FeatureCoordinates& c, const int l = nLevels-1,const FeatureWarping* mpWarp = nullptr,const bool withBorder = false){
for(unsigned int i=0;i<=l;i++){
pyr.levelTranformCoordinates(c,coorTemp_,0,i);
isValidPatch_[i] = true;
if(mpWarp == nullptr){
patches_[i].extractPatchFromImage(pyr.imgs_[i],coorTemp_.get_c(),Eigen::Matrix2f::Identity(),withBorder);
} else {
patches_[i].extractPatchFromImage(pyr.imgs_[i],coorTemp_.get_c(),mpWarp->get_affineTransform(&c),withBorder);
}
}
}
/** \brief Checks if the MultilevelPatchFeature's patches are fully located within the corresponding images.
*
* @param pyr - Image pyramid, which should be checked to fully contain the patches.
* @param l - Maximal pyramid level which should be checked (Note: The maximal level is the critical level.)
* @param mpCoor - Coordinates of the patch in the reference image (subpixel coordinates possible).
* @param mpWarp - Affine warping matrix. If nullptr not warping is considered.
* @param withBorder - If true, the check is executed with the expanded patch dimensions (incorporates the general patch dimensions).
* If false, the check is only executed with the general patch dimensions.
*/
bool isMultilevelPatchInFrame(const ImagePyramid<nLevels>& pyr,const FeatureCoordinates& c, const int l = nLevels-1,const FeatureWarping* mpWarp = nullptr,const bool withBorder = false) const{
if(!c.isInFront()) return false;
pyr.levelTranformCoordinates(c,coorTemp_,0,l);
if(mpWarp == nullptr){
return patches_[l].isPatchInFrame(pyr.imgs_[l],coorTemp_.get_c(),Eigen::Matrix2f::Identity(),withBorder);
} else {
if(!mpWarp->com_affineTransform(&c)){
return false;
}
return patches_[l].isPatchInFrame(pyr.imgs_[l],coorTemp_.get_c(),mpWarp->get_affineTransform(&c),withBorder);
}
}
/** \brief Transforms pixel coordinates between two pyramid levels.
*
* @Note Invalidates camera and bearing vector, since the camera model is not valid for arbitrary image levels.
* @param cIn - Input coordinates
* @param cOut - Output coordinates
* @param l1 - Input pyramid level.
* @param l2 - Output pyramid level.
* @return the corresponding pixel coordinates on pyramid level l2.
*/
void levelTranformCoordinates(const FeatureCoordinates& cIn,FeatureCoordinates& cOut,const int l1, const int l2) const{
assert(l1<n_levels && l2<n_levels && l1>=0 && l2>=0);
cOut.set_c((centers_[l1]-centers_[l2])*pow(0.5,l2)+cIn.get_c()*pow(0.5,l2-l1));
if(cIn.mpCamera_ != nullptr){
if(cIn.com_warp_c()){
cOut.set_warp_c(cIn.get_warp_c());
}
}
cOut.camID_ = -1;
cOut.mpCamera_ = nullptr;
}
// Test align2D_old
TEST_F(MLPTesting, align2D_old) {
FeatureCoordinates cAligned;
c_.set_warp_identity();
c_.set_c(cv::Point2f(imgSize_/2,imgSize_/2));
mp_.extractMultilevelPatchFromImage(pyr2_,c_,nLevels_-1,true);
ASSERT_EQ(mpa_.align2D_old(cAligned,pyr2_,mp_,c_,0,nLevels_-1,100,1e-4),true);
ASSERT_NEAR(cAligned.get_c().x,imgSize_/2,1e-2);
ASSERT_NEAR(cAligned.get_c().y,imgSize_/2,1e-2);
c_.set_c(cv::Point2f(imgSize_/2+1,imgSize_/2+1));
ASSERT_EQ(mpa_.align2D_old(cAligned,pyr2_,mp_,c_,0,nLevels_-1,100,1e-4),true);
ASSERT_NEAR(cAligned.get_c().x,imgSize_/2,1e-2);
ASSERT_NEAR(cAligned.get_c().y,imgSize_/2,1e-2);
ASSERT_EQ(mpa_.align2D_old(cAligned,pyr2_,mp_,c_,0,0,100,1e-4),true);
ASSERT_NEAR(cAligned.get_c().x,imgSize_/2,1e-2);
ASSERT_NEAR(cAligned.get_c().y,imgSize_/2,1e-2);
ASSERT_EQ(mpa_.align2D_old(cAligned,pyr2_,mp_,c_,1,1,100,1e-4),false);
Eigen::Matrix2f aff;
aff << cos(M_PI/2.0), -sin(M_PI/2.0), sin(M_PI/2.0), cos(M_PI/2.0);
c_.set_warp_c(aff);
c_.set_c(cv::Point2f(imgSize_/2,imgSize_/2));
mp_.extractMultilevelPatchFromImage(pyr2_,c_,nLevels_-1,true);
ASSERT_EQ(mpa_.align2D_old(cAligned,pyr2_,mp_,c_,0,nLevels_-1,100,1e-4),true);
ASSERT_NEAR(cAligned.get_c().x,imgSize_/2,1e-2);
ASSERT_NEAR(cAligned.get_c().y,imgSize_/2,1e-2);
c_.set_c(cv::Point2f(imgSize_/2+1,imgSize_/2+1));
ASSERT_EQ(mpa_.align2D_old(cAligned,pyr2_,mp_,c_,0,nLevels_-1,100,1e-4),true);
ASSERT_NEAR(cAligned.get_c().x,imgSize_/2,1e-2);
ASSERT_NEAR(cAligned.get_c().y,imgSize_/2,1e-2);
ASSERT_EQ(mpa_.align2D_old(cAligned,pyr2_,mp_,c_,0,0,100,1e-4),true);
ASSERT_NEAR(cAligned.get_c().x,imgSize_/2,1e-2);
ASSERT_NEAR(cAligned.get_c().y,imgSize_/2,1e-2);
ASSERT_EQ(mpa_.align2D_old(cAligned,pyr2_,mp_,c_,1,1,100,1e-4),false);
}
/** \brief Image callback, handling the tracking of MultilevelPatchFeature%s.
*
* The sequence of the callback can be summarized as follows:
* 1. Extract image from message. Compute the image pyramid from the extracted image.
* 2. Predict the position of the valid MultilevelPatchFeature%s in the current image,
* using the previous 2 image locations of these MultilevelPatchFeature%s.
* 3. Execute 2D patch alignment at the predicted MultilevelPatchFeature locations.
* If successful the matching status of the MultilevelPatchFeature is set to FOUND and its image location is updated.
* 4. Prune: Check the MultilevelPatchFeature%s in the MultilevelPatchSet for their quality (MultilevelPatchFeature::isGoodFeature()).
* If a bad quality of a MultilevelPatchFeature is recognized, it is set to invalid.
* 5. Get new features and add them to the MultilevelPatchSet, if there are too little valid MultilevelPatchFeature%s
* in the MultilevelPatchSet. MultilevelPatchFeature%s which are stated invalid are replaced by new features.
*
* @param img_msg - Image message (ros)
*/
void imgCallback(const sensor_msgs::ImageConstPtr & img_msg){
// Get image from msg
cv_bridge::CvImagePtr cv_ptr;
try {
cv_ptr = cv_bridge::toCvCopy(img_msg, sensor_msgs::image_encodings::TYPE_8UC1);
} catch (cv_bridge::Exception& e) {
ROS_ERROR("cv_bridge exception: %s", e.what());
return;
}
cv_ptr->image.copyTo(img_);
// Timing
static double last_time = 0.0;
double current_time = img_msg->header.stamp.toSec();
// Pyramid
pyr_.computeFromImage(img_,true);
// Drawing
cvtColor(img_, draw_image_, CV_GRAY2RGB);
const int numPatchesPlot = 10;
draw_patches_ = cv::Mat::zeros(numPatchesPlot*(patchSize_*pow(2,nLevels_-1)+4),3*(patchSize_*pow(2,nLevels_-1)+4),CV_8UC1);
// Prediction
cv::Point2f dc;
for(unsigned int i=0;i<nMax_;i++){
if(fsm_.isValid_[i]){
dc = 0.75*(fsm_.features_[i].mpCoordinates_->get_c() - fsm_.features_[i].log_previous_.get_c());
fsm_.features_[i].log_previous_ = *(fsm_.features_[i].mpCoordinates_);
fsm_.features_[i].mpCoordinates_->set_c(fsm_.features_[i].mpCoordinates_->get_c() + dc);
if(!fsm_.features_[i].mpMultilevelPatch_->isMultilevelPatchInFrame(pyr_,*(fsm_.features_[i].mpCoordinates_),nLevels_-1,false)){
fsm_.features_[i].mpCoordinates_->set_c(fsm_.features_[i].log_previous_.get_c());
}
fsm_.features_[i].mpStatistics_->increaseStatistics(current_time);
for(int j=0;j<nCam_;j++){
fsm_.features_[i].mpStatistics_->status_[j] = UNKNOWN;
}
}
}
// Track valid features
FeatureCoordinates alignedCoordinates;
const double t1 = (double) cv::getTickCount();
for(unsigned int i=0;i<nMax_;i++){
if(fsm_.isValid_[i]){
fsm_.features_[i].log_prediction_ = *(fsm_.features_[i].mpCoordinates_);
if(alignment_.align2DComposed(alignedCoordinates,pyr_,*fsm_.features_[i].mpMultilevelPatch_,*fsm_.features_[i].mpCoordinates_,l2,l1,l1)){
fsm_.features_[i].mpStatistics_->status_[0] = TRACKED;
fsm_.features_[i].mpCoordinates_->set_c(alignedCoordinates.get_c());
fsm_.features_[i].log_previous_ = *(fsm_.features_[i].mpCoordinates_);
fsm_.features_[i].mpCoordinates_->drawPoint(draw_image_,cv::Scalar(0,255,255));
fsm_.features_[i].mpCoordinates_->drawLine(draw_image_,fsm_.features_[i].log_prediction_,cv::Scalar(0,255,255));
fsm_.features_[i].mpCoordinates_->drawText(draw_image_,std::to_string(i),cv::Scalar(0,255,255));
if(i==18){
for(int j=0;j<nLevels_;j++){
// std::cout << fsm_.features_[i].mpMultilevelPatch_->isValidPatch_[j] << std::endl;
// std::cout << fsm_.features_[i].mpMultilevelPatch_->patches_[j].dx_[0] << std::endl;
}
// std::cout << alignment_.A_.transpose() << std::endl;
// std::cout << alignment_.b_.transpose() << std::endl;
}
} else {
fsm_.features_[i].mpStatistics_->status_[0] = FAILED_ALIGNEMENT;
fsm_.features_[i].mpCoordinates_->drawPoint(draw_image_,cv::Scalar(0,0,255));
fsm_.features_[i].mpCoordinates_->drawText(draw_image_,std::to_string(fsm_.features_[i].idx_),cv::Scalar(0,0,255));
}
}
}
const double t2 = (double) cv::getTickCount();
ROS_INFO_STREAM(" Matching " << fsm_.getValidCount() << " patches (" << (t2-t1)/cv::getTickFrequency()*1000 << " ms)");
MultilevelPatch<nLevels_,patchSize_> mp;
for(unsigned int i=0;i<numPatchesPlot;i++){
if(fsm_.isValid_[i+10]){
fsm_.features_[i+10].mpMultilevelPatch_->drawMultilevelPatch(draw_patches_,cv::Point2i(2,2+i*(patchSize_*pow(2,nLevels_-1)+4)),1,false);
if(mp.isMultilevelPatchInFrame(pyr_,fsm_.features_[i+10].log_prediction_,nLevels_-1,false)){
mp.extractMultilevelPatchFromImage(pyr_,fsm_.features_[i+10].log_prediction_,nLevels_-1,false);
mp.drawMultilevelPatch(draw_patches_,cv::Point2i(patchSize_*pow(2,nLevels_-1)+6,2+i*(patchSize_*pow(2,nLevels_-1)+4)),1,false);
}
if(fsm_.features_[i+10].mpStatistics_->status_[0] == TRACKED
&& mp.isMultilevelPatchInFrame(pyr_,*fsm_.features_[i+10].mpCoordinates_,nLevels_-1,false)){
mp.extractMultilevelPatchFromImage(pyr_,*fsm_.features_[i+10].mpCoordinates_,nLevels_-1,false);
mp.drawMultilevelPatch(draw_patches_,cv::Point2i(2*patchSize_*pow(2,nLevels_-1)+10,2+i*(patchSize_*pow(2,nLevels_-1)+4)),1,false);
cv::rectangle(draw_patches_,cv::Point2i(0,i*(patchSize_*pow(2,nLevels_-1)+4)),cv::Point2i(patchSize_*pow(2,nLevels_-1)+3,(i+1)*(patchSize_*pow(2,nLevels_-1)+4)-1),cv::Scalar(255),2,8,0);
cv::rectangle(draw_patches_,cv::Point2i(patchSize_*pow(2,nLevels_-1)+4,i*(patchSize_*pow(2,nLevels_-1)+4)),cv::Point2i(2*patchSize_*pow(2,nLevels_-1)+7,(i+1)*(patchSize_*pow(2,nLevels_-1)+4)-1),cv::Scalar(255),2,8,0);
} else {
cv::rectangle(draw_patches_,cv::Point2i(0,i*(patchSize_*pow(2,nLevels_-1)+4)),cv::Point2i(patchSize_*pow(2,nLevels_-1)+3,(i+1)*(patchSize_*pow(2,nLevels_-1)+4)-1),cv::Scalar(0),2,8,0);
cv::rectangle(draw_patches_,cv::Point2i(patchSize_*pow(2,nLevels_-1)+4,i*(patchSize_*pow(2,nLevels_-1)+4)),cv::Point2i(2*patchSize_*pow(2,nLevels_-1)+7,(i+1)*(patchSize_*pow(2,nLevels_-1)+4)-1),cv::Scalar(0),2,8,0);
}
cv::putText(draw_patches_,std::to_string(fsm_.features_[i+10].idx_),cv::Point2i(2,2+i*(patchSize_*pow(2,nLevels_-1)+4)+10),cv::FONT_HERSHEY_SIMPLEX, 0.4, cv::Scalar(255));
}
}
// Prune
// Check the MultilevelPatchFeature%s in the MultilevelPatchSet for their quality (isGoodFeature(...)).
// If a bad quality of a MultilevelPatchFeature is recognized, it is set to invalid. New MultilevelPatchFeature%s
// replace the array places of invalid MultilevelPatchFeature%s in the MultilevelPatchSet.
int prune_count = 0;
for(unsigned int i=0;i<nMax_;i++){
if(fsm_.isValid_[i]){
if(fsm_.features_[i].mpStatistics_->status_[0] == FAILED_ALIGNEMENT){
fsm_.isValid_[i] = false;
prune_count++;
}
}
}
ROS_INFO_STREAM(" Pruned " << prune_count << " features");
// Extract feature patches
// Extract new MultilevelPatchFeature%s at the current tracked feature positions.
// Extracted multilevel patches are aligned with the image axes.
for(unsigned int i=0;i<nMax_;i++){
if(fsm_.isValid_[i]){
if(fsm_.features_[i].mpStatistics_->status_[0] == TRACKED
&& fsm_.features_[i].mpMultilevelPatch_->isMultilevelPatchInFrame(pyr_,*fsm_.features_[i].mpCoordinates_,nLevels_-1,true)){
fsm_.features_[i].mpMultilevelPatch_->extractMultilevelPatchFromImage(pyr_,*fsm_.features_[i].mpCoordinates_,nLevels_-1,true);
}
}
}
// Get new features, if there are too little valid MultilevelPatchFeature%s in the MultilevelPatchSet.
if(fsm_.getValidCount() < min_feature_count_){
std::vector<FeatureCoordinates> candidates;
ROS_INFO_STREAM(" Adding keypoints");
const double t1 = (double) cv::getTickCount();
for(int l=l1;l<=l2;l++){
pyr_.detectFastCorners(candidates,l,detectionThreshold);
}
const double t2 = (double) cv::getTickCount();
ROS_INFO_STREAM(" == Detected " << candidates.size() << " on levels " << l1 << "-" << l2 << " (" << (t2-t1)/cv::getTickFrequency()*1000 << " ms)");
// pruneCandidates(fsm_,candidates,0);
const double t3 = (double) cv::getTickCount();
// ROS_INFO_STREAM(" == Selected " << candidates.size() << " candidates (" << (t3-t2)/cv::getTickFrequency()*1000 << " ms)");
std::unordered_set<unsigned int> newSet = fsm_.addBestCandidates( candidates,pyr_,0,current_time,
l1,l2,max_feature_count_,nDetectionBuckets_, scoreDetectionExponent_,
penaltyDistance_, zeroDistancePenalty_,true,0.0);
const double t4 = (double) cv::getTickCount();
ROS_INFO_STREAM(" == Got " << fsm_.getValidCount() << " after adding " << newSet.size() << " features (" << (t4-t3)/cv::getTickFrequency()*1000 << " ms)");
for(auto it = newSet.begin();it != newSet.end();++it){
fsm_.features_[*it].log_previous_ = *(fsm_.features_[*it].mpCoordinates_);
for(int j=0;j<nCam_;j++){
fsm_.features_[*it].mpStatistics_->status_[j] = TRACKED;
}
}
}
cv::imshow("Tracker", draw_image_);
cv::imshow("Patches", draw_patches_);
cv::waitKey(30);
last_time = current_time;
}
/** \brief Extracts a patch from an image.
*
* @param img - Reference Image.
* @param c - Coordinates of the patch in the reference image (subpixel coordinates possible).
* @param withBorder - If false, the patch object is only initialized with the patch data of the general patch (Patch::patch_).
* If true, the patch object is initialized with both, the patch data of the general patch (Patch::patch_)
* and the patch data of the expanded patch (Patch::patchWithBorder_).
*/
void extractPatchFromImage(const cv::Mat& img,const FeatureCoordinates& c,const bool withBorder = false){
assert(isPatchInFrame(img,c,withBorder));
const int halfpatch_size = patchSize/2+(int)withBorder;
const int refStep = img.step.p[0];
// Get Pointers
uint8_t* img_ptr;
float* patch_ptr;
if(withBorder){
patch_ptr = patchWithBorder_;
} else {
patch_ptr = patch_;
}
if(c.isNearIdentityWarping()){
const int u_r = floor(c.get_c().x);
const int v_r = floor(c.get_c().y);
// compute interpolation weights
const float subpix_x = c.get_c().x-u_r;
const float subpix_y = c.get_c().y-v_r;
const float wTL = (1.0-subpix_x)*(1.0-subpix_y);
const float wTR = subpix_x * (1.0-subpix_y);
const float wBL = (1.0-subpix_x)*subpix_y;
const float wBR = subpix_x * subpix_y;
for(int y=0; y<2*halfpatch_size; ++y){
img_ptr = (uint8_t*) img.data + (v_r+y-halfpatch_size)*refStep + u_r-halfpatch_size;
for(int x=0; x<2*halfpatch_size; ++x, ++img_ptr, ++patch_ptr)
{
*patch_ptr = wTL*img_ptr[0];
if(subpix_x > 0) *patch_ptr += wTR*img_ptr[1];
if(subpix_y > 0) *patch_ptr += wBL*img_ptr[refStep];
if(subpix_x > 0 && subpix_y > 0) *patch_ptr += wBR*img_ptr[refStep+1];
}
}
} else {
for(int y=0; y<2*halfpatch_size; ++y){
for(int x=0; x<2*halfpatch_size; ++x, ++patch_ptr){
const float dx = x - halfpatch_size + 0.5;
const float dy = y - halfpatch_size + 0.5;
const float wdx = c.get_warp_c()(0,0)*dx + c.get_warp_c()(0,1)*dy;
const float wdy = c.get_warp_c()(1,0)*dx + c.get_warp_c()(1,1)*dy;
const float u_pixel = c.get_c().x+wdx - 0.5;
const float v_pixel = c.get_c().y+wdy - 0.5;
const int u_r = floor(u_pixel);
const int v_r = floor(v_pixel);
const float subpix_x = u_pixel-u_r;
const float subpix_y = v_pixel-v_r;
const float wTL = (1.0-subpix_x) * (1.0-subpix_y);
const float wTR = subpix_x * (1.0-subpix_y);
const float wBL = (1.0-subpix_x) * subpix_y;
const float wBR = subpix_x * subpix_y;
img_ptr = (uint8_t*) img.data + v_r*refStep + u_r;
*patch_ptr = wTL*img_ptr[0];
if(subpix_x > 0) *patch_ptr += wTR*img_ptr[1];
if(subpix_y > 0) *patch_ptr += wBL*img_ptr[refStep];
if(subpix_x > 0 && subpix_y > 0) *patch_ptr += wBR*img_ptr[refStep+1];
}
}
}
if(withBorder){
extractPatchFromPatchWithBorder();
}
validGradientParameters_ = false;
}
void FeatureCoordinates::drawLine(cv::Mat& drawImg, const FeatureCoordinates& other, const cv::Scalar& color, int thickness) const{
cv::line(drawImg,get_c(),other.get_c(),color,thickness);
}