opencv/modules/stitching/src/stitcher.cpp
2011-10-25 12:42:08 +00:00

464 lines
15 KiB
C++

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#include "precomp.hpp"
using namespace std;
namespace cv {
Stitcher Stitcher::createDefault(bool try_use_gpu)
{
Stitcher stitcher;
stitcher.setRegistrationResol(0.6);
stitcher.setSeamEstimationResol(0.1);
stitcher.setCompositingResol(ORIG_RESOL);
stitcher.setPanoConfidenceThresh(1);
stitcher.setWaveCorrection(true);
stitcher.setWaveCorrectKind(detail::WAVE_CORRECT_HORIZ);
stitcher.setFeaturesMatcher(new detail::BestOf2NearestMatcher(try_use_gpu));
stitcher.setBundleAdjuster(new detail::BundleAdjusterRay());
#ifndef ANDROID
if (try_use_gpu && gpu::getCudaEnabledDeviceCount() > 0)
{
stitcher.setFeaturesFinder(new detail::SurfFeaturesFinderGpu());
stitcher.setWarper(new SphericalWarperGpu());
stitcher.setSeamFinder(new detail::GraphCutSeamFinderGpu());
}
else
#endif
{
stitcher.setFeaturesFinder(new detail::SurfFeaturesFinder());
stitcher.setWarper(new SphericalWarper());
stitcher.setSeamFinder(new detail::GraphCutSeamFinder(detail::GraphCutSeamFinderBase::COST_COLOR));
}
stitcher.setExposureCompensator(new detail::BlocksGainCompensator());
stitcher.setBlender(new detail::MultiBandBlender(try_use_gpu));
return stitcher;
}
Stitcher::Status Stitcher::estimateTransform(InputArray images)
{
return estimateTransform(images, vector<vector<Rect> >());
}
Stitcher::Status Stitcher::estimateTransform(InputArray images, const vector<vector<Rect> > &rois)
{
images.getMatVector(imgs_);
rois_ = rois;
Status status;
if ((status = matchImages()) != OK)
return status;
estimateCameraParams();
return OK;
}
Stitcher::Status Stitcher::composePanorama(OutputArray pano)
{
return composePanorama(vector<Mat>(), pano);
}
Stitcher::Status Stitcher::composePanorama(InputArray images, OutputArray pano)
{
LOGLN("Warping images (auxiliary)... ");
vector<Mat> imgs;
images.getMatVector(imgs);
if (!imgs.empty())
{
CV_Assert(imgs.size() == imgs_.size());
Mat img;
seam_est_imgs_.resize(imgs.size());
for (size_t i = 0; i < imgs.size(); ++i)
{
imgs_[i] = imgs[i];
resize(imgs[i], img, Size(), seam_scale_, seam_scale_);
seam_est_imgs_[i] = img.clone();
}
vector<Mat> seam_est_imgs_subset;
vector<Mat> imgs_subset;
for (size_t i = 0; i < indices_.size(); ++i)
{
imgs_subset.push_back(imgs_[indices_[i]]);
seam_est_imgs_subset.push_back(seam_est_imgs_[indices_[i]]);
}
seam_est_imgs_ = seam_est_imgs_subset;
imgs_ = imgs_subset;
}
Mat &pano_ = pano.getMatRef();
int64 t = getTickCount();
vector<Point> corners(imgs_.size());
vector<Mat> masks_warped(imgs_.size());
vector<Mat> images_warped(imgs_.size());
vector<Size> sizes(imgs_.size());
vector<Mat> masks(imgs_.size());
// Prepare image masks
for (size_t i = 0; i < imgs_.size(); ++i)
{
masks[i].create(seam_est_imgs_[i].size(), CV_8U);
masks[i].setTo(Scalar::all(255));
}
// Warp images and their masks
Ptr<detail::RotationWarper> warper = warper_->create(float(warped_image_scale_ * seam_work_aspect_));
for (size_t i = 0; i < imgs_.size(); ++i)
{
Mat_<float> K;
cameras_[i].K().convertTo(K, CV_32F);
K(0,0) *= (float)seam_work_aspect_;
K(0,2) *= (float)seam_work_aspect_;
K(1,1) *= (float)seam_work_aspect_;
K(1,2) *= (float)seam_work_aspect_;
corners[i] = warper->warp(seam_est_imgs_[i], K, cameras_[i].R, INTER_LINEAR, BORDER_REFLECT, images_warped[i]);
sizes[i] = images_warped[i].size();
warper->warp(masks[i], K, cameras_[i].R, INTER_NEAREST, BORDER_CONSTANT, masks_warped[i]);
}
vector<Mat> images_warped_f(imgs_.size());
for (size_t i = 0; i < imgs_.size(); ++i)
images_warped[i].convertTo(images_warped_f[i], CV_32F);
LOGLN("Warping images, time: " << ((getTickCount() - t) / getTickFrequency()) << " sec");
// Find seams
exposure_comp_->feed(corners, images_warped, masks_warped);
seam_finder_->find(images_warped_f, corners, masks_warped);
// Release unused memory
seam_est_imgs_.clear();
images_warped.clear();
images_warped_f.clear();
masks.clear();
LOGLN("Compositing...");
t = getTickCount();
Mat img_warped, img_warped_s;
Mat dilated_mask, seam_mask, mask, mask_warped;
double compose_seam_aspect = 1;
double compose_work_aspect = 1;
bool is_blender_prepared = false;
double compose_scale = 1;
bool is_compose_scale_set = false;
Mat full_img, img;
for (size_t img_idx = 0; img_idx < imgs_.size(); ++img_idx)
{
LOGLN("Compositing image #" << indices_[img_idx] + 1);
// Read image and resize it if necessary
full_img = imgs_[img_idx];
if (!is_compose_scale_set)
{
if (compose_resol_ > 0)
compose_scale = min(1.0, sqrt(compose_resol_ * 1e6 / full_img.size().area()));
is_compose_scale_set = true;
// Compute relative scales
compose_seam_aspect = compose_scale / seam_scale_;
compose_work_aspect = compose_scale / work_scale_;
// Update warped image scale
warped_image_scale_ *= static_cast<float>(compose_work_aspect);
warper = warper_->create((float)warped_image_scale_);
// Update corners and sizes
for (size_t i = 0; i < imgs_.size(); ++i)
{
// Update intrinsics
cameras_[i].focal *= compose_work_aspect;
cameras_[i].ppx *= compose_work_aspect;
cameras_[i].ppy *= compose_work_aspect;
// Update corner and size
Size sz = full_img_sizes_[i];
if (std::abs(compose_scale - 1) > 1e-1)
{
sz.width = cvRound(full_img_sizes_[i].width * compose_scale);
sz.height = cvRound(full_img_sizes_[i].height * compose_scale);
}
Mat K;
cameras_[i].K().convertTo(K, CV_32F);
Rect roi = warper->warpRoi(sz, K, cameras_[i].R);
corners[i] = roi.tl();
sizes[i] = roi.size();
}
}
if (std::abs(compose_scale - 1) > 1e-1)
resize(full_img, img, Size(), compose_scale, compose_scale);
else
img = full_img;
full_img.release();
Size img_size = img.size();
Mat K;
cameras_[img_idx].K().convertTo(K, CV_32F);
// Warp the current image
warper->warp(img, K, cameras_[img_idx].R, INTER_LINEAR, BORDER_REFLECT, img_warped);
// Warp the current image mask
mask.create(img_size, CV_8U);
mask.setTo(Scalar::all(255));
warper->warp(mask, K, cameras_[img_idx].R, INTER_NEAREST, BORDER_CONSTANT, mask_warped);
// Compensate exposure
exposure_comp_->apply(img_idx, corners[img_idx], img_warped, mask_warped);
img_warped.convertTo(img_warped_s, CV_16S);
img_warped.release();
img.release();
mask.release();
// Make sure seam mask has proper size
dilate(masks_warped[img_idx], dilated_mask, Mat());
resize(dilated_mask, seam_mask, mask_warped.size());
mask_warped = seam_mask & mask_warped;
if (!is_blender_prepared)
{
blender_->prepare(corners, sizes);
is_blender_prepared = true;
}
// Blend the current image
blender_->feed(img_warped_s, mask_warped, corners[img_idx]);
}
Mat result, result_mask;
blender_->blend(result, result_mask);
LOGLN("Compositing, time: " << ((getTickCount() - t) / getTickFrequency()) << " sec");
// Preliminary result is in CV_16SC3 format, but all values are in [0,255] range,
// so convert it to avoid user confusing
result.convertTo(pano_, CV_8U);
return OK;
}
Stitcher::Status Stitcher::stitch(InputArray images, OutputArray pano)
{
Status status = estimateTransform(images);
if (status != OK)
return status;
return composePanorama(pano);
}
Stitcher::Status Stitcher::stitch(InputArray images, const vector<vector<Rect> > &rois, OutputArray pano)
{
Status status = estimateTransform(images, rois);
if (status != OK)
return status;
return composePanorama(pano);
}
Stitcher::Status Stitcher::matchImages()
{
if ((int)imgs_.size() < 2)
{
LOGLN("Need more images");
return ERR_NEED_MORE_IMGS;
}
work_scale_ = 1;
seam_work_aspect_ = 1;
seam_scale_ = 1;
bool is_work_scale_set = false;
bool is_seam_scale_set = false;
Mat full_img, img;
features_.resize(imgs_.size());
seam_est_imgs_.resize(imgs_.size());
full_img_sizes_.resize(imgs_.size());
LOGLN("Finding features...");
int64 t = getTickCount();
for (size_t i = 0; i < imgs_.size(); ++i)
{
full_img = imgs_[i];
full_img_sizes_[i] = full_img.size();
if (registr_resol_ < 0)
{
img = full_img;
work_scale_ = 1;
is_work_scale_set = true;
}
else
{
if (!is_work_scale_set)
{
work_scale_ = min(1.0, sqrt(registr_resol_ * 1e6 / full_img.size().area()));
is_work_scale_set = true;
}
resize(full_img, img, Size(), work_scale_, work_scale_);
}
if (!is_seam_scale_set)
{
seam_scale_ = min(1.0, sqrt(seam_est_resol_ * 1e6 / full_img.size().area()));
seam_work_aspect_ = seam_scale_ / work_scale_;
is_seam_scale_set = true;
}
if (rois_.empty())
(*features_finder_)(img, features_[i]);
else
(*features_finder_)(img, features_[i], rois_[i]);
features_[i].img_idx = i;
LOGLN("Features in image #" << i+1 << ": " << features_[i].keypoints.size());
resize(full_img, img, Size(), seam_scale_, seam_scale_);
seam_est_imgs_[i] = img.clone();
}
// Do it to save memory
features_finder_->collectGarbage();
full_img.release();
img.release();
LOGLN("Finding features, time: " << ((getTickCount() - t) / getTickFrequency()) << " sec");
LOG("Pairwise matching");
t = getTickCount();
(*features_matcher_)(features_, pairwise_matches_, matching_mask_);
features_matcher_->collectGarbage();
LOGLN("Pairwise matching, time: " << ((getTickCount() - t) / getTickFrequency()) << " sec");
// Leave only images we are sure are from the same panorama
indices_ = detail::leaveBiggestComponent(features_, pairwise_matches_, (float)conf_thresh_);
vector<Mat> seam_est_imgs_subset;
vector<Mat> imgs_subset;
vector<Size> full_img_sizes_subset;
for (size_t i = 0; i < indices_.size(); ++i)
{
imgs_subset.push_back(imgs_[indices_[i]]);
seam_est_imgs_subset.push_back(seam_est_imgs_[indices_[i]]);
full_img_sizes_subset.push_back(full_img_sizes_[indices_[i]]);
}
seam_est_imgs_ = seam_est_imgs_subset;
imgs_ = imgs_subset;
full_img_sizes_ = full_img_sizes_subset;
if ((int)imgs_.size() < 2)
{
LOGLN("Need more images");
return ERR_NEED_MORE_IMGS;
}
return OK;
}
void Stitcher::estimateCameraParams()
{
detail::HomographyBasedEstimator estimator;
estimator(features_, pairwise_matches_, cameras_);
for (size_t i = 0; i < cameras_.size(); ++i)
{
Mat R;
cameras_[i].R.convertTo(R, CV_32F);
cameras_[i].R = R;
LOGLN("Initial intrinsic parameters #" << indices_[i] + 1 << ":\n " << cameras_[i].K());
}
bundle_adjuster_->setConfThresh(conf_thresh_);
(*bundle_adjuster_)(features_, pairwise_matches_, cameras_);
// Find median focal length and use it as final image scale
vector<double> focals;
for (size_t i = 0; i < cameras_.size(); ++i)
{
LOGLN("Camera #" << indices_[i] + 1 << ":\n" << cameras_[i].K());
focals.push_back(cameras_[i].focal);
}
sort(focals.begin(), focals.end());
if (focals.size() % 2 == 1)
warped_image_scale_ = static_cast<float>(focals[focals.size() / 2]);
else
warped_image_scale_ = static_cast<float>(focals[focals.size() / 2 - 1] + focals[focals.size() / 2]) * 0.5f;
if (do_wave_correct_)
{
vector<Mat> rmats;
for (size_t i = 0; i < cameras_.size(); ++i)
rmats.push_back(cameras_[i].R);
detail::waveCorrect(rmats, wave_correct_kind_);
for (size_t i = 0; i < cameras_.size(); ++i)
cameras_[i].R = rmats[i];
}
}
} // namespace cv