sgm: support for different resolution disparity

components/rgbd-sources/src/algorithms/fixstars_sgm.cpp

@@ -12,6 +12,13 @@ using cv::cuda::GpuMat;
 
 FixstarsSGM::FixstarsSGM(nlohmann::json &config) : Disparity(config) {
 	ssgm_ = nullptr;
+
+	int width = value("width", 1280);
+	int height = value("height", 720);
+	
+	size_ = cv::Size(width, height);
+	CHECK((width >= 480) && (height >= 360));
+
 	uniqueness_ = value("uniqueness", 0.95f);
 	P1_ = value("P1", 10);
 	P2_ = value("P2", 120);
@@ -29,11 +36,16 @@ FixstarsSGM::FixstarsSGM(nlohmann::json &config) : Disparity(config) {
 
 		filter_ = cv::cuda::createDisparityBilateralFilter(max_disp_ << 4, radius, iter);
 	}
+
+	init(size_);
 }
 
 void FixstarsSGM::init(const cv::Size size) {
 	if (ssgm_) { delete ssgm_; }
+	lbw_ = GpuMat(size, CV_8UC1);
+	rbw_ = GpuMat(size, CV_8UC1);
 	dispt_ = GpuMat(size, CV_16SC1);
+
 	ssgm_ = new sgm::StereoSGM(size.width, size.height, max_disp_, 8, 16,
 		lbw_.step, dispt_.step / sizeof(short),
 		sgm::EXECUTE_INOUT_CUDA2CUDA,
@@ -41,34 +53,55 @@ void FixstarsSGM::init(const cv::Size size) {
 	);
 }
 
-void FixstarsSGM::compute(const cv::cuda::GpuMat &l, const cv::cuda::GpuMat &r, cv::cuda::GpuMat &disp, cv::cuda::Stream &stream) {
+void FixstarsSGM::compute(const cv::cuda::GpuMat &l, const cv::cuda::GpuMat &r,
+	cv::cuda::GpuMat &disp, cv::cuda::Stream &stream)
+{
+	if (l.size() != size_) {
+		// re-use same buffer for l/r
+		cv::cuda::resize(r, l_downscaled_, size_, 0.0, 0.0, cv::INTER_CUBIC, stream);
+		cv::cuda::cvtColor(l_downscaled_, rbw_, cv::COLOR_BGR2GRAY, 0, stream);
+		cv::cuda::resize(l, l_downscaled_, size_, 0.0, 0.0, cv::INTER_CUBIC, stream);
+		cv::cuda::cvtColor(l_downscaled_, lbw_, cv::COLOR_BGR2GRAY, 0, stream);
+	}
+	else {
 		cv::cuda::cvtColor(l, lbw_, cv::COLOR_BGR2GRAY, 0, stream);
 		cv::cuda::cvtColor(r, rbw_, cv::COLOR_BGR2GRAY, 0, stream);
+	}
 
 	stream.waitForCompletion();
-	if (!ssgm_) { init(l.size()); }
 
-	//auto start = std::chrono::high_resolution_clock::now();
 	ssgm_->execute(lbw_.data, rbw_.data, dispt_.data);
-	//std::chrono::duration<double> elapsed =
-	//		std::chrono::high_resolution_clock::now() - start;
-	//LOG(INFO) << "CUDA sgm in " << elapsed.count() << "s";
 
 	GpuMat left_pixels(dispt_, cv::Rect(0, 0, max_disp_, dispt_.rows));
 	left_pixels.setTo(0);
-
 	cv::cuda::threshold(dispt_, dispt_, 4096.0f, 0.0f, cv::THRESH_TOZERO_INV, stream);
 
-	if (use_filter_) { filter_->apply(dispt_, l, dispt_, stream); }
+	// TODO: filter could be applied after upscaling (to the upscaled disparity image)
+	if (use_filter_) {
+		filter_->apply(dispt_,
+			l.size() != dispt_.size() ? l_downscaled_ : l,
+			dispt_,
+			stream
+		);
+	}
+
+	if (l.size() != size_) {
+		cv::cuda::multiply(dispt_, (double)l.cols / (double)size_.width, dispt_);
+		// invalid areas (bad values) have to be taken into account in interpolation
+		cv::cuda::resize(dispt_, dispt_full_res_, l.size(), 0.0, 0.0, cv::INTER_NEAREST, stream);
+	}
+	else {
+		dispt_full_res_ = dispt_;
+	}
 
-	dispt_.convertTo(disp, CV_32F, 1.0f/16.0f, stream);
+	dispt_full_res_.convertTo(disp, CV_32F, 1.0f / 16.0f, stream);
 }
 
 void FixstarsSGM::setMask(Mat &mask) {
 	return; // TODO(Nick) Not needed, but also code below does not work with new GPU pipeline
 	CHECK(mask.type() == CV_8UC1) << "mask type must be CV_8U";
 
-	if (!ssgm_) { init(mask.size()); }
+	if (!ssgm_) { init(size_); }
 
 	mask_l_ = mask;
 	ssgm_->setMask((uint8_t*)mask.data, mask.cols);

components/rgbd-sources/src/algorithms/fixstars_sgm.hpp

@@ -42,12 +42,16 @@ class FixstarsSGM : public ftl::rgbd::detail::Disparity {
 			float uniqueness_;
 			int P1_;
 			int P2_;
+			cv::Size size_;
 			bool use_filter_;
 			cv::Ptr<cv::cuda::DisparityBilateralFilter> filter_;
 			sgm::StereoSGM *ssgm_;
 			cv::cuda::GpuMat lbw_;
 			cv::cuda::GpuMat rbw_;
 			cv::cuda::GpuMat dispt_;
+
+			cv::cuda::GpuMat l_downscaled_;
+			cv::cuda::GpuMat dispt_full_res_;
 		};
 	};
 };