rtabmap_ros/corelib/src/CameraModel.cpp

/*
Copyright (c) 2010-2016, Mathieu Labbe - IntRoLab - Universite de Sherbrooke
All rights reserved.

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    * Redistributions in binary form must reproduce the above copyright
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      documentation and/or other materials provided with the distribution.
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      names of its contributors may be used to endorse or promote products
      derived from this software without specific prior written permission.

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*/

#include <rtabmap/core/CameraModel.h>
#include <rtabmap/utilite/ULogger.h>
#include <rtabmap/utilite/UDirectory.h>
#include <rtabmap/utilite/UFile.h>
#include <rtabmap/utilite/UConversion.h>
#include <opencv2/imgproc/imgproc.hpp>

namespace rtabmap {

CameraModel::CameraModel()
{

}

CameraModel::CameraModel(
		const std::string & cameraName,
		const cv::Size & imageSize,
		const cv::Mat & K,
		const cv::Mat & D,
		const cv::Mat & R,
		const cv::Mat & P,
		const Transform & localTransform) :
		name_(cameraName),
		imageSize_(imageSize),
		K_(K),
		D_(D),
		R_(R),
		P_(P),
		localTransform_(localTransform)
{
	UASSERT(K_.empty() || (K_.rows == 3 && K_.cols == 3 && K_.type() == CV_64FC1));
	UASSERT(D_.empty() || (D_.rows == 1 && (D_.cols == 4 || D_.cols == 5 || D_.cols == 8) && D_.type() == CV_64FC1));
	UASSERT(R_.empty() || (R_.rows == 3 && R_.cols == 3 && R_.type() == CV_64FC1));
	UASSERT(P_.empty() || (P_.rows == 3 && P_.cols == 4 && P_.type() == CV_64FC1));
}

CameraModel::CameraModel(
		double fx,
		double fy,
		double cx,
		double cy,
		const Transform & localTransform,
		double Tx,
		const cv::Size & imageSize) :
		imageSize_(imageSize),
		K_(cv::Mat::eye(3, 3, CV_64FC1)),
		localTransform_(localTransform)
{
	UASSERT_MSG(fx > 0.0, uFormat("fx=%f", fx).c_str());
	UASSERT_MSG(fy > 0.0, uFormat("fy=%f", fy).c_str());
	UASSERT_MSG(cx >= 0.0, uFormat("cx=%f", cx).c_str());
	UASSERT_MSG(cy >= 0.0, uFormat("cy=%f", cy).c_str());
	UASSERT(!localTransform.isNull());
	if(Tx != 0.0)
	{
		P_ = cv::Mat::eye(3, 4, CV_64FC1),
		P_.at<double>(0,0) = fx;
		P_.at<double>(1,1) = fy;
		P_.at<double>(0,2) = cx;
		P_.at<double>(1,2) = cy;
		P_.at<double>(0,3) = Tx;
	}

	K_.at<double>(0,0) = fx;
	K_.at<double>(1,1) = fy;
	K_.at<double>(0,2) = cx;
	K_.at<double>(1,2) = cy;
}

CameraModel::CameraModel(
		const std::string & name,
		double fx,
		double fy,
		double cx,
		double cy,
		const Transform & localTransform,
		double Tx,
		const cv::Size & imageSize) :
		name_(name),
		imageSize_(imageSize),
		K_(cv::Mat::eye(3, 3, CV_64FC1)),
		localTransform_(localTransform)
{
	UASSERT_MSG(fx > 0.0, uFormat("fx=%f", fx).c_str());
	UASSERT_MSG(fy > 0.0, uFormat("fy=%f", fy).c_str());
	UASSERT_MSG(cx >= 0.0, uFormat("cx=%f", cx).c_str());
	UASSERT_MSG(cy >= 0.0, uFormat("cy=%f", cy).c_str());
	UASSERT(!localTransform.isNull());
	if(Tx != 0.0)
	{
		P_ = cv::Mat::eye(3, 4, CV_64FC1),
		P_.at<double>(0,0) = fx;
		P_.at<double>(1,1) = fy;
		P_.at<double>(0,2) = cx;
		P_.at<double>(1,2) = cy;
		P_.at<double>(0,3) = Tx;
	}

	K_.at<double>(0,0) = fx;
	K_.at<double>(1,1) = fy;
	K_.at<double>(0,2) = cx;
	K_.at<double>(1,2) = cy;
}

void CameraModel::initRectificationMap()
{
	UASSERT(imageSize_.height > 0 && imageSize_.width > 0);
	UASSERT(D_.rows == 1 && (D_.cols == 4 || D_.cols == 5 || D_.cols == 8));
	UASSERT(R_.rows == 3 && R_.cols == 3);
	UASSERT(P_.rows == 3 && P_.cols == 4);
	// init rectification map
	UINFO("Initialize rectify map");
	cv::initUndistortRectifyMap(K_, D_, R_, P_, imageSize_, CV_32FC1, mapX_, mapY_);
}

bool CameraModel::load(const std::string & directory, const std::string & cameraName)
{
	K_ = cv::Mat();
	D_ = cv::Mat();
	R_ = cv::Mat();
	P_ = cv::Mat();
	mapX_ = cv::Mat();
	mapY_ = cv::Mat();
	name_.clear();
	imageSize_ = cv::Size();

	std::string filePath = directory+"/"+cameraName+".yaml";
	if(UFile::exists(filePath))
	{
		try
		{
			UINFO("Reading calibration file \"%s\"", filePath.c_str());
			cv::FileStorage fs(filePath, cv::FileStorage::READ);

			cv::FileNode n,n2;

			n = fs["camera_name"];
			if(n.type() != cv::FileNode::NONE)
			{
				name_ = (int)n;
			}
			else
			{
				UWARN("Missing \"camera_name\" field in \"%s\"", filePath.c_str());
			}

			n = fs["image_width"];
			n2 = fs["image_height"];
			if(n.type() != cv::FileNode::NONE)
			{
				imageSize_.width = (int)fs["image_width"];
				imageSize_.height = (int)fs["image_height"];
			}
			else
			{
				UWARN("Missing \"image_width\" and/or \"image_height\" fields in \"%s\"", filePath.c_str());
			}

			// import from ROS calibration format
			n = fs["camera_matrix"];
			if(n.type() != cv::FileNode::NONE)
			{
				int rows = (int)n["rows"];
				int cols = (int)n["cols"];
				std::vector<double> data;
				n["data"] >> data;
				UASSERT(rows*cols == (int)data.size());
				UASSERT(rows == 3 && cols == 3);
				K_ = cv::Mat(rows, cols, CV_64FC1, data.data()).clone();
			}
			else
			{
				UWARN("Missing \"camera_matrix\" field in \"%s\"", filePath.c_str());
			}

			n = fs["distortion_coefficients"];
			if(n.type() != cv::FileNode::NONE)
			{
				int rows = (int)n["rows"];
				int cols = (int)n["cols"];
				std::vector<double> data;
				n["data"] >> data;
				UASSERT(rows*cols == (int)data.size());
				UASSERT(rows == 1 && (cols == 4 || cols == 5 || cols == 8));
				D_ = cv::Mat(rows, cols, CV_64FC1, data.data()).clone();
			}
			else
			{
				UWARN("Missing \"distorsion_coefficients\" field in \"%s\"", filePath.c_str());
			}

			n = fs["rectification_matrix"];
			if(n.type() != cv::FileNode::NONE)
			{
				int rows = (int)n["rows"];
				int cols = (int)n["cols"];
				std::vector<double> data;
				n["data"] >> data;
				UASSERT(rows*cols == (int)data.size());
				UASSERT(rows == 3 && cols == 3);
				R_ = cv::Mat(rows, cols, CV_64FC1, data.data()).clone();
			}
			else
			{
				UWARN("Missing \"rectification_matrix\" field in \"%s\"", filePath.c_str());
			}

			n = fs["projection_matrix"];
			if(n.type() != cv::FileNode::NONE)
			{
				int rows = (int)n["rows"];
				int cols = (int)n["cols"];
				std::vector<double> data;
				n["data"] >> data;
				UASSERT(rows*cols == (int)data.size());
				UASSERT(rows == 3 && cols == 4);
				P_ = cv::Mat(rows, cols, CV_64FC1, data.data()).clone();
			}
			else
			{
				UWARN("Missing \"projection_matrix\" field in \"%s\"", filePath.c_str());
			}

			fs.release();

			if(isValidForRectification())
			{
				initRectificationMap();
			}

			return true;
		}
		catch(const cv::Exception & e)
		{
			UERROR("Error reading calibration file \"%s\": %s", filePath.c_str(), e.what());
		}
	}
	else
	{
		UWARN("Could not load calibration file \"%s\".", filePath.c_str());
	}
	return false;
}

bool CameraModel::save(const std::string & directory) const
{
	std::string filePath = directory+"/"+name_+".yaml";
	if(!filePath.empty() && (!K_.empty() || !D_.empty() || !R_.empty() || !P_.empty()))
	{
		UINFO("Saving calibration to file \"%s\"", filePath.c_str());
		cv::FileStorage fs(filePath, cv::FileStorage::WRITE);

		// export in ROS calibration format

		if(!name_.empty())
		{
			fs << "camera_name" << name_;
		}
		if(imageSize_.width>0 && imageSize_.height>0)
		{
			fs << "image_width" << imageSize_.width;
			fs << "image_height" << imageSize_.height;
		}

		if(!K_.empty())
		{
			fs << "camera_matrix" << "{";
			fs << "rows" << K_.rows;
			fs << "cols" << K_.cols;
			fs << "data" << std::vector<double>((double*)K_.data, ((double*)K_.data)+(K_.rows*K_.cols));
			fs << "}";
		}

		if(!D_.empty())
		{
			fs << "distortion_coefficients" << "{";
			fs << "rows" << D_.rows;
			fs << "cols" << D_.cols;
			fs << "data" << std::vector<double>((double*)D_.data, ((double*)D_.data)+(D_.rows*D_.cols));
			fs << "}";

			// compaibility with ROS
			if(D_.cols > 5)
			{
				fs << "distortion_model" << "rational_polynomial";
			}
			else
			{
				fs << "distortion_model" << "plumb_bob";
			}
		}

		if(!R_.empty())
		{
			fs << "rectification_matrix" << "{";
			fs << "rows" << R_.rows;
			fs << "cols" << R_.cols;
			fs << "data" << std::vector<double>((double*)R_.data, ((double*)R_.data)+(R_.rows*R_.cols));
			fs << "}";
		}

		if(!P_.empty())
		{
			fs << "projection_matrix" << "{";
			fs << "rows" << P_.rows;
			fs << "cols" << P_.cols;
			fs << "data" << std::vector<double>((double*)P_.data, ((double*)P_.data)+(P_.rows*P_.cols));
			fs << "}";
		}

		fs.release();

		return true;
	}
	else
	{
		UERROR("Cannot save calibration to \"%s\" because it is empty.", filePath.c_str());
	}
	return false;
}

CameraModel CameraModel::scaled(double scale) const
{
	CameraModel scaledModel = *this;
	UASSERT(scale > 0.0);
	if(this->isValidForProjection())
	{
		// has only effect on K and P
		cv::Mat K;
		if(!K_.empty())
		{
			K = K_.clone();
			K.at<double>(0,0) *= scale;
			K.at<double>(1,1) *= scale;
			K.at<double>(0,2) *= scale;
			K.at<double>(1,2) *= scale;
		}

		cv::Mat P;
		if(!P_.empty())
		{
			P = P_.clone();
			P.at<double>(0,0) *= scale;
			P.at<double>(1,1) *= scale;
			P.at<double>(0,2) *= scale;
			P.at<double>(1,2) *= scale;
			P.at<double>(0,3) *= scale;
			P.at<double>(1,3) *= scale;
		}
		scaledModel = CameraModel(name_, cv::Size(double(imageSize_.width)*scale, double(imageSize_.height)*scale), K, D_, R_, P, localTransform_);
	}
	else
	{
		UWARN("Trying to scale a camera model not valid! Ignoring scaling...");
	}
	return scaledModel;
}

double CameraModel::horizontalFOV() const
{
	if(imageWidth() > 0 && fx() > 0.0)
	{
		return atan((double(imageWidth())/2.0)/fx())*2.0*180.0/CV_PI;
	}
	return 0.0;
}

double CameraModel::verticalFOV() const
{
	if(imageHeight() > 0 && fy() > 0.0)
	{
		return atan((double(imageHeight())/2.0)/fy())*2.0*180.0/CV_PI;
	}
	return 0.0;
}

cv::Mat CameraModel::rectifyImage(const cv::Mat & raw, int interpolation) const
{
	UDEBUG("");
	if(!mapX_.empty() && !mapY_.empty())
	{
		cv::Mat rectified;
		cv::remap(raw, rectified, mapX_, mapY_, interpolation);
		return rectified;
	}
	else
	{
		UERROR("Cannot rectify image because the rectify map is not initialized.");
		return raw.clone();
	}
}

//inspired from https://github.com/code-iai/iai_kinect2/blob/master/depth_registration/src/depth_registration_cpu.cpp
cv::Mat CameraModel::rectifyDepth(const cv::Mat & raw) const
{
	UDEBUG("");
	UASSERT(raw.type() == CV_16UC1);
	if(!mapX_.empty() && !mapY_.empty())
	{
		cv::Mat rectified = cv::Mat::zeros(mapX_.rows, mapX_.cols, raw.type());
		for(int y=0; y<mapX_.rows; ++y)
		{
			for(int x=0; x<mapX_.cols; ++x)
			{
				cv::Point2f pt(mapX_.at<float>(y,x), mapY_.at<float>(y,x));
				int xL = (int)floor(pt.x);
				int xH = (int)ceil(pt.x);
				int yL = (int)floor(pt.y);
				int yH = (int)ceil(pt.y);
				if(xL >= 0 && yL >= 0 && xH < raw.cols && yH < raw.rows)
				{
					const unsigned short & pLT = raw.at<unsigned short>(yL, xL);
					const unsigned short & pRT = raw.at<unsigned short>(yL, xH);
					const unsigned short & pLB = raw.at<unsigned short>(yH, xL);
					const unsigned short & pRB = raw.at<unsigned short>(yH, xH);
					if(pLT > 0 && pRT > 0 && pLB > 0 && pRB > 0)
					{
						unsigned short avg = (pLT + pRT + pLB + pRB) / 4;
						unsigned short thres = 0.01 * avg;
						if( abs(pLT - avg) < thres &&
							abs(pRT - avg) < thres &&
							abs(pLB - avg) < thres &&
							abs(pRB - avg) < thres)
						{
							//bilinear interpolation
							float a = pt.x - (float)xL;
							float c = pt.y - (float)yL;

							//http://stackoverflow.com/questions/13299409/how-to-get-the-image-pixel-at-real-locations-in-opencv
							rectified.at<unsigned short>(y,x) =
									(raw.at<unsigned short>(yL, xL) * (1.f - a) + raw.at<unsigned short>(yL, xH) * a) * (1.f - c) +
									(raw.at<unsigned short>(yH, xL) * (1.f - a) + raw.at<unsigned short>(yH, xH) * a) * c;
						}
					}
				}
			}
		}
		return rectified;
	}
	else
	{
		UERROR("Cannot rectify image because the rectify map is not initialized.");
		return raw.clone();
	}
}

} /* namespace rtabmap */