OpenFace/lib/local/Utilities/include/ImageManipulationHelpers.h

///////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2017, Tadas Baltrusaitis all rights reserved.
//
// ACADEMIC OR NON-PROFIT ORGANIZATION NONCOMMERCIAL RESEARCH USE ONLY
//
// BY USING OR DOWNLOADING THE SOFTWARE, YOU ARE AGREEING TO THE TERMS OF THIS LICENSE AGREEMENT.  
// IF YOU DO NOT AGREE WITH THESE TERMS, YOU MAY NOT USE OR DOWNLOAD THE SOFTWARE.
//
// License can be found in OpenFace-license.txt
//
//     * Any publications arising from the use of this software, including but
//       not limited to academic journal and conference publications, technical
//       reports and manuals, must cite at least one of the following works:
//
//       OpenFace 2.0: Facial Behavior Analysis Toolkit
//       Tadas Baltru<72>aitis, Amir Zadeh, Yao Chong Lim, and Louis-Philippe Morency
//       in IEEE International Conference on Automatic Face and Gesture Recognition, 2018  
//
//       Convolutional experts constrained local model for facial landmark detection.
//       A. Zadeh, T. Baltru<72>aitis, and Louis-Philippe Morency,
//       in Computer Vision and Pattern Recognition Workshops, 2017.    
//
//       Rendering of Eyes for Eye-Shape Registration and Gaze Estimation
//       Erroll Wood, Tadas Baltru<72>aitis, Xucong Zhang, Yusuke Sugano, Peter Robinson, and Andreas Bulling 
//       in IEEE International. Conference on Computer Vision (ICCV),  2015 
//
//       Cross-dataset learning and person-specific normalisation for automatic Action Unit detection
//       Tadas Baltru<72>aitis, Marwa Mahmoud, and Peter Robinson 
//       in Facial Expression Recognition and Analysis Challenge, 
//       IEEE International Conference on Automatic Face and Gesture Recognition, 2015 
//
///////////////////////////////////////////////////////////////////////////////

#ifndef IMAGE_MANIPULATION_HELPERS_H
#define IMAGE_MANIPULATION_HELPERS_H

#include <opencv2/core/core.hpp>
#include <opencv2/imgproc.hpp>

namespace Utilities
{
	//===========================================================================
	// Converting between color spaces and bit depths
	//===========================================================================

	static void ConvertToGrayscale_8bit(const cv::Mat& in, cv::Mat& out)
	{
		if (in.channels() == 3)
		{
			// Make sure it's in a correct format
			if (in.depth() == CV_16U)
			{
				cv::Mat tmp = in / 256;
				tmp.convertTo(out, CV_8U);
				cv::cvtColor(out, out, cv::COLOR_BGR2GRAY);
			}
			else
			{
				cv::cvtColor(in, out, cv::COLOR_BGR2GRAY);
			}
		}
		else if (in.channels() == 4)
		{
			if (in.depth() == CV_16U)
			{
				cv::Mat tmp = in / 256;
				tmp.convertTo(out, CV_8U);
				cv::cvtColor(out, out, cv::COLOR_BGRA2GRAY);
			}
			else
			{
				cv::cvtColor(in, out, cv::COLOR_BGRA2GRAY);
			}
		}
		else
		{
			if (in.depth() == CV_16U)
			{
				cv::Mat tmp = in / 256;
				tmp.convertTo(out, CV_8U);
			}
			else if (in.depth() == CV_8U)
			{
				out = in.clone();
			}
		}
	}


}
#endif // IMAGE_MANIPULATION_HELPERS_H