/*M///////////////////////////////////////////////////////////////////////////////////////
//
// IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
//
// By downloading, copying, installing or using the software you agree to this license.
// If you do not agree to this license, do not download, install,
// copy or use the software.
//
//
// License Agreement
// For Open Source Computer Vision Library
//
// Copyright (C) 2013, OpenCV Foundation, all rights reserved.
// Third party copyrights are property of their respective owners.
//
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
//
// * Redistribution's of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// * Redistribution's in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
//
// * The name of the copyright holders may not be used to endorse or promote products
// derived from this software without specific prior written permission.
//
// This software is provided by the copyright holders and contributors "as is" and
// any express or implied warranties, including, but not limited to, the implied
// warranties of merchantability and fitness for a particular purpose are disclaimed.
// In no event shall the OpenCV Foundation or contributors be liable for any direct,
// indirect, incidental, special, exemplary, or consequential damages
// (including, but not limited to, procurement of substitute goods or services;
// loss of use, data, or profits; or business interruption) however caused
// and on any theory of liability, whether in contract, strict liability,
// or tort (including negligence or otherwise) arising in any way out of
// the use of this software, even if advised of the possibility of such damage.
//
//M*/
#include "precomp.hpp"
#include <vector>
#include <algorithm>
#define ABSCLIP(val,threshold) MIN(MAX((val),-(threshold)),(threshold))
namespace cv{
class AddFloatToCharScaled{
public:
AddFloatToCharScaled(double scale):_scale(scale){}
inline double operator()(double a,uchar b){
return a+_scale*((double)b);
}
private:
double _scale;
};
#ifndef OPENCV_NOSTL
using std::transform;
#else
template <class InputIterator, class InputIterator2, class OutputIterator, class BinaryOperator>
static OutputIterator transform (InputIterator first1, InputIterator last1, InputIterator2 first2,
OutputIterator result, BinaryOperator binary_op)
{
while (first1 != last1)
{
*result = binary_op(*first1, *first2);
++result; ++first1; ++first2;
}
return result;
}
#endif
void denoise_TVL1(const std::vector<Mat>& observations,Mat& result, double lambda, int niters){
CV_Assert(observations.size()>0 && niters>0 && lambda>0);
const double L2 = 8.0, tau = 0.02, sigma = 1./(L2*tau), theta = 1.0;
double clambda = (double)lambda;
double s=0;
const int workdepth = CV_64F;
int i, x, y, rows=observations[0].rows, cols=observations[0].cols,count;
for(i=1;i<(int)observations.size();i++){
CV_Assert(observations[i].rows==rows && observations[i].cols==cols);
}
Mat X, P = Mat::zeros(rows, cols, CV_MAKETYPE(workdepth, 2));
observations[0].convertTo(X, workdepth, 1./255);
std::vector< Mat_<double> > Rs(observations.size());
for(count=0;count<(int)Rs.size();count++){
Rs[count]=Mat::zeros(rows,cols,workdepth);
}
for( i = 0; i < niters; i++ )
{
double currsigma = i == 0 ? 1 + sigma : sigma;
// P_ = P + sigma*nabla(X)
// P(x,y) = P_(x,y)/max(||P(x,y)||,1)
for( y = 0; y < rows; y++ )
{
const double* x_curr = X.ptr<double>(y);
const double* x_next = X.ptr<double>(std::min(y+1, rows-1));
Point2d* p_curr = P.ptr<Point2d>(y);
double dx, dy, m;
for( x = 0; x < cols-1; x++ )
{
dx = (x_curr[x+1] - x_curr[x])*currsigma + p_curr[x].x;
dy = (x_next[x] - x_curr[x])*currsigma + p_curr[x].y;
m = 1.0/std::max(std::sqrt(dx*dx + dy*dy), 1.0);
p_curr[x].x = dx*m;
p_curr[x].y = dy*m;
}
dy = (x_next[x] - x_curr[x])*currsigma + p_curr[x].y;
m = 1.0/std::max(std::abs(dy), 1.0);
p_curr[x].x = 0.0;
p_curr[x].y = dy*m;
}
//Rs = clip(Rs + sigma*(X-imgs), -clambda, clambda)
for(count=0;count<(int)Rs.size();count++){
transform<MatIterator_<double>,MatConstIterator_<uchar>,MatIterator_<double>,AddFloatToCharScaled>(
Rs[count].begin(),Rs[count].end(),observations[count].begin<uchar>(),
Rs[count].begin(),AddFloatToCharScaled(-sigma/255.0));
Rs[count]+=sigma*X;
min(Rs[count],clambda,Rs[count]);
max(Rs[count],-clambda,Rs[count]);
}
for( y = 0; y < rows; y++ )
{
double* x_curr = X.ptr<double>(y);
const Point2d* p_curr = P.ptr<Point2d>(y);
const Point2d* p_prev = P.ptr<Point2d>(std::max(y - 1, 0));
// X1 = X + tau*(-nablaT(P))
x = 0;
s=0.0;
for(count=0;count<(int)Rs.size();count++){
s=s+Rs[count](y,x);
}
double x_new = x_curr[x] + tau*(p_curr[x].y - p_prev[x].y)-tau*s;
// X = X2 + theta*(X2 - X)
x_curr[x] = x_new + theta*(x_new - x_curr[x]);
for(x = 1; x < cols; x++ )
{
s=0.0;
for(count=0;count<(int)Rs.size();count++){
s+=Rs[count](y,x);
}
// X1 = X + tau*(-nablaT(P))
x_new = x_curr[x] + tau*(p_curr[x].x - p_curr[x-1].x + p_curr[x].y - p_prev[x].y)-tau*s;
// X = X2 + theta*(X2 - X)
x_curr[x] = x_new + theta*(x_new - x_curr[x]);
}
}
}
result.create(X.rows,X.cols,CV_8U);
X.convertTo(result, CV_8U, 255);
}
}