retinacolor.cpp

/*#******************************************************************************
** 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.
**
**
** bioinspired : interfaces allowing OpenCV users to integrate Human Vision System models. Presented models originate from Jeanny Herault's original research and have been reused and adapted by the author&collaborators for computed vision applications since his thesis with Alice Caplier at Gipsa-Lab.
** Use: extract still images & image sequences features, from contours details to motion spatio-temporal features, etc. for high level visual scene analysis. Also contribute to image enhancement/compression such as tone mapping.
**
** Maintainers : Listic lab (code author current affiliation & applications) and Gipsa Lab (original research origins & applications)
**
**  Creation - enhancement process 2007-2011
**      Author: Alexandre Benoit (benoit.alexandre.vision@gmail.com), LISTIC lab, Annecy le vieux, France
**
** Theses algorithm have been developped by Alexandre BENOIT since his thesis with Alice Caplier at Gipsa-Lab (www.gipsa-lab.inpg.fr) and the research he pursues at LISTIC Lab (www.listic.univ-savoie.fr).
** Refer to the following research paper for more information:
** Benoit A., Caplier A., Durette B., Herault, J., "USING HUMAN VISUAL SYSTEM MODELING FOR BIO-INSPIRED LOW LEVEL IMAGE PROCESSING", Elsevier, Computer Vision and Image Understanding 114 (2010), pp. 758-773, DOI: http://dx.doi.org/10.1016/j.cviu.2010.01.011
** This work have been carried out thanks to Jeanny Herault who's research and great discussions are the basis of all this work, please take a look at his book:
** Vision: Images, Signals and Neural Networks: Models of Neural Processing in Visual Perception (Progress in Neural Processing),By: Jeanny Herault, ISBN: 9814273686. WAPI (Tower ID): 113266891.
**
** The retina filter includes the research contributions of phd/research collegues from which code has been redrawn by the author :
** _take a look at the retinacolor.hpp module to discover Brice Chaix de Lavarene color mosaicing/demosaicing and the reference paper:
** ====> B. Chaix de Lavarene, D. Alleysson, B. Durette, J. Herault (2007). "Efficient demosaicing through recursive filtering", IEEE International Conference on Image Processing ICIP 2007
** _take a look at imagelogpolprojection.hpp to discover retina spatial log sampling which originates from Barthelemy Durette phd with Jeanny Herault. A Retina / V1 cortex projection is also proposed and originates from Jeanny's discussions.
** ====> more informations in the above cited Jeanny Heraults's book.
**
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** Copyright (C) 2008-2011, Willow Garage Inc., all rights reserved.
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**               For Human Visual System tools (bioinspired)
** Copyright (C) 2007-2011, LISTIC Lab, Annecy le Vieux and GIPSA Lab, Grenoble, France, all rights reserved.
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#include "precomp.hpp"

#include "retinacolor.hpp"

// @author Alexandre BENOIT, benoit.alexandre.vision@gmail.com, LISTIC : www.listic.univ-savoie.fr, Gipsa-Lab, France: www.gipsa-lab.inpg.fr/

#include <iostream>
#include <ctime>

namespace cv
{
namespace bioinspired
{
// init static values
static float _LMStoACr1Cr2[]={1.0,  1.0, 0.0,  1.0, -1.0, 0.0,  -0.5, -0.5, 1.0};
//static double _ACr1Cr2toLMS[]={0.5,  0.5, 0.0,   0.5, -0.5, 0.0,  0.5,  0.0, 1.0};
static float _LMStoLab[]={0.5774f, 0.5774f, 0.5774f, 0.4082f, 0.4082f, -0.8165f, 0.7071f, -0.7071f, 0.f};

// constructor/desctructor
RetinaColor::RetinaColor(const unsigned int NBrows, const unsigned int NBcolumns, const int samplingMethod)
:BasicRetinaFilter(NBrows, NBcolumns, 3),
 _colorSampling(NBrows*NBcolumns),
 _RGBmosaic(NBrows*NBcolumns*3),
 _tempMultiplexedFrame(NBrows*NBcolumns),
 _demultiplexedTempBuffer(NBrows*NBcolumns*3),
 _demultiplexedColorFrame(NBrows*NBcolumns*3),
 _chrominance(NBrows*NBcolumns*3),
 _colorLocalDensity(NBrows*NBcolumns*3),
 _imageGradient(NBrows*NBcolumns*2)
{
    // link to parent buffers (let's recycle !)
    _luminance=&_filterOutput;
    _multiplexedFrame=&_localBuffer;

    _objectInit=false;
    _samplingMethod=samplingMethod;
    _saturateColors=false;
    _colorSaturationValue=4.0;

    // set default spatio-temporal filter parameters
    setLPfilterParameters(0.0, 0.0, 1.5);
    setLPfilterParameters(0.0, 0.0, 10.5, 1);// for the low pass filter dedicated to contours energy extraction (demultiplexing process)
    setLPfilterParameters(0.f, 0.f, 0.9f, 2);

    // init default value on image Gradient
    _imageGradient=0.57f;

    // init color sampling map
    _initColorSampling();

    // flush all buffers
    clearAllBuffers();
}

RetinaColor::~RetinaColor()
{

}

/**
* function that clears all buffers of the object
*/
void RetinaColor::clearAllBuffers()
{
    BasicRetinaFilter::clearAllBuffers();
    _tempMultiplexedFrame=0.f;
    _demultiplexedTempBuffer=0.f;

    _demultiplexedColorFrame=0.f;
    _chrominance=0.f;
    _imageGradient=0.57f;
}

/**
* resize retina color filter object (resize all allocated buffers)
* @param NBrows: the new height size
* @param NBcolumns: the new width size
*/
void RetinaColor::resize(const unsigned int NBrows, const unsigned int NBcolumns)
{
    BasicRetinaFilter::clearAllBuffers();
    _colorSampling.resize(NBrows*NBcolumns);
    _RGBmosaic.resize(NBrows*NBcolumns*3);
    _tempMultiplexedFrame.resize(NBrows*NBcolumns);
    _demultiplexedTempBuffer.resize(NBrows*NBcolumns*3);
    _demultiplexedColorFrame.resize(NBrows*NBcolumns*3);
    _chrominance.resize(NBrows*NBcolumns*3);
    _colorLocalDensity.resize(NBrows*NBcolumns*3);
    _imageGradient.resize(NBrows*NBcolumns*2);

    // link to parent buffers (let's recycle !)
    _luminance=&_filterOutput;
    _multiplexedFrame=&_localBuffer;

    // init color sampling map
    _initColorSampling();

    // clean buffers
    clearAllBuffers();
}


void RetinaColor::_initColorSampling()
{

    // filling the conversion table for multiplexed <=> demultiplexed frame
    srand((unsigned)time(NULL));

    // preInit cones probabilities
    _pR=_pB=_pG=0;
    switch (_samplingMethod)
    {
    case RETINA_COLOR_RANDOM:
        for (unsigned int index=0 ; index<this->getNBpixels(); ++index)
        {

            // random RGB sampling
            unsigned int colorIndex=rand()%24;

            if (colorIndex<8){
                colorIndex=0;

                ++_pR;
            }else
            {
                if (colorIndex<21){
                    colorIndex=1;
                    ++_pG;
                }else{
                    colorIndex=2;
                    ++_pB;
                }
            }
            _colorSampling[index] = colorIndex*this->getNBpixels()+index;
        }
        _pR/=(float)this->getNBpixels();
        _pG/=(float)this->getNBpixels();
        _pB/=(float)this->getNBpixels();
        std::cout<<"Color channels proportions: pR, pG, pB= "<<_pR<<", "<<_pG<<", "<<_pB<<", "<<std::endl;
        break;
    case RETINA_COLOR_DIAGONAL:
        for (unsigned int index=0 ; index<this->getNBpixels(); ++index)
        {
            _colorSampling[index] = index+((index%3+(index%_filterOutput.getNBcolumns()))%3)*_filterOutput.getNBpixels();
        }
        _pR=_pB=_pG=1.f/3;
        break;
    case RETINA_COLOR_BAYER: // default sets bayer sampling
        for (unsigned int index=0 ; index<_filterOutput.getNBpixels(); ++index)
        {
            //First line: R G R G
            _colorSampling[index] = index+((index/_filterOutput.getNBcolumns())%2)*_filterOutput.getNBpixels()+((index%_filterOutput.getNBcolumns())%2)*_filterOutput.getNBpixels();
            //First line: G R G R
            //_colorSampling[index] = 3*index+((index/_filterOutput.getNBcolumns())%2)+((index%_filterOutput.getNBcolumns()+1)%2);
        }
        _pR=_pB=0.25;
        _pG=0.5;
        break;
    default:
#ifdef RETINACOLORDEBUG
        std::cerr<<"RetinaColor::No or wrong color sampling method, skeeping"<<std::endl;
#endif
        return;
        break;//.. not useful, yes

    }
    // feeling the mosaic buffer:
    _RGBmosaic=0;
    for (unsigned int index=0 ; index<_filterOutput.getNBpixels(); ++index)
        // the RGB _RGBmosaic buffer contains 1 where the pixel corresponds to a sampled color
        _RGBmosaic[_colorSampling[index]]=1.0;

    // computing photoreceptors local density
    _spatiotemporalLPfilter(&_RGBmosaic[0], &_colorLocalDensity[0]);
    _spatiotemporalLPfilter(&_RGBmosaic[0]+_filterOutput.getNBpixels(), &_colorLocalDensity[0]+_filterOutput.getNBpixels());
    _spatiotemporalLPfilter(&_RGBmosaic[0]+_filterOutput.getDoubleNBpixels(), &_colorLocalDensity[0]+_filterOutput.getDoubleNBpixels());
    unsigned int maxNBpixels=3*_filterOutput.getNBpixels();
    float *colorLocalDensityPTR=&_colorLocalDensity[0];
    for (unsigned int i=0;i<maxNBpixels;++i, ++colorLocalDensityPTR)
        *colorLocalDensityPTR=1.f/ *colorLocalDensityPTR;

#ifdef RETINACOLORDEBUG
    std::cout<<"INIT    _colorLocalDensity max, min: "<<_colorLocalDensity.max()<<", "<<_colorLocalDensity.min()<<std::endl;
#endif
    // end of the init step
    _objectInit=true;
}

// public functions

void RetinaColor::runColorDemultiplexing(const std::valarray<float> &multiplexedColorFrame, const bool adaptiveFiltering, const float maxInputValue)
{
    // demultiplex the grey frame to RGB frame
    // -> first set demultiplexed frame to 0
    _demultiplexedTempBuffer=0;
    // -> demultiplex process
    unsigned int *colorSamplingPRT=&_colorSampling[0];
    const float *multiplexedColorFramePtr=get_data(multiplexedColorFrame);
    for (unsigned int indexa=0; indexa<_filterOutput.getNBpixels() ; ++indexa)
        _demultiplexedTempBuffer[*(colorSamplingPRT++)]=*(multiplexedColorFramePtr++);

    // interpolate the demultiplexed frame depending on the color sampling method
    if (!adaptiveFiltering)
        _interpolateImageDemultiplexedImage(&_demultiplexedTempBuffer[0]);

    // low pass filtering the demultiplexed frame
    _spatiotemporalLPfilter(&_demultiplexedTempBuffer[0], &_chrominance[0]);
    _spatiotemporalLPfilter(&_demultiplexedTempBuffer[0]+_filterOutput.getNBpixels(), &_chrominance[0]+_filterOutput.getNBpixels());
    _spatiotemporalLPfilter(&_demultiplexedTempBuffer[0]+_filterOutput.getDoubleNBpixels(), &_chrominance[0]+_filterOutput.getDoubleNBpixels());

    /*if (_samplingMethod=BAYER)
    {
        _applyRIFfilter(_chrominance, _chrominance);
        _applyRIFfilter(_chrominance+_filterOutput.getNBpixels(), _chrominance+_filterOutput.getNBpixels());
        _applyRIFfilter(_chrominance+_filterOutput.getDoubleNBpixels(), _chrominance+_filterOutput.getDoubleNBpixels());
    }*/

    // normalize by the photoreceptors local density and retrieve the local luminance
    float *chrominancePTR= &_chrominance[0];
    float *colorLocalDensityPTR= &_colorLocalDensity[0];
    float *luminance= &(*_luminance)[0];
    if (!adaptiveFiltering)// compute the gradient on the luminance
    {
        if (_samplingMethod==RETINA_COLOR_RANDOM)
            for (unsigned int indexc=0; indexc<_filterOutput.getNBpixels() ; ++indexc, ++chrominancePTR, ++colorLocalDensityPTR, ++luminance)
            {
                // normalize by photoreceptors density
                float Cr=*(chrominancePTR)*_colorLocalDensity[indexc];
                float Cg=*(chrominancePTR+_filterOutput.getNBpixels())*_colorLocalDensity[indexc+_filterOutput.getNBpixels()];
                float Cb=*(chrominancePTR+_filterOutput.getDoubleNBpixels())*_colorLocalDensity[indexc+_filterOutput.getDoubleNBpixels()];
                *luminance=(Cr+Cg+Cb)*_pG;
                *(chrominancePTR)=Cr-*luminance;
                *(chrominancePTR+_filterOutput.getNBpixels())=Cg-*luminance;
                *(chrominancePTR+_filterOutput.getDoubleNBpixels())=Cb-*luminance;
            }
        else
            for (unsigned int indexc=0; indexc<_filterOutput.getNBpixels() ; ++indexc, ++chrominancePTR, ++colorLocalDensityPTR, ++luminance)
            {
                float Cr=*(chrominancePTR);
                float Cg=*(chrominancePTR+_filterOutput.getNBpixels());
                float Cb=*(chrominancePTR+_filterOutput.getDoubleNBpixels());
                *luminance=_pR*Cr+_pG*Cg+_pB*Cb;
                *(chrominancePTR)=Cr-*luminance;
                *(chrominancePTR+_filterOutput.getNBpixels())=Cg-*luminance;
                *(chrominancePTR+_filterOutput.getDoubleNBpixels())=Cb-*luminance;
            }

        // in order to get the color image, each colored map needs to be added the luminance
        // -> to do so, compute:  multiplexedColorFrame - remultiplexed chrominances
        runColorMultiplexing(_chrominance, _tempMultiplexedFrame);
        //lum = 1/3((f*(ImR))/(f*mR) + (f*(ImG))/(f*mG) + (f*(ImB))/(f*mB));
        float *luminancePTR= &(*_luminance)[0];
        chrominancePTR= &_chrominance[0];
        float *demultiplexedColorFramePTR= &_demultiplexedColorFrame[0];
        for (unsigned int indexp=0; indexp<_filterOutput.getNBpixels() ; ++indexp, ++luminancePTR, ++chrominancePTR, ++demultiplexedColorFramePTR)
        {
            *luminancePTR=(multiplexedColorFrame[indexp]-_tempMultiplexedFrame[indexp]);
            *(demultiplexedColorFramePTR)=*(chrominancePTR)+*luminancePTR;
            *(demultiplexedColorFramePTR+_filterOutput.getNBpixels())=*(chrominancePTR+_filterOutput.getNBpixels())+*luminancePTR;
            *(demultiplexedColorFramePTR+_filterOutput.getDoubleNBpixels())=*(chrominancePTR+_filterOutput.getDoubleNBpixels())+*luminancePTR;
        }

    }else
    {
        const float *multiplexedColorFramePTR= get_data(multiplexedColorFrame);
        for (unsigned int indexc=0; indexc<_filterOutput.getNBpixels() ; ++indexc, ++chrominancePTR, ++colorLocalDensityPTR, ++luminance, ++multiplexedColorFramePTR)
        {
            // normalize by photoreceptors density
            float Cr=*(chrominancePTR)*_colorLocalDensity[indexc];
            float Cg=*(chrominancePTR+_filterOutput.getNBpixels())*_colorLocalDensity[indexc+_filterOutput.getNBpixels()];
            float Cb=*(chrominancePTR+_filterOutput.getDoubleNBpixels())*_colorLocalDensity[indexc+_filterOutput.getDoubleNBpixels()];
            *luminance=(Cr+Cg+Cb)*_pG;
            _demultiplexedTempBuffer[_colorSampling[indexc]] = *multiplexedColorFramePTR - *luminance;

        }

        // compute the gradient of the luminance
#ifdef MAKE_PARALLEL // call the TemplateBuffer TBB clipping method
        cv::parallel_for_(cv::Range(2,_filterOutput.getNBrows()-2), Parallel_computeGradient(_filterOutput.getNBcolumns(), _filterOutput.getNBrows(), &(*_luminance)[0], &_imageGradient[0]));
#else
        _computeGradient(&(*_luminance)[0]);
#endif
        // adaptively filter the submosaics to get the adaptive densities, here the buffer _chrominance is used as a temp buffer
        _adaptiveSpatialLPfilter(&_RGBmosaic[0], &_chrominance[0]);
        _adaptiveSpatialLPfilter(&_RGBmosaic[0]+_filterOutput.getNBpixels(), &_chrominance[0]+_filterOutput.getNBpixels());
        _adaptiveSpatialLPfilter(&_RGBmosaic[0]+_filterOutput.getDoubleNBpixels(), &_chrominance[0]+_filterOutput.getDoubleNBpixels());

        _adaptiveSpatialLPfilter(&_demultiplexedTempBuffer[0], &_demultiplexedColorFrame[0]);
        _adaptiveSpatialLPfilter(&_demultiplexedTempBuffer[0]+_filterOutput.getNBpixels(), &_demultiplexedColorFrame[0]+_filterOutput.getNBpixels());
        _adaptiveSpatialLPfilter(&_demultiplexedTempBuffer[0]+_filterOutput.getDoubleNBpixels(), &_demultiplexedColorFrame[0]+_filterOutput.getDoubleNBpixels());

/*      for (unsigned int index=0; index<_filterOutput.getNBpixels()*3 ; ++index) // cette boucle pourrait �tre supprimee en passant la densit� � la fonction de filtrage
            _demultiplexedColorFrame[index] /= _chrominance[index];*/
        _demultiplexedColorFrame/=_chrominance; // more optimal ;o)

        // compute and substract the residual luminance
        for (unsigned int index=0; index<_filterOutput.getNBpixels() ; ++index)
        {
            float residu = _pR*_demultiplexedColorFrame[index] + _pG*_demultiplexedColorFrame[index+_filterOutput.getNBpixels()] + _pB*_demultiplexedColorFrame[index+_filterOutput.getDoubleNBpixels()];
            _demultiplexedColorFrame[index] = _demultiplexedColorFrame[index] - residu;
            _demultiplexedColorFrame[index+_filterOutput.getNBpixels()] = _demultiplexedColorFrame[index+_filterOutput.getNBpixels()] - residu;
            _demultiplexedColorFrame[index+_filterOutput.getDoubleNBpixels()] = _demultiplexedColorFrame[index+_filterOutput.getDoubleNBpixels()] - residu;
        }

        // multiplex the obtained chrominance
        runColorMultiplexing(_demultiplexedColorFrame, _tempMultiplexedFrame);
        _demultiplexedTempBuffer=0;

        // get the luminance, et and add it to each chrominance
        for (unsigned int index=0; index<_filterOutput.getNBpixels() ; ++index)
        {
            (*_luminance)[index]=multiplexedColorFrame[index]-_tempMultiplexedFrame[index];
            _demultiplexedTempBuffer[_colorSampling[index]] = _demultiplexedColorFrame[_colorSampling[index]];//multiplexedColorFrame[index] - (*_luminance)[index];
        }

        _spatiotemporalLPfilter(&_demultiplexedTempBuffer[0], &_demultiplexedTempBuffer[0]);
        _spatiotemporalLPfilter(&_demultiplexedTempBuffer[0]+_filterOutput.getNBpixels(), &_demultiplexedTempBuffer[0]+_filterOutput.getNBpixels());
        _spatiotemporalLPfilter(&_demultiplexedTempBuffer[0]+_filterOutput.getDoubleNBpixels(), &_demultiplexedTempBuffer[0]+_filterOutput.getDoubleNBpixels());

        // get the luminance and add it to each chrominance
        for (unsigned int index=0; index<_filterOutput.getNBpixels() ; ++index)
        {
            _demultiplexedColorFrame[index] = _demultiplexedTempBuffer[index]*_colorLocalDensity[index]+ (*_luminance)[index];
            _demultiplexedColorFrame[index+_filterOutput.getNBpixels()] = _demultiplexedTempBuffer[index+_filterOutput.getNBpixels()]*_colorLocalDensity[index+_filterOutput.getNBpixels()]+ (*_luminance)[index];
            _demultiplexedColorFrame[index+_filterOutput.getDoubleNBpixels()] = _demultiplexedTempBuffer[index+_filterOutput.getDoubleNBpixels()]*_colorLocalDensity[index+_filterOutput.getDoubleNBpixels()]+ (*_luminance)[index];
        }
    }

    // eliminate saturated colors by simple clipping values to the input range
    clipRGBOutput_0_maxInputValue(NULL, maxInputValue);

    /* transfert image gradient in order to check validity
    memcpy((*_luminance), _imageGradient, sizeof(float)*_filterOutput.getNBpixels());
    memcpy(_demultiplexedColorFrame, _imageGradient+_filterOutput.getNBpixels(), sizeof(float)*_filterOutput.getNBpixels());
    memcpy(_demultiplexedColorFrame+_filterOutput.getNBpixels(), _imageGradient+_filterOutput.getNBpixels(), sizeof(float)*_filterOutput.getNBpixels());
    memcpy(_demultiplexedColorFrame+2*_filterOutput.getNBpixels(), _imageGradient+_filterOutput.getNBpixels(), sizeof(float)*_filterOutput.getNBpixels());
     */

    if (_saturateColors)
    {
        TemplateBuffer<float>::normalizeGrayOutputCentredSigmoide(128, _colorSaturationValue, maxInputValue, &_demultiplexedColorFrame[0], &_demultiplexedColorFrame[0], _filterOutput.getNBpixels());
        TemplateBuffer<float>::normalizeGrayOutputCentredSigmoide(128, _colorSaturationValue, maxInputValue, &_demultiplexedColorFrame[0]+_filterOutput.getNBpixels(), &_demultiplexedColorFrame[0]+_filterOutput.getNBpixels(), _filterOutput.getNBpixels());
        TemplateBuffer<float>::normalizeGrayOutputCentredSigmoide(128, _colorSaturationValue, maxInputValue, &_demultiplexedColorFrame[0]+_filterOutput.getNBpixels()*2, &_demultiplexedColorFrame[0]+_filterOutput.getNBpixels()*2, _filterOutput.getNBpixels());
    }
}

// color multiplexing: input frame size=_NBrows*_filterOutput.getNBcolumns()*3, multiplexedFrame output size=_NBrows*_filterOutput.getNBcolumns()
void RetinaColor::runColorMultiplexing(const std::valarray<float> &demultiplexedInputFrame, std::valarray<float> &multiplexedFrame)
{
    // multiply each color layer by its bayer mask
    unsigned int *colorSamplingPTR= &_colorSampling[0];
    float *multiplexedFramePTR= &multiplexedFrame[0];
    for (unsigned int indexp=0; indexp<_filterOutput.getNBpixels(); ++indexp)
        *(multiplexedFramePTR++)=demultiplexedInputFrame[*(colorSamplingPTR++)];
}

void RetinaColor::normalizeRGBOutput_0_maxOutputValue(const float maxOutputValue)
{
    //normalizeGrayOutputCentredSigmoide(0.0, 2, _chrominance);
    TemplateBuffer<float>::normalizeGrayOutput_0_maxOutputValue(&_demultiplexedColorFrame[0], 3*_filterOutput.getNBpixels(), maxOutputValue);
    //normalizeGrayOutputCentredSigmoide(0.0, 2, _chrominance+_filterOutput.getNBpixels());
    //normalizeGrayOutput_0_maxOutputValue(_demultiplexedColorFrame+_filterOutput.getNBpixels(), _filterOutput.getNBpixels(), maxOutputValue);
    //normalizeGrayOutputCentredSigmoide(0.0, 2, _chrominance+2*_filterOutput.getNBpixels());
    //normalizeGrayOutput_0_maxOutputValue(_demultiplexedColorFrame+_filterOutput.getDoubleNBpixels(), _filterOutput.getNBpixels(), maxOutputValue);
    TemplateBuffer<float>::normalizeGrayOutput_0_maxOutputValue(&(*_luminance)[0], _filterOutput.getNBpixels(), maxOutputValue);
}

/// normalize output between 0 and maxOutputValue;
void RetinaColor::clipRGBOutput_0_maxInputValue(float *inputOutputBuffer, const float maxInputValue)
{
    //std::cout<<"RetinaColor::normalizing RGB frame..."<<std::endl;
    // if outputBuffer unsassigned, the rewrite the buffer
    if (inputOutputBuffer==NULL)
        inputOutputBuffer= &_demultiplexedColorFrame[0];

#ifdef MAKE_PARALLEL // call the TemplateBuffer TBB clipping method
        cv::parallel_for_(cv::Range(0,_filterOutput.getNBpixels()*3), Parallel_clipBufferValues<float>(inputOutputBuffer, 0,  maxInputValue));
#else
    float *inputOutputBufferPTR=inputOutputBuffer;
    for (unsigned int jf = 0; jf < _filterOutput.getNBpixels()*3; ++jf, ++inputOutputBufferPTR)
    {
        if (*inputOutputBufferPTR>maxInputValue)
            *inputOutputBufferPTR=maxInputValue;
        else if (*inputOutputBufferPTR<0)
            *inputOutputBufferPTR=0;
    }
#endif
    //std::cout<<"RetinaColor::...normalizing RGB frame OK"<<std::endl;
}

void RetinaColor::_interpolateImageDemultiplexedImage(float *inputOutputBuffer)
{

    switch(_samplingMethod)
    {

    case RETINA_COLOR_RANDOM:
        return; // no need to interpolate
        break;

    case RETINA_COLOR_DIAGONAL:
        _interpolateSingleChannelImage111(inputOutputBuffer);
        break;

    case RETINA_COLOR_BAYER: // default sets bayer sampling
        _interpolateBayerRGBchannels(inputOutputBuffer);
        break;
    default:
        std::cerr<<"RetinaColor::No or wrong color sampling method, skeeping"<<std::endl;
        return;
        break;//.. not useful, yes

    }

}

void RetinaColor::_interpolateSingleChannelImage111(float *inputOutputBuffer)
{
    for (unsigned int indexr=0 ; indexr<_filterOutput.getNBrows(); ++indexr)
    {
        for (unsigned int indexc=1 ; indexc<_filterOutput.getNBcolumns()-1; ++indexc)
        {
            unsigned int index=indexc+indexr*_filterOutput.getNBcolumns();
            inputOutputBuffer[index]=(inputOutputBuffer[index-1]+inputOutputBuffer[index]+inputOutputBuffer[index+1])/3.f;
        }
    }
    for (unsigned int indexc=0 ; indexc<_filterOutput.getNBcolumns(); ++indexc)
    {
        for (unsigned int indexr=1 ; indexr<_filterOutput.getNBrows()-1; ++indexr)
        {
            unsigned int index=indexc+indexr*_filterOutput.getNBcolumns();
            inputOutputBuffer[index]=(inputOutputBuffer[index-_filterOutput.getNBcolumns()]+inputOutputBuffer[index]+inputOutputBuffer[index+_filterOutput.getNBcolumns()])/3.f;
        }
    }
}

void RetinaColor::_interpolateBayerRGBchannels(float *inputOutputBuffer)
{
    for (unsigned int indexr=0 ; indexr<_filterOutput.getNBrows()-1; indexr+=2)
    {
        for (unsigned int indexc=1 ; indexc<_filterOutput.getNBcolumns()-1; indexc+=2)
        {
            unsigned int indexR=indexc+indexr*_filterOutput.getNBcolumns();
            unsigned int indexB=_filterOutput.getDoubleNBpixels()+indexc+1+(indexr+1)*_filterOutput.getNBcolumns();
            inputOutputBuffer[indexR]=(inputOutputBuffer[indexR-1]+inputOutputBuffer[indexR+1])/2.f;
            inputOutputBuffer[indexB]=(inputOutputBuffer[indexB-1]+inputOutputBuffer[indexB+1])/2.f;
        }
    }
    for (unsigned int indexr=1 ; indexr<_filterOutput.getNBrows()-1; indexr+=2)
    {
        for (unsigned int indexc=0 ; indexc<_filterOutput.getNBcolumns(); ++indexc)
        {
            unsigned int indexR=indexc+indexr*_filterOutput.getNBcolumns();
            unsigned int indexB=_filterOutput.getDoubleNBpixels()+indexc+1+(indexr+1)*_filterOutput.getNBcolumns();
            inputOutputBuffer[indexR]=(inputOutputBuffer[indexR-_filterOutput.getNBcolumns()]+inputOutputBuffer[indexR+_filterOutput.getNBcolumns()])/2.f;
            inputOutputBuffer[indexB]=(inputOutputBuffer[indexB-_filterOutput.getNBcolumns()]+inputOutputBuffer[indexB+_filterOutput.getNBcolumns()])/2.f;

        }
    }
    for (unsigned int indexr=1 ; indexr<_filterOutput.getNBrows()-1; ++indexr)
        for (unsigned int indexc=0 ; indexc<_filterOutput.getNBcolumns(); indexc+=2)
        {
            unsigned int indexG=_filterOutput.getNBpixels()+indexc+(indexr)*_filterOutput.getNBcolumns()+indexr%2;
            inputOutputBuffer[indexG]=(inputOutputBuffer[indexG-1]+inputOutputBuffer[indexG+1]+inputOutputBuffer[indexG-_filterOutput.getNBcolumns()]+inputOutputBuffer[indexG+_filterOutput.getNBcolumns()])*0.25f;
        }
}

void RetinaColor::_applyRIFfilter(const float *sourceBuffer, float *destinationBuffer)
{
    for (unsigned int indexr=1 ; indexr<_filterOutput.getNBrows()-1; ++indexr)
    {
        for (unsigned int indexc=1 ; indexc<_filterOutput.getNBcolumns()-1; ++indexc)
        {
            unsigned int index=indexc+indexr*_filterOutput.getNBcolumns();
            _tempMultiplexedFrame[index]=(4.f*sourceBuffer[index]+sourceBuffer[index-1-_filterOutput.getNBcolumns()]+sourceBuffer[index-1+_filterOutput.getNBcolumns()]+sourceBuffer[index+1-_filterOutput.getNBcolumns()]+sourceBuffer[index+1+_filterOutput.getNBcolumns()])*0.125f;
        }
    }
    memcpy(destinationBuffer, &_tempMultiplexedFrame[0], sizeof(float)*_filterOutput.getNBpixels());
}

void RetinaColor::_getNormalizedContoursImage(const float *inputFrame, float *outputFrame)
{
    float maxValue=0.f;
    float normalisationFactor=1.f/3.f;
    for (unsigned int indexr=1 ; indexr<_filterOutput.getNBrows()-1; ++indexr)
    {
        for (unsigned int indexc=1 ; indexc<_filterOutput.getNBcolumns()-1; ++indexc)
        {
            unsigned int index=indexc+indexr*_filterOutput.getNBcolumns();
            outputFrame[index]=normalisationFactor*fabs(8.f*inputFrame[index]-inputFrame[index-1]-inputFrame[index+1]-inputFrame[index-_filterOutput.getNBcolumns()]-inputFrame[index+_filterOutput.getNBcolumns()]-inputFrame[index-1-_filterOutput.getNBcolumns()]-inputFrame[index-1+_filterOutput.getNBcolumns()]-inputFrame[index+1-_filterOutput.getNBcolumns()]-inputFrame[index+1+_filterOutput.getNBcolumns()]);
            if (outputFrame[index]>maxValue)
                maxValue=outputFrame[index];
        }
    }
    normalisationFactor=1.f/maxValue;
    // normalisation [0, 1]
    for (unsigned int indexp=1 ; indexp<_filterOutput.getNBrows()-1; ++indexp)
       outputFrame[indexp]=outputFrame[indexp]*normalisationFactor;
}

//////////////////////////////////////////////////////////
//        ADAPTIVE BASIC RETINA FILTER
//////////////////////////////////////////////////////////
// run LP filter for a new frame input and save result at a specific output adress
void RetinaColor::_adaptiveSpatialLPfilter(const float *inputFrame, float *outputFrame)
{

    /**********/
    _gain = (1-0.57f)*(1-0.57f)*(1-0.06f)*(1-0.06f);

    // launch the serie of 1D directional filters in order to compute the 2D low pass filter
    // -> horizontal filters work with the first layer of imageGradient
    _adaptiveHorizontalCausalFilter_addInput(inputFrame, outputFrame, 0, _filterOutput.getNBrows());
    _horizontalAnticausalFilter_Irregular(outputFrame, 0, _filterOutput.getNBrows(), &_imageGradient[0]);
    // -> horizontal filters work with the second layer of imageGradient
    _verticalCausalFilter_Irregular(outputFrame, 0, _filterOutput.getNBcolumns(), &_imageGradient[0]+_filterOutput.getNBpixels());
    _adaptiveVerticalAnticausalFilter_multGain(outputFrame, 0, _filterOutput.getNBcolumns());
}

//  horizontal causal filter which adds the input inside... replaces the parent _horizontalCausalFilter_Irregular_addInput by avoiding a product for each pixel
void RetinaColor::_adaptiveHorizontalCausalFilter_addInput(const float *inputFrame, float *outputFrame, unsigned int IDrowStart, unsigned int IDrowEnd)
{
#ifdef MAKE_PARALLEL
        cv::parallel_for_(cv::Range(IDrowStart,IDrowEnd), Parallel_adaptiveHorizontalCausalFilter_addInput(inputFrame, outputFrame, &_imageGradient[0], _filterOutput.getNBcolumns()));
#else
    float* outputPTR=outputFrame+IDrowStart*_filterOutput.getNBcolumns();
    const float* inputPTR=inputFrame+IDrowStart*_filterOutput.getNBcolumns();
    const float *imageGradientPTR= &_imageGradient[0]+IDrowStart*_filterOutput.getNBcolumns();
    for (unsigned int IDrow=IDrowStart; IDrow<IDrowEnd; ++IDrow)
    {
        float result=0;
        for (unsigned int index=0; index<_filterOutput.getNBcolumns(); ++index)
        {
            //std::cout<<(*imageGradientPTR)<<" ";
            result = *(inputPTR++) + (*imageGradientPTR)* result;
            *(outputPTR++) = result;
            ++imageGradientPTR;
        }
        //        std::cout<<" "<<std::endl;
    }
#endif
}

//  vertical anticausal filter which multiplies the output by _gain... replaces the parent _verticalAnticausalFilter_multGain by avoiding a product for each pixel and taking into account the second layer of the _imageGradient buffer
void RetinaColor::_adaptiveVerticalAnticausalFilter_multGain(float *outputFrame, unsigned int IDcolumnStart, unsigned int IDcolumnEnd)
{
#ifdef MAKE_PARALLEL
        cv::parallel_for_(cv::Range(IDcolumnStart,IDcolumnEnd), Parallel_adaptiveVerticalAnticausalFilter_multGain(outputFrame, &_imageGradient[0]+_filterOutput.getNBpixels(), _filterOutput.getNBrows(), _filterOutput.getNBcolumns(), _gain));
#else
    float* outputOffset=outputFrame+_filterOutput.getNBpixels()-_filterOutput.getNBcolumns();
    float* gradOffset= &_imageGradient[0]+_filterOutput.getNBpixels()*2-_filterOutput.getNBcolumns();

    for (unsigned int IDcolumn=IDcolumnStart; IDcolumn<IDcolumnEnd; ++IDcolumn)
    {
        float result=0;
        float *outputPTR=outputOffset+IDcolumn;
        float *imageGradientPTR=gradOffset+IDcolumn;
        for (unsigned int index=0; index<_filterOutput.getNBrows(); ++index)
        {
            result = *(outputPTR) + (*(imageGradientPTR)) * result;
            *(outputPTR) = _gain*result;
            outputPTR-=_filterOutput.getNBcolumns();
            imageGradientPTR-=_filterOutput.getNBcolumns();
        }
    }
#endif
}

///////////////////////////
void RetinaColor::_computeGradient(const float *luminance)
{
    for (unsigned int idLine=2;idLine<_filterOutput.getNBrows()-2;++idLine)
    {
        for (unsigned int idColumn=2;idColumn<_filterOutput.getNBcolumns()-2;++idColumn)
        {
            const unsigned int pixelIndex=idColumn+_filterOutput.getNBcolumns()*idLine;

            // horizontal and vertical local gradients
            const float verticalGrad=fabs(luminance[pixelIndex+_filterOutput.getNBcolumns()]-luminance[pixelIndex-_filterOutput.getNBcolumns()]);
            const float horizontalGrad=fabs(luminance[pixelIndex+1]-luminance[pixelIndex-1]);

            // neighborhood horizontal and vertical gradients
            const float verticalGrad_p=fabs(luminance[pixelIndex]-luminance[pixelIndex-2*_filterOutput.getNBcolumns()]);
            const float horizontalGrad_p=fabs(luminance[pixelIndex]-luminance[pixelIndex-2]);
            const float verticalGrad_n=fabs(luminance[pixelIndex+2*_filterOutput.getNBcolumns()]-luminance[pixelIndex]);
            const float horizontalGrad_n=fabs(luminance[pixelIndex+2]-luminance[pixelIndex]);

            const float horizontalGradient=0.5f*horizontalGrad+0.25f*(horizontalGrad_p+horizontalGrad_n);
            const float verticalGradient=0.5f*verticalGrad+0.25f*(verticalGrad_p+verticalGrad_n);

            // compare local gradient means and fill the appropriate filtering coefficient value that will be used in adaptative filters
            if (horizontalGradient<verticalGradient)
            {
                _imageGradient[pixelIndex+_filterOutput.getNBpixels()]=0.06f;
                _imageGradient[pixelIndex]=0.57f;
            }
            else
            {
                _imageGradient[pixelIndex+_filterOutput.getNBpixels()]=0.57f;
                _imageGradient[pixelIndex]=0.06f;
            }
        }
    }
}

bool RetinaColor::applyKrauskopfLMS2Acr1cr2Transform(std::valarray<float> &result)
{
    bool processSuccess=true;
    // basic preliminary error check
    if (result.size()!=_demultiplexedColorFrame.size())
    {
        std::cerr<<"RetinaColor::applyKrauskopfLMS2Acr1cr2Transform: input buffer does not match retina buffer size, conversion aborted"<<std::endl;
        return false;
    }

    // apply transformation
    _applyImageColorSpaceConversion(_demultiplexedColorFrame, result, _LMStoACr1Cr2);

    return processSuccess;
}

bool RetinaColor::applyLMS2LabTransform(std::valarray<float> &result)
{
    bool processSuccess=true;
    // basic preliminary error check
    if (result.size()!=_demultiplexedColorFrame.size())
    {
        std::cerr<<"RetinaColor::applyKrauskopfLMS2Acr1cr2Transform: input buffer does not match retina buffer size, conversion aborted"<<std::endl;
        return false;
    }

    // apply transformation
    _applyImageColorSpaceConversion(_demultiplexedColorFrame, result, _LMStoLab);

    return processSuccess;
}

// template function able to perform a custom color space transformation
void RetinaColor::_applyImageColorSpaceConversion(const std::valarray<float> &inputFrameBuffer, std::valarray<float> &outputFrameBuffer, const float *transformTable)
{
    // two step methods in order to allow inputFrame and outputFrame to be the same
    unsigned int nbPixels=(unsigned int)(inputFrameBuffer.size()/3), dbpixels=(unsigned int)(2*inputFrameBuffer.size()/3);

    const float *inputFrame=get_data(inputFrameBuffer);
    float *outputFrame= &outputFrameBuffer[0];

    for (unsigned int dataIndex=0; dataIndex<nbPixels;++dataIndex, ++outputFrame, ++inputFrame)
    {
        // first step, compute each new values
        float layer1 = *(inputFrame)**(transformTable+0)  +*(inputFrame+nbPixels)**(transformTable+1)  +*(inputFrame+dbpixels)**(transformTable+2);
        float layer2 = *(inputFrame)**(transformTable+3)  +*(inputFrame+nbPixels)**(transformTable+4)  +*(inputFrame+dbpixels)**(transformTable+5);
        float layer3 = *(inputFrame)**(transformTable+6)  +*(inputFrame+nbPixels)**(transformTable+7)  +*(inputFrame+dbpixels)**(transformTable+8);
        // second, affect the output
        *(outputFrame)          = layer1;
        *(outputFrame+nbPixels) = layer2;
        *(outputFrame+dbpixels) = layer3;
    }
}

}// end of namespace bioinspired
}// end of namespace cv