Quadrotor

////////////////////////////////////////////////////////////////////////////

//        File:                PyramidCU.cpp

//        Author:                Changchang Wu

//        Description : implementation of the PyramidCU class.

//                                CUDA-based implementation of SiftPyramid

//

//        Copyright (c) 2007 University of North Carolina at Chapel Hill

//        All Rights Reserved

//

//        Permission to use, copy, modify and distribute this software and its

//        documentation for educational, research and non-profit purposes, without

//        fee, and without a written agreement is hereby granted, provided that the

//        above copyright notice and the following paragraph appear in all copies.

//        

//        The University of North Carolina at Chapel Hill make no representations

//        about the suitability of this software for any purpose. It is provided

//        'as is' without express or implied warranty. 

//

//        Please send BUG REPORTS to ccwu@cs.unc.edu

//

////////////////////////////////////////////////////////////////////////////

#if defined(CUDA_SIFTGPU_ENABLED)

#include "GL/glew.h"

#include <iostream>

#include <vector>

#include <algorithm>

#include <stdlib.h>

#include <string.h>

#include <math.h>

using namespace std;

#include "GlobalUtil.h"

#include "GLTexImage.h"

#include "CuTexImage.h" 

#include "SiftGPU.h"

#include "SiftPyramid.h"

#include "ProgramCU.h"

#include "PyramidCU.h"

//#include "imdebug/imdebuggl.h"

//#pragma comment (lib, "../lib/imdebug.lib")

#define USE_TIMING()                double t, t0, tt;

#define OCTAVE_START()                if(GlobalUtil::_timingO){        t = t0 = CLOCK();        cout<<"#"<<i+_down_sample_factor<<"\t";        }

#define LEVEL_FINISH()                if(GlobalUtil::_timingL){        ProgramCU::FinishCUDA();        tt = CLOCK();cout<<(tt-t)<<"\t";        t = CLOCK();}

#define OCTAVE_FINISH()                if(GlobalUtil::_timingO)cout<<"|\t"<<(CLOCK()-t0)<<endl;

PyramidCU::PyramidCU(SiftParam& sp) : SiftPyramid(sp)

{

        _allPyramid = NULL;

        _histoPyramidTex = NULL;

        _featureTex = NULL;

        _descriptorTex = NULL;

        _orientationTex = NULL;

        _bufferPBO = 0;

    _bufferTEX = NULL;

        _inputTex = new CuTexImage();

    /////////////////////////

    InitializeContext();

}

PyramidCU::~PyramidCU()

{

        DestroyPerLevelData();

        DestroySharedData();

        DestroyPyramidData();

        if(_inputTex) delete _inputTex;

    if(_bufferPBO) glDeleteBuffers(1, &_bufferPBO);

    if(_bufferTEX) delete _bufferTEX;

}

void PyramidCU::InitializeContext()

{

    GlobalUtil::InitGLParam(1);

    GlobalUtil::_GoodOpenGL = max(GlobalUtil::_GoodOpenGL, 1); 

}

void PyramidCU::InitPyramid(int w, int h, int ds)

{

        int wp, hp, toobig = 0;

        if(ds == 0)

        {

                //

                TruncateWidth(w);

                ////

                _down_sample_factor = 0;

                if(GlobalUtil::_octave_min_default>=0)

                {

                        wp = w >> _octave_min_default;

                        hp = h >> _octave_min_default;

                }else

                {

                        //can't upsample by more than 8

                        _octave_min_default = max(-3, _octave_min_default);

                        //

                        wp = w << (-_octave_min_default);

                        hp = h << (-_octave_min_default);

                }

                _octave_min = _octave_min_default;

        }else

        {

                //must use 0 as _octave_min; 

                _octave_min = 0;

                _down_sample_factor = ds;

                w >>= ds;

                h >>= ds;

                /////

                TruncateWidth(w);

                wp = w;

                hp = h; 

        }

        while(wp > GlobalUtil::_texMaxDim  || hp > GlobalUtil::_texMaxDim )

        {

                _octave_min ++;

                wp >>= 1;

                hp >>= 1;

                toobig = 1;

        }

        if(toobig && GlobalUtil::_verbose && _octave_min > 0)

        {

                std::cout<< "**************************************************************\n"

                                        "Image larger than allowed dimension, data will be downsampled!\n"

                                        "use -maxd to change the settings\n"

                                        "***************************************************************\n";

        }

        //ResizePyramid(wp, hp);

        if( wp == _pyramid_width && hp == _pyramid_height && _allocated )

        {

                FitPyramid(wp, hp);

        }else if(GlobalUtil::_ForceTightPyramid || _allocated ==0)

        {

                ResizePyramid(wp, hp);

        }

        else if( wp > _pyramid_width || hp > _pyramid_height )

        {

                ResizePyramid(max(wp, _pyramid_width), max(hp, _pyramid_height));

                if(wp < _pyramid_width || hp < _pyramid_height)  FitPyramid(wp, hp);

        }

        else

        {

                //try use the pyramid allocated for large image on small input images

                FitPyramid(wp, hp);

        }

}

void PyramidCU::ResizePyramid(int w, int h)

{

        //

        unsigned int totalkb = 0;

        int _octave_num_new, input_sz, i, j;

        //

        if(_pyramid_width == w && _pyramid_height == h && _allocated) return;

        if(w > GlobalUtil::_texMaxDim || h > GlobalUtil::_texMaxDim) return ;

        if(GlobalUtil::_verbose && GlobalUtil::_timingS) std::cout<<"[Allocate Pyramid]:\t" <<w<<"x"<<h<<endl;

        //first octave does not change

        _pyramid_octave_first = 0;

        //compute # of octaves

        input_sz = min(w,h) ;

        _pyramid_width =  w;

        _pyramid_height =  h;

        //reset to preset parameters

        _octave_num_new  = GlobalUtil::_octave_num_default;

        if(_octave_num_new < 1) 

        {

                _octave_num_new = (int) floor (log ( double(input_sz))/log(2.0)) -3 ;

                if(_octave_num_new<1 ) _octave_num_new = 1;

        }

        if(_pyramid_octave_num != _octave_num_new)

        {

                //destroy the original pyramid if the # of octave changes

                if(_octave_num >0) 

                {

                        DestroyPerLevelData();

                        DestroyPyramidData();

                }

                _pyramid_octave_num = _octave_num_new;

        }

        _octave_num = _pyramid_octave_num;

        int noct = _octave_num;

        int nlev = param._level_num;

        //        //initialize the pyramid

        if(_allPyramid==NULL)        _allPyramid = new CuTexImage[ noct* nlev * DATA_NUM];

        CuTexImage * gus =  GetBaseLevel(_octave_min, DATA_GAUSSIAN);

        CuTexImage * dog =  GetBaseLevel(_octave_min, DATA_DOG);

        CuTexImage * got =  GetBaseLevel(_octave_min, DATA_GRAD);

        CuTexImage * key =  GetBaseLevel(_octave_min, DATA_KEYPOINT);

        ////////////there could be "out of memory" happening during the allocation

        for(i = 0; i< noct; i++)

        {

                int wa = ((w + 3) / 4) * 4;

                totalkb += ((nlev *8 -19)* (wa * h) * 4 / 1024);

                for( j = 0; j< nlev; j++, gus++, dog++, got++, key++)

                {

                        gus->InitTexture(wa, h); //nlev

                        if(j==0)continue;

                        dog->InitTexture(wa, h);  //nlev -1

                        if(        j >= 1 && j < 1 + param._dog_level_num)

                        {

                                got->InitTexture(wa, h, 2); //2 * nlev - 6

                                got->InitTexture2D();

                        }

                        if(j > 1 && j < nlev -1)        key->InitTexture(wa, h, 4); // nlev -3 ; 4 * nlev - 12

                }

                w>>=1;

                h>>=1;

        }

        totalkb += ResizeFeatureStorage();

        if(ProgramCU::CheckErrorCUDA("ResizePyramid")) SetFailStatus(); 

        _allocated = 1;

        if(GlobalUtil::_verbose && GlobalUtil::_timingS) std::cout<<"[Allocate Pyramid]:\t" <<(totalkb/1024)<<"MB\n";

}

void PyramidCU::FitPyramid(int w, int h)

{

        _pyramid_octave_first = 0;

        //

        _octave_num  = GlobalUtil::_octave_num_default;

        int _octave_num_max = max(1, (int) floor (log ( double(min(w, h)))/log(2.0))  -3 );

        if(_octave_num < 1 || _octave_num > _octave_num_max) 

        {

                _octave_num = _octave_num_max;

        }

        int pw = _pyramid_width>>1, ph = _pyramid_height>>1;

        while(_pyramid_octave_first + _octave_num < _pyramid_octave_num &&  

                pw >= w && ph >= h)

        {

                _pyramid_octave_first++;

                pw >>= 1;

                ph >>= 1;

        }

        //////////////////

        int nlev = param._level_num;

        CuTexImage * gus =  GetBaseLevel(_octave_min, DATA_GAUSSIAN);

        CuTexImage * dog =  GetBaseLevel(_octave_min, DATA_DOG);

        CuTexImage * got =  GetBaseLevel(_octave_min, DATA_GRAD);

        CuTexImage * key =  GetBaseLevel(_octave_min, DATA_KEYPOINT);

        for(int i = 0; i< _octave_num; i++)

        {

                int wa = ((w + 3) / 4) * 4;

                for(int j = 0; j< nlev; j++, gus++, dog++, got++, key++)

                {

                        gus->InitTexture(wa, h); //nlev

                        if(j==0)continue;

                        dog->InitTexture(wa, h);  //nlev -1

                        if(        j >= 1 && j < 1 + param._dog_level_num)

                        {

                                got->InitTexture(wa, h, 2); //2 * nlev - 6

                                got->InitTexture2D();

                        }

                        if(j > 1 && j < nlev -1)        key->InitTexture(wa, h, 4); // nlev -3 ; 4 * nlev - 12

                }

                w>>=1;

                h>>=1;

        }

}

int PyramidCU::CheckCudaDevice(int device)

{

    return ProgramCU::CheckCudaDevice(device);

}

void PyramidCU::SetLevelFeatureNum(int idx, int fcount)

{

        _featureTex[idx].InitTexture(fcount, 1, 4);

        _levelFeatureNum[idx] = fcount;

}

int PyramidCU::ResizeFeatureStorage()

{

        int totalkb = 0;

        if(_levelFeatureNum==NULL)        _levelFeatureNum = new int[_octave_num * param._dog_level_num];

        std::fill(_levelFeatureNum, _levelFeatureNum+_octave_num * param._dog_level_num, 0); 

        int wmax = GetBaseLevel(_octave_min)->GetImgWidth();

        int hmax = GetBaseLevel(_octave_min)->GetImgHeight();

        int whmax = max(wmax, hmax);

        int w,  i;

        //

        int num = (int)ceil(log(double(whmax))/log(4.0));

        if( _hpLevelNum != num)

        {

                _hpLevelNum = num;

                if(_histoPyramidTex ) delete [] _histoPyramidTex;

                _histoPyramidTex = new CuTexImage[_hpLevelNum];

        }

        for(i = 0, w = 1; i < _hpLevelNum; i++)

        {

                _histoPyramidTex[i].InitTexture(w, whmax, 4);

                w<<=2;

        }

        // (4 ^ (_hpLevelNum) -1 / 3) pixels

        totalkb += (((1 << (2 * _hpLevelNum)) -1) / 3 * 16 / 1024);

        //initialize the feature texture

        int idx = 0, n = _octave_num * param._dog_level_num;

        if(_featureTex==NULL)        _featureTex = new CuTexImage[n];

        if(GlobalUtil::_MaxOrientation >1 && GlobalUtil::_OrientationPack2==0 && _orientationTex== NULL)

                _orientationTex = new CuTexImage[n];

        for(i = 0; i < _octave_num; i++)

        {

                CuTexImage * tex = GetBaseLevel(i+_octave_min);

                int fmax = int(tex->GetImgWidth() * tex->GetImgHeight()*GlobalUtil::_MaxFeaturePercent);

                //

                if(fmax > GlobalUtil::_MaxLevelFeatureNum) fmax = GlobalUtil::_MaxLevelFeatureNum;

                else if(fmax < 32) fmax = 32;        //give it at least a space of 32 feature

                for(int j = 0; j < param._dog_level_num; j++, idx++)

                {

                        _featureTex[idx].InitTexture(fmax, 1, 4);

                        totalkb += fmax * 16 /1024;

                        //

                        if(GlobalUtil::_MaxOrientation>1 && GlobalUtil::_OrientationPack2 == 0)

                        {

                                _orientationTex[idx].InitTexture(fmax, 1, 4);

                                totalkb += fmax * 16 /1024;

                        }

                }

        }

        //this just need be initialized once

        if(_descriptorTex==NULL)

        {

                //initialize feature texture pyramid

                int fmax = _featureTex->GetImgWidth();

                _descriptorTex = new CuTexImage;

                totalkb += ( fmax /2);

                _descriptorTex->InitTexture(fmax *128, 1, 1);

        }else

        {

                totalkb +=  _descriptorTex->GetDataSize()/1024;

        }

        return totalkb;

}

void PyramidCU::GetFeatureDescriptors() 

{

        //descriptors...

        float* pd =  &_descriptor_buffer[0];

        vector<float> descriptor_buffer2;

        //use another buffer if we need to re-order the descriptors

        if(_keypoint_index.size() > 0)

        {

                descriptor_buffer2.resize(_descriptor_buffer.size());

                pd = &descriptor_buffer2[0];

        }

        CuTexImage * got, * ftex= _featureTex;

        for(int i = 0, idx = 0; i < _octave_num; i++)

        {

                got = GetBaseLevel(i + _octave_min, DATA_GRAD) + 1;

                for(int j = 0; j < param._dog_level_num; j++, ftex++, idx++, got++)

                {

                        if(_levelFeatureNum[idx]==0) continue;

            ProgramCU::ComputeDescriptor(ftex, got, _descriptorTex, IsUsingRectDescription());//process

                        _descriptorTex->CopyToHost(pd); //readback descriptor

                        pd += 128*_levelFeatureNum[idx];

                }

        }

        if(GlobalUtil::_timingS) ProgramCU::FinishCUDA();

        if(_keypoint_index.size() > 0)

        {

            //put the descriptor back to the original order for keypoint list.

                for(int i = 0; i < _featureNum; ++i)

                {

                        int index = _keypoint_index[i];

                        memcpy(&_descriptor_buffer[index*128], &descriptor_buffer2[i*128], 128 * sizeof(float));

                }

        }

        if(ProgramCU::CheckErrorCUDA("PyramidCU::GetFeatureDescriptors")) SetFailStatus(); 

}

void PyramidCU::GenerateFeatureListTex() 

{

        vector<float> list;

        int idx = 0;

        const double twopi = 2.0*3.14159265358979323846;

        float sigma_half_step = powf(2.0f, 0.5f / param._dog_level_num);

        float octave_sigma = _octave_min>=0? float(1<<_octave_min): 1.0f/(1<<(-_octave_min));

        float offset = GlobalUtil::_LoweOrigin? 0 : 0.5f; 

        if(_down_sample_factor>0) octave_sigma *= float(1<<_down_sample_factor); 

        _keypoint_index.resize(0); // should already be 0

        for(int i = 0; i < _octave_num; i++, octave_sigma*= 2.0f)

        {

                for(int j = 0; j < param._dog_level_num; j++, idx++)

                {

                        list.resize(0);

                        float level_sigma = param.GetLevelSigma(j + param._level_min + 1) * octave_sigma;

                        float sigma_min = level_sigma / sigma_half_step;

                        float sigma_max = level_sigma * sigma_half_step;

                        int fcount = 0 ;

                        for(int k = 0; k < _featureNum; k++)

                        {

                                float * key = &_keypoint_buffer[k*4];

                float sigmak = key[2]; 

                //////////////////////////////////////

                if(IsUsingRectDescription()) sigmak = min(key[2], key[3]) / 12.0f; 

                                if(   (sigmak >= sigma_min && sigmak < sigma_max)

                                        ||(sigmak < sigma_min && i ==0 && j == 0)

                                        ||(sigmak > sigma_max && i == _octave_num -1 && j == param._dog_level_num - 1))

                                {

                                        //add this keypoint to the list

                                        list.push_back((key[0] - offset) / octave_sigma + 0.5f);

                                        list.push_back((key[1] - offset) / octave_sigma + 0.5f);

                    if(IsUsingRectDescription())

                    {

                        list.push_back(key[2] / octave_sigma);

                        list.push_back(key[3] / octave_sigma);

                    }else

                    {

                                            list.push_back(key[2] / octave_sigma);

                                            list.push_back((float)fmod(twopi-key[3], twopi));

                    }

                                        fcount ++;

                                        //save the index of keypoints

                                        _keypoint_index.push_back(k);

                                }

                        }

                        _levelFeatureNum[idx] = fcount;

                        if(fcount==0)continue;

                        CuTexImage * ftex = _featureTex+idx;

                        SetLevelFeatureNum(idx, fcount);

                        ftex->CopyFromHost(&list[0]);

                }

        }

        if(GlobalUtil::_verbose)

        {

                std::cout<<"#Features:\t"<<_featureNum<<"\n";

        }

}

void PyramidCU::ReshapeFeatureListCPU() 

{

        int i, szmax =0, sz;

        int n = param._dog_level_num*_octave_num;

        for( i = 0; i < n; i++) 

        {

                sz = _levelFeatureNum[i];

                if(sz > szmax ) szmax = sz;

        }

        float * buffer = new float[szmax*16];

        float * buffer1 = buffer;

        float * buffer2 = buffer + szmax*4;

        _featureNum = 0;

#ifdef NO_DUPLICATE_DOWNLOAD

        const double twopi = 2.0*3.14159265358979323846;

        _keypoint_buffer.resize(0);

        float os = _octave_min>=0? float(1<<_octave_min): 1.0f/(1<<(-_octave_min));

        if(_down_sample_factor>0) os *= float(1<<_down_sample_factor); 

        float offset = GlobalUtil::_LoweOrigin? 0 : 0.5f;

#endif

        for(i = 0; i < n; i++)

        {

                if(_levelFeatureNum[i]==0)continue;

                _featureTex[i].CopyToHost(buffer1);

                int fcount =0;

                float * src = buffer1;

                float * des = buffer2;

                const static double factor  = 2.0*3.14159265358979323846/65535.0;

                for(int j = 0; j < _levelFeatureNum[i]; j++, src+=4)

                {

                        unsigned short * orientations = (unsigned short*) (&src[3]);

                        if(orientations[0] != 65535)

                        {

                                des[0] = src[0];

                                des[1] = src[1];

                                des[2] = src[2];

                                des[3] = float( factor* orientations[0]);

                                fcount++;

                                des += 4;

                                if(orientations[1] != 65535 && orientations[1] != orientations[0])

                                {

                                        des[0] = src[0];

                                        des[1] = src[1];

                                        des[2] = src[2];

                                        des[3] = float(factor* orientations[1]);        

                                        fcount++;

                                        des += 4;

                                }

                        }

                }

                //texture size

                SetLevelFeatureNum(i, fcount);

                _featureTex[i].CopyFromHost(buffer2);

                if(fcount == 0) continue;

#ifdef NO_DUPLICATE_DOWNLOAD

                float oss = os * (1 << (i / param._dog_level_num));

                _keypoint_buffer.resize((_featureNum + fcount) * 4);

                float* ds = &_keypoint_buffer[_featureNum * 4];

                float* fs = buffer2;

                for(int k = 0;  k < fcount; k++, ds+=4, fs+=4)

                {

                        ds[0] = oss*(fs[0]-0.5f) + offset;        //x

                        ds[1] = oss*(fs[1]-0.5f) + offset;        //y

                        ds[2] = oss*fs[2];  //scale

                        ds[3] = (float)fmod(twopi-fs[3], twopi);        //orientation, mirrored

                }

#endif

                _featureNum += fcount;

        }

        delete[] buffer;

        if(GlobalUtil::_verbose)

        {

                std::cout<<"#Features MO:\t"<<_featureNum<<endl;

        }

}

void PyramidCU::GenerateFeatureDisplayVBO() 

{

        //it is weried that this part is very slow.

        //use a big VBO to save all the SIFT box vertices

        int nvbo = _octave_num * param._dog_level_num;

        if(_featureDisplayVBO==NULL)

        {

                //initialize the vbos

                _featureDisplayVBO = new GLuint[nvbo];

                _featurePointVBO = new GLuint[nvbo];

                glGenBuffers(nvbo, _featureDisplayVBO);        

                glGenBuffers(nvbo, _featurePointVBO);

        }

        for(int i = 0; i < nvbo; i++)

        {

                if(_levelFeatureNum[i]<=0)continue;

                CuTexImage * ftex  = _featureTex + i;

                CuTexImage texPBO1( _levelFeatureNum[i]* 10, 1, 4, _featureDisplayVBO[i]);

                CuTexImage texPBO2(_levelFeatureNum[i], 1, 4, _featurePointVBO[i]);

                ProgramCU::DisplayKeyBox(ftex, &texPBO1);

                ProgramCU::DisplayKeyPoint(ftex, &texPBO2);        

        }

}

void PyramidCU::DestroySharedData() 

{

        //histogram reduction

        if(_histoPyramidTex)

        {

                delete[]        _histoPyramidTex;

                _hpLevelNum = 0;

                _histoPyramidTex = NULL;

        }

        //descriptor storage shared by all levels

        if(_descriptorTex)

        {

                delete _descriptorTex;

                _descriptorTex = NULL;

        }

        //cpu reduction buffer.

        if(_histo_buffer)

        {

                delete[] _histo_buffer;

                _histo_buffer = 0;

        }

}

void PyramidCU::DestroyPerLevelData() 

{

        //integers vector to store the feature numbers.

        if(_levelFeatureNum)

        {

                delete [] _levelFeatureNum;

                _levelFeatureNum = NULL;

        }

        //texture used to store features

        if(        _featureTex)

        {

                delete [] _featureTex;

                _featureTex =        NULL;

        }

        //texture used for multi-orientation 

        if(_orientationTex)

        {

                delete [] _orientationTex;

                _orientationTex = NULL;

        }

        int no = _octave_num* param._dog_level_num;

        //two sets of vbos used to display the features

        if(_featureDisplayVBO)

        {

                glDeleteBuffers(no, _featureDisplayVBO);

                delete [] _featureDisplayVBO;

                _featureDisplayVBO = NULL;

        }

        if( _featurePointVBO)

        {

                glDeleteBuffers(no, _featurePointVBO);

                delete [] _featurePointVBO;

                _featurePointVBO = NULL;

        }

}

void PyramidCU::DestroyPyramidData()

{

        if(_allPyramid)

        {

                delete [] _allPyramid;

                _allPyramid = NULL;

        }

}

void PyramidCU::DownloadKeypoints() 

{

        const double twopi = 2.0*3.14159265358979323846;

        int idx = 0;

        float * buffer = &_keypoint_buffer[0];

        vector<float> keypoint_buffer2;

        //use a different keypoint buffer when processing with an exisint features list

        //without orientation information. 

        if(_keypoint_index.size() > 0)

        {

                keypoint_buffer2.resize(_keypoint_buffer.size());

                buffer = &keypoint_buffer2[0];

        }

        float * p = buffer, *ps;

        CuTexImage * ftex = _featureTex;

        /////////////////////

        float os = _octave_min>=0? float(1<<_octave_min): 1.0f/(1<<(-_octave_min));

        if(_down_sample_factor>0) os *= float(1<<_down_sample_factor); 

        float offset = GlobalUtil::_LoweOrigin? 0 : 0.5f;

        /////////////////////

        for(int i = 0; i < _octave_num; i++, os *= 2.0f)

        {

                for(int j = 0; j  < param._dog_level_num; j++, idx++, ftex++)

                {

                        if(_levelFeatureNum[idx]>0)

                        {        

                                ftex->CopyToHost(ps = p);

                                for(int k = 0;  k < _levelFeatureNum[idx]; k++, ps+=4)

                                {

                                        ps[0] = os*(ps[0]-0.5f) + offset;        //x

                                        ps[1] = os*(ps[1]-0.5f) + offset;        //y

                                        ps[2] = os*ps[2]; 

                                        ps[3] = (float)fmod(twopi-ps[3], twopi);        //orientation, mirrored

                                }

                                p+= 4* _levelFeatureNum[idx];

                        }

                }

        }

        //put the feature into their original order for existing keypoint 

        if(_keypoint_index.size() > 0)

        {

                for(int i = 0; i < _featureNum; ++i)

                {

                        int index = _keypoint_index[i];

                        memcpy(&_keypoint_buffer[index*4], &keypoint_buffer2[i*4], 4 * sizeof(float));

                }

        }

}

void PyramidCU::GenerateFeatureListCPU()

{

        //no cpu version provided

        GenerateFeatureList();

}

void PyramidCU::GenerateFeatureList(int i, int j, int reduction_count, vector<int>& hbuffer)

{

    int fcount = 0, idx = i * param._dog_level_num  + j;

        int hist_level_num = _hpLevelNum - _pyramid_octave_first /2; 

        int ii, k, len; 

        CuTexImage * htex, * ftex, * tex, *got;

        ftex = _featureTex + idx;

        htex = _histoPyramidTex + hist_level_num -1;

        tex = GetBaseLevel(_octave_min + i, DATA_KEYPOINT) + 2 + j;

        got = GetBaseLevel(_octave_min + i, DATA_GRAD) + 2 + j;

        ProgramCU::InitHistogram(tex, htex);

        for(k = 0; k < reduction_count - 1; k++, htex--)

        {

                ProgramCU::ReduceHistogram(htex, htex -1);        

        }

        //htex has the row reduction result

        len = htex->GetImgHeight() * 4;

        hbuffer.resize(len);

        ProgramCU::FinishCUDA();

        htex->CopyToHost(&hbuffer[0]);

    ////TO DO: track the error found here..

        for(ii = 0; ii < len; ++ii)     {if(!(hbuffer[ii]>= 0)) hbuffer[ii] = 0; }//?

    for(ii = 0; ii < len; ++ii)                fcount += hbuffer[ii];

        SetLevelFeatureNum(idx, fcount);

    //build the feature list

        if(fcount > 0)

        {

                _featureNum += fcount;

                _keypoint_buffer.resize(fcount * 4);

                //vector<int> ikbuf(fcount*4);

                int* ibuf = (int*) (&_keypoint_buffer[0]);

                for(ii = 0; ii < len; ++ii)

                {

                        int x = ii%4, y = ii / 4;

                        for(int jj = 0 ; jj < hbuffer[ii]; ++jj, ibuf+=4)

                        {

                                ibuf[0] = x; ibuf[1] = y; ibuf[2] = jj; ibuf[3] = 0;

                        }

                }

                _featureTex[idx].CopyFromHost(&_keypoint_buffer[0]);

                ////////////////////////////////////////////

                ProgramCU::GenerateList(_featureTex + idx, ++htex);

                for(k = 2; k < reduction_count; k++)

                {

                        ProgramCU::GenerateList(_featureTex + idx, ++htex);

                }

        }

}

void PyramidCU::GenerateFeatureList()

{

        double t1, t2; 

        int ocount = 0, reduction_count;

    int reverse = (GlobalUtil::_TruncateMethod == 1);

        vector<int> hbuffer;

        _featureNum = 0;

        //for(int i = 0, idx = 0; i < _octave_num; i++)

    FOR_EACH_OCTAVE(i, reverse)

        {

        CuTexImage* tex = GetBaseLevel(_octave_min + i, DATA_KEYPOINT) + 2;

                reduction_count = FitHistogramPyramid(tex);

                if(GlobalUtil::_timingO)

                {

                        t1 = CLOCK(); 

                        ocount = 0;

                        std::cout<<"#"<<i+_octave_min + _down_sample_factor<<":\t";

                }

                //for(int j = 0; j < param._dog_level_num; j++, idx++)

        FOR_EACH_LEVEL(j, reverse)

                {

            if(GlobalUtil::_TruncateMethod && GlobalUtil::_FeatureCountThreshold > 0 && _featureNum > GlobalUtil::_FeatureCountThreshold) continue;

                GenerateFeatureList(i, j, reduction_count, hbuffer);

                        /////////////////////////////

                        if(GlobalUtil::_timingO)

                        {

                int idx = i * param._dog_level_num + j;

                                ocount += _levelFeatureNum[idx];

                                std::cout<< _levelFeatureNum[idx] <<"\t";

                        }

                }

                if(GlobalUtil::_timingO)

                {        

                        t2 = CLOCK(); 

                        std::cout << "| \t" << int(ocount) << " :\t(" << (t2 - t1) << ")\n";

                }

        }

        /////

        CopyGradientTex();

        /////

        if(GlobalUtil::_timingS)ProgramCU::FinishCUDA();

        if(GlobalUtil::_verbose)

        {

                std::cout<<"#Features:\t"<<_featureNum<<"\n";

        }

        if(ProgramCU::CheckErrorCUDA("PyramidCU::GenerateFeatureList")) SetFailStatus();

}

GLTexImage* PyramidCU::GetLevelTexture(int octave, int level)

{

        return GetLevelTexture(octave, level, DATA_GAUSSIAN);

}

GLTexImage* PyramidCU::ConvertTexCU2GL(CuTexImage* tex, int dataName)

{

        GLenum format = GL_LUMINANCE;

        int convert_done = 1;

    if(_bufferPBO == 0) glGenBuffers(1, &_bufferPBO);

    if(_bufferTEX == NULL) _bufferTEX = new GLTexImage;

        switch(dataName)

        {

        case DATA_GAUSSIAN:

                {

                        convert_done = tex->CopyToPBO(_bufferPBO);

                        break;

                }

        case DATA_DOG:

                {

                        CuTexImage texPBO(tex->GetImgWidth(), tex->GetImgHeight(), 1, _bufferPBO);

                        if(texPBO._cuData == 0 || tex->_cuData == NULL) convert_done = 0;

                        else ProgramCU::DisplayConvertDOG(tex, &texPBO);

                        break;

                }

        case DATA_GRAD:

                {

                        CuTexImage texPBO(tex->GetImgWidth(), tex->GetImgHeight(), 1, _bufferPBO);

                        if(texPBO._cuData == 0 || tex->_cuData == NULL) convert_done = 0;

                        else ProgramCU::DisplayConvertGRD(tex, &texPBO);

                        break;

                }

        case DATA_KEYPOINT:

                {

                        CuTexImage * dog = tex - param._level_num * _pyramid_octave_num;

                        format = GL_RGBA;

                        CuTexImage texPBO(tex->GetImgWidth(), tex->GetImgHeight(), 4, _bufferPBO);

                        if(texPBO._cuData == 0 || tex->_cuData == NULL) convert_done = 0;

                        else ProgramCU::DisplayConvertKEY(tex, dog, &texPBO);

                        break;

                }

        default:

                        convert_done = 0;

                        break;

        }

        if(convert_done)

        {

                _bufferTEX->InitTexture(max(_bufferTEX->GetTexWidth(), tex->GetImgWidth()), max(_bufferTEX->GetTexHeight(), tex->GetImgHeight()));

                _bufferTEX->CopyFromPBO(_bufferPBO, tex->GetImgWidth(), tex->GetImgHeight(), format);

        }else

        {

                _bufferTEX->SetImageSize(0, 0);

        }

        return _bufferTEX;

}

GLTexImage* PyramidCU::GetLevelTexture(int octave, int level, int dataName) 

{

        CuTexImage* tex = GetBaseLevel(octave, dataName) + (level - param._level_min);

        //CuTexImage* gus = GetBaseLevel(octave, DATA_GAUSSIAN) + (level - param._level_min); 

        return ConvertTexCU2GL(tex, dataName);

}

void PyramidCU::ConvertInputToCU(GLTexInput* input)

{

        int ws = input->GetImgWidth(), hs = input->GetImgHeight();

        TruncateWidth(ws);

        //copy the input image to pixel buffer object

    if(input->_pixel_data)

    {

        _inputTex->InitTexture(ws, hs, 1);

        _inputTex->CopyFromHost(input->_pixel_data); 

    }else

    {

        if(_bufferPBO == 0) glGenBuffers(1, &_bufferPBO);

        if(input->_rgb_converted && input->CopyToPBO(_bufferPBO, ws, hs, GL_LUMINANCE))

        {

                    _inputTex->InitTexture(ws, hs, 1);

            _inputTex->CopyFromPBO(ws, hs, _bufferPBO); 

        }else if(input->CopyToPBO(_bufferPBO, ws, hs))

            {

                    CuTexImage texPBO(ws, hs, 4, _bufferPBO);

                    _inputTex->InitTexture(ws, hs, 1);

                    ProgramCU::ReduceToSingleChannel(_inputTex, &texPBO, !input->_rgb_converted);

            }else

            {

                    std::cerr<< "Unable To Convert Intput\n";

            }

    }

}

void PyramidCU::BuildPyramid(GLTexInput * input)

{

        USE_TIMING();

        int i, j;

        for ( i = _octave_min; i < _octave_min + _octave_num; i++)

        {

                float* filter_sigma = param._sigma;

                CuTexImage *tex = GetBaseLevel(i);

                CuTexImage *buf = GetBaseLevel(i, DATA_KEYPOINT) +2;

                j = param._level_min + 1;

                OCTAVE_START();

                if( i == _octave_min )

                {        

                        ConvertInputToCU(input);

                        if(i == 0)

                        {

                                ProgramCU::FilterImage(tex, _inputTex, buf, 

                    param.GetInitialSmoothSigma(_octave_min + _down_sample_factor));

                        }else

                        {

                                if(i < 0)        ProgramCU::SampleImageU(tex, _inputTex, -i);                        

                                else                ProgramCU::SampleImageD(tex, _inputTex, i);

                                ProgramCU::FilterImage(tex, tex, buf, 

                    param.GetInitialSmoothSigma(_octave_min + _down_sample_factor));

                        }

                }else

                {

                        ProgramCU::SampleImageD(tex, GetBaseLevel(i - 1) + param._level_ds - param._level_min); 

                        if(param._sigma_skip1 > 0)

                        {

                                ProgramCU::FilterImage(tex, tex, buf, param._sigma_skip1);

                        }

                }

                LEVEL_FINISH();

                for( ; j <=  param._level_max ; j++, tex++, filter_sigma++)

                {

                        // filtering

                        ProgramCU::FilterImage(tex + 1, tex, buf, *filter_sigma);

                        LEVEL_FINISH();

                }

                OCTAVE_FINISH();