SiftPyramid.cpp

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//      File:           SiftPyramid.cpp
//      Author:         Changchang Wu
//      Description :   Implementation of the SiftPyramid class.
//                                      
//
//
//      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
//


#include "GL/glew.h"
#include <string.h>
#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>
#include <fstream>
#include <math.h>
using namespace std;

#include "GlobalUtil.h"
#include "SiftPyramid.h"
#include "SiftGPU.h"


#ifdef DEBUG_SIFTGPU
#include "IL/il.h"
#include "direct.h"
#include "io.h"
#include <sys/stat.h> 
#endif



void SiftPyramid::RunSIFT(GLTexInput*input)
{
    CleanupBeforeSIFT(); 

        if(_existing_keypoints & SIFT_SKIP_FILTERING)
        {
                
        }else
        {
                GlobalUtil::StartTimer("Build    Pyramid");
                BuildPyramid(input);
                GlobalUtil::StopTimer();
                _timing[0] = GetElapsedTime();
        }


        if(_existing_keypoints)
        {
                //existing keypoint list should at least have the locations and scale
                GlobalUtil::StartTimer("Upload Feature List");
                if(!(_existing_keypoints & SIFT_SKIP_FILTERING)) ComputeGradient();
                GenerateFeatureListTex();
                GlobalUtil::StopTimer();
                _timing[2] = GetElapsedTime();
        }else
        {

                GlobalUtil::StartTimer("Detect Keypoints");
                DetectKeypointsEX();
                GlobalUtil::StopTimer();
                _timing[1] = GetElapsedTime();

                if(GlobalUtil::_ListGenGPU ==1)
                {
                        GlobalUtil::StartTimer("Get Feature List");
                        GenerateFeatureList();
                        GlobalUtil::StopTimer();

                }else
                {
                        GlobalUtil::StartTimer("Transfer Feature List");
                        GenerateFeatureListCPU();
                        GlobalUtil::StopTimer();
                }
            LimitFeatureCount(0);
                _timing[2] = GetElapsedTime();
        }


        
        if(_existing_keypoints& SIFT_SKIP_ORIENTATION)
        {
                //use exisitng feature orientation or
        }else   if(GlobalUtil::_MaxOrientation>0)
        {
                //some extra tricks are done to handle existing keypoint list
                GlobalUtil::StartTimer("Feature Orientations");
                GetFeatureOrientations();
                GlobalUtil::StopTimer();
                _timing[3] = GetElapsedTime();

                //for existing keypoint list, only the strongest orientation is kept.
                if(GlobalUtil::_MaxOrientation >1 && !_existing_keypoints && !GlobalUtil::_FixedOrientation)
                {
                        GlobalUtil::StartTimer("MultiO Feature List");
                        ReshapeFeatureListCPU();
            LimitFeatureCount(1);
                        GlobalUtil::StopTimer();        
                        _timing[4] = GetElapsedTime();
                }
        }else
        {
                GlobalUtil::StartTimer("Feature Orientations");
                GetSimplifiedOrientation();
                GlobalUtil::StopTimer();
                _timing[3] = GetElapsedTime();
        }

        PrepareBuffer();

        if(_existing_keypoints & SIFT_SKIP_ORIENTATION)
        {
                //no need to read back feature if all fields of keypoints are already specified
        }else
        {
                GlobalUtil::StartTimer("Download Keypoints");
#ifdef NO_DUPLICATE_DOWNLOAD
                if(GlobalUtil::_MaxOrientation < 2 || GlobalUtil::_FixedOrientation)
#endif
                DownloadKeypoints();
                GlobalUtil::StopTimer();
                _timing[5] =  GetElapsedTime(); 
        }



        if(GlobalUtil::_DescriptorPPT)
        {
                //desciprotrs are downloaded in descriptor computation of each level
                GlobalUtil::StartTimer("Get Descriptor");
                GetFeatureDescriptors();
                GlobalUtil::StopTimer();
                _timing[6] =  GetElapsedTime(); 
        }

        //reset the existing keypoints
        _existing_keypoints = 0;
        _keypoint_index.resize(0);

    if(GlobalUtil::_UseSiftGPUEX)
        {
                GlobalUtil::StartTimer("Gen. Display VBO");
                GenerateFeatureDisplayVBO();
                GlobalUtil::StopTimer();
                _timing[7] = GlobalUtil::GetElapsedTime();
        }
    //clean up
    CleanUpAfterSIFT();
}


void SiftPyramid::LimitFeatureCount(int have_keylist)
{

        if(GlobalUtil::_FeatureCountThreshold <= 0 || _existing_keypoints) return;
        //skip the lowest levels to reduce number of features. 

    if(GlobalUtil::_TruncateMethod == 2)
    {
        int i = 0, new_feature_num = 0, level_num = param._dog_level_num * _octave_num;
        for(; new_feature_num < _FeatureCountThreshold && i < level_num; ++i) new_feature_num += _levelFeatureNum[i];
        for(; i < level_num; ++i)            _levelFeatureNum[i] = 0; 

        if(new_feature_num < _featureNum)
        {
            _featureNum = new_feature_num;
            if(GlobalUtil::_verbose )
            {
                    std::cout<<"#Features Reduced:\t"<<_featureNum<<endl;
            }
        }
    }else
    {
        int i = 0, num_to_erase = 0;
        while(_featureNum - _levelFeatureNum[i] > _FeatureCountThreshold)
        {
            num_to_erase += _levelFeatureNum[i];
                _featureNum -= _levelFeatureNum[i];
                _levelFeatureNum[i++] = 0;
        }
        if(num_to_erase > 0 && have_keylist)
        {
            _keypoint_buffer.erase(_keypoint_buffer.begin(), _keypoint_buffer.begin() + num_to_erase * 4);
        }
        if(GlobalUtil::_verbose &&  num_to_erase > 0)
        {
                std::cout<<"#Features Reduced:\t"<<_featureNum<<endl;
        }
    }


}

void SiftPyramid::PrepareBuffer()
{
        //when there is no existing keypoint list, the feature list need to be downloaded
        //when an existing keypoint list does not have orientaiton, we need to download them again.
        if(!(_existing_keypoints & SIFT_SKIP_ORIENTATION)) 
        {
                //_keypoint_buffer.resize(4 * (_featureNum +align));
                _keypoint_buffer.resize(4 * (_featureNum + GlobalUtil::_texMaxDim)); //11/19/2008
        }
        if(GlobalUtil::_DescriptorPPT)
        {
                //_descriptor_buffer.resize(128*(_featureNum + align)); 
                _descriptor_buffer.resize(128 * _featureNum + 16 * GlobalUtil::_texMaxDim);//11/19/2008
        }

}

int SiftPyramid:: GetRequiredOctaveNum(int inputsz)
{
    //[2 ^ i,  2 ^ (i + 1)) -> i - 3...
    //768 in [2^9, 2^10)  -> 6 -> smallest will be 768 / 32 = 24
    int num =  (int) floor (log ( inputsz * 2.0 / GlobalUtil::_texMinDim )/log(2.0));
    return num <= 0 ? 1 : num; 
}

void SiftPyramid::CopyFeatureVector(float*keys, float *descriptors)
{
        if(keys)                memcpy(keys, &_keypoint_buffer[0], 4*_featureNum*sizeof(float));
        if(descriptors) memcpy(descriptors, &_descriptor_buffer[0], 128*_featureNum*sizeof(float));
}

void SiftPyramid:: SetKeypointList(int num, const float * keys, int run_on_current, int skip_orientation)
{
        //for each input keypoint
        //sort the key point list by size, and assign them to corresponding levels
        if(num <=0) return;
        _featureNum = num;
        _keypoint_buffer.resize(num * 4);
        memcpy(&_keypoint_buffer[0], keys, 4 * num * sizeof(float));
        //location and scale can be skipped
        _existing_keypoints = SIFT_SKIP_DETECTION;
        //filtering is skipped if it is running on the same image
        if(run_on_current) _existing_keypoints |= SIFT_SKIP_FILTERING;
        //orientation can be skipped if specified
        if(skip_orientation) _existing_keypoints |= SIFT_SKIP_ORIENTATION;
    //hacking parameter for using rectangle description mode
    if(skip_orientation == -1) _existing_keypoints |= SIFT_RECT_DESCRIPTION;
}


void SiftPyramid::SaveSIFT(const char * szFileName)
{
        if (_featureNum <=0) return;
        float * pk = &_keypoint_buffer[0];

        if(GlobalUtil::_BinarySIFT)
        {
                std::ofstream out(szFileName, ios::binary);
                out.write((char* )(&_featureNum), sizeof(int));

                if(GlobalUtil::_DescriptorPPT)
                {
                        int dim = 128;
                        out.write((char* )(&dim), sizeof(int));
                        float * pd = &_descriptor_buffer[0] ;
                        for(int i = 0; i < _featureNum; i++, pk+=4, pd +=128)
                        {
                                out.write((char* )(pk +1), sizeof(float));
                                out.write((char* )(pk), sizeof(float));
                                out.write((char* )(pk+2), 2 * sizeof(float));
                                out.write((char* )(pd), 128 * sizeof(float));
                        }
                }else
                {
                        int dim = 0;
                        out.write((char* )(&dim), sizeof(int));
                        for(int i = 0; i < _featureNum; i++, pk+=4)
                        {
                                out.write((char* )(pk +1), sizeof(float));
                                out.write((char* )(pk), sizeof(float));
                                out.write((char* )(pk+2), 2 * sizeof(float));
                        }
                }
        }else
        {
                std::ofstream out(szFileName);
                out.flags(ios::fixed);

                if(GlobalUtil::_DescriptorPPT)
                {
                        float * pd = &_descriptor_buffer[0] ;
                        out<<_featureNum<<" 128"<<endl;

                        for(int i = 0; i < _featureNum; i++)
                        {
                                //in y, x, scale, orientation order
                                out<<setprecision(2) << pk[1]<<" "<<setprecision(2) << pk[0]<<" "
                                        <<setprecision(3) << pk[2]<<" " <<setprecision(3) <<  pk[3]<< endl; 

                                pk+=4;
                                for(int k = 0; k < 128; k ++, pd++) 
                                {
                                        if(GlobalUtil::_NormalizedSIFT)
                                                out<< ((unsigned int)floor(0.5+512.0f*(*pd)))<<" ";
                                        else
                                                out << setprecision(8) << pd[0] << " ";

                                        if ( (k+1)%20 == 0 ) out<<endl; //suggested by Martin Schneider

                                }
                                out<<endl;

                        }
                
                }else
                {
                        out<<_featureNum<<" 0"<<endl;
                        for(int i = 0; i < _featureNum; i++, pk+=4)
                        {
                                out<<pk[1]<<" "<<pk[0]<<" "<<pk[2]<<" " << pk[3]<<endl;
                        }
                }
        }
}

#ifdef DEBUG_SIFTGPU
void SiftPyramid::BeginDEBUG(const char *imagepath)
{
        if(imagepath && imagepath[0])
        {
                strcpy(_debug_path, imagepath);
                strcat(_debug_path, ".debug");
        }else
        {
                strcpy(_debug_path, ".debug");
        }

        mkdir(_debug_path);
        chmod(_debug_path, _S_IREAD | _S_IWRITE);
}

void SiftPyramid::StopDEBUG()
{
        _debug_path[0] = 0;
}


void SiftPyramid::WriteTextureForDEBUG(GLTexImage * tex, const char *namet, ...)
{
        char name[_MAX_PATH];
        char * p = name, * ps = _debug_path;
        while(*ps) *p++ = *ps ++;
        *p++ = '/';
        va_list marker;
        va_start(marker, namet);
        vsprintf(p, namet, marker);
        va_end(marker);
        unsigned int imID;
        int width = tex->GetImgWidth();
        int height = tex->GetImgHeight();
        float* buffer1 = new float[ width * height  * 4];
        float* buffer2 = new float[ width * height  * 4];

        //read data back
        glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);
        tex->AttachToFBO(0);
        tex->FitTexViewPort();
        glReadPixels(0, 0, width, height, GL_RGBA , GL_FLOAT, buffer1);

        //Tiffs saved with IL are flipped
        for(int i = 0; i < height; i++)
        {
                memcpy(buffer2 + i * width * 4, 
                        buffer1 + (height - i - 1) * width * 4,  
                        width * 4 * sizeof(float));
        }

        //save data as floating point tiff file
        ilGenImages(1, &imID);
        ilBindImage(imID); 
        ilEnable(IL_FILE_OVERWRITE);
        ilTexImage(width, height, 1, 4, IL_RGBA, IL_FLOAT, buffer2);
        ilSave(IL_TIF, name); 
        ilDeleteImages(1, &imID); 

        delete[] buffer1;
        delete[] buffer2;
        glReadBuffer(GL_NONE);
}


#endif