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// KeyPoint.cpp: implementation of the CKeyPoint class. 
// 
////////////////////////////////////////////////////////////////////// 
 
#include "stdafx.h" 
#include "TestSIFT.h" 
#include "KeyPoint.h" 
 
#ifdef _DEBUG 
#undef THIS_FILE 
static char THIS_FILE[]=__FILE__; 
#define new DEBUG_NEW 
#endif 
 
////////////////////////////////////////////////////////////////////// 
// Construction/Destruction 
////////////////////////////////////////////////////////////////////// 
 
CKeyPoint::	CKeyPoint (IplImage* gaussImg, double x, double y, double imgScale, 
		double kpScale, double orientation) 
{ 
	m_gaussImg = gaussImg; 
	m_x = x; 
	m_y = y; 
	m_imgScale = imgScale; 
	m_kpScale = kpScale; 
	m_orientation = orientation; 
	m_featureVec = NULL; 
} 
 
CKeyPoint::~CKeyPoint() 
{ 
	if (m_featureVec != NULL) 
		delete m_featureVec; 
} 
 
void CKeyPoint::CreateVector (int xDim, int yDim, int oDim) 
{ 
	m_xDim = xDim; 
	m_yDim = yDim; 
	m_oDim = oDim; 
	m_featureVec = new double[yDim * xDim * oDim]; 
	memset (m_featureVec,0,sizeof(double)*yDim*xDim*oDim); 
} 
 
 
void CKeyPoint::FVSet(int xI, int yI, int oI, double value) 
{ 
	// row major 
	m_featureVec[(yI * m_xDim * m_oDim) + (xI * m_oDim) + oI] = value; 
} 
 
double CKeyPoint::FVGet(int xI, int yI, int oI) 
{ 
	// row major 
	return m_featureVec[(yI * m_xDim * m_oDim) + (xI * m_oDim) + oI]; 
} 
 
// Threshhold and normalize feature vector. 
// Note that the feature vector as a whole is normalized (Lowe's paper is 
// a bit unclear at that point). 
void CKeyPoint::CapAndNormalizeFV (double fvGradHicap) 
{ 
	// Straight normalization 
	int len = m_xDim * m_yDim * m_oDim; 
	double norm = 0.0; 
	for (int i = 0 ; i < len ; i++) 
		norm += m_featureVec[i]*m_featureVec[i]; 
 
	norm = sqrt (norm); 
	if (norm == 0.0) 
		return; 
 
	for (i = 0 ; i < len; i++) 
		m_featureVec[i] /= norm; 
 
	// Hicap after normalization 
	for (i = 0 ; i < len; i++)  
		if (m_featureVec[i] > fvGradHicap)  
			m_featureVec[i] = fvGradHicap; 
 
	// Renormalize again 
	norm = 0; 
	for (i = 0 ; i < len ; i++) 
		norm += m_featureVec[i]*m_featureVec[i]; 
	norm = sqrt (norm); 
	 
	for (i = 0 ; i < len; i++) 
		m_featureVec[i] /= norm; 
}