www.pudn.com > edgehist.rar > edgehist.cpp

/*
 *  IMAGE EXTRACTION LIBRARY
 *
 *  DISCOVIR - Distributed Content-based Visual Information Retrieval System on Peer-to-Peer(P2P) Network
 *  http://www.cse.cuhk.edu.hk/~miplab/discovir
 *
 *  Copyright (C) 2002  Multimedia Information Processing Laboratory
 *  http://www.cse.cuhk.edu.hk/~miplab
 *  The Chinese University of Hong Kong
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  
 *
 */

#include 
#include 
#include 
#define FRONT	 255
#define BKGRND   0
/////////////////////////////////////////////////////////////////////////////
unsigned char *ImageConvertedFromFloatArray(int n, float *array)
{
  unsigned char *img=new unsigned char[n];
  for(int i=0; i=0)&&(i2=0)&&(j20)
	  result[j*m_X+i]=(unsigned char)(temp/summask);
	else
	  result[j*m_X+i]=pImageBuf[j*m_X+i];
      }
  return result;   
}
/////////////////////////////////////////////////////////////////////////////
float *ImageGradient(unsigned char *pImageBuf, int m_X, int m_Y, int masksize, float *mask, int number)
{
  float *gradient= new float[m_X*m_Y];
  int i, j, i1, j1, i2, j2, width;
  width=masksize/2;
  float temp;
  for(j=0;jm_Y-width-1)||(im_Y-width-1))
	  gradient[j*m_X+i]=0;
	else
	  {
	    temp=0;
	    for(j1=-width; j1<= width; j1++)
	      for(i1=-width; i1<= width; i1++)
		{
		  i2=i+i1;
		  j2=j+j1;
		  temp+=float(pImageBuf[j2*m_X+i2])*mask[(j1+width)*masksize+(i1+width)];
		}
	    gradient[j*m_X+i]=temp/number;
	  }
      }
  return gradient;   
}
/////////////////////////////////////////////////////////////////////////////
int MyMathFunctionAtan(float p, float q)
{
  float theta, pi;
  int degree;
  pi=float(3.1415926);
  theta=float(atan(double(q)/double(p)));
  if(p<0)
    theta+=pi;
  if(theta<0)
    theta+=2*pi;
  if(theta>2*pi)
    theta-=2*pi;
  degree=int(360*theta/(2*pi));
  return degree;
}
/////////////////////////////////////////////////////////////////////////////
float *ImageEdgeDirectionHistogram(unsigned char *edge, float *p, float *q, int n, float thr, int BIN_NUM)
{
  int i, degree, bin_width, nEdge;
  float magnitude;
  bin_width=360/BIN_NUM;
  float *histogram=new float[BIN_NUM];
  for(i=0; ithr)
	{
	  edge[i]=FRONT;
	  degree=MyMathFunctionAtan(p[i], q[i]);
	  histogram[degree/bin_width]+=1;
	  nEdge+=1;
	}
      else
	edge[i]=BKGRND;
    }
  if(nEdge!=0)
    {
      for(i=0; i