// Fourier.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include "stdio.h"
#include "math.h"
#include <cv.h>
#include <highgui.h>
#include "cxcore.h"

int main(int argc, char* argv[])
{
 IplImage *img;
 IplImage *simg;

 CvMat *mat_R;
 CvMat *mat_I;
 CvMat *mat_SRC; 
 CvMat *mat_Row;
 CvMat *mat_Col;
 CvMat *dst;
 CvMat *dst_R;
 CvMat *dst_I;
 CvMat *dst_Row;
 CvMat *dst_Col;
 int i,j,k;
 double temp;
 int height,width,step,channels;

 //載入一幅圖片
 img=cvLoadImage("c:\\1.bmp",0);

 //mat_R初始化
 mat_R=cvCreateMat(img->height,img->width,CV_64FC1);
 //mat_I初始化
 mat_I=cvCreateMat(img->height,img->width,CV_64FC1);
 //mat_SRC初始化
 mat_SRC=cvCreateMat(img->height,img->width,CV_64FC2);
 //將圖片數(shù)據(jù)存入mat_R（實(shí)部）
 cvConvert(img,mat_R);
 //將虛部初始化為零
 cvZero(mat_I);
 //合并實(shí)部、虛部
 cvMerge(mat_R,mat_I,NULL,NULL,mat_SRC);
 //創(chuàng)建雙通道double類型數(shù)組
 dst=cvCreateMat(img->height,img->width,CV_64FC2);
 dst_R=cvCreateMat(img->height,img->width,CV_64FC1);
 dst_I=cvCreateMat(img->height,img->width,CV_64FC1);
 //為循環(huán)變量賦值
 height=img->height;
 width=img->width;
 channels=2;
 step=channels*width;
 //局部變量，值為正一或負(fù)一
 int check;
 //將輸入數(shù)據(jù)乘以(-1)^(i+j),用于中心化
 for(j=0;j<height;j++)
 {
 for(i=0;i<width;i++)
 {
  check=(i+j)%2>0?1:-1;
  for(k=0;k<channels;k++)
  {
  mat_SRC->data.db[j*step+i*channels+k]=check*mat_SRC->data.db[j*step+i*channels+k];
  }
 }
 }
 //創(chuàng)建一個(gè)mat用于臨時(shí)存儲(chǔ)一行數(shù)據(jù)
 CvMat mat_Header=cvMat(4,4,CV_64FC2);
 mat_Row=cvCreateMat(1,width,CV_64FC2);
 mat_Col=cvCreateMat(1,height,CV_64FC2);
 //創(chuàng)建一個(gè)dst用于臨時(shí)存儲(chǔ)一行數(shù)據(jù)
 dst_Row=cvCreateMat(1,width,CV_64FC2);
 dst_Col=cvCreateMat(height,1,CV_64FC2);
 //為循環(huán)變量賦值
 height=img->height;
 width=img->width;
 channels=2;
 step=channels*width;
 //行的傅里葉變換
 for(j=0;j<height;j++)
 {
 //取得第j行數(shù)據(jù)
 mat_Row=cvGetRow(mat_SRC,&mat_Header,j);
 //正向傅里葉變換
 cvDFT(mat_Row,dst_Row,CV_DXT_FORWARD);
 //執(zhí)行循環(huán)，賦值到dst
 for(i=0;i<width;i++)
 {
  for(k=0;k<channels;k++)
  {
  dst->data.db[j*step+i*channels+k]=dst_Row->data.db[i*channels+k];
  }
 }
 }

 //列的傅里葉變換
 for(i=0;i<width;i++)
 {
 //取得第i列
 mat_Col=cvGetCol(dst,&mat_Header,i);
  
 //正向傅里葉變換
 cvDFT(mat_Col,dst_Col,CV_DXT_FORWARD);
 //執(zhí)行循環(huán)，賦值到dst
 for(j=0;j<height;j++)
 {
  for(k=0;k<channels;k++)
  {
  dst->data.db[j*step+i*channels+k]=dst_Col->data.db[j*channels+k];
  }
 }
 }
 
 //分成兩個(gè)矩陣
 cvSplit(dst,dst_R,dst_I,NULL,NULL);

 //創(chuàng)建臨時(shí)指針指向dst_R,dst_I
 double *pR,*pI;
 pR=(double *)dst_R->data.ptr;
 pI=(double *)dst_I->data.ptr;
 //創(chuàng)建一張用于顯示的圖像
 simg=cvCreateImage(cvGetSize(img),8,1);
 //為循環(huán)變量賦值
 height=simg->height;
 width=simg->width;
 channels=1;
 step=channels*width;

 for(j=0;j<height;j++)
 {
 for(i=0;i<width;i++)
 {
  for(k=0;k<channels;k++)
  {
  temp=pR[j*step+i*channels+k]*pR[j*step+i*channels+k]+pI[j*step+i*channels+k]*pI[j*step+i*channels+k];
  temp=temp/(height*width);
  simg->imageData[j*step+i*channels+k]=sqrt(temp);
  }
 }
 }

 cvNamedWindow("Mar",CV_WINDOW_AUTOSIZE);
 cvShowImage("Mar",simg);
 cvWaitKey(0);
 
 cvReleaseMat(&mat_R);
 cvReleaseMat(&mat_I);
 cvReleaseMat(&mat_SRC);
 //cvReleaseMat(&mat_Row);//這里無法正常釋放，有待解決
 //cvReleaseMat(&mat_Col);
 cvReleaseMat(&dst);
 cvReleaseMat(&dst_R);
 cvReleaseMat(&dst_I);
 cvReleaseImage(&img);
 cvReleaseImage(&simg);
 return 0;
}