分享一下我老師大神的人工智慧教程！零基礎，通俗易懂！http://blog.csdn.net/jiangjunshow

也歡迎大家轉載本篇文章。分享知識，造福人民，實現我們中華民族偉大復興！

void fft2(IplImage *src, IplImage *dst){   //實部、虛部 IplImage *image_Re = 0, *image_Im = 0
 
, *Fourier = 0; //   int i, j; image_Re = cvCreateImage(cvGetSize(src), IPL_DEPTH_64F, 1);  //實部 //Imaginary part image_Im = cvCreateImage(cvGetSize(src), IPL_DEPTH_64F, 1);  //虛部 //2 channels (image_Re, image_Im) Fourier = cvCreateImage(cvGetSize(src), IPL_DEPTH_64F, 2
 
); // Real part conversion from u8 to 64f (double) cvConvertScale(src, image_Re); // Imaginary part (zeros) cvZero(image_Im); // Join real and imaginary parts and stock them in Fourier image cvMerge(image_Re, image_Im, 0, 0, Fourier); // Application of the forward Fourier transform
 
 cvDFT(Fourier, dst, CV_DXT_FORWARD); cvReleaseImage(&image_Re); cvReleaseImage(&image_Im); cvReleaseImage(&Fourier);}void fft2shift(IplImage *src, IplImage *dst){ IplImage *image_Re = 0, *image_Im = 0; int nRow, nCol, i, j, cy, cx; double scale, shift, tmp13, tmp24; image_Re = cvCreateImage(cvGetSize(src), IPL_DEPTH_64F, 1); //Imaginary part image_Im = cvCreateImage(cvGetSize(src), IPL_DEPTH_64F, 1); cvSplit( src, image_Re, image_Im, 0, 0 ); //具體原理見岡薩雷斯數字影象處理p123 // Compute the magnitude of the spectrum Mag = sqrt(Re^2 + Im^2) //計算傅立葉譜 cvPow( image_Re, image_Re, 2.0); cvPow( image_Im, image_Im, 2.0); cvAdd( image_Re, image_Im, image_Re); cvPow( image_Re, image_Re, 0.5 ); //對數變換以增強灰度級細節(這種變換使以窄帶低灰度輸入影象值對映 //一寬頻輸出值，具體可見岡薩雷斯數字影象處理p62) // Compute log(1 + Mag); cvAddS( image_Re, cvScalar(1.0), image_Re ); // 1 + Mag cvLog( image_Re, image_Re ); // log(1 + Mag) //Rearrange the quadrants of Fourier image so that the origin is at the image center nRow = src->height; nCol = src->width; cy = nRow/2; // image center cx = nCol/2; //CV_IMAGE_ELEM為OpenCV定義的巨集，用來讀取影象的畫素值，這一部分就是進行中心變換 for( j = 0; j < cy; j++ ){  for( i = 0; i < cx; i++ ){   //中心化，將整體份成四塊進行對角交換   tmp13 = CV_IMAGE_ELEM( image_Re, double, j, i);   CV_IMAGE_ELEM( image_Re, double, j, i) = CV_IMAGE_ELEM(    image_Re, double, j+cy, i+cx);   CV_IMAGE_ELEM( image_Re, double, j+cy, i+cx) = tmp13;   tmp24 = CV_IMAGE_ELEM( image_Re, double, j, i+cx);   CV_IMAGE_ELEM( image_Re, double, j, i+cx) =    CV_IMAGE_ELEM( image_Re, double, j+cy, i);   CV_IMAGE_ELEM( image_Re, double, j+cy, i) = tmp24;  } } //歸一化處理將矩陣的元素值歸一為[0,255] //[(f(x,y)-minVal)/(maxVal-minVal)]*255 double minVal = 0, maxVal = 0; // Localize minimum and maximum values cvMinMaxLoc( image_Re, &minVal, &maxVal ); // Normalize image (0 - 255) to be observed as an u8 image scale = 255/(maxVal - minVal); shift = -minVal * scale; cvConvertScale(image_Re, dst, scale, shift); cvReleaseImage(&image_Re); cvReleaseImage(&image_Im);}void CCVMFCView::OnFuliyeTransform(){ IplImage *src; IplImage *Fourier;   //傅立葉係數 IplImage *dst ; IplImage *ImageRe; IplImage *ImageIm; IplImage *Image; IplImage *ImageDst; double m,M; double scale; double shift; //src = workImg; if(workImg->nChannels==3)  OnColorToGray(); src=cvCreateImage(cvGetSize(workImg),IPL_DEPTH_64F,workImg->nChannels);  //源影象 imageClone(workImg,&src); cvFlip(src); Fourier = cvCreateImage(cvGetSize(src),IPL_DEPTH_64F,2); dst = cvCreateImage(cvGetSize(src),IPL_DEPTH_64F,2); ImageRe = cvCreateImage(cvGetSize(src),IPL_DEPTH_64F,1); ImageIm = cvCreateImage(cvGetSize(src),IPL_DEPTH_64F,1); Image = cvCreateImage(cvGetSize(src),src->depth,src->nChannels); ImageDst = cvCreateImage(cvGetSize(src),src->depth,src->nChannels); fft2(src,Fourier);                  //傅立葉變換 fft2shift(Fourier, Image);          //中心化 cvDFT(Fourier,dst,CV_DXT_INV_SCALE);//實現傅立葉逆變換，並對結果進行縮放 cvSplit(dst,ImageRe,ImageIm,0,0); cvNamedWindow("源影象",0); cvShowImage("源影象",src);              //對陣列每個元素平方並存儲在第二個引數中 cvPow(ImageRe,ImageRe,2);                cvPow(ImageIm,ImageIm,2); cvAdd(ImageRe,ImageIm,ImageRe,NULL); cvPow(ImageRe,ImageRe,0.5); cvMinMaxLoc(ImageRe,&m,&M,NULL,NULL); scale = 255/(M - m); shift = -m * scale; //將shift加在ImageRe各元素按比例縮放的結果上，儲存為ImageDst cvConvertScale(ImageRe,ImageDst,scale,shift); cvNamedWindow("傅立葉譜",0); cvShowImage("傅立葉譜",Image); cvNamedWindow("傅立葉逆變換",0); cvShowImage("傅立葉逆變換",ImageDst); //釋放影象 cvWaitKey(10000); cvReleaseImage(&src); cvReleaseImage(&Image); cvReleaseImage(&ImageIm); cvReleaseImage(&ImageRe); cvReleaseImage(&Fourier); cvReleaseImage(&dst); cvReleaseImage(&ImageDst); Invalidate();}

給我老師的人工智慧教程打call！http://blog.csdn.net/jiangjunshow