c - OpenCV 上的逆向过滤——访问 DFT 值并乘以 DFT 矩阵

Question

我正在尝试在频域中执行逆滤波和伪逆滤波。

但是我在访问 DFT 系数和之后乘以 DFT 矩阵时遇到问题，因为我得到了复数，因此实际上是两个矩阵......

基本上逆向过滤执行

F = G/H,

其中 F 是恢复图像，G 是模糊图像，H 是模糊图像的内核。

伪逆需要访问 H 中的值，因为如果值接近 0，则应将其替换以避免恢复中出现问题。为此，我们必须更改 H，以便:

H(u,v) = 1/H(u,v) 如果 H(u,v) > 阈值并且 = 0 否则

我有一个 kernel1 (h_1)，以及图像 imf(恢复)和 img(模糊)。这是代码:

  // compute the DFTs of the kernel (DFT_B) and the blurred image (DBF_A)
  cvDFT( dft_A, dft_A, CV_DXT_FORWARD, complexInput1->height );
  cvDFT( dft_B, dft_B, CV_DXT_FORWARD, complexInput2->height );

  // the first type is the inverse fitlering
  if (type == 1) {
      printf("...performing inverse filtering\n");
      // dividing the transforms
      cvDiv(dft_A, dft_B, dft_C, 1);
  }
  // the second type is the pseudo-inverse filtering
  else {
      printf("...prepare kernel for pseudo-inverse filtering\n");
      // will try to access the real values in order to see if value is above a threshold
      cvSplit( dft_B, image_Re1, image_Im1, 0, 0 );
      // pointers to access the data into the real and imaginary matrices
      uchar * dRe1 = (uchar *)image_Re1->imageData;
      uchar * dIm1 = (uchar *)image_Im1->imageData;
      int width  = image_Re1->width;
      int height = image_Re1->height;
      int step = image_Re1->widthStep;
      image_Re2 = cvCreateImage(cvGetSize(image_Re1), IPL_DEPTH_32F, 1);
      image_Im2 = cvCreateImage(cvGetSize(image_Im2), IPL_DEPTH_32F, 1);
      // pointers to access the data into the real and imaginary matrices
      // it will be the resulting pseudo-inverse filter
      uchar * dRe2 = (uchar *)image_Re2->imageData;
      uchar * dIm2 = (uchar *)image_Im2->imageData;

      printf("...building kernel for pseudo-inverse filtering\n");
      for ( i = 0; i < height; i++ )  {
      for ( j = 0; j < width; j++ ) {
                // generate the 1/H(i,j) value
        if (dRe1[i * step + j] > threshold) {
            float realsq = dRe1[i * step + j]*dRe1[i * step + j];
            float imagsq = dIm1[i * step + j]*dIm1[i * step + j];

            dRe2[i * step + j] = dRe1[i * step + j] / (realsq + imagsq);
            dIm2[i * step + j] = -1 * (dIm1[i * step + j] / (realsq + imagsq));
        }
        else {
            dRe2[i * step + j] = 0;
            dIm2[i * step + j] = 0;
        }
      }
      }
      printf("...merging final kernel\n");
      cvMerge(image_Re2, image_Im2, 0, 0, dft_B);
      printf("...performing pseudo-inverse filtering\n");
      cvMulSpectrums(dft_A, dft_B, dft_C, 1);
  }
  printf("...performing IDFT\n");
  cvDFT(dft_C, dft_H, CV_DXT_INV_SCALE, 1);

  printf("...getting size\n");
  cvGetSubRect(dft_H, &tmp3, cvRect(0, 0, img->width, img->height));

  printf("......(%d, %d) - (%d, %d)\n", tmp3.cols, tmp3.rows, restored->width, restored->height);

  cvSplit( &tmp3, image_Re1, image_Im1, 0, 0 );

  cvNamedWindow("re", 0);
  cvShowImage("re", image_Re2);
  cvWaitKey(0);

  printf("...copying final image\n");
  // error is in the line below
  cvCopy(image_Re1, imf, NULL);

我在最后一行有一个错误:--- OpenCV Error: Assertion failed (src.depth() == dst.depth() && src.size() == dst.size()) in cvCopy,文件/build/buildd/opencv-2.1.0/src/cxcore/cxcopy.cpp，第466行

我知道这与大小或深度有关，但我不知道如何控制。无论如何，我试图显示 image_Re1 并且它是空的......

任何人都可以阐明它吗？

Answer 1

您似乎没有初始化您的 imf 图片!cvCopy 需要一个初始化的矩阵做一个:

IplImage* imf=   cvCreateImage(cvGetSize(image_Re1), IPL_DEPTH_32F, 1);

首先，我认为它会起作用。

此外，您不会在此代码中释放图像空间 (cvReleaseImage(&image))