Question

Can anyone tell me if there is an inbuilt function present in emgucv 2.3 for finding out fourier transform of images ?

Thanks in advance

Answer 1

From my answer Fourier Transform + emgucv

The function you are after is CvInvoke.cvDFT it is technically calling the opencv method but it should be what your after

Here is the code that splits the Imaginary and Real parts from cvDFT:

Image<Gray, float> image = new Image<Gray, float>(open.FileName);
IntPtr complexImage = CvInvoke.cvCreateImage(image.Size, Emgu.CV.CvEnum.IPL_DEPTH.IPL_DEPTH_32F, 2);

CvInvoke.cvSetZero(complexImage);  // Initialize all elements to Zero
CvInvoke.cvSetImageCOI(complexImage, 1);
CvInvoke.cvCopy(image, complexImage, IntPtr.Zero);
CvInvoke.cvSetImageCOI(complexImage, 0);

Matrix<float> dft = new Matrix<float>(image.Rows, image.Cols, 2);
CvInvoke.cvDFT(complexImage, dft, Emgu.CV.CvEnum.CV_DXT.CV_DXT_FORWARD, 0);

//The Real part of the Fourier Transform
Matrix<float> outReal = new Matrix<float>(image.Size);
//The imaginary part of the Fourier Transform
Matrix<float> outIm = new Matrix<float>(image.Size);
CvInvoke.cvSplit(dft, outReal, outIm, IntPtr.Zero, IntPtr.Zero);

//Show The Data       
CvInvoke.cvShowImage("Real", outReal);
CvInvoke.cvShowImage("Imaginary ", outIm);

Cheers,

Chris