mirror of
https://github.com/opencv/opencv.git
synced 2024-12-02 16:00:17 +08:00
116 lines
3.4 KiB
Mathematica
116 lines
3.4 KiB
Mathematica
#! /usr/bin/env octave
|
|
cv;
|
|
highgui;
|
|
|
|
## Rearrange the quadrants of Fourier image so that the origin is at
|
|
## the image center
|
|
## src & dst arrays of equal size & type
|
|
function cvShiftDFT(src_arr, dst_arr )
|
|
|
|
size = cvGetSize(src_arr);
|
|
dst_size = cvGetSize(dst_arr);
|
|
|
|
if(dst_size.width != size.width || \
|
|
dst_size.height != size.height)
|
|
cvError( CV_StsUnmatchedSizes, "cvShiftDFT", \
|
|
"Source and Destination arrays must have equal sizes", \
|
|
__FILE__, __LINE__ );
|
|
endif
|
|
|
|
if(swig_this(src_arr) == swig_this(dst_arr))
|
|
tmp = cvCreateMat(size.height/2, size.width/2, cvGetElemType(src_arr));
|
|
endif
|
|
|
|
cx = size.width/2;
|
|
cy = size.height/2; # image center
|
|
|
|
q1 = cvGetSubRect( src_arr, cvRect(0,0,cx, cy) );
|
|
q2 = cvGetSubRect( src_arr, cvRect(cx,0,cx,cy) );
|
|
q3 = cvGetSubRect( src_arr, cvRect(cx,cy,cx,cy) );
|
|
q4 = cvGetSubRect( src_arr, cvRect(0,cy,cx,cy) );
|
|
d1 = cvGetSubRect( src_arr, cvRect(0,0,cx,cy) );
|
|
d2 = cvGetSubRect( src_arr, cvRect(cx,0,cx,cy) );
|
|
d3 = cvGetSubRect( src_arr, cvRect(cx,cy,cx,cy) );
|
|
d4 = cvGetSubRect( src_arr, cvRect(0,cy,cx,cy) );
|
|
|
|
if(swig_this(src_arr) != swig_this(dst_arr))
|
|
if( !CV_ARE_TYPES_EQ( q1, d1 ))
|
|
cvError( CV_StsUnmatchedFormats, \
|
|
"cvShiftDFT", "Source and Destination arrays must have the same format", \
|
|
__FILE__, __LINE__ );
|
|
endif
|
|
|
|
cvCopy(q3, d1);
|
|
cvCopy(q4, d2);
|
|
cvCopy(q1, d3);
|
|
cvCopy(q2, d4);
|
|
|
|
else
|
|
cvCopy(q3, tmp);
|
|
cvCopy(q1, q3);
|
|
cvCopy(tmp, q1);
|
|
cvCopy(q4, tmp);
|
|
cvCopy(q2, q4);
|
|
cvCopy(tmp, q2);
|
|
endif
|
|
endfunction
|
|
|
|
|
|
im = cvLoadImage( argv(){1}, CV_LOAD_IMAGE_GRAYSCALE);
|
|
|
|
realInput = cvCreateImage( cvGetSize(im), IPL_DEPTH_64F, 1);
|
|
imaginaryInput = cvCreateImage( cvGetSize(im), IPL_DEPTH_64F, 1);
|
|
complexInput = cvCreateImage( cvGetSize(im), IPL_DEPTH_64F, 2);
|
|
|
|
cvScale(im, realInput, 1.0, 0.0);
|
|
cvZero(imaginaryInput);
|
|
cvMerge(realInput, imaginaryInput, [], [], complexInput);
|
|
|
|
dft_M = cvGetOptimalDFTSize( im.height - 1 );
|
|
dft_N = cvGetOptimalDFTSize( im.width - 1 );
|
|
|
|
dft_A = cvCreateMat( dft_M, dft_N, CV_64FC2 );
|
|
image_Re = cvCreateImage( cvSize(dft_N, dft_M), IPL_DEPTH_64F, 1);
|
|
image_Im = cvCreateImage( cvSize(dft_N, dft_M), IPL_DEPTH_64F, 1);
|
|
|
|
## copy A to dft_A and pad dft_A with zeros
|
|
tmp = cvGetSubRect( dft_A, cvRect(0,0, im.width, im.height));
|
|
cvCopy( complexInput, tmp, [] );
|
|
if(dft_A.width > im.width)
|
|
tmp = cvGetSubRect( dft_A, cvRect(im.width,0, dft_N - im.width, im.height));
|
|
cvZero( tmp );
|
|
endif
|
|
|
|
## no need to pad bottom part of dft_A with zeros because of
|
|
## use nonzero_rows parameter in cvDFT() call below
|
|
|
|
cvDFT( dft_A, dft_A, CV_DXT_FORWARD, complexInput.height );
|
|
|
|
cvNamedWindow("win", 0);
|
|
cvNamedWindow("magnitude", 0);
|
|
cvShowImage("win", im);
|
|
|
|
## Split Fourier in real and imaginary parts
|
|
cvSplit( dft_A, image_Re, image_Im, [], [] );
|
|
|
|
## Compute the magnitude of the spectrum Mag = sqrt(Re^2 + Im^2)
|
|
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 );
|
|
|
|
## Compute log(1 + Mag)
|
|
cvAddS( image_Re, cvScalarAll(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
|
|
cvShiftDFT( image_Re, image_Re );
|
|
|
|
[min, max] = cvMinMaxLoc(image_Re);
|
|
cvScale(image_Re, image_Re, 1.0/(max-min), 1.0*(-min)/(max-min));
|
|
cvShowImage("magnitude", image_Re);
|
|
|
|
cvWaitKey(-1);
|