phase correlation for image registration(image stitching)

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I'm trying to stitch 2 images using cross correlation (phase correlation).Images are the same size.Only shift is present. I tried opencv with cvDFT and opencv+FFTW it seems to work, but for some reason coorelation peak coordinate is not the shift coordinate, maybe it depends on quadrant where correlation point is. So the question is how to obtain shift point from correlation point.

Note: I don't need "interest points" SIFT-like approaches.

My suggestion commented in code. Here is the code that I use:

class Peak
{
public:
    CvPoint pt;
    double  maxval;
};
Peak old_opencv_FFT(IplImage* src,IplImage* temp)
{
    CvSize imgSize = cvSize(src->width, src->height);
    // Allocate floating point frames used for DFT (real, imaginary, and complex) 
    IplImage* realInput = cvCreateImage( imgSize, IPL_DEPTH_64F, 1 ); 
    IplImage* imaginaryInput = cvCreateImage( imgSize, IPL_DEPTH_64F, 1 ); 
    IplImage* complexInput = cvCreateImage( imgSize, IPL_DEPTH_64F, 2 );
    int nDFTHeight= cvGetOptimalDFTSize( imgSize.height ); 
    int nDFTWidth= cvGetOptimalDFTSize( imgSize.width ); 
    CvMat* src_DFT = cvCreateMat( nDFTHeight, nDFTWidth, CV_64FC2 ); 
    CvMat* temp_DFT = cvCreateMat( nDFTHeight, nDFTWidth, CV_64FC2 );
    CvSize dftSize = cvSize(nDFTWidth, nDFTHeight);
    IplImage* imageRe = cvCreateImage( dftSize, IPL_DEPTH_64F, 1 ); 
    IplImage* imageIm = cvCreateImage( dftSize, IPL_DEPTH_64F, 1 );
    IplImage* imageImMag = cvCreateImage( dftSize, IPL_DEPTH_64F, 1 ); 
    IplImage* imageMag = cvCreateImage( dftSize, IPL_DEPTH_64F, 1 ); 

    CvMat tmp; 
    // Processing of src 
    cvScale(src,realInput,1.0,0);
    cvZero(imaginaryInput); 
    cvMerge(realInput,imaginaryInput,NULL,NULL,complexInput);
    cvGetSubRect(src_DFT,&tmp,cvRect(0,0,src->width,src->height)); 
    cvCopy(complexInput,&tmp,NULL);
    if (src_DFT->cols>src->width)
    { 
        cvGetSubRect(src_DFT,&tmp,cvRect(src->width,0,src_DFT->cols-src->width,src->height)); 
        cvZero(&tmp); 
    } 
    cvDFT(src_DFT,src_DFT,CV_DXT_FORWARD,complexInput->height); 
    cvSplit(src_DFT,imageRe,imageIm,0,0);  

    // Processing of temp
    cvScale(temp,realInput,1.0,0); 
    cvMerge(realInput,imaginaryInput,NULL,NULL,complexInput); 
    cvGetSubRect(temp_DFT,&tmp,cvRect(0,0,temp->width,temp->height)); 
    cvCopy(complexInput,&tmp,NULL); 
    if (temp_DFT->cols>temp->width) 
    { 
        cvGetSubRect(temp_DFT,&tmp,cvRect(temp->width,0,temp_DFT->cols-temp->width,temp->height)); 
        cvZero( &tmp ); 
    } 
    cvDFT(temp_DFT,temp_DFT,CV_DXT_FORWARD,complexInput->height);

    // Multiply spectrums of the scene and the model (use CV_DXT_MUL_CONJ to get correlation instead of convolution) 
    cvMulSpectrums(src_DFT,temp_DFT,src_DFT,CV_DXT_MUL_CONJ); 

    // Split Fourier in real and imaginary parts 
    cvSplit(src_DFT,imageRe,imageIm,0,0); 

    // Compute the magnitude of the spectrum components: Mag = sqrt(Re^2 + Im^2) 
    cvPow( imageRe, imageMag, 2.0 ); 
    cvPow( imageIm, imageImMag, 2.0 ); 
    cvAdd( imageMag, imageImMag, imageMag, NULL ); 
    cvPow( imageMag, imageMag, 0.5 ); 

    // Normalize correlation (Divide real and imaginary components by magnitude) 
    cvDiv(imageRe,imageMag,imageRe,1.0); 
    cvDiv(imageIm,imageMag,imageIm,1.0); 
    cvMerge(imageRe,imageIm,NULL,NULL,src_DFT); 

    // inverse dft 
    cvDFT( src_DFT, src_DFT, CV_DXT_INVERSE_SCALE, complexInput->height ); 
    cvSplit( src_DFT, imageRe, imageIm, 0, 0 ); 

    double minval = 0.0; 
    double maxval = 0.0; 
    CvPoint minloc; 
    CvPoint maxloc; 
    cvMinMaxLoc(imageRe,&minval,&maxval,&minloc,&maxloc,NULL); 

    int x=maxloc.x; // log range 
    //if (x>(imageRe->width/2)) 
    //        x = x-imageRe->width; // positive or negative values 
    int y=maxloc.y; // angle 
    //if (y>(imageRe->height/2)) 
    //        y = y-imageRe->height; // positive or negative values 

    Peak pk;
    pk.maxval= maxval;
    pk.pt=cvPoint(x,y);
    return pk;
}
void phase_correlation2D( IplImage* src, IplImage *tpl, IplImage *poc )
{
    int     i, j, k;
    double  tmp;

    /* get image properties */
    int width    = src->width ...