// TODO L_THRESH_NEG_TO_BLACK
static hc_dpix_t *hcApplyFilter( hc_dpix_t *src, hc_dpix_t *filter )
{
uint32_t w, h;
uint32_t i, j, k;
fftw_complex *output;
double *data;
hc_dpix_t *dpixd;
if (!src && !filter)
{
ERROR("src or filter not defined");
return(NULL);
}
w=src->width;
h=src->height;
if (filter->width > w / 2 + 1 || filter->height > h)
{
ERROR("filter is smaller than source");
return(NULL);
}
/* Calculate the DFT of pixs */
// TODO was with L_WITH_SHIFTING, does it make a difference?
if (NULL == (output = dpixDFT( src )))
{
ERROR("src DFT not computed");
return(NULL);
}
/* Filter the DFT results */
data = filter->data;
for (i = 0, k = 0; i < h; i++)
{
for (j = 0; j < w / 2 + 1; j++, k++)
{
output[k] *= (*data);
data++;
}
}
/* Compute the inverse of the DFT */
dpixd = dpixInverseDFT(output, w, h );
/* Release the allocated resources */
fftw_free(output);
return dpixd;
}
/*!
* pixInverseDFT()
*
* Input: dft
* w, h (image size)
* shiftflag (L_NO_SHIFTING or L_WITH_SHIFTING)
* outflag (L_CLIP_TO_ZERO, L_TAKE_ABSVAL,
* L_THRESH_NEG_TO_BLACK or L_THRESH_NEG_TO_WHITE)
* Return: pixd (8bpp), or null on error
*
* Notes:
* (1) Set @shiftflag to L_WITH_SHIFTING if the DC was moved to the
* center of the image during the DFT computation. Reshifting it
* will move the DC back to the top left corner (0, 0).
* (2) It is the responsibility of the caller to release the allocated
* complex array by invoking fftw_free().
*/
PIX *
pixInverseDFT(fftw_complex *dft,
l_int32 w,
l_int32 h,
l_int32 shiftflag,
l_int32 outflag)
{
PIX *pixd;
DPIX *dpix;
PROCNAME("pixInverseDFT");
dpix = dpixInverseDFT(dft, w, h);
/* Convert DPix to a Pix */
pixd = dpixConvertToPix(dpix, 8, outflag, 0, shiftflag);
dpixDestroy(&dpix);
return pixd;
}
