// Wrapper around FFTW3 that computes the real-valued inverse Fourier transform
// of a complex-valued frequantial image.
// The input data must be hermitic.
static void ifft_2dfloat(float *ifx, fftwf_complex *fx, int w, int h)
{
fftwf_complex *a = fftwf_xmalloc(w*h*sizeof*a);
fftwf_complex *b = fftwf_xmalloc(w*h*sizeof*b);
//fprintf(stderr, "planning...\n");
evoke_wisdom();
fftwf_plan p = fftwf_plan_dft_2d(h, w, a, b,
FFTW_BACKWARD, FFTW_ESTIMATE);
bequeath_wisdom();
//fprintf(stderr, "...planned!\n");
FORI(w*h) a[i] = fx[i];
fftwf_execute(p);
float scale = 1.0/(w*h);
FORI(w*h) {
fftwf_complex z = b[i] * scale;
ifx[i] = crealf(z);
if (FIWARN() > 0)
{
if (cimagf(z) > 0.001)
fail("z is not real {cimagf(z)=%g} (set FIWARN=0 to run anyway)", cimagf(z));
//assert(cimagf(z) < 0.001);
}
}
static void transform_roi_buffers(float *y, float *x, int n, int roi)
{
float x_p0[3*n*n], *x_p = x_p0;
ppsmooth_vec(x_p0, x, n, n, 3);
if (roi == 2) x_p = x;
if (roi == 3) { for (int i = 0; i < 3*n*n; i++) y[i]=x_p0[i]; return; }
float *c = xmalloc(n*n*sizeof*c);
float *ys = xmalloc(n*n*sizeof*c);
fftwf_complex *fc = fftwf_xmalloc(n*n*sizeof*fc);
for (int l = 0; l < 3; l++)
{
for (int i = 0; i < n*n; i++)
c[i] = x_p[3*i+l];
fft_2dfloat(fc, c, n, n);
for (int i = 0; i < n*n; i++)
//ys[i] = cabs(fc[i]);
ys[i] = 255*(log(cabs(fc[i])/255)+0.5)/5;
//float fac = n*13;
float fac = n*3;
for (int j = 0; j < n; j++)
for (int i = 0; i < n; i++)
{
int ii = (i + n/2) % n;
int jj = (j + n/2) % n;
float norm = hypot(i-n/2-1, j-n/2-1) / fac;
y[3*(j*n+i)+l] = ys[jj*n+ii] * 1;//norm;
}
}
free(ys);
free(c);
fftwf_free(fc);
//float param[1] = {0.5};
//blur_2d(y, y, n, n, 3, "cauchy", param, 1);
}
// wrapper around FFTW3 that computes the complex-valued Fourier transform
// of a real-valued image
static void fft_2dfloat(fftwf_complex *fx, float *x, int w, int h)
{
fftwf_complex *a = fftwf_xmalloc(w*h*sizeof*a);
//fprintf(stderr, "planning...\n");
evoke_wisdom();
fftwf_plan p = fftwf_plan_dft_2d(h, w, a, fx,
FFTW_FORWARD, FFTW_ESTIMATE);
bequeath_wisdom();
//fprintf(stderr, "...planned!\n");
FORI(w*h) a[i] = x[i]; // complex assignment!
fftwf_execute(p);
fftwf_destroy_plan(p);
fftwf_free(a);
fftwf_cleanup();
}
