/** * gwy_data_field_correlate: * @data_field: A data field. * @kernel_field: Correlation kernel. * @score: Data field to store correlation scores to. * @method: Correlation score calculation method. * * Computes correlation score for all positions in a data field. * * Correlation score is compute for all points in data field @data_field * and full size of correlation kernel @kernel_field. * * The points in @score correspond to centers of kernel. More precisely, the * point ((@kxres-1)/2, (@kyres-1)/2) in @score corresponds to kernel field * top left corner coincident with data field top left corner. Points outside * the area where the kernel field fits into the data field completely are * set to -1 for %GWY_CORRELATION_NORMAL. **/ void gwy_data_field_correlate(GwyDataField *data_field, GwyDataField *kernel_field, GwyDataField *score, GwyCorrelationType method) { gint xres, yres, kxres, kyres, i, j, k, fftxres, fftyres; GwyDataField *data_in_re, *data_out_re, *data_out_im; GwyDataField *kernel_in_re, *kernel_out_re, *kernel_out_im; gdouble norm; g_return_if_fail(data_field != NULL && kernel_field != NULL); xres = data_field->xres; yres = data_field->yres; kxres = kernel_field->xres; kyres = kernel_field->yres; if (kxres <= 0 || kyres <= 0) { g_warning("Correlation kernel has nonpositive size."); return; } switch (method) { case GWY_CORRELATION_NORMAL: gwy_data_field_fill(score, -1); /*correlation request outside kernel */ if (kxres > xres || kyres > yres) { return; } { GwyDataField *avg, *rms; gdouble s, davg, drms, kavg, krms; gint xoff, yoff; /* The number of pixels the correlation kernel extends to the * negative direction */ xoff = (kxres - 1)/2; yoff = (kyres - 1)/2; kavg = gwy_data_field_get_avg(kernel_field); krms = gwy_data_field_get_rms(kernel_field); avg = gwy_data_field_duplicate(data_field); rms = gwy_data_field_duplicate(data_field); calculate_normalization(avg, rms, kxres, kyres); for (i = yoff; i + kyres - yoff <= yres; i++) { for (j = xoff; j + kxres - xoff <= xres; j++) { k = i*xres + j; davg = avg->data[k]; drms = rms->data[k]; if (!krms || !drms) { score->data[k] = 0.0; continue; } s = gwy_data_field_get_raw_correlation_score(data_field, kernel_field, j - xoff, i - yoff, 0, 0, kxres, kyres, davg, kavg); score->data[k] = s/(drms*krms); } } g_object_unref(avg); g_object_unref(rms); } break; case GWY_CORRELATION_FFT: case GWY_CORRELATION_POC: fftxres = gwy_fft_find_nice_size(xres); fftyres = gwy_fft_find_nice_size(yres); data_in_re = gwy_data_field_new_resampled(data_field, fftxres, fftyres, GWY_INTERPOLATION_BILINEAR); kernel_in_re = gwy_data_field_new_alike(data_field, TRUE); gwy_data_field_area_copy(kernel_field, kernel_in_re, 0, 0, kernel_field->xres, kernel_field->yres, kernel_in_re->xres/2 - kernel_field->xres/2, kernel_in_re->yres/2 - kernel_field->yres/2); gwy_data_field_resample(kernel_in_re, fftxres, fftyres, GWY_INTERPOLATION_BILINEAR); gwy_data_field_resample(score, fftxres, fftyres, GWY_INTERPOLATION_NONE); data_out_re = gwy_data_field_new_alike(data_in_re, TRUE); data_out_im = gwy_data_field_new_alike(data_in_re, TRUE); kernel_out_re = gwy_data_field_new_alike(data_in_re, TRUE); kernel_out_im = gwy_data_field_new_alike(data_in_re, TRUE); gwy_data_field_2dfft(data_in_re, NULL, data_out_re, data_out_im, GWY_WINDOWING_NONE, GWY_TRANSFORM_DIRECTION_FORWARD, GWY_INTERPOLATION_BILINEAR, FALSE, FALSE); gwy_data_field_2dfft(kernel_in_re, NULL, kernel_out_re, kernel_out_im, GWY_WINDOWING_NONE, GWY_TRANSFORM_DIRECTION_FORWARD, GWY_INTERPOLATION_BILINEAR, FALSE, FALSE); for (i = 0; i < fftxres*fftyres; i++) { /*NOTE: now we construct new "complex field" from data * and kernel fields, just to save memory*/ data_in_re->data[i] = data_out_re->data[i]*kernel_out_re->data[i] + data_out_im->data[i]*kernel_out_im->data[i]; kernel_in_re->data[i] = -data_out_re->data[i]*kernel_out_im->data[i] + data_out_im->data[i]*kernel_out_re->data[i]; if (method == GWY_CORRELATION_POC) { norm = hypot(data_in_re->data[i], kernel_in_re->data[i]); data_in_re->data[i] /= norm; kernel_in_re->data[i] /= norm; } } gwy_data_field_2dfft(data_in_re, kernel_in_re, score, data_out_im, GWY_WINDOWING_NONE, GWY_TRANSFORM_DIRECTION_BACKWARD, GWY_INTERPOLATION_BILINEAR, FALSE, FALSE); gwy_data_field_2dfft_humanize(score); /*TODO compute it and put to score field*/ g_object_unref(data_in_re); g_object_unref(data_out_re); g_object_unref(data_out_im); g_object_unref(kernel_in_re); g_object_unref(kernel_out_re); g_object_unref(kernel_out_im); break; } gwy_data_field_invalidate(score); }
static void psdflp_do(const PSDFLPArgs *args, GwyDataField *dfield, GwyDataField *lpsdf) { enum { N = 4 }; GwyDataField *reout, *imout; gint pxres, pyres, fxres, fyres; gint i, j, fi, pi; gdouble *ldata, *redata, *imdata; gdouble *cosphi, *sinphi; gdouble xreal, yreal, f0, f_max, b, p; reout = gwy_data_field_new_alike(dfield, FALSE); imout = gwy_data_field_new_alike(dfield, FALSE); gwy_data_field_2dfft(dfield, NULL, reout, imout, args->window, GWY_TRANSFORM_DIRECTION_FORWARD, GWY_INTERPOLATION_ROUND, /* Ignored */ TRUE, 1); pxres = reout->xres; pyres = reout->yres; redata = gwy_data_field_get_data(reout); imdata = gwy_data_field_get_data(imout); for (i = 0; i < pxres*pyres; i++) redata[i] = redata[i]*redata[i] + imdata[i]*imdata[i]; gwy_data_field_2dfft_humanize(reout); gwy_data_field_filter_gaussian(reout, args->sigma); for (i = 0; i < pxres*pyres; i++) redata[i] = sqrt(redata[i]); fxres = pxres/2; fyres = pyres/2; gwy_data_field_resample(lpsdf, fxres, fyres, GWY_INTERPOLATION_NONE); ldata = gwy_data_field_get_data(lpsdf); xreal = dfield->xreal; yreal = dfield->yreal; f0 = 2.0/MIN(xreal, yreal); f_max = 0.5*MIN(pxres/xreal, pyres/yreal); if (f_max <= f0) { g_warning("Minimum frequency is not smaller than maximum frequency."); } b = log(f_max/f0)/fyres; /* Incorporate some prefactors to sinphi[] and cosphi[], knowing that * cosine is only ever used for x and sine for y frequencies. */ cosphi = g_new(gdouble, (N+1)*fxres); sinphi = g_new(gdouble, (N+1)*fxres); for (j = 0; j < fxres; j++) { gdouble phi_from = 2.0*G_PI*j/fxres; gdouble phi_to = 2.0*G_PI*(j + 1.0)/fxres; for (pi = 0; pi <= N; pi++) { gdouble phi = ((pi + 0.5)*phi_from + (N - 0.5 - pi)*phi_to)/N; cosphi[j*(N+1) + pi] = cos(phi)*xreal; sinphi[j*(N+1) + pi] = sin(phi)*yreal; } } for (i = 0; i < fyres; i++) { gdouble f_from = f0*exp(b*i); gdouble f_to = f0*exp(b*(i + 1.0)); for (j = 0; j < fxres; j++) { const gdouble *cosphi_j = cosphi + j*(N+1); const gdouble *sinphi_j = sinphi + j*(N+1); guint n = 0; gdouble s = 0.0; for (fi = 0; fi <= N; fi++) { gdouble f = ((fi + 0.5)*f_from + (N - 0.5 - fi)*f_to)/N; for (pi = 0; pi <= N; pi++) { gdouble x = f*cosphi_j[pi] + pxres/2.0, y = f*sinphi_j[pi] + pyres/2.0; if (G_UNLIKELY(x < 0.5 || y < 0.5 || x > pxres - 1.5 || y > pyres - 1.5)) continue; p = gwy_data_field_get_dval(reout, x, y, GWY_INTERPOLATION_SCHAUM); s += p; n++; } } if (!n) n = 1; ldata[i*fxres + j] = 2.0*G_PI/fxres * s/n*(f_to - f_from); } } g_object_unref(imout); g_object_unref(reout); gwy_data_field_set_xreal(lpsdf, 2.0*G_PI); gwy_data_field_set_xoffset(lpsdf, 0.0); gwy_data_field_set_yreal(lpsdf, log(f_max/f0)); gwy_data_field_set_yoffset(lpsdf, log(f0)); gwy_si_unit_set_from_string(gwy_data_field_get_si_unit_xy(lpsdf), ""); gwy_si_unit_set_from_string(gwy_data_field_get_si_unit_z(lpsdf), ""); gwy_data_field_normalize(lpsdf); }