| /* wavelet/dwt.c |
| * |
| * Copyright (C) 2004 Ivo Alxneit |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or (at |
| * your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, but |
| * WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. |
| */ |
| |
| /* function dwt_step is based on the public domain function pwt.c |
| * available from http://www.numerical-recipes.com |
| */ |
| |
| #include <config.h> |
| #include <gsl/gsl_errno.h> |
| #include <gsl/gsl_wavelet.h> |
| #include <gsl/gsl_wavelet2d.h> |
| |
| #define ELEMENT(a,stride,i) ((a)[(stride)*(i)]) |
| |
| static int binary_logn (const size_t n); |
| static void dwt_step (const gsl_wavelet * w, double *a, size_t stride, size_t n, gsl_wavelet_direction dir, gsl_wavelet_workspace * work); |
| |
| static int |
| binary_logn (const size_t n) |
| { |
| size_t ntest; |
| size_t logn = 0; |
| size_t k = 1; |
| |
| while (k < n) |
| { |
| k *= 2; |
| logn++; |
| } |
| |
| ntest = (1 << logn); |
| |
| if (n != ntest) |
| { |
| return -1; /* n is not a power of 2 */ |
| } |
| |
| return logn; |
| } |
| |
| static void |
| dwt_step (const gsl_wavelet * w, double *a, size_t stride, size_t n, |
| gsl_wavelet_direction dir, gsl_wavelet_workspace * work) |
| { |
| double ai, ai1; |
| size_t i, ii; |
| size_t jf; |
| size_t k; |
| size_t n1, ni, nh, nmod; |
| |
| for (i = 0; i < work->n; i++) |
| { |
| work->scratch[i] = 0.0; |
| } |
| |
| nmod = w->nc * n; |
| nmod -= w->offset; /* center support */ |
| |
| n1 = n - 1; |
| nh = n >> 1; |
| |
| if (dir == gsl_wavelet_forward) |
| { |
| for (ii = 0, i = 0; i < n; i += 2, ii++) |
| { |
| ni = i + nmod; |
| for (k = 0; k < w->nc; k++) |
| { |
| jf = n1 & (ni + k); |
| work->scratch[ii] += w->h1[k] * ELEMENT (a, stride, jf); |
| work->scratch[ii + nh] += w->g1[k] * ELEMENT (a, stride, jf); |
| } |
| } |
| } |
| else |
| { |
| for (ii = 0, i = 0; i < n; i += 2, ii++) |
| { |
| ai = ELEMENT (a, stride, ii); |
| ai1 = ELEMENT (a, stride, ii + nh); |
| ni = i + nmod; |
| for (k = 0; k < w->nc; k++) |
| { |
| jf = (n1 & (ni + k)); |
| work->scratch[jf] += (w->h2[k] * ai + w->g2[k] * ai1); |
| } |
| } |
| } |
| |
| for (i = 0; i < n; i++) |
| { |
| ELEMENT (a, stride, i) = work->scratch[i]; |
| } |
| } |
| |
| int |
| gsl_wavelet_transform (const gsl_wavelet * w, |
| double *data, size_t stride, size_t n, |
| gsl_wavelet_direction dir, |
| gsl_wavelet_workspace * work) |
| { |
| size_t i; |
| |
| if (work->n < n) |
| { |
| GSL_ERROR ("not enough workspace provided", GSL_EINVAL); |
| } |
| |
| if (binary_logn (n) == -1) |
| { |
| GSL_ERROR ("n is not a power of 2", GSL_EINVAL); |
| } |
| |
| if (n < 2) |
| { |
| return GSL_SUCCESS; |
| } |
| |
| if (dir == gsl_wavelet_forward) |
| { |
| for (i = n; i >= 2; i >>= 1) |
| { |
| dwt_step (w, data, stride, i, dir, work); |
| } |
| } |
| else |
| { |
| for (i = 2; i <= n; i <<= 1) |
| { |
| dwt_step (w, data, stride, i, dir, work); |
| } |
| } |
| |
| return GSL_SUCCESS; |
| } |
| |
| int |
| gsl_wavelet_transform_forward (const gsl_wavelet * w, |
| double *data, size_t stride, size_t n, |
| gsl_wavelet_workspace * work) |
| { |
| return gsl_wavelet_transform (w, data, stride, n, gsl_wavelet_forward, work); |
| } |
| |
| int |
| gsl_wavelet_transform_inverse (const gsl_wavelet * w, |
| double *data, size_t stride, size_t n, |
| gsl_wavelet_workspace * work) |
| { |
| return gsl_wavelet_transform (w, data, stride, n, gsl_wavelet_backward, work); |
| } |
| |
| |
| /* Leaving this out for now BJG */ |
| #if 0 |
| int |
| gsl_dwt_vector (const gsl_wavelet * w, gsl_vector *v, gsl_wavelet_direction |
| dir, gsl_wavelet_workspace * work) |
| { |
| return gsl_dwt (w, v->data, v->stride, v->size, dir, work); |
| } |
| #endif |
| |
| int |
| gsl_wavelet2d_transform (const gsl_wavelet * w, |
| double *data, size_t tda, size_t size1, |
| size_t size2, gsl_wavelet_direction dir, |
| gsl_wavelet_workspace * work) |
| { |
| size_t i; |
| |
| if (size1 != size2) |
| { |
| GSL_ERROR ("2d dwt works only with square matrix", GSL_EINVAL); |
| } |
| |
| if (work->n < size1) |
| { |
| GSL_ERROR ("not enough workspace provided", GSL_EINVAL); |
| } |
| |
| if (binary_logn (size1) == -1) |
| { |
| GSL_ERROR ("n is not a power of 2", GSL_EINVAL); |
| } |
| |
| if (size1 < 2) |
| { |
| return GSL_SUCCESS; |
| } |
| |
| if (dir == gsl_wavelet_forward) |
| { |
| for (i = 0; i < size1; i++) /* for every row j */ |
| { |
| gsl_wavelet_transform (w, &ELEMENT(data, tda, i), 1, size1, dir, work); |
| } |
| for (i = 0; i < size2; i++) /* for every column j */ |
| { |
| gsl_wavelet_transform (w, &ELEMENT(data, 1, i), tda, size2, dir, work); |
| } |
| } |
| else |
| { |
| for (i = 0; i < size2; i++) /* for every column j */ |
| { |
| gsl_wavelet_transform (w, &ELEMENT(data, 1, i), tda, size2, dir, work); |
| } |
| for (i = 0; i < size1; i++) /* for every row j */ |
| { |
| gsl_wavelet_transform (w, &ELEMENT(data, tda, i), 1, size1, dir, work); |
| } |
| } |
| |
| return GSL_SUCCESS; |
| } |
| |
| int |
| gsl_wavelet2d_nstransform (const gsl_wavelet * w, |
| double *data, size_t tda, size_t size1, |
| size_t size2, gsl_wavelet_direction dir, |
| gsl_wavelet_workspace * work) |
| { |
| size_t i, j; |
| |
| if (size1 != size2) |
| { |
| GSL_ERROR ("2d dwt works only with square matrix", GSL_EINVAL); |
| } |
| |
| if (work->n < size1) |
| { |
| GSL_ERROR ("not enough workspace provided", GSL_EINVAL); |
| } |
| |
| if (binary_logn (size1) == -1) |
| { |
| GSL_ERROR ("n is not a power of 2", GSL_EINVAL); |
| } |
| |
| if (size1 < 2) |
| { |
| return GSL_SUCCESS; |
| } |
| |
| if (dir == gsl_wavelet_forward) |
| { |
| for (i = size1; i >= 2; i >>= 1) |
| { |
| for (j = 0; j < i; j++) /* for every row j */ |
| { |
| dwt_step (w, &ELEMENT(data, tda, j), 1, i, dir, work); |
| } |
| for (j = 0; j < i; j++) /* for every column j */ |
| { |
| dwt_step (w, &ELEMENT(data, 1, j), tda, i, dir, work); |
| } |
| } |
| } |
| else |
| { |
| for (i = 2; i <= size1; i <<= 1) |
| { |
| for (j = 0; j < i; j++) /* for every column j */ |
| { |
| dwt_step (w, &ELEMENT(data, 1, j), tda, i, dir, work); |
| } |
| for (j = 0; j < i; j++) /* for every row j */ |
| { |
| dwt_step (w, &ELEMENT(data, tda, j), 1, i, dir, work); |
| } |
| } |
| } |
| |
| return GSL_SUCCESS; |
| } |
| |
| |
| int |
| gsl_wavelet2d_transform_forward (const gsl_wavelet * w, |
| double *data, size_t tda, size_t size1, |
| size_t size2, gsl_wavelet_workspace * work) |
| { |
| return gsl_wavelet2d_transform (w, data, tda, size1, size2, gsl_wavelet_forward, work); |
| } |
| |
| int |
| gsl_wavelet2d_transform_inverse (const gsl_wavelet * w, |
| double *data, size_t tda, size_t size1, |
| size_t size2, gsl_wavelet_workspace * work) |
| { |
| return gsl_wavelet2d_transform (w, data, tda, size1, size2, gsl_wavelet_backward, work); |
| } |
| |
| int |
| gsl_wavelet2d_nstransform_forward (const gsl_wavelet * w, |
| double *data, size_t tda, size_t size1, |
| size_t size2, gsl_wavelet_workspace * work) |
| { |
| return gsl_wavelet2d_nstransform (w, data, tda, size1, size2, gsl_wavelet_forward, work); |
| } |
| |
| int |
| gsl_wavelet2d_nstransform_inverse (const gsl_wavelet * w, |
| double *data, size_t tda, size_t size1, |
| size_t size2, gsl_wavelet_workspace * work) |
| { |
| return gsl_wavelet2d_nstransform (w, data, tda, size1, size2, gsl_wavelet_backward, work); |
| } |
| |
| |
| int |
| gsl_wavelet2d_transform_matrix (const gsl_wavelet * w, |
| gsl_matrix * a, |
| gsl_wavelet_direction dir, |
| gsl_wavelet_workspace * work) |
| { |
| return gsl_wavelet2d_transform (w, a->data, |
| a->tda, a->size1, a->size2, |
| dir, work); |
| } |
| |
| int |
| gsl_wavelet2d_transform_matrix_forward (const gsl_wavelet * w, |
| gsl_matrix * a, |
| gsl_wavelet_workspace * work) |
| { |
| return gsl_wavelet2d_transform (w, a->data, |
| a->tda, a->size1, a->size2, |
| gsl_wavelet_forward, work); |
| } |
| |
| int |
| gsl_wavelet2d_transform_matrix_inverse (const gsl_wavelet * w, |
| gsl_matrix * a, |
| gsl_wavelet_workspace * work) |
| { |
| return gsl_wavelet2d_transform (w, a->data, |
| a->tda, a->size1, a->size2, |
| gsl_wavelet_backward, work); |
| } |
| |
| int |
| gsl_wavelet2d_nstransform_matrix (const gsl_wavelet * w, |
| gsl_matrix * a, |
| gsl_wavelet_direction dir, |
| gsl_wavelet_workspace * work) |
| { |
| return gsl_wavelet2d_nstransform (w, a->data, |
| a->tda, a->size1, a->size2, |
| dir, work); |
| } |
| |
| int |
| gsl_wavelet2d_nstransform_matrix_forward (const gsl_wavelet * w, |
| gsl_matrix * a, |
| gsl_wavelet_workspace * work) |
| { |
| return gsl_wavelet2d_nstransform (w, a->data, |
| a->tda, a->size1, a->size2, |
| gsl_wavelet_forward, work); |
| } |
| |
| int |
| gsl_wavelet2d_nstransform_matrix_inverse (const gsl_wavelet * w, |
| gsl_matrix * a, |
| gsl_wavelet_workspace * work) |
| { |
| return gsl_wavelet2d_nstransform (w, a->data, |
| a->tda, a->size1, a->size2, |
| gsl_wavelet_backward, work); |
| } |
| |
| |