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| Copyright (C) 2005-2006 | Hervé Jégou |
| Vivien Chappelier | |
| Francois Cayre |
00001 /* 00002 libit - Library for basic source and channel coding functions 00003 Copyright (C) 2005-2005 Vivien Chappelier, Herve Jegou 00004 00005 This library is free software; you can redistribute it and/or 00006 modify it under the terms of the GNU Library General Public 00007 License as published by the Free Software Foundation; either 00008 version 2 of the License, or (at your option) any later version. 00009 00010 This library is distributed in the hope that it will be useful, 00011 but WITHOUT ANY WARRANTY; without even the implied warranty of 00012 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00013 Library General Public License for more details. 00014 00015 You should have received a copy of the GNU Library General Public 00016 License along with this library; if not, write to the Free 00017 Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 00018 */ 00019 00020 /* 00021 1D wavelet transform using lifting. 00022 Copyright (C) 2005 Vivien Chappelier, Herve Jegou 00023 */ 00024 00025 #ifndef __it_wavelet_h 00026 #define __it_wavelet_h 00027 00028 #include <it/types.h> 00029 #include <it/mat.h> 00030 #include <it/transform.h> 00031 00032 /*---------------------------------------------------------------------------*/ 00033 /*! \addtogroup transform */ 00034 /* @{ */ 00035 /*---------------------------------------------------------------------------*/ 00036 00037 /* the lifting structure */ 00038 typedef struct _wavelet_lifting_ { 00039 int const count; /* number of lifting steps, must be even and > 0 */ 00040 double const scale; /* final scaling coefficient */ 00041 double const *step; /* steps in predict/update order */ 00042 } it_wavelet_lifting_t; 00043 00044 /* some predefined filters */ 00045 extern it_wavelet_lifting_t const *it_wavelet_lifting_97; 00046 extern it_wavelet_lifting_t const *it_wavelet_lifting_53; 00047 00048 typedef struct _it_wavelet_ { 00049 it_extends (it_transform_t); 00050 00051 void (*it_overloaded (destructor)) (it_object_t * it_this); 00052 00053 it_wavelet_lifting_t *lifting; 00054 idx_t length; /* length of the vector to decompose */ 00055 int level; /* current decomposition level */ 00056 int levels; /* number of decomposition levels */ 00057 vec current; /* a double buffer of vectors */ 00058 vec next; /* for temporary processing */ 00059 00060 } it_wavelet_t; 00061 00062 #define IT_WAVELET(x) IT_CAST(it_wavelet_t, x) 00063 00064 it_instanciate (it_wavelet_t); 00065 00066 static inline it_wavelet_t *it_wavelet_new (it_wavelet_lifting_t const 00067 *lifting, int level) { 00068 return (it_new_va (it_wavelet_t) (it_va, lifting, level)); 00069 } 00070 /* 1D wavelet transform and inverse transform */ 00071 #define it_wavelet_transform(t, v) ((vec) it_transform(IT_WAVELET(t), (vec) v)) 00072 #define it_wavelet_itransform(t, v) ((vec) it_itransform(IT_WAVELET(t), (vec) v)) 00073 vec it_dwt (vec v, it_wavelet_lifting_t const *lifting, int levels); 00074 vec it_idwt (vec t, it_wavelet_lifting_t const *lifting, int levels); 00075 00076 /*--------------------------------------------------------------------*/ 00077 /* Split a vector containing all wavelet coefficients into several vectors, 00078 one for each subband. 00079 All the memory is allocated inside. */ 00080 vec *it_wavelet_split (vec wav, int nb_levels); 00081 vec it_wavelet_merge (vec * subbands, int nb_level); 00082 00083 /* @} */ 00084 00085 #endif
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