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00013 #include "mathop.h"
00014
00015 #include <math.h>
00016 #include <stdlib.h>
00017
00018 #undef VL_IMSMOOTH
00019 #undef VL_IMSMOOTH_
00020 #undef VL_CONVTRANSP
00021 #undef VL_CONVTRANSP_
00022
00023 #define VL_IMSMOOTH(SFX) vl_imsmooth_ ## SFX
00024 #define VL_IMSMOOTH_(SFX) VL_IMSMOOTH(SFX)
00025 #define VL_CONVTRANSP(SFX) vl_convtransp_ ## SFX
00026 #define VL_CONVTRANSP_(SFX) VL_CONVTRANSP(SFX)
00027
00028 VL_EXPORT
00029 void
00030 VL_CONVTRANSP_(SFX) (PIX *dst,
00031 PIX const *src,
00032 PIX const *filt,
00033 int width, int height, int filt_width,
00034 int mode)
00035 {
00036 int i, j ;
00037
00038
00039
00040
00041
00042
00043
00044
00045
00046 switch (mode) {
00047 case VL_CONV_CONT :
00048 for(j = 0 ; j < height ; ++j) {
00049 for(i = 0 ; i < width ; ++i) {
00050 PIX acc = 0.0 ;
00051 PIX const *g = filt ;
00052 PIX const *start = src + (i - filt_width) ;
00053 PIX const *stop ;
00054 PIX x ;
00055
00056
00057 stop = src + VL_MAX(0, i - filt_width) ;
00058 x = *stop ;
00059 while (start <= stop) { acc += (*g++) * x ; start++ ; }
00060
00061
00062 stop = src + VL_MIN(width - 1, i + filt_width) ;
00063 while (start < stop) acc += (*g++) * (*start++) ;
00064
00065
00066 x = *start ;
00067 stop = src + (i + filt_width) ;
00068 while (start <= stop) { acc += (*g++) * x ; start++ ; }
00069
00070
00071 *dst = acc ;
00072 dst += height ;
00073
00074 assert (g - filt == 2 * filt_width +1) ;
00075 }
00076
00077 src += width ;
00078 dst -= width*height - 1 ;
00079 }
00080 break ;
00081
00082 default:
00083 assert (0) ;
00084 }
00085 }
00086
00087 VL_EXPORT
00088 void
00089 VL_IMSMOOTH_(SFX)(PIX *dst,
00090 PIX *temp,
00091 PIX const *src,
00092 int width, int height, double sigma)
00093 {
00094
00095
00096 static PIX *filt = 0 ;
00097 static int filt_width = -1 ;
00098 static double filt_static_sigma = -1.0 ;
00099 enum { filt_static_res = 1024 } ;
00100 static PIX filt_static [2 * filt_static_res + 1] ;
00101
00102 int j ;
00103
00104 if (sigma < (PIX)(1e-5)) {
00105 dst = memcpy(dst,src,width*height*sizeof(PIX)) ;
00106 return ;
00107 }
00108
00109
00110 filt_width = ceil (4.0 * sigma) ;
00111
00112
00113 if (filt_static_sigma != sigma) {
00114 PIX acc = 0.0 ;
00115
00116 if (filt_width <= filt_static_res) {
00117
00118 filt = filt_static ;
00119 filt_static_sigma = sigma ;
00120 } else {
00121
00122 filt = vl_malloc (sizeof(PIX) * (2*filt_width+1)) ;
00123 }
00124
00125 for (j = 0 ; j < 2 * filt_width + 1 ; ++j) {
00126 PIX d = (PIX)(j - filt_width) / (PIX)(sigma) ;
00127 filt [j] = exp (- 0.5 * d * d) ;
00128 acc += filt [j] ;
00129 }
00130
00131
00132 for (j = 0 ; j < 2 * filt_width + 1 ; ++j) {
00133 filt [j] /= acc ;
00134 }
00135 }
00136
00137
00138 VL_CONVTRANSP_(SFX) (temp, src, filt,
00139 width, height, filt_width,
00140 VL_CONV_CONT) ;
00141 VL_CONVTRANSP_(SFX) (dst, temp, filt,
00142 height, width, filt_width,
00143 VL_CONV_CONT) ;
00144
00145
00146 if (filt_static_sigma != sigma) {
00147 vl_free (filt) ;
00148 }
00149 }
00150
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00155