【opencv源码解析】 三、resize
resize.cpp
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 | void cv::resize( InputArray _src, OutputArray _dst, Size dsize, double inv_scale_x, double inv_scale_y, int interpolation ) { CV_INSTRUMENT_REGION() Size ssize = _src.size(); CV_Assert( ssize.width > 0 && ssize.height > 0 ); CV_Assert( dsize.area() > 0 || (inv_scale_x > 0 && inv_scale_y > 0) ); if ( dsize.area() == 0 ) { dsize = Size(saturate_cast< int >(ssize.width*inv_scale_x), saturate_cast< int >(ssize.height*inv_scale_y)); CV_Assert( dsize.area() > 0 ); } else { inv_scale_x = ( double )dsize.width/ssize.width; inv_scale_y = ( double )dsize.height/ssize.height; } CV_OCL_RUN(_src.dims() <= 2 && _dst.isUMat() && _src.cols() > 10 && _src.rows() > 10, ocl_resize(_src, _dst, dsize, inv_scale_x, inv_scale_y, interpolation)) Mat src = _src.getMat(); _dst.create(dsize, src.type()); Mat dst = _dst.getMat(); if (dsize == ssize) { // Source and destination are of same size. Use simple copy. src.copyTo(dst); return ; } hal::resize(src.type(), src.data, src.step, src.cols, src.rows, dst.data, dst.step, dst.cols, dst.rows, inv_scale_x, inv_scale_y, interpolation); } |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 | namespace hal { void resize( int src_type, const uchar * src_data, size_t src_step, int src_width, int src_height, uchar * dst_data, size_t dst_step, int dst_width, int dst_height, double inv_scale_x, double inv_scale_y, int interpolation) { CV_INSTRUMENT_REGION() CV_Assert((dst_width * dst_height > 0) || (inv_scale_x > 0 && inv_scale_y > 0)); if (inv_scale_x < DBL_EPSILON || inv_scale_y < DBL_EPSILON) { inv_scale_x = static_cast< double >(dst_width) / src_width; inv_scale_y = static_cast< double >(dst_height) / src_height; } CALL_HAL(resize, cv_hal_resize, src_type, src_data, src_step, src_width, src_height, dst_data, dst_step, dst_width, dst_height, inv_scale_x, inv_scale_y, interpolation); int depth = CV_MAT_DEPTH(src_type), cn = CV_MAT_CN(src_type); Size dsize = Size(saturate_cast< int >(src_width*inv_scale_x), saturate_cast< int >(src_height*inv_scale_y)); CV_Assert( dsize.area() > 0 ); CV_IPP_RUN_FAST(ipp_resize(src_data, src_step, src_width, src_height, dst_data, dst_step, dsize.width, dsize.height, inv_scale_x, inv_scale_y, depth, cn, interpolation)) static ResizeFunc linear_tab[] = { resizeGeneric_< HResizeLinear<uchar, int , short , INTER_RESIZE_COEF_SCALE, HResizeLinearVec_8u32s>, VResizeLinear<uchar, int , short , FixedPtCast< int , uchar, INTER_RESIZE_COEF_BITS*2>, VResizeLinearVec_32s8u> >, 0, resizeGeneric_< HResizeLinear< ushort , float , float , 1, HResizeLinearVec_16u32f>, VResizeLinear< ushort , float , float , Cast< float , ushort >, VResizeLinearVec_32f16u> >, resizeGeneric_< HResizeLinear< short , float , float , 1, HResizeLinearVec_16s32f>, VResizeLinear< short , float , float , Cast< float , short >, VResizeLinearVec_32f16s> >, 0, resizeGeneric_< HResizeLinear< float , float , float , 1, HResizeLinearVec_32f>, VResizeLinear< float , float , float , Cast< float , float >, VResizeLinearVec_32f> >, resizeGeneric_< HResizeLinear< double , double , float , 1, HResizeNoVec>, VResizeLinear< double , double , float , Cast< double , double >, VResizeNoVec> >, 0 }; static ResizeFunc cubic_tab[] = { resizeGeneric_< HResizeCubic<uchar, int , short >, VResizeCubic<uchar, int , short , FixedPtCast< int , uchar, INTER_RESIZE_COEF_BITS*2>, VResizeCubicVec_32s8u> >, 0, resizeGeneric_< HResizeCubic< ushort , float , float >, VResizeCubic< ushort , float , float , Cast< float , ushort >, VResizeCubicVec_32f16u> >, resizeGeneric_< HResizeCubic< short , float , float >, VResizeCubic< short , float , float , Cast< float , short >, VResizeCubicVec_32f16s> >, 0, resizeGeneric_< HResizeCubic< float , float , float >, VResizeCubic< float , float , float , Cast< float , float >, VResizeCubicVec_32f> >, resizeGeneric_< HResizeCubic< double , double , float >, VResizeCubic< double , double , float , Cast< double , double >, VResizeNoVec> >, 0 }; static ResizeFunc lanczos4_tab[] = { resizeGeneric_<HResizeLanczos4<uchar, int , short >, VResizeLanczos4<uchar, int , short , FixedPtCast< int , uchar, INTER_RESIZE_COEF_BITS*2>, VResizeNoVec> >, 0, resizeGeneric_<HResizeLanczos4< ushort , float , float >, VResizeLanczos4< ushort , float , float , Cast< float , ushort >, VResizeLanczos4Vec_32f16u> >, resizeGeneric_<HResizeLanczos4< short , float , float >, VResizeLanczos4< short , float , float , Cast< float , short >, VResizeLanczos4Vec_32f16s> >, 0, resizeGeneric_<HResizeLanczos4< float , float , float >, VResizeLanczos4< float , float , float , Cast< float , float >, VResizeLanczos4Vec_32f> >, resizeGeneric_<HResizeLanczos4< double , double , float >, VResizeLanczos4< double , double , float , Cast< double , double >, VResizeNoVec> >, 0 }; static ResizeAreaFastFunc areafast_tab[] = { resizeAreaFast_<uchar, int , ResizeAreaFastVec<uchar, ResizeAreaFastVec_SIMD_8u> >, 0, resizeAreaFast_< ushort , float , ResizeAreaFastVec< ushort , ResizeAreaFastVec_SIMD_16u> >, resizeAreaFast_< short , float , ResizeAreaFastVec< short , ResizeAreaFastVec_SIMD_16s> >, 0, resizeAreaFast_< float , float , ResizeAreaFastVec_SIMD_32f>, resizeAreaFast_< double , double , ResizeAreaFastNoVec< double , double > >, 0 }; static ResizeAreaFunc area_tab[] = { resizeArea_<uchar, float >, 0, resizeArea_< ushort , float >, resizeArea_< short , float >, 0, resizeArea_< float , float >, resizeArea_< double , double >, 0 }; double scale_x = 1./inv_scale_x, scale_y = 1./inv_scale_y; int iscale_x = saturate_cast< int >(scale_x); int iscale_y = saturate_cast< int >(scale_y); bool is_area_fast = std::abs(scale_x - iscale_x) < DBL_EPSILON && std::abs(scale_y - iscale_y) < DBL_EPSILON; Mat src(Size(src_width, src_height), src_type, const_cast<uchar*>(src_data), src_step); Mat dst(dsize, src_type, dst_data, dst_step); if ( interpolation == INTER_NEAREST ) { resizeNN( src, dst, inv_scale_x, inv_scale_y ); return ; } int k, sx, sy, dx, dy; { // in case of scale_x && scale_y is equal to 2 // INTER_AREA (fast) also is equal to INTER_LINEAR///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////双线性插值////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// if ( interpolation == INTER_LINEAR && is_area_fast && iscale_x == 2 && iscale_y == 2 ) interpolation = INTER_AREA; // true "area" interpolation is only implemented for the case (scale_x <= 1 && scale_y <= 1). // In other cases it is emulated using some variant of bilinear interpolation if ( interpolation == INTER_AREA && scale_x >= 1 && scale_y >= 1 ) { if ( is_area_fast ) { int area = iscale_x*iscale_y; size_t srcstep = src_step / src.elemSize1(); AutoBuffer< int > _ofs(area + dsize.width*cn); int * ofs = _ofs; int * xofs = ofs + area; ResizeAreaFastFunc func = areafast_tab[depth]; CV_Assert( func != 0 ); for ( sy = 0, k = 0; sy < iscale_y; sy++ ) for ( sx = 0; sx < iscale_x; sx++ ) ofs[k++] = ( int )(sy*srcstep + sx*cn); for ( dx = 0; dx < dsize.width; dx++ ) { int j = dx * cn; sx = iscale_x * j; for ( k = 0; k < cn; k++ ) xofs[j + k] = sx + k; } func( src, dst, ofs, xofs, iscale_x, iscale_y ); return ; } ResizeAreaFunc func = area_tab[depth]; CV_Assert( func != 0 && cn <= 4 ); AutoBuffer<DecimateAlpha> _xytab((src_width + src_height)*2); DecimateAlpha* xtab = _xytab, *ytab = xtab + src_width*2; int xtab_size = computeResizeAreaTab(src_width, dsize.width, cn, scale_x, xtab); int ytab_size = computeResizeAreaTab(src_height, dsize.height, 1, scale_y, ytab); AutoBuffer< int > _tabofs(dsize.height + 1); int * tabofs = _tabofs; for ( k = 0, dy = 0; k < ytab_size; k++ ) { if ( k == 0 || ytab[k].di != ytab[k-1].di ) { assert( ytab[k].di == dy ); tabofs[dy++] = k; } } tabofs[dy] = ytab_size; func( src, dst, xtab, xtab_size, ytab, ytab_size, tabofs ); return ; } } int xmin = 0, xmax = dsize.width, width = dsize.width*cn; bool area_mode = interpolation == INTER_AREA; bool fixpt = depth == CV_8U; float fx, fy; ResizeFunc func=0; int ksize=0, ksize2; if ( interpolation == INTER_CUBIC ) ksize = 4, func = cubic_tab[depth]; else if ( interpolation == INTER_LANCZOS4 ) ksize = 8, func = lanczos4_tab[depth]; else if ( interpolation == INTER_LINEAR || interpolation == INTER_AREA ) ksize = 2, func = linear_tab[depth]; else CV_Error( CV_StsBadArg, "Unknown interpolation method" ); ksize2 = ksize/2; CV_Assert( func != 0 ); AutoBuffer<uchar> _buffer((width + dsize.height)*( sizeof ( int ) + sizeof ( float )*ksize)); int * xofs = ( int *)(uchar*)_buffer; int * yofs = xofs + width; float * alpha = ( float *)(yofs + dsize.height); short * ialpha = ( short *)alpha; float * beta = alpha + width*ksize; short * ibeta = ialpha + width*ksize; float cbuf[MAX_ESIZE] = {0}; for ( dx = 0; dx < dsize.width; dx++ ) { if ( !area_mode ) { fx = ( float )((dx+0.5)*scale_x - 0.5); sx = cvFloor(fx); fx -= sx; } else { sx = cvFloor(dx*scale_x); fx = ( float )((dx+1) - (sx+1)*inv_scale_x); fx = fx <= 0 ? 0.f : fx - cvFloor(fx); } if ( sx < ksize2-1 ) { xmin = dx+1; if ( sx < 0 && (interpolation != INTER_CUBIC && interpolation != INTER_LANCZOS4)) fx = 0, sx = 0; } if ( sx + ksize2 >= src_width ) { xmax = std::min( xmax, dx ); if ( sx >= src_width-1 && (interpolation != INTER_CUBIC && interpolation != INTER_LANCZOS4)) fx = 0, sx = src_width-1; } for ( k = 0, sx *= cn; k < cn; k++ ) xofs[dx*cn + k] = sx + k; if ( interpolation == INTER_CUBIC ) interpolateCubic( fx, cbuf ); else if ( interpolation == INTER_LANCZOS4 ) interpolateLanczos4( fx, cbuf ); else { cbuf[0] = 1.f - fx; cbuf[1] = fx; } if ( fixpt ) { for ( k = 0; k < ksize; k++ ) ialpha[dx*cn*ksize + k] = saturate_cast< short >(cbuf[k]*INTER_RESIZE_COEF_SCALE); for ( ; k < cn*ksize; k++ ) ialpha[dx*cn*ksize + k] = ialpha[dx*cn*ksize + k - ksize]; } else { for ( k = 0; k < ksize; k++ ) alpha[dx*cn*ksize + k] = cbuf[k]; for ( ; k < cn*ksize; k++ ) alpha[dx*cn*ksize + k] = alpha[dx*cn*ksize + k - ksize]; } } for ( dy = 0; dy < dsize.height; dy++ ) { if ( !area_mode ) { fy = ( float )((dy+0.5)*scale_y - 0.5); sy = cvFloor(fy); fy -= sy; } else { sy = cvFloor(dy*scale_y); fy = ( float )((dy+1) - (sy+1)*inv_scale_y); fy = fy <= 0 ? 0.f : fy - cvFloor(fy); } yofs[dy] = sy; if ( interpolation == INTER_CUBIC ) interpolateCubic( fy, cbuf ); else if ( interpolation == INTER_LANCZOS4 ) interpolateLanczos4( fy, cbuf ); else { cbuf[0] = 1.f - fy; cbuf[1] = fy; } if ( fixpt ) { for ( k = 0; k < ksize; k++ ) ibeta[dy*ksize + k] = saturate_cast< short >(cbuf[k]*INTER_RESIZE_COEF_SCALE); } else { for ( k = 0; k < ksize; k++ ) beta[dy*ksize + k] = cbuf[k]; } } func( src, dst, xofs, fixpt ? ( void *)ialpha : ( void *)alpha, yofs, fixpt ? ( void *)ibeta : ( void *)beta, xmin, xmax, ksize ); } } // cv::hal:: } // cv:: |
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