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# vigra/resampling_convolution.hxx

    00001 /************************************************************************/
    00002 /*                                                                      */
    00003 /*               Copyright 1998-2004 by Ullrich Koethe                  */
    00004 /*       Cognitive Systems Group, University of Hamburg, Germany        */
    00005 /*                                                                      */
    00006 /*    This file is part of the VIGRA computer vision library.           */
    00007 /*    ( Version 1.6.0, Aug 13 2008 )                                    */
    00008 /*    The VIGRA Website is                                              */
    00009 /*        http://kogs-www.informatik.uni-hamburg.de/~koethe/vigra/      */
    00010 /*    Please direct questions, bug reports, and contributions to        */
    00011 /*        ullrich.koethe@iwr.uni-heidelberg.de    or                    */
    00012 /*        vigra@informatik.uni-hamburg.de                               */
    00013 /*                                                                      */
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    00021 /*    conditions:                                                       */
    00022 /*                                                                      */
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    00024 /*    included in all copies or substantial portions of the             */
    00025 /*    Software.                                                         */
    00026 /*                                                                      */
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    00035 /*                                                                      */
    00036 /************************************************************************/
    00037
    00038 #ifndef VIGRA_RESAMPLING_CONVOLUTION_HXX
    00039 #define VIGRA_RESAMPLING_CONVOLUTION_HXX
    00040
    00041 #include <cmath>
    00042 #include "stdimage.hxx"
    00043 #include "array_vector.hxx"
    00044 #include "rational.hxx"
    00045 #include "functortraits.hxx"
    00046 #include "functorexpression.hxx"
    00047 #include "transformimage.hxx"
    00048 #include "imagecontainer.hxx"
    00049
    00050 namespace vigra {
    00051
    00052 namespace resampling_detail
    00053 {
    00054
    00055 struct MapTargetToSourceCoordinate
    00056 {
    00057     MapTargetToSourceCoordinate(Rational<int> const & samplingRatio,
    00058                                 Rational<int> const & offset)
    00059     : a(samplingRatio.denominator()*offset.denominator()),
    00060       b(samplingRatio.numerator()*offset.numerator()),
    00061       c(samplingRatio.numerator()*offset.denominator())
    00062     {}
    00063
    00064 //        the following functions are more efficient realizations of:
    00065 //             rational_cast<T>(i / samplingRatio + offset);
    00066 //        we need efficiency because this may be called in the inner loop
    00067
    00068     int operator()(int i) const
    00069     {
    00070         return (i * a + b) / c;
    00071     }
    00072
    00073     double toDouble(int i) const
    00074     {
    00075         return double(i * a + b) / c;
    00076     }
    00077
    00078     Rational<int> toRational(int i) const
    00079     {
    00080         return Rational<int>(i * a + b, c);
    00081     }
    00082
    00083     bool isExpand2() const
    00084     {
    00085         return a == 1 && b == 0 && c == 2;
    00086     }
    00087
    00088     bool isReduce2() const
    00089     {
    00090         return a == 2 && b == 0 && c == 1;
    00091     }
    00092
    00093     int a, b, c;
    00094 };
    00095
    00096 } // namespace resampling_detail
    00097
    00098 template <>
    00099 class FunctorTraits<resampling_detail::MapTargetToSourceCoordinate>
    00100 : public FunctorTraitsBase<resampling_detail::MapTargetToSourceCoordinate>
    00101 {
    00102   public:
    00103     typedef VigraTrueType isUnaryFunctor;
    00104 };
    00105
    00106 template <class SrcIter, class SrcAcc,
    00107           class DestIter, class DestAcc,
    00108           class KernelArray>
    00109 void
    00110 resamplingExpandLine2(SrcIter s, SrcIter send, SrcAcc src,
    00111                        DestIter d, DestIter dend, DestAcc dest,
    00112                        KernelArray const & kernels)
    00113 {
    00114     typedef typename KernelArray::value_type Kernel;
    00115     typedef typename KernelArray::const_reference KernelRef;
    00116     typedef typename Kernel::const_iterator KernelIter;
    00117
    00118     typedef typename
    00119         PromoteTraits<typename SrcAcc::value_type, typename Kernel::value_type>::Promote
    00120         TmpType;
    00121
    00122     int wo = send - s;
    00123     int wn = dend - d;
    00124     int wo2 = 2*wo - 2;
    00125
    00126     int ileft = std::max(kernels[0].right(), kernels[1].right());
    00127     int iright = wo + std::min(kernels[0].left(), kernels[1].left()) - 1;
    00128     for(int i = 0; i < wn; ++i, ++d)
    00129     {
    00130         int is = i / 2;
    00131         KernelRef kernel = kernels[i & 1];
    00132         KernelIter k = kernel.center() + kernel.right();
    00133         TmpType sum = NumericTraits<TmpType>::zero();
    00134         if(is < ileft)
    00135         {
    00136             for(int m=is-kernel.right(); m <= is-kernel.left(); ++m, --k)
    00137             {
    00138                 int mm = (m < 0)
    00139                         ? -m
    00140                         : m;
    00141                 sum += *k * src(s, mm);
    00142             }
    00143         }
    00144         else if(is > iright)
    00145         {
    00146             for(int m=is-kernel.right(); m <= is-kernel.left(); ++m, --k)
    00147             {
    00148                 int mm =  (m >= wo)
    00149                             ? wo2 - m
    00150                             : m;
    00151                 sum += *k * src(s, mm);
    00152             }
    00153         }
    00154         else
    00155         {
    00156             SrcIter ss = s + is - kernel.right();
    00157             for(int m = 0; m < kernel.size(); ++m, --k, ++ss)
    00158             {
    00159                 sum += *k * src(ss);
    00160             }
    00161         }
    00162         dest.set(sum, d);
    00163     }
    00164 }
    00165
    00166 template <class SrcIter, class SrcAcc,
    00167           class DestIter, class DestAcc,
    00168           class KernelArray>
    00169 void
    00170 resamplingReduceLine2(SrcIter s, SrcIter send, SrcAcc src,
    00171                        DestIter d, DestIter dend, DestAcc dest,
    00172                        KernelArray const & kernels)
    00173 {
    00174     typedef typename KernelArray::value_type Kernel;
    00175     typedef typename KernelArray::const_reference KernelRef;
    00176     typedef typename Kernel::const_iterator KernelIter;
    00177
    00178     KernelRef kernel = kernels[0];
    00179     KernelIter kbegin = kernel.center() + kernel.right();
    00180
    00181     typedef typename
    00182         PromoteTraits<typename SrcAcc::value_type, typename Kernel::value_type>::Promote
    00183         TmpType;
    00184
    00185     int wo = send - s;
    00186     int wn = dend - d;
    00187     int wo2 = 2*wo - 2;
    00188
    00189     int ileft = kernel.right();
    00190     int iright = wo + kernel.left() - 1;
    00191     for(int i = 0; i < wn; ++i, ++d)
    00192     {
    00193         int is = 2 * i;
    00194         KernelIter k = kbegin;
    00195         TmpType sum = NumericTraits<TmpType>::zero();
    00196         if(is < ileft)
    00197         {
    00198             for(int m=is-kernel.right(); m <= is-kernel.left(); ++m, --k)
    00199             {
    00200                 int mm = (m < 0)
    00201                         ? -m
    00202                         : m;
    00203                 sum += *k * src(s, mm);
    00204             }
    00205         }
    00206         else if(is > iright)
    00207         {
    00208             for(int m=is-kernel.right(); m <= is-kernel.left(); ++m, --k)
    00209             {
    00210                 int mm =  (m >= wo)
    00211                             ? wo2 - m
    00212                             : m;
    00213                 sum += *k * src(s, mm);
    00214             }
    00215         }
    00216         else
    00217         {
    00218             SrcIter ss = s + is - kernel.right();
    00219             for(int m = 0; m < kernel.size(); ++m, --k, ++ss)
    00220             {
    00221                 sum += *k * src(ss);
    00222             }
    00223         }
    00224         dest.set(sum, d);
    00225     }
    00226 }
    00227
    00228 /** \addtogroup ResamplingConvolutionFilters Resampling Convolution Filters
    00229
    00230     These functions implement the convolution operation when the source and target images
    00231     have different sizes. This is realized by accessing a continous kernel at the
    00232     appropriate non-integer positions. The technique is, for example, described in
    00233     D. Schumacher: <i>General Filtered Image Rescaling</i>, in: Graphics Gems III,
    00234     Academic Press, 1992.
    00235 */
    00236 //@{
    00237
    00238 /********************************************************/
    00239 /*                                                      */
    00240 /*                resamplingConvolveLine                */
    00241 /*                                                      */
    00242 /********************************************************/
    00243
    00244 /** \brief Performs a 1-dimensional resampling convolution of the source signal using the given
    00245     set of kernels.
    00246
    00247     This function is mainly used internally: It is called for each dimension of a
    00248     higher dimensional array in order to perform a separable resize operation.
    00249
    00250     <b> Declaration:</b>
    00251
    00252     <b>\#include</b> <<a href="resampling__convolution_8hxx-source.html">vigra/resampling_convolution.hxx</a>>
    00253
    00254     \code
    00255     namespace vigra {
    00256         template <class SrcIter, class SrcAcc,
    00257                   class DestIter, class DestAcc,
    00258                   class KernelArray,
    00259                   class Functor>
    00260         void
    00261         resamplingConvolveLine(SrcIter s, SrcIter send, SrcAcc src,
    00262                                DestIter d, DestIter dend, DestAcc dest,
    00263                                KernelArray const & kernels,
    00264                                Functor mapTargetToSourceCoordinate)
    00265     }
    00266     \endcode
    00267
    00268 */
    00269 doxygen_overloaded_function(template <...> void resamplingConvolveLine)
    00270
    00271 template <class SrcIter, class SrcAcc,
    00272           class DestIter, class DestAcc,
    00273           class KernelArray,
    00274           class Functor>
    00275 void
    00276 resamplingConvolveLine(SrcIter s, SrcIter send, SrcAcc src,
    00277                        DestIter d, DestIter dend, DestAcc dest,
    00278                        KernelArray const & kernels,
    00279                        Functor mapTargetToSourceCoordinate)
    00280 {
    00281     if(mapTargetToSourceCoordinate.isExpand2())
    00282     {
    00283         resamplingExpandLine2(s, send, src, d, dend, dest, kernels);
    00284         return;
    00285     }
    00286     if(mapTargetToSourceCoordinate.isReduce2())
    00287     {
    00288         resamplingReduceLine2(s, send, src, d, dend, dest, kernels);
    00289         return;
    00290     }
    00291
    00292     typedef typename
    00293         NumericTraits<typename SrcAcc::value_type>::RealPromote
    00294         TmpType;
    00295     typedef typename KernelArray::value_type Kernel;
    00296     typedef typename Kernel::const_iterator KernelIter;
    00297
    00298     int wo = send - s;
    00299     int wn = dend - d;
    00300     int wo2 = 2*wo - 2;
    00301
    00302     int i;
    00303     typename KernelArray::const_iterator kernel = kernels.begin();
    00304     for(i=0; i<wn; ++i, ++d, ++kernel)
    00305     {
    00306         // use the kernels periodically
    00307         if(kernel == kernels.end())
    00308             kernel = kernels.begin();
    00309
    00310         // calculate current target point into source location
    00311         int is = mapTargetToSourceCoordinate(i);
    00312
    00313         TmpType sum = NumericTraits<TmpType>::zero();
    00314
    00315         int lbound = is - kernel->right(),
    00316             hbound = is - kernel->left();
    00317
    00318         KernelIter k = kernel->center() + kernel->right();
    00319         if(lbound < 0 || hbound >= wo)
    00320         {
    00321             vigra_precondition(-lbound < wo && wo2 - hbound >= 0,
    00322                 "resamplingConvolveLine(): kernel or offset larger than image.");
    00323             for(int m=lbound; m <= hbound; ++m, --k)
    00324             {
    00325                 int mm = (m < 0) ?
    00326                             -m :
    00327                             (m >= wo) ?
    00328                                 wo2 - m :
    00329                                 m;
    00330                 sum += *k * src(s, mm);
    00331             }
    00332         }
    00333         else
    00334         {
    00335             SrcIter ss = s + lbound;
    00336             SrcIter ssend = s + hbound;
    00337
    00338             for(; ss <= ssend; ++ss, --k)
    00339             {
    00340                 sum += *k * src(ss);
    00341             }
    00342         }
    00343
    00344         dest.set(sum, d);
    00345     }
    00346 }
    00347
    00348 template <class Kernel, class MapCoordinate, class KernelArray>
    00349 void
    00350 createResamplingKernels(Kernel const & kernel,
    00351              MapCoordinate const & mapCoordinate, KernelArray & kernels)
    00352 {
    00353     for(unsigned int idest = 0; idest < kernels.size(); ++idest)
    00354     {
    00355         int isrc = mapCoordinate(idest);
    00356         double idsrc = mapCoordinate.toDouble(idest);
    00357         double offset = idsrc - isrc;
    00358         double radius = kernel.radius();
    00359         int left = int(ceil(-radius - offset));
    00360         int right = int(floor(radius - offset));
    00361         kernels[idest].initExplicitly(left, right);
    00362
    00363         double x = left + offset;
    00364         for(int i = left; i <= right; ++i, ++x)
    00365             kernels[idest][i] = kernel(x);
    00366         kernels[idest].normalize(1.0, kernel.derivativeOrder(), offset);
    00367     }
    00368 }
    00369
    00370 /** \brief Apply a resampling filter in the x-direction.
    00371
    00372     This function implements a convolution operation in x-direction
    00373     (i.e. applies a 1D filter to every row) where the width of the source
    00374     and destination images differ. This is typically used to avoid aliasing if
    00375     the image is scaled down, or to interpolate smoothly if the image is scaled up.
    00376     The target coordinates are transformed into source coordinates by
    00377
    00378     \code
    00379     xsource = (xtarget - offset) / samplingRatio
    00380     \endcode
    00381
    00382     The <tt>samplingRatio</tt> and <tt>offset</tt> must be given as \ref vigra::Rational
    00383     in order to avoid rounding errors in this transformation. It is required that for all
    00384     pixels of the target image, <tt>xsource</tt> remains within the range of the source
    00385     image (i.e. <tt>0 <= xsource <= sourceWidth-1</tt>. Since <tt>xsource</tt> is
    00386     in general not an integer, the <tt>kernel</tt> must be a functor that can be accessed at
    00387     arbitrary (<tt>double</tt>) coordinates. It must also provide a member function <tt>radius()</tt>
    00388     which specifies the support (non-zero interval) of the kernel. VIGRA already
    00389     provides a number of suitable functors, e.g. \ref vigra::Gaussian, \ref vigra::BSpline
    00390     \ref vigra::CatmullRomSpline, and \ref vigra::CoscotFunction. The function
    00391     \ref resizeImageSplineInterpolation() is implemented by means resamplingConvolveX() and
    00392     resamplingConvolveY().
    00393
    00394     <b> Declarations:</b>
    00395
    00396     pass arguments explicitly:
    00397     \code
    00398     namespace vigra {
    00399         template <class SrcIter, class SrcAcc,
    00400                   class DestIter, class DestAcc,
    00401                   class Kernel>
    00402         void
    00403         resamplingConvolveX(SrcIter sul, SrcIter slr, SrcAcc src,
    00404                             DestIter dul, DestIter dlr, DestAcc dest,
    00405                             Kernel const & kernel,
    00406                             Rational<int> const & samplingRatio, Rational<int> const & offset);
    00407     }
    00408     \endcode
    00409
    00410
    00411     use argument objects in conjunction with \ref ArgumentObjectFactories :
    00412     \code
    00413     namespace vigra {
    00414         template <class SrcIter, class SrcAcc,
    00415                   class DestIter, class DestAcc,
    00416                   class Kernel>
    00417         void
    00418         resamplingConvolveX(triple<SrcIter, SrcIter, SrcAcc> src,
    00419                             triple<DestIter, DestIter, DestAcc> dest,
    00420                             Kernel const & kernel,
    00421                             Rational<int> const & samplingRatio, Rational<int> const & offset);
    00422     }
    00423     \endcode
    00424
    00425     <b> Usage:</b>
    00426
    00427     <b>\#include</b> <<a href="resampling__convolution_8hxx-source.html">vigra/resampling_convolution.hxx</a>>
    00428
    00429
    00430     \code
    00431     Rational<int> ratio(2), offset(0);
    00432
    00433     FImage src(w,h),
    00434            dest(rational_cast<int>(ratio*w), h);
    00435
    00436     float sigma = 2.0;
    00437     Gaussian<float> smooth(sigma);
    00438     ...
    00439
    00440     // simpultaneously enlarge and smooth source image
    00441     resamplingConvolveX(srcImageRange(src), destImageRange(dest),
    00442                         smooth, ratio, offset);
    00443     \endcode
    00444
    00445     <b> Required Interface:</b>
    00446
    00447     \code
    00448     Kernel kernel;
    00449     int kernelRadius = kernel.radius();
    00450     double x = ...;  // must be <= radius()
    00451     double value = kernel(x);
    00452     \endcode
    00453 */
    00454 doxygen_overloaded_function(template <...> void resamplingConvolveX)
    00455
    00456 template <class SrcIter, class SrcAcc,
    00457           class DestIter, class DestAcc,
    00458           class Kernel>
    00459 void
    00460 resamplingConvolveX(SrcIter sul, SrcIter slr, SrcAcc src,
    00461                     DestIter dul, DestIter dlr, DestAcc dest,
    00462                     Kernel const & kernel,
    00463                     Rational<int> const & samplingRatio, Rational<int> const & offset)
    00464 {
    00465     int wold = slr.x - sul.x;
    00466     int wnew = dlr.x - dul.x;
    00467
    00468     vigra_precondition(!samplingRatio.is_inf() && samplingRatio > 0,
    00469                 "resamplingConvolveX(): sampling ratio must be > 0 and < infinity");
    00470     vigra_precondition(!offset.is_inf(),
    00471                 "resamplingConvolveX(): offset must be < infinity");
    00472
    00473     int period = lcm(samplingRatio.numerator(), samplingRatio.denominator());
    00474     resampling_detail::MapTargetToSourceCoordinate mapCoordinate(samplingRatio, offset);
    00475
    00476     ArrayVector<Kernel1D<double> > kernels(period);
    00477
    00478     createResamplingKernels(kernel, mapCoordinate, kernels);
    00479
    00480     for(; sul.y < slr.y; ++sul.y, ++dul.y)
    00481     {
    00482         typename SrcIter::row_iterator sr = sul.rowIterator();
    00483         typename DestIter::row_iterator dr = dul.rowIterator();
    00484         resamplingConvolveLine(sr, sr+wold, src, dr, dr+wnew, dest,
    00485                                kernels, mapCoordinate);
    00486     }
    00487 }
    00488
    00489 template <class SrcIter, class SrcAcc,
    00490           class DestIter, class DestAcc,
    00491           class Kernel>
    00492 inline void
    00493 resamplingConvolveX(triple<SrcIter, SrcIter, SrcAcc> src,
    00494                     triple<DestIter, DestIter, DestAcc> dest,
    00495                     Kernel const & kernel,
    00496                     Rational<int> const & samplingRatio, Rational<int> const & offset)
    00497 {
    00498     resamplingConvolveX(src.first, src.second, src.third,
    00499                         dest.first, dest.second, dest.third,
    00500                         kernel, samplingRatio, offset);
    00501 }
    00502
    00503 /********************************************************/
    00504 /*                                                      */
    00505 /*                  resamplingConvolveY                 */
    00506 /*                                                      */
    00507 /********************************************************/
    00508
    00509 /** \brief Apply a resampling filter in the y-direction.
    00510
    00511     This function implements a convolution operation in y-direction
    00512     (i.e. applies a 1D filter to every column) where the height of the source
    00513     and destination images differ. This is typically used to avoid aliasing if
    00514     the image is scaled down, or to interpolate smoothly if the image is scaled up.
    00515     The target coordinates are transformed into source coordinates by
    00516
    00517     \code
    00518     ysource = (ytarget - offset) / samplingRatio
    00519     \endcode
    00520
    00521     The <tt>samplingRatio</tt> and <tt>offset</tt> must be given as \ref vigra::Rational
    00522     in order to avoid rounding errors in this transformation. It is required that for all
    00523     pixels of the target image, <tt>ysource</tt> remains within the range of the source
    00524     image (i.e. <tt>0 <= ysource <= sourceHeight-1</tt>. Since <tt>ysource</tt> is
    00525     in general not an integer, the <tt>kernel</tt> must be a functor that can be accessed at
    00526     arbitrary (<tt>double</tt>) coordinates. It must also provide a member function <tt>radius()</tt>
    00527     which specifies the support (non-zero interval) of the kernel. VIGRA already
    00528     provides a number of suitable functors, e.g. \ref vigra::Gaussian, \ref vigra::BSpline
    00529     \ref vigra::CatmullRomSpline, and \ref vigra::CoscotFunction. The function
    00530     \ref resizeImageSplineInterpolation() is implemented by means resamplingConvolveX() and
    00531     resamplingConvolveY().
    00532
    00533     <b> Declarations:</b>
    00534
    00535     pass arguments explicitly:
    00536     \code
    00537     namespace vigra {
    00538         template <class SrcIter, class SrcAcc,
    00539                   class DestIter, class DestAcc,
    00540                   class Kernel>
    00541         void
    00542         resamplingConvolveY(SrcIter sul, SrcIter slr, SrcAcc src,
    00543                             DestIter dul, DestIter dlr, DestAcc dest,
    00544                             Kernel const & kernel,
    00545                             Rational<int> const & samplingRatio, Rational<int> const & offset);
    00546     }
    00547     \endcode
    00548
    00549
    00550     use argument objects in conjunction with \ref ArgumentObjectFactories :
    00551     \code
    00552     namespace vigra {
    00553         template <class SrcIter, class SrcAcc,
    00554                   class DestIter, class DestAcc,
    00555                   class Kernel>
    00556         void
    00557         resamplingConvolveY(triple<SrcIter, SrcIter, SrcAcc> src,
    00558                             triple<DestIter, DestIter, DestAcc> dest,
    00559                             Kernel const & kernel,
    00560                             Rational<int> const & samplingRatio, Rational<int> const & offset);
    00561     }
    00562     \endcode
    00563
    00564     <b> Usage:</b>
    00565
    00566     <b>\#include</b> <<a href="resampling__convolution_8hxx-source.html">vigra/resampling_convolution.hxx</a>>
    00567
    00568
    00569     \code
    00570     Rational<int> ratio(2), offset(0);
    00571
    00572     FImage src(w,h),
    00573            dest(w, rational_cast<int>(ratio*h));
    00574
    00575     float sigma = 2.0;
    00576     Gaussian<float> smooth(sigma);
    00577     ...
    00578
    00579     // simpultaneously enlarge and smooth source image
    00580     resamplingConvolveY(srcImageRange(src), destImageRange(dest),
    00581                         smooth, ratio, offset);
    00582     \endcode
    00583
    00584     <b> Required Interface:</b>
    00585
    00586     \code
    00587     Kernel kernel;
    00588     int kernelRadius = kernel.radius();
    00589     double y = ...;  // must be <= radius()
    00590     double value = kernel(y);
    00591     \endcode
    00592 */
    00593 doxygen_overloaded_function(template <...> void resamplingConvolveY)
    00594
    00595 template <class SrcIter, class SrcAcc,
    00596           class DestIter, class DestAcc,
    00597           class Kernel>
    00598 void
    00599 resamplingConvolveY(SrcIter sul, SrcIter slr, SrcAcc src,
    00600                     DestIter dul, DestIter dlr, DestAcc dest,
    00601                     Kernel const & kernel,
    00602                     Rational<int> const & samplingRatio, Rational<int> const & offset)
    00603 {
    00604     int hold = slr.y - sul.y;
    00605     int hnew = dlr.y - dul.y;
    00606
    00607     vigra_precondition(!samplingRatio.is_inf() && samplingRatio > 0,
    00608                 "resamplingConvolveY(): sampling ratio must be > 0 and < infinity");
    00609     vigra_precondition(!offset.is_inf(),
    00610                 "resamplingConvolveY(): offset must be < infinity");
    00611
    00612     int period = lcm(samplingRatio.numerator(), samplingRatio.denominator());
    00613
    00614     resampling_detail::MapTargetToSourceCoordinate mapCoordinate(samplingRatio, offset);
    00615
    00616     ArrayVector<Kernel1D<double> > kernels(period);
    00617
    00618     createResamplingKernels(kernel, mapCoordinate, kernels);
    00619
    00620     for(; sul.x < slr.x; ++sul.x, ++dul.x)
    00621     {
    00622         typename SrcIter::column_iterator sc = sul.columnIterator();
    00623         typename DestIter::column_iterator dc = dul.columnIterator();
    00624         resamplingConvolveLine(sc, sc+hold, src, dc, dc+hnew, dest,
    00625                                kernels, mapCoordinate);
    00626     }
    00627 }
    00628
    00629 template <class SrcIter, class SrcAcc,
    00630           class DestIter, class DestAcc,
    00631           class Kernel>
    00632 inline void
    00633 resamplingConvolveY(triple<SrcIter, SrcIter, SrcAcc> src,
    00634                     triple<DestIter, DestIter, DestAcc> dest,
    00635                     Kernel const & kernel,
    00636                     Rational<int> const & samplingRatio, Rational<int> const & offset)
    00637 {
    00638     resamplingConvolveY(src.first, src.second, src.third,
    00639                         dest.first, dest.second, dest.third,
    00640                         kernel, samplingRatio, offset);
    00641 }
    00642
    00643 /********************************************************/
    00644 /*                                                      */
    00645 /*               resamplingConvolveImage                */
    00646 /*                                                      */
    00647 /********************************************************/
    00648
    00649 /** \brief Apply two separable resampling filters successively, the first in x-direction,
    00650            the second in y-direction.
    00651
    00652     This function is a shorthand for the concatenation of a call to
    00653     \ref resamplingConvolveX() and \ref resamplingConvolveY()
    00654     with the given kernels. See there for detailed documentation.
    00655
    00656     <b> Declarations:</b>
    00657
    00658     pass arguments explicitly:
    00659     \code
    00660     namespace vigra {
    00661         template <class SrcIterator, class SrcAccessor,
    00662                   class DestIterator, class DestAccessor,
    00663                   class KernelX, class KernelY>
    00664         void resamplingConvolveImage(SrcIterator sul,SrcIterator slr, SrcAccessor src,
    00665                            DestIterator dul, DestIterator dlr, DestAccessor dest,
    00666                            KernelX const & kx,
    00667                            Rational<int> const & samplingRatioX, Rational<int> const & offsetX,
    00668                            KernelY const & ky,
    00669                            Rational<int> const & samplingRatioY, Rational<int> const & offsetY);
    00670     }
    00671     \endcode
    00672
    00673
    00674     use argument objects in conjunction with \ref ArgumentObjectFactories :
    00675     \code
    00676     namespace vigra {
    00677         template <class SrcIterator, class SrcAccessor,
    00678                   class DestIterator, class DestAccessor,
    00679                   class KernelX, class KernelY>
    00680         void
    00681         resamplingConvolveImage(triple<SrcIterator, SrcIterator, SrcAccessor> src,
    00682                            triple<DestIterator, DestIterator, DestAccessor> dest,
    00683                            KernelX const & kx,
    00684                            Rational<int> const & samplingRatioX, Rational<int> const & offsetX,
    00685                            KernelY const & ky,
    00686                            Rational<int> const & samplingRatioY, Rational<int> const & offsetY);
    00687     }
    00688     \endcode
    00689
    00690     <b> Usage:</b>
    00691
    00692     <b>\#include</b> <<a href="resampling__convolution_8hxx-source.html">vigra/resampling_convolution.hxx</a>>
    00693
    00694
    00695     \code
    00696     Rational<int> xratio(2), yratio(3), offset(0);
    00697
    00698     FImage src(w,h),
    00699            dest(rational_cast<int>(xratio*w), rational_cast<int>(yratio*h));
    00700
    00701     float sigma = 2.0;
    00702     Gaussian<float> smooth(sigma);
    00703     ...
    00704
    00705     // simpultaneously enlarge and smooth source image
    00706     resamplingConvolveImage(srcImageRange(src), destImageRange(dest),
    00707                             smooth, xratio, offset,
    00708                             smooth, yratio, offset);
    00709
    00710     \endcode
    00711
    00712 */
    00713 doxygen_overloaded_function(template <...> void resamplingConvolveImage)
    00714
    00715 template <class SrcIterator, class SrcAccessor,
    00716           class DestIterator, class DestAccessor,
    00717           class KernelX, class KernelY>
    00718 void resamplingConvolveImage(SrcIterator sul,SrcIterator slr, SrcAccessor src,
    00719                    DestIterator dul, DestIterator dlr, DestAccessor dest,
    00720                    KernelX const & kx,
    00721                    Rational<int> const & samplingRatioX, Rational<int> const & offsetX,
    00722                    KernelY const & ky,
    00723                    Rational<int> const & samplingRatioY, Rational<int> const & offsetY)
    00724 {
    00725     typedef typename
    00726         NumericTraits<typename SrcAccessor::value_type>::RealPromote
    00727         TmpType;
    00728
    00729     BasicImage<TmpType> tmp(dlr.x - dul.x, slr.y - sul.y);
    00730
    00731     resamplingConvolveX(srcIterRange(sul, slr, src),
    00732                         destImageRange(tmp),
    00733                         kx, samplingRatioX, offsetX);
    00734     resamplingConvolveY(srcImageRange(tmp),
    00735                         destIterRange(dul, dlr, dest),
    00736                         ky, samplingRatioY, offsetY);
    00737 }
    00738
    00739 template <class SrcIterator, class SrcAccessor,
    00740           class DestIterator, class DestAccessor,
    00741           class KernelX, class KernelY>
    00742 inline void
    00743 resamplingConvolveImage(triple<SrcIterator, SrcIterator, SrcAccessor> src,
    00744                    triple<DestIterator, DestIterator, DestAccessor> dest,
    00745                    KernelX const & kx,
    00746                    Rational<int> const & samplingRatioX, Rational<int> const & offsetX,
    00747                    KernelY const & ky,
    00748                    Rational<int> const & samplingRatioY, Rational<int> const & offsetY)
    00749 {
    00750     resamplingConvolveImage(src.first, src.second, src.third,
    00751                             dest.first, dest.second, dest.third,
    00752                             kx, samplingRatioX, offsetX,
    00753                             ky, samplingRatioY, offsetY);
    00754 }
    00755
    00756 /** \brief Two-fold down-sampling for image pyramid construction.
    00757
    00758     Sorry, no \ref detailedDocumentation() available yet.
    00759
    00760     <b> Declarations:</b>
    00761
    00762     <b>\#include</b> <<a href="resampling__convolution_8hxx-source.html">vigra/resampling_convolution.hxx</a>><br>
    00763     Namespace: vigra
    00764
    00765     pass arguments explicitly:
    00766     \code
    00767     namespace vigra {
    00768         template <class SrcIterator, class SrcAccessor,
    00769                   class DestIterator, class DestAccessor>
    00770         void pyramidReduceBurtFilter(SrcIterator sul, SrcIterator slr, SrcAccessor src,
    00771                                      DestIterator dul, DestIterator dlr, DestAccessor dest,
    00772                                      double centerValue = 0.4);
    00773     }
    00774     \endcode
    00775
    00776     use argument objects in conjunction with \ref ArgumentObjectFactories :
    00777     \code
    00778     namespace vigra {
    00779         template <class SrcIterator, class SrcAccessor,
    00780                   class DestIterator, class DestAccessor>
    00781         void pyramidReduceBurtFilter(triple<SrcIterator, SrcIterator, SrcAccessor> src,
    00782                                      triple<DestIterator, DestIterator, DestAccessor> dest,
    00783                                      double centerValue = 0.4);
    00784     }
    00785     \endcode
    00786
    00787     use a \ref vigra::ImagePyramid :
    00788     \code
    00789     namespace vigra {
    00790         template <class Image, class Alloc>
    00791         void pyramidReduceBurtFilter(ImagePyramid<Image, Alloc> & pyramid, int fromLevel, int toLevel,
    00792                                      double centerValue = 0.4);
    00793     }
    00794     \endcode
    00795 */
    00796 doxygen_overloaded_function(template <...> void pyramidReduceBurtFilter)
    00797
    00798 template <class SrcIterator, class SrcAccessor,
    00799           class DestIterator, class DestAccessor>
    00800 void pyramidReduceBurtFilter(SrcIterator sul, SrcIterator slr, SrcAccessor src,
    00801                              DestIterator dul, DestIterator dlr, DestAccessor dest,
    00802                              double centerValue = 0.4)
    00803 {
    00804     vigra_precondition(0.25 <= centerValue && centerValue <= 0.5,
    00805              "pyramidReduceBurtFilter(): centerValue must be between 0.25 and 0.5.");
    00806
    00807     int wold = slr.x - sul.x;
    00808     int wnew = dlr.x - dul.x;
    00809     int hold = slr.y - sul.y;
    00810     int hnew = dlr.y - dul.y;
    00811
    00812     Rational<int> samplingRatio(1,2), offset(0);
    00813     resampling_detail::MapTargetToSourceCoordinate mapCoordinate(samplingRatio, offset);
    00814
    00815     ArrayVector<Kernel1D<double> > kernels(1);
    00816     kernels[0].initExplicitly(-2, 2) = 0.25 - centerValue / 2.0, 0.25, centerValue, 0.25, 0.25 - centerValue / 2.0;
    00817
    00818     typedef typename
    00819         NumericTraits<typename SrcAccessor::value_type>::RealPromote
    00820         TmpType;
    00821     typedef BasicImage<TmpType> TmpImage;
    00822     typedef typename TmpImage::traverser TmpIterator;
    00823
    00824     BasicImage<TmpType> tmp(wnew, hold);
    00825
    00826     TmpIterator tul = tmp.upperLeft();
    00827
    00828     for(; sul.y < slr.y; ++sul.y, ++tul.y)
    00829     {
    00830         typename SrcIterator::row_iterator sr = sul.rowIterator();
    00831         typename TmpIterator::row_iterator tr = tul.rowIterator();
    00832         // FIXME: replace with reduceLineBurtFilter()
    00833         resamplingConvolveLine(sr, sr+wold, src, tr, tr+wnew, tmp.accessor(),
    00834                                kernels, mapCoordinate);
    00835     }
    00836
    00837     tul  = tmp.upperLeft();
    00838
    00839     for(; dul.x < dlr.x; ++dul.x, ++tul.x)
    00840     {
    00841         typename DestIterator::column_iterator dc = dul.columnIterator();
    00842         typename TmpIterator::column_iterator tc = tul.columnIterator();
    00843         resamplingConvolveLine(tc, tc+hold, tmp.accessor(), dc, dc+hnew, dest,
    00844                                kernels, mapCoordinate);
    00845     }
    00846 }
    00847
    00848 template <class SrcIterator, class SrcAccessor,
    00849           class DestIterator, class DestAccessor>
    00850 inline
    00851 void pyramidReduceBurtFilter(triple<SrcIterator, SrcIterator, SrcAccessor> src,
    00852                              triple<DestIterator, DestIterator, DestAccessor> dest,
    00853                              double centerValue = 0.4)
    00854 {
    00855     pyramidReduceBurtFilter(src.first, src.second, src.third,
    00856                             dest.first, dest.second, dest.third, centerValue);
    00857 }
    00858
    00859 template <class Image, class Alloc>
    00860 inline
    00861 void pyramidReduceBurtFilter(ImagePyramid<Image, Alloc> & pyramid, int fromLevel, int toLevel,
    00862                              double centerValue = 0.4)
    00863 {
    00864     vigra_precondition(fromLevel  < toLevel,
    00865        "pyramidReduceBurtFilter(): fromLevel must be smaller than toLevel.");
    00866     vigra_precondition(pyramid.lowestLevel() <= fromLevel && toLevel <= pyramid.highestLevel(),
    00867        "pyramidReduceBurtFilter(): fromLevel and toLevel must be between the lowest and highest pyramid levels (inclusive).");
    00868
    00869     for(int i=fromLevel+1; i <= toLevel; ++i)
    00870         pyramidReduceBurtFilter(srcImageRange(pyramid[i-1]), destImageRange(pyramid[i]), centerValue);
    00871 }
    00872
    00873 /** \brief Two-fold up-sampling for image pyramid reconstruction.
    00874
    00875     Sorry, no \ref detailedDocumentation() available yet.
    00876
    00877     <b> Declarations:</b>
    00878
    00879     <b>\#include</b> <<a href="resampling__convolution_8hxx-source.html">vigra/resampling_convolution.hxx</a>><br>
    00880     Namespace: vigra
    00881
    00882     pass arguments explicitly:
    00883     \code
    00884     namespace vigra {
    00885         template <class SrcIterator, class SrcAccessor,
    00886                   class DestIterator, class DestAccessor>
    00887         void pyramidExpandBurtFilter(SrcIterator sul, SrcIterator slr, SrcAccessor src,
    00888                                      DestIterator dul, DestIterator dlr, DestAccessor dest,
    00889                                      double centerValue = 0.4);
    00890     }
    00891     \endcode
    00892
    00893
    00894     use argument objects in conjunction with \ref ArgumentObjectFactories :
    00895     \code
    00896     namespace vigra {
    00897         template <class SrcIterator, class SrcAccessor,
    00898                   class DestIterator, class DestAccessor>
    00899         void pyramidExpandBurtFilter(triple<SrcIterator, SrcIterator, SrcAccessor> src,
    00900                                      triple<DestIterator, DestIterator, DestAccessor> dest,
    00901                                      double centerValue = 0.4);
    00902     }
    00903     \endcode
    00904
    00905     use a \ref vigra::ImagePyramid :
    00906     \code
    00907     namespace vigra {
    00908         template <class Image, class Alloc>
    00909         void pyramidExpandBurtFilter(ImagePyramid<Image, Alloc> & pyramid, int fromLevel, int toLevel,
    00910                                      double centerValue = 0.4);
    00911     }
    00912     \endcode
    00913 */
    00914 doxygen_overloaded_function(template <...> void pyramidExpandBurtFilter)
    00915
    00916 template <class SrcIterator, class SrcAccessor,
    00917           class DestIterator, class DestAccessor>
    00918 void pyramidExpandBurtFilter(SrcIterator sul, SrcIterator slr, SrcAccessor src,
    00919                              DestIterator dul, DestIterator dlr, DestAccessor dest,
    00920                              double centerValue = 0.4)
    00921 {
    00922     vigra_precondition(0.25 <= centerValue && centerValue <= 0.5,
    00923              "pyramidExpandBurtFilter(): centerValue must be between 0.25 and 0.5.");
    00924
    00925     int wold = slr.x - sul.x;
    00926     int wnew = dlr.x - dul.x;
    00927     int hold = slr.y - sul.y;
    00928     int hnew = dlr.y - dul.y;
    00929
    00930     Rational<int> samplingRatio(2), offset(0);
    00931     resampling_detail::MapTargetToSourceCoordinate mapCoordinate(samplingRatio, offset);
    00932
    00933     ArrayVector<Kernel1D<double> > kernels(2);
    00934     kernels[0].initExplicitly(-1, 1) = 0.5 - centerValue, 2.0*centerValue, 0.5 - centerValue;
    00935     kernels[1].initExplicitly(-1, 0) = 0.5, 0.5;
    00936
    00937     typedef typename
    00938         NumericTraits<typename SrcAccessor::value_type>::RealPromote
    00939         TmpType;
    00940     typedef BasicImage<TmpType> TmpImage;
    00941     typedef typename TmpImage::traverser TmpIterator;
    00942
    00943     BasicImage<TmpType> tmp(wnew, hold);
    00944
    00945     TmpIterator tul = tmp.upperLeft();
    00946
    00947     for(; sul.y < slr.y; ++sul.y, ++tul.y)
    00948     {
    00949         typename SrcIterator::row_iterator sr = sul.rowIterator();
    00950         typename TmpIterator::row_iterator tr = tul.rowIterator();
    00951         // FIXME: replace with expandLineBurtFilter()
    00952         resamplingConvolveLine(sr, sr+wold, src, tr, tr+wnew, tmp.accessor(),
    00953                                kernels, mapCoordinate);
    00954     }
    00955
    00956     tul  = tmp.upperLeft();
    00957
    00958     for(; dul.x < dlr.x; ++dul.x, ++tul.x)
    00959     {
    00960         typename DestIterator::column_iterator dc = dul.columnIterator();
    00961         typename TmpIterator::column_iterator tc = tul.columnIterator();
    00962         resamplingConvolveLine(tc, tc+hold, tmp.accessor(), dc, dc+hnew, dest,
    00963                                kernels, mapCoordinate);
    00964     }
    00965 }
    00966
    00967 template <class SrcIterator, class SrcAccessor,
    00968           class DestIterator, class DestAccessor>
    00969 inline
    00970 void pyramidExpandBurtFilter(triple<SrcIterator, SrcIterator, SrcAccessor> src,
    00971                              triple<DestIterator, DestIterator, DestAccessor> dest,
    00972                              double centerValue = 0.4)
    00973 {
    00974     pyramidExpandBurtFilter(src.first, src.second, src.third,
    00975                             dest.first, dest.second, dest.third, centerValue);
    00976 }
    00977
    00978
    00979 template <class Image, class Alloc>
    00980 inline
    00981 void pyramidExpandBurtFilter(ImagePyramid<Image, Alloc> & pyramid, int fromLevel, int toLevel,
    00982                              double centerValue = 0.4)
    00983 {
    00984     vigra_precondition(fromLevel  > toLevel,
    00985        "pyramidExpandBurtFilter(): fromLevel must be larger than toLevel.");
    00986     vigra_precondition(pyramid.lowestLevel() <= toLevel && fromLevel <= pyramid.highestLevel(),
    00987        "pyramidExpandBurtFilter(): fromLevel and toLevel must be between the lowest and highest pyramid levels (inclusive).");
    00988
    00989     for(int i=fromLevel-1; i >= toLevel; --i)
    00990         pyramidExpandBurtFilter(srcImageRange(pyramid[i+1]), destImageRange(pyramid[i]), centerValue);
    00991 }
    00992
    00993 /** \brief Create a Laplacian pyramid.
    00994
    00995     Sorry, no \ref detailedDocumentation() available yet.
    00996
    00997     <b>\#include</b> <<a href="resampling__convolution_8hxx-source.html">vigra/resampling_convolution.hxx</a>><br>
    00998     Namespace: vigra
    00999 */
    01000 template <class Image, class Alloc>
    01001 inline
    01002 void pyramidReduceBurtLaplacian(ImagePyramid<Image, Alloc> & pyramid, int fromLevel, int toLevel,
    01003                              double centerValue = 0.4)
    01004 {
    01005     using namespace functor;
    01006
    01007     pyramidReduceBurtFilter(pyramid, fromLevel, toLevel, centerValue);
    01008     for(int i=fromLevel; i < toLevel; ++i)
    01009     {
    01010         typename ImagePyramid<Image, Alloc>::value_type tmpImage(pyramid[i].size());
    01011         pyramidExpandBurtFilter(srcImageRange(pyramid[i+1]), destImageRange(tmpImage), centerValue);
    01012         combineTwoImages(srcImageRange(tmpImage), srcImage(pyramid[i]), destImage(pyramid[i]),
    01013                        Arg1() - Arg2());
    01014     }
    01015 }
    01016
    01017 /** \brief Reconstruct a Laplacian pyramid.
    01018
    01019     Sorry, no \ref detailedDocumentation() available yet.
    01020
    01021     <b>\#include</b> <<a href="resampling__convolution_8hxx-source.html">vigra/resampling_convolution.hxx</a>><br>
    01022     Namespace: vigra
    01023 */
    01024 template <class Image, class Alloc>
    01025 inline
    01026 void pyramidExpandBurtLaplacian(ImagePyramid<Image, Alloc> & pyramid, int fromLevel, int toLevel,
    01027                                 double centerValue = 0.4)
    01028 {
    01029     using namespace functor;
    01030
    01031     vigra_precondition(fromLevel  > toLevel,
    01032        "pyramidExpandBurtLaplacian(): fromLevel must be larger than toLevel.");
    01033     vigra_precondition(pyramid.lowestLevel() <= toLevel && fromLevel <= pyramid.highestLevel(),
    01034        "pyramidExpandBurtLaplacian(): fromLevel and toLevel must be between the lowest and highest pyramid levels (inclusive).");
    01035
    01036     for(int i=fromLevel-1; i >= toLevel; --i)
    01037     {
    01038         typename ImagePyramid<Image, Alloc>::value_type tmpImage(pyramid[i].size());
    01039         pyramidExpandBurtFilter(srcImageRange(pyramid[i+1]), destImageRange(tmpImage), centerValue);
    01040         combineTwoImages(srcImageRange(tmpImage), srcImage(pyramid[i]), destImage(pyramid[i]),
    01041                        Arg1() - Arg2());
    01042     }
    01043 }
    01044
    01045 //@}
    01046
    01047 } // namespace vigra
    01048
    01049
    01050 #endif /* VIGRA_RESAMPLING_CONVOLUTION_HXX */

© Ullrich Köthe (ullrich.koethe@iwr.uni-heidelberg.de) Heidelberg Collaboratory for Image Processing, University of Heidelberg, Germany | html generated using doxygen and Python VIGRA 1.6.0 (13 Aug 2008)