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# vigra/resizeimage.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 /*                                                                      */
    00014 /*    Permission is hereby granted, free of charge, to any person       */
    00015 /*    obtaining a copy of this software and associated documentation    */
    00016 /*    files (the "Software"), to deal in the Software without           */
    00017 /*    restriction, including without limitation the rights to use,      */
    00018 /*    copy, modify, merge, publish, distribute, sublicense, and/or      */
    00019 /*    sell copies of the Software, and to permit persons to whom the    */
    00020 /*    Software is furnished to do so, subject to the following          */
    00021 /*    conditions:                                                       */
    00022 /*                                                                      */
    00023 /*    The above copyright notice and this permission notice shall be    */
    00024 /*    included in all copies or substantial portions of the             */
    00025 /*    Software.                                                         */
    00026 /*                                                                      */
    00027 /*    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND    */
    00028 /*    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES   */
    00029 /*    OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND          */
    00030 /*    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT       */
    00031 /*    HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,      */
    00032 /*    WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING      */
    00033 /*    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR     */
    00034 /*    OTHER DEALINGS IN THE SOFTWARE.                                   */
    00035 /*                                                                      */
    00036 /************************************************************************/
    00037
    00038
    00039 #ifndef VIGRA_RESIZEIMAGE_HXX
    00040 #define VIGRA_RESIZEIMAGE_HXX
    00041
    00042 #include <vector>
    00043 #include "utilities.hxx"
    00044 #include "numerictraits.hxx"
    00045 #include "stdimage.hxx"
    00046 #include "recursiveconvolution.hxx"
    00047 #include "separableconvolution.hxx"
    00048 #include "resampling_convolution.hxx"
    00049 #include "splines.hxx"
    00050
    00051 namespace vigra {
    00052
    00053 /*****************************************************************/
    00054 /*                                                               */
    00055 /*                         CoscotFunction                        */
    00056 /*                                                               */
    00057 /*****************************************************************/
    00058
    00059 /*! The Coscot interpolation function.
    00060
    00061     Implements the Coscot interpolation function proposed by Maria Magnusson Seger
    00062     (maria@isy.liu.se) in the context of tomographic reconstruction. It provides a fast
    00063     transition between the pass- and stop-bands and minimal ripple outside the transition
    00064     region. Both properties are important for this application and can be tuned by the parameters
    00065     <i>m</i> and <i>h</i> (with defaults 3 and 0.5). The function is defined by
    00066
    00067     \f[ f_{m,h}(x) = \left\{ \begin{array}{ll}
    00068                                    \frac{1}{2m}\sin(\pi x)\cot(\pi x / (2 m))(h + (1-h)\cos(\pi x/m)) & |x| \leq m \\
    00069                                   0 & \mbox{otherwise}
    00070                         \end{array}\right.
    00071     \f]
    00072
    00073     It can be used as a functor, and as a kernel for
    00074     \ref resamplingConvolveImage() to create a differentiable interpolant
    00075     of an image.
    00076
    00077     <b>\#include</b> <<a href="resizeimage_8hxx-source.html">vigra/resizeimage.hxx</a>><br>
    00078     Namespace: vigra
    00079
    00080     \ingroup MathFunctions
    00081 */
    00082 template <class T>
    00083 class CoscotFunction
    00084 {
    00085   public:
    00086
    00087         /** the kernel's value type
    00088         */
    00089     typedef T            value_type;
    00090         /** the unary functor's argument type
    00091         */
    00092     typedef T            argument_type;
    00093         /** the splines polynomial order
    00094         */
    00095     typedef T            result_type;
    00096
    00097     CoscotFunction(unsigned int m = 3, double h = 0.5)
    00098     : m_(m),
    00099       h_(h)
    00100     {}
    00101
    00102         /** function (functor) call
    00103         */
    00104     result_type operator()(argument_type x) const
    00105     {
    00106         return x == 0.0 ?
    00107                     1.0
    00108                   : abs(x) < m_ ?
    00109                         VIGRA_CSTD::sin(M_PI*x) / VIGRA_CSTD::tan(M_PI * x / 2.0 / m_) *
    00110                              (h_ + (1.0 - h_) * VIGRA_CSTD::cos(M_PI * x / m_)) / 2.0 / m_
    00111                       : 0.0;
    00112     }
    00113
    00114         /** index operator -- same as operator()
    00115         */
    00116     value_type operator[](value_type x) const
    00117         { return operator()(x); }
    00118
    00119         /** Radius of the function's support.
    00120             Needed for  \ref resamplingConvolveImage(), equals m.
    00121         */
    00122     double radius() const
    00123         { return m_; }
    00124
    00125         /** Derivative order of the function: always 0.
    00126         */
    00127     unsigned int derivativeOrder() const
    00128         { return 0; }
    00129
    00130         /** Prefilter coefficients for compatibility with \ref vigra::BSpline.
    00131             (array has zero length, since prefiltering is not necessary).
    00132         */
    00133     ArrayVector<double> const & prefilterCoefficients() const
    00134     {
    00135         static ArrayVector<double> b;
    00136         return b;
    00137     }
    00138
    00139   protected:
    00140
    00141     unsigned int m_;
    00142     double h_;
    00143 };
    00144
    00145 /** \addtogroup GeometricTransformations Geometric Transformations
    00146     Zoom up and down by repeating pixels, or using various interpolation schemes.
    00147
    00148     See also: \ref resamplingConvolveImage(), \ref resampleImage(), \ref resizeMultiArraySplineInterpolation()
    00149
    00150     <b>\#include</b> <<a href="stdimagefunctions_8hxx-source.html">vigra/stdimagefunctions.hxx</a>><br>
    00151     <b>or</b><br>
    00152     <b>\#include</b> <<a href="resizeimage_8hxx-source.html">vigra/resizeimage.hxx</a>><br>
    00153 */
    00154 //@{
    00155
    00156 /********************************************************/
    00157 /*                                                      */
    00158 /*               resizeLineNoInterpolation              */
    00159 /*                                                      */
    00160 /********************************************************/
    00161
    00162 template <class SrcIterator, class SrcAccessor,
    00163           class DestIterator, class DestAccessor>
    00164 void
    00165 resizeLineNoInterpolation(SrcIterator i1, SrcIterator iend, SrcAccessor as,
    00166                            DestIterator id, DestIterator idend, DestAccessor ad)
    00167 {
    00168     int wold = iend - i1;
    00169     int wnew = idend - id;
    00170
    00171     if((wold <= 1) || (wnew <= 1)) return; // oder error ?
    00172
    00173     ad.set(as(i1), id);
    00174     ++id;
    00175
    00176     --iend, --idend;
    00177     ad.set(as(iend), idend);
    00178
    00179     double dx = (double)(wold - 1) / (wnew - 1);
    00180     double x = dx;
    00181
    00182     for(; id != idend; ++id, x += dx)
    00183     {
    00184     if(x >= 1.0)
    00185     {
    00186         int xx = (int)x;
    00187         i1 += xx;
    00188         x -= (double)xx;
    00189     }
    00190
    00191     ad.set(as(i1), id);
    00192     }
    00193 }
    00194
    00195 /********************************************************/
    00196 /*                                                      */
    00197 /*              resizeImageNoInterpolation              */
    00198 /*                                                      */
    00199 /********************************************************/
    00200
    00201 /** \brief Resize image by repeating the nearest pixel values.
    00202
    00203     This algorithm is very fast and does not require any arithmetic on
    00204     the pixel types.
    00205
    00206     The range of both the input and output images (resp. regions) must
    00207     be given. Both images must have a size of at least 2x2 pixels. The
    00208     scaling factors are then calculated accordingly. Destination
    00209     pixels are directly copied from the appropriate source pixels.
    00210
    00211     The function uses accessors.
    00212
    00213     <b> Declarations:</b>
    00214
    00215     pass arguments explicitly:
    00216     \code
    00217     namespace vigra {
    00218         template <class SrcImageIterator, class SrcAccessor,
    00219                   class DestImageIterator, class DestAccessor>
    00220         void
    00221         resizeImageNoInterpolation(
    00222               SrcImageIterator is, SrcImageIterator iend, SrcAccessor sa,
    00223               DestImageIterator id, DestImageIterator idend, DestAccessor da)
    00224     }
    00225     \endcode
    00226
    00227
    00228     use argument objects in conjunction with \ref ArgumentObjectFactories :
    00229     \code
    00230     namespace vigra {
    00231         template <class SrcImageIterator, class SrcAccessor,
    00232                   class DestImageIterator, class DestAccessor>
    00233         void
    00234         resizeImageNoInterpolation(
    00235               triple<SrcImageIterator, SrcImageIterator, SrcAccessor> src,
    00236               triple<DestImageIterator, DestImageIterator, DestAccessor> dest)
    00237     }
    00238     \endcode
    00239
    00240     <b> Usage:</b>
    00241
    00242         <b>\#include</b> <<a href="resizeimage_8hxx-source.html">vigra/resizeimage.hxx</a>><br>
    00243         Namespace: vigra
    00244
    00245     \code
    00246     vigra::resizeImageNoInterpolation(
    00247                src.upperLeft(), src.lowerRight(), src.accessor(),
    00248                dest.upperLeft(), dest.lowerRight(), dest.accessor());
    00249
    00250     \endcode
    00251
    00252     <b> Required Interface:</b>
    00253
    00254     \code
    00255     SrcImageIterator src_upperleft, src_lowerright;
    00256     DestImageIterator dest_upperleft, src_lowerright;
    00257
    00258     SrcAccessor src_accessor;
    00259     DestAccessor dest_accessor;
    00260
    00261     dest_accessor.set(src_accessor(src_upperleft), dest_upperleft);
    00262
    00263     \endcode
    00264
    00265     <b> Preconditions:</b>
    00266
    00267     \code
    00268     src_lowerright.x - src_upperleft.x > 1
    00269     src_lowerright.y - src_upperleft.y > 1
    00270     dest_lowerright.x - dest_upperleft.x > 1
    00271     dest_lowerright.y - dest_upperleft.y > 1
    00272     \endcode
    00273
    00274 */
    00275 doxygen_overloaded_function(template <...> void resizeImageNoInterpolation)
    00276
    00277 template <class SrcIterator, class SrcAccessor,
    00278           class DestIterator, class DestAccessor>
    00279 void
    00280 resizeImageNoInterpolation(SrcIterator is, SrcIterator iend, SrcAccessor sa,
    00281                       DestIterator id, DestIterator idend, DestAccessor da)
    00282 {
    00283     int w = iend.x - is.x;
    00284     int h = iend.y - is.y;
    00285
    00286     int wnew = idend.x - id.x;
    00287     int hnew = idend.y - id.y;
    00288
    00289     vigra_precondition((w > 1) && (h > 1),
    00290                  "resizeImageNoInterpolation(): "
    00291                  "Source image to small.\n");
    00292     vigra_precondition((wnew > 1) && (hnew > 1),
    00293                  "resizeImageNoInterpolation(): "
    00294                  "Destination image to small.\n");
    00295
    00296     typedef BasicImage<typename SrcAccessor::value_type> TmpImage;
    00297     typedef typename TmpImage::traverser TmpImageIterator;
    00298
    00299     TmpImage tmp(w, hnew);
    00300
    00301     TmpImageIterator yt = tmp.upperLeft();
    00302
    00303     for(int x=0; x<w; ++x, ++is.x, ++yt.x)
    00304     {
    00305         typename SrcIterator::column_iterator c1 = is.columnIterator();
    00306         typename TmpImageIterator::column_iterator ct = yt.columnIterator();
    00307
    00308         resizeLineNoInterpolation(c1, c1 + h, sa, ct, ct + hnew, tmp.accessor());
    00309     }
    00310
    00311     yt = tmp.upperLeft();
    00312
    00313     for(int y=0; y < hnew; ++y, ++yt.y, ++id.y)
    00314     {
    00315         typename DestIterator::row_iterator rd = id.rowIterator();
    00316         typename TmpImageIterator::row_iterator rt = yt.rowIterator();
    00317
    00318         resizeLineNoInterpolation(rt, rt + w, tmp.accessor(), rd, rd + wnew, da);
    00319     }
    00320 }
    00321
    00322 template <class SrcIterator, class SrcAccessor,
    00323           class DestIterator, class DestAccessor>
    00324 inline
    00325 void
    00326 resizeImageNoInterpolation(triple<SrcIterator, SrcIterator, SrcAccessor> src,
    00327                            triple<DestIterator, DestIterator, DestAccessor> dest)
    00328 {
    00329     resizeImageNoInterpolation(src.first, src.second, src.third,
    00330                                    dest.first, dest.second, dest.third);
    00331 }
    00332
    00333 /********************************************************/
    00334 /*                                                      */
    00335 /*             resizeLineLinearInterpolation            */
    00336 /*                                                      */
    00337 /********************************************************/
    00338
    00339 template <class SrcIterator, class SrcAccessor,
    00340           class DestIterator, class DestAccessor>
    00341 void
    00342 resizeLineLinearInterpolation(SrcIterator i1, SrcIterator iend, SrcAccessor as,
    00343                            DestIterator id, DestIterator idend, DestAccessor ad)
    00344 {
    00345     int wold = iend - i1;
    00346     int wnew = idend - id;
    00347
    00348     if((wold <= 1) || (wnew <= 1)) return; // oder error ?
    00349
    00350     typedef
    00351         NumericTraits<typename DestAccessor::value_type> DestTraits;
    00352
    00353     ad.set(DestTraits::fromRealPromote(as(i1)), id);
    00354     ++id;
    00355
    00356     --iend, --idend;
    00357     ad.set(DestTraits::fromRealPromote(as(iend)), idend);
    00358
    00359     double dx = (double)(wold - 1) / (wnew - 1);
    00360     double x = dx;
    00361
    00362     for(; id != idend; ++id, x += dx)
    00363     {
    00364         if(x >= 1.0)
    00365         {
    00366             int xx = (int)x;
    00367             i1 += xx;
    00368             x -= (double)xx;
    00369         }
    00370         double x1 = 1.0 - x;
    00371
    00372         ad.set(DestTraits::fromRealPromote(x1 * as(i1) + x * as(i1, 1)), id);
    00373     }
    00374 }
    00375
    00376 /********************************************************/
    00377 /*                                                      */
    00378 /*           resizeImageLinearInterpolation             */
    00379 /*                                                      */
    00380 /********************************************************/
    00381
    00382 /** \brief Resize image using linear interpolation.
    00383
    00384     The function uses the standard separable bilinear interpolation algorithm to
    00385     obtain a good compromize between quality and speed.
    00386
    00387     The range must of both the input and output images (resp. regions)
    00388     must be given. Both images must have a size of at
    00389     least 2x2. The scaling factors are then calculated
    00390     accordingly. If the source image is larger than the destination, it
    00391     is smoothed (band limited) using a recursive
    00392     exponential filter. The source value_type (SrcAccessor::value_type) must
    00393     be a linear space, i.e. it must support addition, multiplication
    00394     with a scalar real number and \ref NumericTraits "NumericTraits".
    00395     The function uses accessors.
    00396
    00397     <b> Declarations:</b>
    00398
    00399     pass arguments explicitly:
    00400     \code
    00401     namespace vigra {
    00402         template <class SrcImageIterator, class SrcAccessor,
    00403                   class DestImageIterator, class DestAccessor>
    00404         void
    00405         resizeImageLinearInterpolation(
    00406               SrcImageIterator is, SrcImageIterator iend, SrcAccessor sa,
    00407               DestImageIterator id, DestImageIterator idend, DestAccessor da)
    00408     }
    00409     \endcode
    00410
    00411
    00412     use argument objects in conjunction with \ref ArgumentObjectFactories :
    00413     \code
    00414     namespace vigra {
    00415         template <class SrcImageIterator, class SrcAccessor,
    00416                   class DestImageIterator, class DestAccessor>
    00417         void
    00418         resizeImageLinearInterpolation(
    00419               triple<SrcImageIterator, SrcImageIterator, SrcAccessor> src,
    00420               triple<DestImageIterator, DestImageIterator, DestAccessor> dest)
    00421     }
    00422     \endcode
    00423
    00424     <b> Usage:</b>
    00425
    00426         <b>\#include</b> <<a href="resizeimage_8hxx-source.html">vigra/resizeimage.hxx</a>><br>
    00427         Namespace: vigra
    00428
    00429     \code
    00430     vigra::resizeImageLinearInterpolation(
    00431                src.upperLeft(), src.lowerRight(), src.accessor(),
    00432                dest.upperLeft(), dest.lowerRight(), dest.accessor());
    00433
    00434     \endcode
    00435
    00436     <b> Required Interface:</b>
    00437
    00438     \code
    00439     SrcImageIterator src_upperleft, src_lowerright;
    00440     DestImageIterator dest_upperleft, src_lowerright;
    00441
    00442     SrcAccessor src_accessor;
    00443     DestAccessor dest_accessor;
    00444
    00445     NumericTraits<SrcAccessor::value_type>::RealPromote
    00446                              u = src_accessor(src_upperleft),
    00447                  v = src_accessor(src_upperleft, 1);
    00448     double d;
    00449
    00450     u = d * v;
    00451     u = u + v;
    00452
    00453     dest_accessor.set(
    00454         NumericTraits<DestAccessor::value_type>::fromRealPromote(u),
    00455     dest_upperleft);
    00456
    00457     \endcode
    00458
    00459     <b> Preconditions:</b>
    00460
    00461     \code
    00462     src_lowerright.x - src_upperleft.x > 1
    00463     src_lowerright.y - src_upperleft.y > 1
    00464     dest_lowerright.x - dest_upperleft.x > 1
    00465     dest_lowerright.y - dest_upperleft.y > 1
    00466     \endcode
    00467
    00468 */
    00469 doxygen_overloaded_function(template <...> void resizeImageLinearInterpolation)
    00470
    00471 template <class SrcIterator, class SrcAccessor,
    00472           class DestIterator, class DestAccessor>
    00473 void
    00474 resizeImageLinearInterpolation(SrcIterator is, SrcIterator iend, SrcAccessor sa,
    00475                       DestIterator id, DestIterator idend, DestAccessor da)
    00476 {
    00477     int w = iend.x - is.x;
    00478     int h = iend.y - is.y;
    00479
    00480     int wnew = idend.x - id.x;
    00481     int hnew = idend.y - id.y;
    00482
    00483     vigra_precondition((w > 1) && (h > 1),
    00484                  "resizeImageLinearInterpolation(): "
    00485                  "Source image to small.\n");
    00486     vigra_precondition((wnew > 1) && (hnew > 1),
    00487                  "resizeImageLinearInterpolation(): "
    00488                  "Destination image to small.\n");
    00489
    00490     double const scale = 2.0;
    00491
    00492     typedef typename SrcAccessor::value_type SRCVT;
    00493     typedef typename NumericTraits<SRCVT>::RealPromote TMPTYPE;
    00494     typedef BasicImage<TMPTYPE> TmpImage;
    00495     typedef typename TmpImage::traverser TmpImageIterator;
    00496
    00497     BasicImage<TMPTYPE> tmp(w, hnew);
    00498     BasicImage<TMPTYPE> line((h > w) ? h : w, 1);
    00499
    00500     int x,y;
    00501
    00502     typename BasicImage<TMPTYPE>::Iterator yt = tmp.upperLeft();
    00503     typename TmpImageIterator::row_iterator lt = line.upperLeft().rowIterator();
    00504
    00505     for(x=0; x<w; ++x, ++is.x, ++yt.x)
    00506     {
    00507         typename SrcIterator::column_iterator c1 = is.columnIterator();
    00508         typename TmpImageIterator::column_iterator ct = yt.columnIterator();
    00509
    00510         if(hnew < h)
    00511         {
    00512             recursiveSmoothLine(c1, c1 + h, sa,
    00513                  lt, line.accessor(), (double)h/hnew/scale);
    00514
    00515             resizeLineLinearInterpolation(lt, lt + h, line.accessor(),
    00516                                           ct, ct + hnew, tmp.accessor());
    00517         }
    00518         else
    00519         {
    00520             resizeLineLinearInterpolation(c1, c1 + h, sa,
    00521                                           ct, ct + hnew, tmp.accessor());
    00522         }
    00523     }
    00524
    00525     yt = tmp.upperLeft();
    00526
    00527     for(y=0; y < hnew; ++y, ++yt.y, ++id.y)
    00528     {
    00529         typename DestIterator::row_iterator rd = id.rowIterator();
    00530         typename TmpImageIterator::row_iterator rt = yt.rowIterator();
    00531
    00532         if(wnew < w)
    00533         {
    00534             recursiveSmoothLine(rt, rt + w, tmp.accessor(),
    00535                               lt, line.accessor(), (double)w/wnew/scale);
    00536
    00537             resizeLineLinearInterpolation(lt, lt + w, line.accessor(),
    00538                                           rd, rd + wnew, da);
    00539         }
    00540         else
    00541         {
    00542             resizeLineLinearInterpolation(rt, rt + w, tmp.accessor(),
    00543                                           rd, rd + wnew, da);
    00544         }
    00545     }
    00546 }
    00547
    00548 template <class SrcIterator, class SrcAccessor,
    00549           class DestIterator, class DestAccessor>
    00550 inline
    00551 void
    00552 resizeImageLinearInterpolation(triple<SrcIterator, SrcIterator, SrcAccessor> src,
    00553                                triple<DestIterator, DestIterator, DestAccessor> dest)
    00554 {
    00555     resizeImageLinearInterpolation(src.first, src.second, src.third,
    00556                                    dest.first, dest.second, dest.third);
    00557 }
    00558
    00559 /***************************************************************/
    00560 /*                                                             */
    00561 /*                resizeImageSplineInterpolation               */
    00562 /*                                                             */
    00563 /***************************************************************/
    00564
    00565 /** \brief Resize image using B-spline interpolation.
    00566
    00567     The function implements separable spline interpolation algorithm described in
    00568
    00569     M. Unser, A. Aldroubi, M. Eden, <i>"B-Spline Signal Processing"</i>
    00570     IEEE Transactions on Signal Processing, vol. 41, no. 2, pp. 821-833 (part I),
    00571     pp. 834-848 (part II), 1993.
    00572
    00573     to obtain optimal interpolation quality and speed. You may pass the funcion
    00574     a spline of arbitrary order (e.g. <TT>BSpline<ORDER, double></tt> or
    00575     <TT>CatmullRomSpline<double></tt>). The default is a third order spline
    00576     which gives a twice continuously differentiable interpolant.
    00577     The implementation ensures that image values are interpolated rather
    00578     than smoothed by first calling a recursive (sharpening) prefilter as
    00579     described in the above paper. Then the actual interpolation is done
    00580     using \ref resamplingConvolveLine().
    00581
    00582     The range of both the input and output images (resp. regions)
    00583     must be given. The input image must have a size of at
    00584     least 4x4, the destination of at least 2x2. The scaling factors are then calculated
    00585     accordingly. If the source image is larger than the destination, it
    00586     is smoothed (band limited) using a recursive
    00587     exponential filter. The source value_type (SrcAccessor::value_type) must
    00588     be a linear algebra, i.e. it must support addition, subtraction,
    00589     and multiplication (+, -, *), multiplication with a scalar
    00590     real number and \ref NumericTraits "NumericTraits".
    00591     The function uses accessors.
    00592
    00593     <b> Declarations:</b>
    00594
    00595     pass arguments explicitly:
    00596     \code
    00597     namespace vigra {
    00598         template <class SrcImageIterator, class SrcAccessor,
    00599                   class DestImageIterator, class DestAccessor,
    00600                   class SPLINE>
    00601         void
    00602         resizeImageSplineInterpolation(
    00603               SrcImageIterator is, SrcImageIterator iend, SrcAccessor sa,
    00604               DestImageIterator id, DestImageIterator idend, DestAccessor da,
    00605               SPLINE spline = BSpline<3, double>())
    00606     }
    00607     \endcode
    00608
    00609
    00610     use argument objects in conjunction with \ref ArgumentObjectFactories :
    00611     \code
    00612     namespace vigra {
    00613         template <class SrcImageIterator, class SrcAccessor,
    00614                   class DestImageIterator, class DestAccessor,
    00615                   class SPLINE>
    00616         void
    00617         resizeImageSplineInterpolation(
    00618               triple<SrcImageIterator, SrcImageIterator, SrcAccessor> src,
    00619               triple<DestImageIterator, DestImageIterator, DestAccessor> dest,
    00620               SPLINE spline = BSpline<3, double>())
    00621     }
    00622     \endcode
    00623
    00624     <b> Usage:</b>
    00625
    00626         <b>\#include</b> <<a href="resizeimage_8hxx-source.html">vigra/resizeimage.hxx</a>><br>
    00627         Namespace: vigra
    00628
    00629     \code
    00630     vigra::resizeImageSplineInterpolation(
    00631                src.upperLeft(), src.lowerRight(), src.accessor(),
    00632                dest.upperLeft(), dest.lowerRight(), dest.accessor());
    00633
    00634     \endcode
    00635
    00636     <b> Required Interface:</b>
    00637
    00638     \code
    00639     SrcImageIterator src_upperleft, src_lowerright;
    00640     DestImageIterator dest_upperleft, src_lowerright;
    00641
    00642     SrcAccessor src_accessor;
    00643     DestAccessor dest_accessor;
    00644
    00645     NumericTraits<SrcAccessor::value_type>::RealPromote
    00646                              u = src_accessor(src_upperleft),
    00647                  v = src_accessor(src_upperleft, 1);
    00648     double d;
    00649
    00650     u = d * v;
    00651     u = u + v;
    00652     u = u - v;
    00653     u = u * v;
    00654     u += v;
    00655     u -= v;
    00656
    00657     dest_accessor.set(
    00658         NumericTraits<DestAccessor::value_type>::fromRealPromote(u),
    00659     dest_upperleft);
    00660
    00661     \endcode
    00662
    00663     <b> Preconditions:</b>
    00664
    00665     \code
    00666     src_lowerright.x - src_upperleft.x > 3
    00667     src_lowerright.y - src_upperleft.y > 3
    00668     dest_lowerright.x - dest_upperleft.x > 1
    00669     dest_lowerright.y - dest_upperleft.y > 1
    00670     \endcode
    00671
    00672 */
    00673 doxygen_overloaded_function(template <...> void resizeImageSplineInterpolation)
    00674
    00675 template <class SrcIterator, class SrcAccessor,
    00676           class DestIterator, class DestAccessor,
    00677           class SPLINE>
    00678 void
    00679 resizeImageSplineInterpolation(
    00680     SrcIterator src_iter, SrcIterator src_iter_end, SrcAccessor src_acc,
    00681     DestIterator dest_iter, DestIterator dest_iter_end, DestAccessor dest_acc,
    00682     SPLINE const & spline)
    00683 {
    00684
    00685     int width_old = src_iter_end.x - src_iter.x;
    00686     int height_old = src_iter_end.y - src_iter.y;
    00687
    00688     int width_new = dest_iter_end.x - dest_iter.x;
    00689     int height_new = dest_iter_end.y - dest_iter.y;
    00690
    00691     vigra_precondition((width_old > 1) && (height_old > 1),
    00692                  "resizeImageSplineInterpolation(): "
    00693                  "Source image to small.\n");
    00694
    00695     vigra_precondition((width_new > 1) && (height_new > 1),
    00696                  "resizeImageSplineInterpolation(): "
    00697                  "Destination image to small.\n");
    00698
    00699     Rational<int> xratio(width_new - 1, width_old - 1);
    00700     Rational<int> yratio(height_new - 1, height_old - 1);
    00701     Rational<int> offset(0);
    00702     resampling_detail::MapTargetToSourceCoordinate xmapCoordinate(xratio, offset);
    00703     resampling_detail::MapTargetToSourceCoordinate ymapCoordinate(yratio, offset);
    00704     int xperiod = lcm(xratio.numerator(), xratio.denominator());
    00705     int yperiod = lcm(yratio.numerator(), yratio.denominator());
    00706
    00707     double const scale = 2.0;
    00708
    00709     typedef typename SrcAccessor::value_type SRCVT;
    00710     typedef typename NumericTraits<SRCVT>::RealPromote TMPTYPE;
    00711     typedef BasicImage<TMPTYPE> TmpImage;
    00712     typedef typename TmpImage::traverser TmpImageIterator;
    00713
    00714     BasicImage<TMPTYPE> tmp(width_old, height_new);
    00715
    00716     BasicImage<TMPTYPE> line((height_old > width_old) ? height_old : width_old, 1);
    00717     typename BasicImage<TMPTYPE>::Accessor tmp_acc = tmp.accessor();
    00718     ArrayVector<double> const & prefilterCoeffs = spline.prefilterCoefficients();
    00719
    00720     int x,y;
    00721
    00722     ArrayVector<Kernel1D<double> > kernels(yperiod);
    00723     createResamplingKernels(spline, ymapCoordinate, kernels);
    00724
    00725     typename BasicImage<TMPTYPE>::Iterator y_tmp = tmp.upperLeft();
    00726     typename TmpImageIterator::row_iterator line_tmp = line.upperLeft().rowIterator();
    00727
    00728     for(x=0; x<width_old; ++x, ++src_iter.x, ++y_tmp.x)
    00729     {
    00730
    00731         typename SrcIterator::column_iterator c_src = src_iter.columnIterator();
    00732         typename TmpImageIterator::column_iterator c_tmp = y_tmp.columnIterator();
    00733
    00734         if(prefilterCoeffs.size() == 0)
    00735         {
    00736             if(height_new >= height_old)
    00737             {
    00738                 resamplingConvolveLine(c_src, c_src + height_old, src_acc,
    00739                                        c_tmp, c_tmp + height_new, tmp_acc,
    00740                                        kernels, ymapCoordinate);
    00741             }
    00742             else
    00743             {
    00744                 recursiveSmoothLine(c_src, c_src + height_old, src_acc,
    00745                      line_tmp, line.accessor(), (double)height_old/height_new/scale);
    00746                 resamplingConvolveLine(line_tmp, line_tmp + height_old, line.accessor(),
    00747                                        c_tmp, c_tmp + height_new, tmp_acc,
    00748                                        kernels, ymapCoordinate);
    00749             }
    00750         }
    00751         else
    00752         {
    00753             recursiveFilterLine(c_src, c_src + height_old, src_acc,
    00754                                 line_tmp, line.accessor(),
    00755                                 prefilterCoeffs[0], BORDER_TREATMENT_REFLECT);
    00756             for(unsigned int b = 1; b < prefilterCoeffs.size(); ++b)
    00757             {
    00758                 recursiveFilterLine(line_tmp, line_tmp + height_old, line.accessor(),
    00759                                     line_tmp, line.accessor(),
    00760                                     prefilterCoeffs[b], BORDER_TREATMENT_REFLECT);
    00761             }
    00762             if(height_new < height_old)
    00763             {
    00764                 recursiveSmoothLine(line_tmp, line_tmp + height_old, line.accessor(),
    00765                      line_tmp, line.accessor(), (double)height_old/height_new/scale);
    00766             }
    00767             resamplingConvolveLine(line_tmp, line_tmp + height_old, line.accessor(),
    00768                                    c_tmp, c_tmp + height_new, tmp_acc,
    00769                                    kernels, ymapCoordinate);
    00770         }
    00771     }
    00772
    00773     y_tmp = tmp.upperLeft();
    00774
    00775     DestIterator dest = dest_iter;
    00776
    00777     kernels.resize(xperiod);
    00778     createResamplingKernels(spline, xmapCoordinate, kernels);
    00779
    00780     for(y=0; y < height_new; ++y, ++y_tmp.y, ++dest_iter.y)
    00781     {
    00782         typename DestIterator::row_iterator r_dest = dest_iter.rowIterator();
    00783         typename TmpImageIterator::row_iterator r_tmp = y_tmp.rowIterator();
    00784
    00785         if(prefilterCoeffs.size() == 0)
    00786         {
    00787             if(width_new >= width_old)
    00788             {
    00789                 resamplingConvolveLine(r_tmp, r_tmp + width_old, tmp.accessor(),
    00790                                        r_dest, r_dest + width_new, dest_acc,
    00791                                        kernels, xmapCoordinate);
    00792             }
    00793             else
    00794             {
    00795                 recursiveSmoothLine(r_tmp, r_tmp + width_old, tmp.accessor(),
    00796                                   line_tmp, line.accessor(), (double)width_old/width_new/scale);
    00797                 resamplingConvolveLine(line_tmp, line_tmp + width_old, line.accessor(),
    00798                                        r_dest, r_dest + width_new, dest_acc,
    00799                                        kernels, xmapCoordinate);
    00800             }
    00801         }
    00802         else
    00803         {
    00804             recursiveFilterLine(r_tmp, r_tmp + width_old, tmp.accessor(),
    00805                                 line_tmp, line.accessor(),
    00806                                 prefilterCoeffs[0], BORDER_TREATMENT_REFLECT);
    00807             for(unsigned int b = 1; b < prefilterCoeffs.size(); ++b)
    00808             {
    00809                 recursiveFilterLine(line_tmp, line_tmp + width_old, line.accessor(),
    00810                                     line_tmp, line.accessor(),
    00811                                     prefilterCoeffs[b], BORDER_TREATMENT_REFLECT);
    00812             }
    00813             if(width_new < width_old)
    00814             {
    00815                 recursiveSmoothLine(line_tmp, line_tmp + width_old, line.accessor(),
    00816                                     line_tmp, line.accessor(), (double)width_old/width_new/scale);
    00817             }
    00818             resamplingConvolveLine(line_tmp, line_tmp + width_old, line.accessor(),
    00819                                    r_dest, r_dest + width_new, dest_acc,
    00820                                    kernels, xmapCoordinate);
    00821         }
    00822     }
    00823 }
    00824
    00825 template <class SrcIterator, class SrcAccessor,
    00826           class DestIterator, class DestAccessor,
    00827           class SPLINE>
    00828 inline
    00829 void
    00830 resizeImageSplineInterpolation(triple<SrcIterator, SrcIterator, SrcAccessor> src,
    00831                       triple<DestIterator, DestIterator, DestAccessor> dest,
    00832                       SPLINE const & spline)
    00833 {
    00834     resizeImageSplineInterpolation(src.first, src.second, src.third,
    00835                                    dest.first, dest.second, dest.third, spline);
    00836 }
    00837
    00838 template <class SrcIterator, class SrcAccessor,
    00839           class DestIterator, class DestAccessor>
    00840 void
    00841 resizeImageSplineInterpolation(SrcIterator is, SrcIterator iend, SrcAccessor sa,
    00842                       DestIterator id, DestIterator idend, DestAccessor da)
    00843 {
    00844     resizeImageSplineInterpolation(is, iend, sa, id, idend, da, BSpline<3, double>());
    00845 }
    00846
    00847 template <class SrcIterator, class SrcAccessor,
    00848           class DestIterator, class DestAccessor>
    00849 inline
    00850 void
    00851 resizeImageSplineInterpolation(triple<SrcIterator, SrcIterator, SrcAccessor> src,
    00852                       triple<DestIterator, DestIterator, DestAccessor> dest)
    00853 {
    00854     resizeImageSplineInterpolation(src.first, src.second, src.third,
    00855                                    dest.first, dest.second, dest.third);
    00856 }
    00857
    00858 /*****************************************************************/
    00859 /*                                                               */
    00860 /*              resizeImageCatmullRomInterpolation               */
    00861 /*                                                               */
    00862 /*****************************************************************/
    00863
    00864 /** \brief Resize image using the Catmull/Rom interpolation function.
    00865
    00866     The function calls like \ref resizeImageSplineInterpolation() with
    00867     \ref vigra::CatmullRomSpline as an interpolation kernel.
    00868     The interpolated function has one continuous derivative.
    00869     (See \ref resizeImageSplineInterpolation() for more documentation)
    00870
    00871     <b> Declarations:</b>
    00872
    00873     pass arguments explicitly:
    00874     \code
    00875     namespace vigra {
    00876         template <class SrcIterator, class SrcAccessor,
    00877                   class DestIterator, class DestAccessor>
    00878         void
    00879         resizeImageCatmullRomInterpolation(SrcIterator src_iter, SrcIterator src_iter_end, SrcAccessor src_acc,
    00880                               DestIterator dest_iter, DestIterator dest_iter_end, DestAccessor dest_acc);
    00881     }
    00882     \endcode
    00883
    00884
    00885     use argument objects in conjunction with \ref ArgumentObjectFactories :
    00886     \code
    00887     namespace vigra {
    00888         template <class SrcIterator, class SrcAccessor,
    00889                   class DestIterator, class DestAccessor>
    00890         void
    00891         resizeImageCatmullRomInterpolation(triple<SrcIterator, SrcIterator, SrcAccessor> src,
    00892                               triple<DestIterator, DestIterator, DestAccessor> dest);
    00893     }
    00894     \endcode
    00895
    00896
    00897     <b>\#include</b> <<a href="resizeimage_8hxx-source.html">vigra/resizeimage.hxx</a>><br>
    00898     Namespace: vigra
    00899
    00900 */
    00901 doxygen_overloaded_function(template <...> void resizeImageCatmullRomInterpolation)
    00902
    00903 template <class SrcIterator, class SrcAccessor,
    00904           class DestIterator, class DestAccessor>
    00905 inline void
    00906 resizeImageCatmullRomInterpolation(SrcIterator src_iter, SrcIterator src_iter_end, SrcAccessor src_acc,
    00907                       DestIterator dest_iter, DestIterator dest_iter_end, DestAccessor dest_acc)
    00908 {
    00909     resizeImageSplineInterpolation(src_iter, src_iter_end, src_acc, dest_iter, dest_iter_end, dest_acc,
    00910                                   CatmullRomSpline<double>());
    00911 }
    00912
    00913 template <class SrcIterator, class SrcAccessor,
    00914           class DestIterator, class DestAccessor>
    00915 inline
    00916 void
    00917 resizeImageCatmullRomInterpolation(triple<SrcIterator, SrcIterator, SrcAccessor> src,
    00918                       triple<DestIterator, DestIterator, DestAccessor> dest)
    00919 {
    00920     resizeImageCatmullRomInterpolation(src.first, src.second, src.third,
    00921                                      dest.first, dest.second, dest.third);
    00922 }
    00923
    00924 #if 0
    00925 /*****************************************************************/
    00926 /*                                                               */
    00927 /*              resizeImageCubicInterpolation                    */
    00928 /*                                                               */
    00929 /*****************************************************************/
    00930
    00931 /** \brief Resize image using the cardinal B-spline interpolation function.
    00932
    00933     The function calls like \ref resizeImageSplineInterpolation() with
    00934     \ref vigra::BSpline<3, double> and prefiltering as an interpolation kernel.
    00935     The interpolated function has two continuous derivatives.
    00936     (See \ref resizeImageSplineInterpolation() for more documentation)
    00937
    00938     <b>\#include</b> <<a href="resizeimage_8hxx-source.html">vigra/resizeimage.hxx</a>><br>
    00939     Namespace: vigra
    00940
    00941 */
    00942 template <class SrcIterator, class SrcAccessor,
    00943           class DestIterator, class DestAccessor>
    00944 void
    00945 resizeImageCubicInterpolation(SrcIterator src_iter, SrcIterator src_iter_end, SrcAccessor src_acc,
    00946                       DestIterator dest_iter, DestIterator dest_iter_end, DestAccessor dest_acc)
    00947 {
    00948     resizeImageSplineInterpolation(src_iter, src_iter_end, src_acc, dest_iter, dest_iter_end, dest_acc,
    00949                                   BSpline<3, double>());
    00950 }
    00951
    00952 template <class SrcIterator, class SrcAccessor,
    00953           class DestIterator, class DestAccessor>
    00954 inline
    00955 void
    00956 resizeImageCubicInterpolation(triple<SrcIterator, SrcIterator, SrcAccessor> src,
    00957                       triple<DestIterator, DestIterator, DestAccessor> dest)
    00958 {
    00959     resizeImageCubicInterpolation(src.first, src.second, src.third,
    00960                                    dest.first, dest.second, dest.third);
    00961 }
    00962 #endif
    00963
    00964 /*****************************************************************/
    00965 /*                                                               */
    00966 /*              resizeImageCoscotInterpolation                   */
    00967 /*                                                               */
    00968 /*****************************************************************/
    00969
    00970 /** \brief Resize image using the Coscot interpolation function.
    00971
    00972     The function calls \ref resizeImageSplineInterpolation() with
    00973     \ref vigra::CoscotFunction as an interpolation kernel.
    00974     The interpolated function has one continuous derivative.
    00975     (See \ref resizeImageSplineInterpolation() for more documentation)
    00976
    00977     <b> Declarations:</b>
    00978
    00979     pass arguments explicitly:
    00980     \code
    00981     namespace vigra {
    00982         template <class SrcIterator, class SrcAccessor,
    00983                   class DestIterator, class DestAccessor>
    00984         void
    00985         resizeImageCoscotInterpolation(SrcIterator src_iter, SrcIterator src_iter_end, SrcAccessor src_acc,
    00986                               DestIterator dest_iter, DestIterator dest_iter_end, DestAccessor dest_acc);
    00987     }
    00988     \endcode
    00989
    00990
    00991     use argument objects in conjunction with \ref ArgumentObjectFactories :
    00992     \code
    00993     namespace vigra {
    00994         template <class SrcIterator, class SrcAccessor,
    00995                   class DestIterator, class DestAccessor>
    00996         void
    00997         resizeImageCoscotInterpolation(triple<SrcIterator, SrcIterator, SrcAccessor> src,
    00998                               triple<DestIterator, DestIterator, DestAccessor> dest);
    00999     }
    01000     \endcode
    01001
    01002
    01003     <b>\#include</b> <<a href="resizeimage_8hxx-source.html">vigra/resizeimage.hxx</a>><br>
    01004     Namespace: vigra
    01005
    01006 */
    01007 doxygen_overloaded_function(template <...> void resizeImageCoscotInterpolation)
    01008
    01009 template <class SrcIterator, class SrcAccessor,
    01010           class DestIterator, class DestAccessor>
    01011 void
    01012 resizeImageCoscotInterpolation(SrcIterator src_iter, SrcIterator src_iter_end, SrcAccessor src_acc,
    01013                       DestIterator dest_iter, DestIterator dest_iter_end, DestAccessor dest_acc)
    01014 {
    01015     resizeImageSplineInterpolation(src_iter, src_iter_end, src_acc, dest_iter, dest_iter_end, dest_acc,
    01016                                    CoscotFunction<double>());
    01017 }
    01018
    01019 template <class SrcIterator, class SrcAccessor,
    01020           class DestIterator, class DestAccessor>
    01021 inline
    01022 void
    01023 resizeImageCoscotInterpolation(triple<SrcIterator, SrcIterator, SrcAccessor> src,
    01024                       triple<DestIterator, DestIterator, DestAccessor> dest)
    01025 {
    01026     resizeImageCoscotInterpolation(src.first, src.second, src.third,
    01027                                    dest.first, dest.second, dest.third);
    01028 }
    01029
    01030
    01031 #if 0 // old version of the spline interpolation algorithm
    01032
    01033 /********************************************************/
    01034 /*                                                      */
    01035 /*           resizeCalculateSplineCoefficients          */
    01036 /*         (internally used by resize functions)        */
    01037 /*                                                      */
    01038 /********************************************************/
    01039
    01040 template <class SrcIterator, class SrcAccessor, class VALUETYPE>
    01041 void
    01042 resizeCalculateSplineCoefficients(SrcIterator i1, SrcIterator iend,
    01043                 SrcAccessor a, VALUETYPE * i2)
    01044 {
    01045     int n = iend - i1;
    01046
    01047     if(n <= 0) return;
    01048
    01049     VALUETYPE zero = NumericTraits<VALUETYPE>::zero();
    01050     VALUETYPE two = 2.0 * NumericTraits<VALUETYPE>::one();
    01051     VALUETYPE half = 0.5 * NumericTraits<VALUETYPE>::one();
    01052
    01053     *i2 = zero;
    01054     if(n == 1) return;
    01055
    01056     std::vector<VALUETYPE> vec(n);
    01057     typename std::vector<VALUETYPE>::iterator u = vec.begin();
    01058
    01059     *u = zero;
    01060
    01061     for(++i1, ++i2, ++u, --iend; i1 != iend; ++i1, ++i2, ++u)
    01062     {
    01063         VALUETYPE p = 0.5 * i2[-1] + two;
    01064         *i2 = half / p;
    01065         *u = 3.0 *(a(i1,1) - 2.0 * a(i1) + a(i1, -1)) - 0.5 * u[-1] / p;
    01066     }
    01067
    01068     *i2 = zero;
    01069
    01070     for(--i2, --u; u != vec; --u, --i2)
    01071     {
    01072         *i2 = *i2 * i2[1] + *u;
    01073     }
    01074 }
    01075
    01076 /********************************************************/
    01077 /*                                                      */
    01078 /*         resizeImageInternalSplineGradient            */
    01079 /*                                                      */
    01080 /********************************************************/
    01081
    01082 template <class SrcIterator, class SrcAccessor,
    01083           class DoubleIterator, class TempIterator, class DestIterator>
    01084 void
    01085 resizeImageInternalSplineGradient(SrcIterator in, SrcIterator inend, SrcAccessor sa,
    01086                          DoubleIterator tmp, TempIterator r, DestIterator id)
    01087 {
    01088     int w = inend - in;
    01089
    01090     int x;
    01091
    01092     typedef typename SrcAccessor::value_type SRCVT;
    01093     typedef typename NumericTraits<SRCVT>::RealPromote TMPTYPE;
    01094
    01095     // calculate border derivatives
    01096     SrcIterator xs = in;
    01097     TMPTYPE p0 = -11.0/6.0 * sa(xs);  ++xs;
    01098             p0 += 3.0 * sa(xs);  ++xs;
    01099             p0 += -1.5 * sa(xs);  ++xs;
    01100             p0 += 1.0/3.0 * sa(xs);
    01101
    01102     xs = in + w-1;
    01103     TMPTYPE pw = 11.0/6.0 * sa(xs);  --xs;
    01104             pw += -3.0 * sa(xs);  --xs;
    01105             pw +=  1.5 * sa(xs);  --xs;
    01106             pw += -1.0/3.0 * sa(xs);
    01107
    01108     xs = in + 2;
    01109     SrcIterator xs1 = in;
    01110
    01111     for(x=1; x<w-1; ++x, ++xs, ++xs1)
    01112     {
    01113         r[x] = 3.0 * (sa(xs) - sa(xs1));
    01114     }
    01115
    01116     r[1] -= p0;
    01117     r[w-2] -= pw;
    01118
    01119     double q = 0.25;
    01120
    01121     id[0] = p0;
    01122     id[w-1] = pw;
    01123     id[1] = 0.25 * r[1];
    01124
    01125     for(x=2; x<w-1; ++x)
    01126     {
    01127         tmp[x] = q;
    01128         q = 1.0 / (4.0 - q);
    01129         id[x] = q * (r[x] - id[x-1]);
    01130     }
    01131
    01132     for(x=w-3; x>=1; --x)
    01133     {
    01134         id[x] -= tmp[x+1]*id[x+1];
    01135     }
    01136 }
    01137
    01138 /********************************************************/
    01139 /*                                                      */
    01140 /*         resizeImageInternalSplineInterpolation       */
    01141 /*                                                      */
    01142 /********************************************************/
    01143
    01144 template <class SrcIterator, class SrcAccessor,
    01145           class DestIterator, class DestAccessor>
    01146 void
    01147 resizeImageInternalSplineInterpolation(SrcIterator is, SrcIterator iend, SrcAccessor sa,
    01148                       DestIterator id, DestIterator idend, DestAccessor da)
    01149 {
    01150     int w = iend.x - is.x;
    01151     int h = iend.y - is.y;
    01152
    01153     int wnew = idend.x - id.x;
    01154     int hnew = idend.y - id.y;
    01155
    01156     typedef typename SrcAccessor::value_type SRCVT;
    01157     typedef typename NumericTraits<SRCVT>::RealPromote TMPTYPE;
    01158     typedef typename BasicImage<TMPTYPE>::Iterator TMPITER;
    01159     typedef
    01160         NumericTraits<typename DestAccessor::value_type> DestTraits;
    01161
    01162     BasicImage<TMPTYPE> dx(w,h);
    01163     BasicImage<TMPTYPE> dy(w,h);
    01164     BasicImage<TMPTYPE> dxy(w,h);
    01165     BasicImage<TMPTYPE> W(4,4), W1(4,4);
    01166     std::vector<TMPTYPE> R(w > h ? w : h);
    01167     std::vector<double> tmp(w > h ? w : h);
    01168
    01169     typename BasicImage<TMPTYPE>::Accessor ta;
    01170
    01171     SrcIterator in = is;
    01172
    01173     TMPITER idx = dx.upperLeft();
    01174     TMPITER idy = dy.upperLeft();
    01175     TMPITER idxy = dxy.upperLeft();
    01176     typename std::vector<TMPTYPE>::iterator r = R.begin();
    01177     typename std::vector<double>::iterator it = tmp.begin();
    01178
    01179     double ig[] = { 1.0, 0.0, -3.0,  2.0,
    01180                     0.0, 1.0, -2.0,  1.0,
    01181                     0.0, 0.0,  3.0, -2.0,
    01182                     0.0, 0.0, -1.0,  1.0 };
    01183
    01184     int x, y, i, j, k;
    01185
    01186
    01187     // calculate x derivatives
    01188     for(y=0; y<h; ++y, ++in.y, ++idx.y)
    01189     {
    01190         typename SrcIterator::row_iterator sr = in.rowIterator();
    01191         typename TMPITER::row_iterator dr = idx.rowIterator();
    01192         resizeImageInternalSplineGradient(sr, sr+w, sa,
    01193                                           it, r, dr);
    01194     }
    01195
    01196     in = is;
    01197
    01198     // calculate y derivatives
    01199     for(x=0; x<w; ++x, ++in.x, ++idy.x)
    01200     {
    01201         typename SrcIterator::column_iterator sc = in.columnIterator();
    01202         typename TMPITER::column_iterator dc = idy.columnIterator();
    01203         resizeImageInternalSplineGradient(sc, sc+h, sa,
    01204                                           it, r, dc);
    01205     }
    01206
    01207     in = is;
    01208     idy = dy.upperLeft();
    01209
    01210     // calculate mixed derivatives
    01211     for(y=0; y<h; ++y, ++idy.y, ++idxy.y)
    01212     {
    01213         typename TMPITER::row_iterator sr = idy.rowIterator();
    01214         typename TMPITER::row_iterator dr = idxy.rowIterator();
    01215         resizeImageInternalSplineGradient(sr, sr+w, ta,
    01216                                           it, r, dr);
    01217     }
    01218
    01219     double du = (double)(w-1) / (wnew-1);
    01220     double dv = (double)(h-1) / (hnew-1);
    01221     double ov = 0.0;
    01222     int oy = 0;
    01223     int yy = oy;
    01224
    01225     DestIterator xxd = id, yyd = id;
    01226
    01227     static Diff2D down(0,1), right(1,0), downright(1,1);
    01228
    01229     for(y=0; y<h-1; ++y, ++in.y, ov -= 1.0)
    01230     {
    01231         if(y < h-2 && ov >= 1.0) continue;
    01232         int y1 = y+1;
    01233         double v = ov;
    01234         double ou = 0.0;
    01235         int ox = 0;
    01236         int xx = ox;
    01237
    01238         SrcIterator xs = in;
    01239         for(x=0; x<w-1; ++x, ++xs.x, ou -= 1.0)
    01240         {
    01241             if(x < w-2 && ou >= 1.0) continue;
    01242             int x1 = x+1;
    01243             double u = ou;
    01244
    01245             DestIterator xd = id + Diff2D(ox,oy);
    01246             W[0][0] = sa(xs);
    01247             W[0][1] = dy(x, y);
    01248             W[0][2] = sa(xs, down);
    01249             W[0][3] = dy(x, y1);
    01250             W[1][0] = dx(x, y);
    01251             W[1][1] = dxy(x, y);
    01252             W[1][2] = dx(x, y1);
    01253             W[1][3] = dxy(x, y1);
    01254             W[2][0] = sa(xs, right);
    01255             W[2][1] = dy(x1,y);
    01256             W[2][2] = sa(xs, downright);
    01257             W[2][3] = dy(x1, y1);
    01258             W[3][0] = dx(x1, y);
    01259             W[3][1] = dxy(x1, y);
    01260             W[3][2] = dx(x1, y1);
    01261             W[3][3] = dxy(x1, y1);
    01262
    01263             for(i=0; i<4; ++i)
    01264             {
    01265                 for(j=0; j<4; ++j)
    01266                 {
    01267                     W1[j][i] = ig[j] * W[0][i];
    01268                     for(k=1; k<4; ++k)
    01269                     {
    01270                         W1[j][i] += ig[j+4*k] * W[k][i];
    01271                     }
    01272                 }
    01273             }
    01274             for(i=0; i<4; ++i)
    01275             {
    01276                 for(j=0; j<4; ++j)
    01277                 {
    01278                     W[j][i] = ig[i] * W1[j][0];
    01279                     for(k=1; k<4; ++k)
    01280                     {
    01281                        W[j][i] += ig[4*k+i] * W1[j][k];
    01282                     }
    01283                 }
    01284             }
    01285
    01286             TMPTYPE a1,a2,a3,a4;
    01287
    01288             yyd = xd;
    01289             for(v=ov, yy=oy; v<1.0; v+=dv, ++yyd.y, ++yy)
    01290             {
    01291                 a1 = W[0][0] + v * (W[0][1] +
    01292                                v * (W[0][2] + v * W[0][3]));
    01293                 a2 = W[1][0] + v * (W[1][1] +
    01294                                v * (W[1][2] + v * W[1][3]));
    01295                 a3 = W[2][0] + v * (W[2][1] +
    01296                                v * (W[2][2] + v * W[2][3]));
    01297                 a4 = W[3][0] + v * (W[3][1] +
    01298                                v * (W[3][2] + v * W[3][3]));
    01299
    01300                 xxd = yyd;
    01301                 for(u=ou, xx=ox; u<1.0; u+=du, ++xxd.x, ++xx)
    01302                 {
    01303                     da.set(DestTraits::fromRealPromote(a1 + u * (a2 + u * (a3 + u * a4))), xxd);
    01304                 }
    01305
    01306                 if(xx == wnew-1)
    01307                 {
    01308                     da.set(DestTraits::fromRealPromote(a1 + a2 + a3 + a4), xxd);
    01309                 }
    01310             }
    01311
    01312             if(yy == hnew-1)
    01313             {
    01314                 a1 = W[0][0] + W[0][1] + W[0][2] + W[0][3];
    01315                 a2 = W[1][0] + W[1][1] + W[1][2] + W[1][3];
    01316                 a3 = W[2][0] + W[2][1] + W[2][2] + W[2][3];
    01317                 a4 = W[3][0] + W[3][1] + W[3][2] + W[3][3];
    01318
    01319                 DestIterator xxd = yyd;
    01320                 for(u=ou, xx=ox; u<1.0; u+=du, ++xxd.x, ++xx)
    01321                 {
    01322                     da.set(DestTraits::fromRealPromote(a1 + u * (a2 + u * (a3 + u * a4))), xxd);
    01323                 }
    01324
    01325                 if(xx == wnew-1)
    01326                 {
    01327                     da.set(DestTraits::fromRealPromote(a1 + a2 + a3 + a4), xxd);
    01328                 }
    01329             }
    01330
    01331             ou = u;
    01332             ox = xx;
    01333         }
    01334         ov = v;
    01335         oy = yy;
    01336     }
    01337 }
    01338
    01339 template <class SrcIterator, class SrcAccessor,
    01340           class DestIterator, class DestAccessor>
    01341 void
    01342 resizeImageSplineInterpolation(SrcIterator is, SrcIterator iend, SrcAccessor sa,
    01343                       DestIterator id, DestIterator idend, DestAccessor da)
    01344 {
    01345     int w = iend.x - is.x;
    01346     int h = iend.y - is.y;
    01347
    01348     int wnew = idend.x - id.x;
    01349     int hnew = idend.y - id.y;
    01350
    01351     vigra_precondition((w > 3) && (h > 3),
    01352                  "resizeImageSplineInterpolation(): "
    01353                  "Source image to small.\n");
    01354     vigra_precondition((wnew > 1) && (hnew > 1),
    01355                  "resizeImageSplineInterpolation(): "
    01356                  "Destination image to small.\n");
    01357
    01358     double scale = 2.0;
    01359
    01360     if(wnew < w || hnew < h)
    01361     {
    01362         typedef typename SrcAccessor::value_type SRCVT;
    01363         typedef typename NumericTraits<SRCVT>::RealPromote TMPTYPE;
    01364         typedef typename BasicImage<TMPTYPE>::Iterator TMPITER;
    01365
    01366         BasicImage<TMPTYPE> t(w,h);
    01367         TMPITER it = t.upperLeft();
    01368
    01369         if(wnew < w)
    01370         {
    01371             recursiveSmoothX(is, iend, sa,
    01372                     it, t.accessor(), (double)w/wnew/scale);
    01373
    01374             if(hnew < h)
    01375             {
    01376                recursiveSmoothY(it, t.lowerRight(), t.accessor(),
    01377                     it, t.accessor(), (double)h/hnew/scale);
    01378             }
    01379         }
    01380         else
    01381         {
    01382            recursiveSmoothY(is, iend, sa,
    01383                     it, t.accessor(), (double)h/hnew/scale);
    01384         }
    01385
    01386         resizeImageInternalSplineInterpolation(it, t.lowerRight(), t.accessor(),
    01387                                                id, idend, da);
    01388     }
    01389     else
    01390     {
    01391         resizeImageInternalSplineInterpolation(is, iend, sa, id, idend, da);
    01392     }
    01393 }
    01394
    01395 template <class SrcIterator, class SrcAccessor,
    01396           class DestIterator, class DestAccessor>
    01397 inline
    01398 void
    01399 resizeImageSplineInterpolation(triple<SrcIterator, SrcIterator, SrcAccessor> src,
    01400                       triple<DestIterator, DestIterator, DestAccessor> dest)
    01401 {
    01402     resizeImageSplineInterpolation(src.first, src.second, src.third,
    01403                                    dest.first, dest.second, dest.third);
    01404 }
    01405 #endif  // old alghorithm version
    01406
    01407 //@}
    01408
    01409 } // namespace vigra
    01410
    01411 #endif // VIGRA_RESIZEIMAGE_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)