[ VIGRA Homepage | Class Index | Function Index | File Index | Main Page ]

| vigra/fftw.hxx |
--- | --- | ---

    00001 /************************************************************************/
    00002 /*                                                                      */
    00003 /*               Copyright 1998-2002 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 1.4.0, Dec 21 2005 )                                    */
    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 /*        koethe@informatik.uni-hamburg.de          or                  */
    00012 /*        vigra@kogs1.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 #ifndef VIGRA_FFTW_HXX
    00039 #define VIGRA_FFTW_HXX
    00040
    00041 #include <cmath>
    00042 #include <functional>
    00043 #include "vigra/stdimage.hxx"
    00044 #include "vigra/copyimage.hxx"
    00045 #include "vigra/transformimage.hxx"
    00046 #include "vigra/combineimages.hxx"
    00047 #include "vigra/numerictraits.hxx"
    00048 #include "vigra/imagecontainer.hxx"
    00049 #include <fftw.h>
    00050
    00051 namespace vigra {
    00052
    00053 /********************************************************/
    00054 /*                                                      */
    00055 /*                    FFTWComplex                       */
    00056 /*                                                      */
    00057 /********************************************************/
    00058
    00059 /* documentation: see fftw3.hxx
    00060 */
    00061 class FFTWComplex
    00062 : public fftw_complex
    00063 {
    00064   public:
    00065         /** The complex' component type, as defined in '<TT>fftw.h</TT>'
    00066         */
    00067     typedef fftw_real value_type;
    00068
    00069         /** reference type (result of operator[])
    00070         */
    00071     typedef fftw_real & reference;
    00072
    00073         /** const reference type (result of operator[] const)
    00074         */
    00075     typedef fftw_real const & const_reference;
    00076
    00077         /** iterator type (result of begin() )
    00078         */
    00079     typedef fftw_real * iterator;
    00080
    00081         /** const iterator type (result of begin() const)
    00082         */
    00083     typedef fftw_real const * const_iterator;
    00084
    00085         /** The norm type (result of magnitde())
    00086         */
    00087     typedef fftw_real NormType;
    00088
    00089         /** The squared norm type (result of squaredMagnitde())
    00090         */
    00091     typedef fftw_real SquaredNormType;
    00092
    00093         /** Construct from real and imaginary part.
    00094             Default: 0.
    00095         */
    00096     FFTWComplex(value_type const & ire = 0.0, value_type const & iim = 0.0)
    00097     {
    00098         re = ire;
    00099         im = iim;
    00100     }
    00101
    00102         /** Copy constructor.
    00103         */
    00104     FFTWComplex(FFTWComplex const & o)
    00105     : fftw_complex(o)
    00106     {}
    00107
    00108         /** Construct from plain <TT>fftw_complex</TT>.
    00109         */
    00110     FFTWComplex(fftw_complex const & o)
    00111     : fftw_complex(o)
    00112     {}
    00113
    00114         /** Construct from TinyVector.
    00115         */
    00116     template <class T>
    00117     FFTWComplex(TinyVector<T, 2> const & o)
    00118     {
    00119         re = o[0];
    00120         im = o[1];
    00121     }
    00122
    00123         /** Assignment.
    00124         */
    00125     FFTWComplex& operator=(FFTWComplex const & o)
    00126     {
    00127         re = o.re;
    00128         im = o.im;
    00129         return *this;
    00130     }
    00131
    00132         /** Assignment.
    00133         */
    00134     FFTWComplex& operator=(fftw_complex const & o)
    00135     {
    00136         re = o.re;
    00137         im = o.im;
    00138         return *this;
    00139     }
    00140
    00141         /** Assignment.
    00142         */
    00143     FFTWComplex& operator=(fftw_real const & o)
    00144     {
    00145         re = o;
    00146         im = 0.0;
    00147         return *this;
    00148     }
    00149
    00150         /** Assignment.
    00151         */
    00152     template <class T>
    00153     FFTWComplex& operator=(TinyVector<T, 2> const & o)
    00154     {
    00155         re = o[0];
    00156         im = o[1];
    00157         return *this;
    00158     }
    00159
    00160         /** Unary negation.
    00161         */
    00162     FFTWComplex operator-() const
    00163         { return FFTWComplex(-re, -im); }
    00164
    00165         /** Squared magnitude x*conj(x)
    00166         */
    00167     SquaredNormType squaredMagnitude() const
    00168         { return c_re(*this)*c_re(*this)+c_im(*this)*c_im(*this); }
    00169
    00170         /** Magnitude (length of radius vector).
    00171         */
    00172     NormType magnitude() const
    00173         { return VIGRA_CSTD::sqrt(squaredMagnitude()); }
    00174
    00175         /** Phase angle.
    00176         */
    00177     value_type phase() const
    00178         { return VIGRA_CSTD::atan2(c_im(*this),c_re(*this)); }
    00179
    00180         /** Access components as if number were a vector.
    00181         */
    00182     reference operator[](int i)
    00183         { return (&re)[i]; }
    00184
    00185         /** Read components as if number were a vector.
    00186         */
    00187     const_reference operator[](int i) const
    00188         { return (&re)[i]; }
    00189
    00190         /** Length of complex number (always 2).
    00191         */
    00192     int size() const
    00193         { return 2; }
    00194
    00195     iterator begin()
    00196         { return &re; }
    00197
    00198     iterator end()
    00199         { return &re + 2; }
    00200
    00201     const_iterator begin() const
    00202         { return &re; }
    00203
    00204     const_iterator end() const
    00205         { return &re + 2; }
    00206 };
    00207
    00208 /********************************************************/
    00209 /*                                                      */
    00210 /*                    FFTWComplex Traits                */
    00211 /*                                                      */
    00212 /********************************************************/
    00213
    00214 /* documentation: see fftw3.hxx
    00215 */
    00216 template<>
    00217 struct NumericTraits<fftw_complex>
    00218 {
    00219     typedef fftw_complex Type;
    00220     typedef fftw_complex Promote;
    00221     typedef fftw_complex RealPromote;
    00222     typedef fftw_complex ComplexPromote;
    00223     typedef fftw_real    ValueType;
    00224
    00225     typedef VigraFalseType isIntegral;
    00226     typedef VigraFalseType isScalar;
    00227     typedef NumericTraits<fftw_real>::isSigned isSigned;
    00228     typedef VigraFalseType isOrdered;
    00229     typedef VigraTrueType  isComplex;
    00230
    00231     static FFTWComplex zero() { return FFTWComplex(0.0, 0.0); }
    00232     static FFTWComplex one() { return FFTWComplex(1.0, 0.0); }
    00233     static FFTWComplex nonZero() { return one(); }
    00234
    00235     static const Promote & toPromote(const Type & v) { return v; }
    00236     static const RealPromote & toRealPromote(const Type & v) { return v; }
    00237     static const Type & fromPromote(const Promote & v) { return v; }
    00238     static const Type & fromRealPromote(const RealPromote & v) { return v; }
    00239 };
    00240
    00241 template<>
    00242 struct NumericTraits<FFTWComplex>
    00243 : public NumericTraits<fftw_complex>
    00244 {
    00245     typedef FFTWComplex Type;
    00246     typedef FFTWComplex Promote;
    00247     typedef FFTWComplex RealPromote;
    00248     typedef FFTWComplex ComplexPromote;
    00249     typedef fftw_real   ValueType;
    00250
    00251     typedef VigraFalseType isIntegral;
    00252     typedef VigraFalseType isScalar;
    00253     typedef NumericTraits<fftw_real>::isSigned isSigned;
    00254     typedef VigraFalseType isOrdered;
    00255     typedef VigraTrueType  isComplex;
    00256 };
    00257
    00258 template<>
    00259 struct NormTraits<fftw_complex>
    00260 {
    00261     typedef fftw_complex Type;
    00262     typedef fftw_real    SquaredNormType;
    00263     typedef fftw_real    NormType;
    00264 };
    00265
    00266 template<>
    00267 struct NormTraits<FFTWComplex>
    00268 {
    00269     typedef FFTWComplex Type;
    00270     typedef fftw_real   SquaredNormType;
    00271     typedef fftw_real   NormType;
    00272 };
    00273
    00274
    00275 template <>
    00276 struct PromoteTraits<fftw_complex, fftw_complex>
    00277 {
    00278     typedef fftw_complex Promote;
    00279 };
    00280
    00281 template <>
    00282 struct PromoteTraits<fftw_complex, double>
    00283 {
    00284     typedef fftw_complex Promote;
    00285 };
    00286
    00287 template <>
    00288 struct PromoteTraits<double, fftw_complex>
    00289 {
    00290     typedef fftw_complex Promote;
    00291 };
    00292
    00293 template <>
    00294 struct PromoteTraits<FFTWComplex, FFTWComplex>
    00295 {
    00296     typedef FFTWComplex Promote;
    00297 };
    00298
    00299 template <>
    00300 struct PromoteTraits<FFTWComplex, double>
    00301 {
    00302     typedef FFTWComplex Promote;
    00303 };
    00304
    00305 template <>
    00306 struct PromoteTraits<double, FFTWComplex>
    00307 {
    00308     typedef FFTWComplex Promote;
    00309 };
    00310
    00311
    00312 /********************************************************/
    00313 /*                                                      */
    00314 /*                    FFTWComplex Operations            */
    00315 /*                                                      */
    00316 /********************************************************/
    00317
    00318 /* documentation: see fftw3.hxx
    00319 */
    00320 inline bool operator ==(FFTWComplex const &a, const FFTWComplex &b) {
    00321     return c_re(a) == c_re(b) && c_im(a) == c_im(b);
    00322 }
    00323
    00324 inline bool operator !=(FFTWComplex const &a, const FFTWComplex &b) {
    00325     return c_re(a) != c_re(b) || c_im(a) != c_im(b);
    00326 }
    00327
    00328 inline FFTWComplex &operator +=(FFTWComplex &a, const FFTWComplex &b) {
    00329     c_re(a) += c_re(b);
    00330     c_im(a) += c_im(b);
    00331     return a;
    00332 }
    00333
    00334 inline FFTWComplex &operator -=(FFTWComplex &a, const FFTWComplex &b) {
    00335     c_re(a) -= c_re(b);
    00336     c_im(a) -= c_im(b);
    00337     return a;
    00338 }
    00339
    00340 inline FFTWComplex &operator *=(FFTWComplex &a, const FFTWComplex &b) {
    00341     FFTWComplex::value_type t = c_re(a)*c_re(b)-c_im(a)*c_im(b);
    00342     c_im(a) = c_re(a)*c_im(b)+c_im(a)*c_re(b);
    00343     c_re(a) = t;
    00344     return a;
    00345 }
    00346
    00347 inline FFTWComplex &operator /=(FFTWComplex &a, const FFTWComplex &b) {
    00348     FFTWComplex::value_type sm = b.squaredMagnitude();
    00349     FFTWComplex::value_type t = (c_re(a)*c_re(b)+c_im(a)*c_im(b))/sm;
    00350     c_im(a) = (c_re(b)*c_im(a)-c_re(a)*c_im(b))/sm;
    00351     c_re(a) = t;
    00352     return a;
    00353 }
    00354
    00355 inline FFTWComplex &operator *=(FFTWComplex &a, const double &b) {
    00356     c_re(a) *= b;
    00357     c_im(a) *= b;
    00358     return a;
    00359 }
    00360
    00361 inline FFTWComplex &operator /=(FFTWComplex &a, const double &b) {
    00362     c_re(a) /= b;
    00363     c_im(a) /= b;
    00364     return a;
    00365 }
    00366
    00367 inline FFTWComplex operator +(FFTWComplex a, const FFTWComplex &b) {
    00368     a += b;
    00369     return a;
    00370 }
    00371
    00372 inline FFTWComplex operator -(FFTWComplex a, const FFTWComplex &b) {
    00373     a -= b;
    00374     return a;
    00375 }
    00376
    00377 inline FFTWComplex operator *(FFTWComplex a, const FFTWComplex &b) {
    00378     a *= b;
    00379     return a;
    00380 }
    00381
    00382 inline FFTWComplex operator *(FFTWComplex a, const double &b) {
    00383     a *= b;
    00384     return a;
    00385 }
    00386
    00387 inline FFTWComplex operator *(const double &a, FFTWComplex b) {
    00388     b *= a;
    00389     return b;
    00390 }
    00391
    00392 inline FFTWComplex operator /(FFTWComplex a, const FFTWComplex &b) {
    00393     a /= b;
    00394     return a;
    00395 }
    00396
    00397 inline FFTWComplex operator /(FFTWComplex a, const double &b) {
    00398     a /= b;
    00399     return a;
    00400 }
    00401
    00402 using VIGRA_CSTD::abs;
    00403
    00404 inline FFTWComplex::value_type abs(const FFTWComplex &a)
    00405 {
    00406     return a.magnitude();
    00407 }
    00408
    00409 inline FFTWComplex conj(const FFTWComplex &a)
    00410 {
    00411     return FFTWComplex(a.re, -a.im);
    00412 }
    00413
    00414 inline FFTWComplex::NormType norm(const FFTWComplex &a)
    00415 {
    00416     return a.magnitude();
    00417 }
    00418
    00419 inline FFTWComplex::SquaredNormType squaredNorm(const FFTWComplex &a)
    00420 {
    00421     return a.squaredMagnitude();
    00422 }
    00423
    00424 /********************************************************/
    00425 /*                                                      */
    00426 /*                      FFTWRealImage                   */
    00427 /*                                                      */
    00428 /********************************************************/
    00429
    00430 /* documentation: see fftw3.hxx
    00431 */
    00432 typedef BasicImage<fftw_real> FFTWRealImage;
    00433
    00434 /********************************************************/
    00435 /*                                                      */
    00436 /*                     FFTWComplexImage                 */
    00437 /*                                                      */
    00438 /********************************************************/
    00439
    00440 template<>
    00441 struct IteratorTraits<
    00442         BasicImageIterator<FFTWComplex, FFTWComplex **> >
    00443 {
    00444     typedef BasicImageIterator<FFTWComplex, FFTWComplex **>  Iterator;
    00445     typedef Iterator                             iterator;
    00446     typedef BasicImageIterator<FFTWComplex, FFTWComplex **>         mutable_iterator;
    00447     typedef ConstBasicImageIterator<FFTWComplex, FFTWComplex **>    const_iterator;
    00448     typedef iterator::iterator_category          iterator_category;
    00449     typedef iterator::value_type                 value_type;
    00450     typedef iterator::reference                  reference;
    00451     typedef iterator::index_reference            index_reference;
    00452     typedef iterator::pointer                    pointer;
    00453     typedef iterator::difference_type            difference_type;
    00454     typedef iterator::row_iterator               row_iterator;
    00455     typedef iterator::column_iterator            column_iterator;
    00456     typedef VectorAccessor<FFTWComplex>          default_accessor;
    00457     typedef VectorAccessor<FFTWComplex>          DefaultAccessor;
    00458     typedef VigraTrueType                        hasConstantStrides;
    00459 };
    00460
    00461 template<>
    00462 struct IteratorTraits<
    00463         ConstBasicImageIterator<FFTWComplex, FFTWComplex **> >
    00464 {
    00465     typedef ConstBasicImageIterator<FFTWComplex, FFTWComplex **>    Iterator;
    00466     typedef Iterator                             iterator;
    00467     typedef BasicImageIterator<FFTWComplex, FFTWComplex **>         mutable_iterator;
    00468     typedef ConstBasicImageIterator<FFTWComplex, FFTWComplex **>    const_iterator;
    00469     typedef iterator::iterator_category          iterator_category;
    00470     typedef iterator::value_type                 value_type;
    00471     typedef iterator::reference                  reference;
    00472     typedef iterator::index_reference            index_reference;
    00473     typedef iterator::pointer                    pointer;
    00474     typedef iterator::difference_type            difference_type;
    00475     typedef iterator::row_iterator               row_iterator;
    00476     typedef iterator::column_iterator            column_iterator;
    00477     typedef VectorAccessor<FFTWComplex>          default_accessor;
    00478     typedef VectorAccessor<FFTWComplex>          DefaultAccessor;
    00479     typedef VigraTrueType                        hasConstantStrides;
    00480 };
    00481
    00482 /* documentation: see fftw3.hxx
    00483 */
    00484 typedef BasicImage<FFTWComplex> FFTWComplexImage;
    00485
    00486 /********************************************************/
    00487 /*                                                      */
    00488 /*                  FFTWComplex-Accessors               */
    00489 /*                                                      */
    00490 /********************************************************/
    00491
    00492 /* documentation: see fftw3.hxx
    00493 */
    00494 class FFTWRealAccessor
    00495 {
    00496   public:
    00497
    00498         /// The accessor's value type.
    00499     typedef fftw_real value_type;
    00500
    00501         /// Read real part at iterator position.
    00502     template <class ITERATOR>
    00503     value_type operator()(ITERATOR const & i) const {
    00504         return c_re(*i);
    00505     }
    00506
    00507         /// Read real part at offset from iterator position.
    00508     template <class ITERATOR, class DIFFERENCE>
    00509     value_type operator()(ITERATOR const & i, DIFFERENCE d) const {
    00510         return c_re(i[d]);
    00511     }
    00512
    00513         /// Write real part at iterator position.
    00514     template <class ITERATOR>
    00515     void set(value_type const & v, ITERATOR const & i) const {
    00516         c_re(*i)= v;
    00517     }
    00518
    00519         /// Write real part at offset from iterator position.
    00520     template <class ITERATOR, class DIFFERENCE>
    00521     void set(value_type const & v, ITERATOR const & i, DIFFERENCE d) const {
    00522         c_re(i[d])= v;
    00523     }
    00524 };
    00525
    00526 /* documentation: see fftw3.hxx
    00527 */
    00528 class FFTWImaginaryAccessor
    00529 {
    00530   public:
    00531         /// The accessor's value type.
    00532     typedef fftw_real value_type;
    00533
    00534         /// Read imaginary part at iterator position.
    00535     template <class ITERATOR>
    00536     value_type operator()(ITERATOR const & i) const {
    00537         return c_im(*i);
    00538     }
    00539
    00540         /// Read imaginary part at offset from iterator position.
    00541     template <class ITERATOR, class DIFFERENCE>
    00542     value_type operator()(ITERATOR const & i, DIFFERENCE d) const {
    00543         return c_im(i[d]);
    00544     }
    00545
    00546         /// Write imaginary part at iterator position.
    00547     template <class ITERATOR>
    00548     void set(value_type const & v, ITERATOR const & i) const {
    00549         c_im(*i)= v;
    00550     }
    00551
    00552         /// Write imaginary part at offset from iterator position.
    00553     template <class ITERATOR, class DIFFERENCE>
    00554     void set(value_type const & v, ITERATOR const & i, DIFFERENCE d) const {
    00555         c_im(i[d])= v;
    00556     }
    00557 };
    00558
    00559 /* documentation: see fftw3.hxx
    00560 */
    00561 class FFTWWriteRealAccessor: public FFTWRealAccessor
    00562 {
    00563   public:
    00564         /// The accessor's value type.
    00565     typedef fftw_real value_type;
    00566
    00567         /** Write real number at iterator position. Set imaginary part
    00568             to 0.
    00569         */
    00570     template <class ITERATOR>
    00571     void set(value_type const & v, ITERATOR const & i) const {
    00572         c_re(*i)= v;
    00573         c_im(*i)= 0;
    00574     }
    00575
    00576         /** Write real number at offset from iterator position. Set imaginary part
    00577             to 0.
    00578         */
    00579     template <class ITERATOR, class DIFFERENCE>
    00580     void set(value_type const & v, ITERATOR const & i, DIFFERENCE d) const {
    00581         c_re(i[d])= v;
    00582         c_im(i[d])= 0;
    00583     }
    00584 };
    00585
    00586 /* documentation: see fftw3.hxx
    00587 */
    00588 class FFTWMagnitudeAccessor
    00589 {
    00590   public:
    00591         /// The accessor's value type.
    00592     typedef fftw_real value_type;
    00593
    00594         /// Read magnitude at iterator position.
    00595     template <class ITERATOR>
    00596     value_type operator()(ITERATOR const & i) const {
    00597         return (*i).magnitude();
    00598     }
    00599
    00600         /// Read magnitude at offset from iterator position.
    00601     template <class ITERATOR, class DIFFERENCE>
    00602     value_type operator()(ITERATOR const & i, DIFFERENCE d) const {
    00603         return (i[d]).magnitude();
    00604     }
    00605 };
    00606
    00607 /* documentation: see fftw3.hxx
    00608 */
    00609 class FFTWPhaseAccessor
    00610 {
    00611   public:
    00612         /// The accessor's value type.
    00613     typedef fftw_real value_type;
    00614
    00615         /// Read phase at iterator position.
    00616     template <class ITERATOR>
    00617     value_type operator()(ITERATOR const & i) const {
    00618         return (*i).phase();
    00619     }
    00620
    00621         /// Read phase at offset from iterator position.
    00622     template <class ITERATOR, class DIFFERENCE>
    00623     value_type operator()(ITERATOR const & i, DIFFERENCE d) const {
    00624         return (i[d]).phase();
    00625     }
    00626 };
    00627
    00628 /********************************************************/
    00629 /*                                                      */
    00630 /*                    Fourier Transform                 */
    00631 /*                                                      */
    00632 /********************************************************/
    00633
    00634 /** \page FourierTransformFFTW2 Fast Fourier Transform
    00635
    00636     This documentation describes the deprecated VIGRA interface to
    00637     FFTW 2. Use the \link FourierTransform interface to the newer
    00638     version FFTW 3\endlink instead.
    00639
    00640     VIGRA uses the <a href="http://www.fftw.org/">FFTW Fast Fourier
    00641     Transform</a> package to perform Fourier transformations. VIGRA
    00642     provides a wrapper for FFTW's complex number type (FFTWComplex),
    00643     but FFTW's functions are used verbatim. If the image is stored as
    00644     a FFTWComplexImage, a FFT is performed like this:
    00645
    00646     \code
    00647     vigra::FFTWComplexImage spatial(width,height), fourier(width,height);
    00648     ... // fill image with data
    00649
    00650     // create a plan for optimal performance
    00651     fftwnd_plan forwardPlan=
    00652         fftw2d_create_plan(height, width, FFTW_FORWARD, FFTW_ESTIMATE );
    00653
    00654     // calculate FFT
    00655     fftwnd_one(forwardPlan, spatial.begin(), fourier.begin());
    00656     \endcode
    00657
    00658     Note that in the creation of a plan, the height must be given
    00659     first. Note also that <TT>spatial.begin()</TT> may only be passed
    00660     to <TT>fftwnd_one</TT> if the transform shall be applied to the
    00661     entire image. When you want to retrict operation to an ROI, you
    00662     create a copy of the ROI in an image of appropriate size.
    00663
    00664     More information on using FFTW can be found <a href="http://www.fftw.org/doc/">here</a>.
    00665
    00666     FFTW produces fourier images that have the DC component (the
    00667     origin of the Fourier space) in the upper left corner. Often, one
    00668     wants the origin in the center of the image, so that frequencies
    00669     always increase towards the border of the image. This can be
    00670     achieved by calling \ref moveDCToCenter(). The inverse
    00671     transformation is done by \ref moveDCToUpperLeft().
    00672
    00673     <b>\#include</b> "<a href="fftw_8hxx-source.html">vigra/fftw.hxx</a>"<br>
    00674     Namespace: vigra
    00675 */
    00676
    00677 /********************************************************/
    00678 /*                                                      */
    00679 /*                     moveDCToCenter                   */
    00680 /*                                                      */
    00681 /********************************************************/
    00682
    00683 /* documentation: see fftw3.hxx
    00684 */
    00685 template <class SrcImageIterator, class SrcAccessor,
    00686           class DestImageIterator, class DestAccessor>
    00687 void moveDCToCenter(SrcImageIterator src_upperleft,
    00688                                SrcImageIterator src_lowerright, SrcAccessor sa,
    00689                                DestImageIterator dest_upperleft, DestAccessor da)
    00690 {
    00691     int w= src_lowerright.x - src_upperleft.x;
    00692     int h= src_lowerright.y - src_upperleft.y;
    00693     int w1 = w/2;
    00694     int h1 = h/2;
    00695     int w2 = (w+1)/2;
    00696     int h2 = (h+1)/2;
    00697
    00698     // 2. Quadrant  zum 4.
    00699     copyImage(srcIterRange(src_upperleft,
    00700                            src_upperleft  + Diff2D(w2, h2), sa),
    00701               destIter    (dest_upperleft + Diff2D(w1, h1), da));
    00702
    00703     // 4. Quadrant zum 2.
    00704     copyImage(srcIterRange(src_upperleft + Diff2D(w2, h2),
    00705                            src_lowerright, sa),
    00706               destIter    (dest_upperleft, da));
    00707
    00708     // 1. Quadrant zum 3.
    00709     copyImage(srcIterRange(src_upperleft  + Diff2D(w2, 0),
    00710                            src_upperleft  + Diff2D(w,  h2), sa),
    00711               destIter    (dest_upperleft + Diff2D(0,  h1), da));
    00712
    00713     // 3. Quadrant zum 1.
    00714     copyImage(srcIterRange(src_upperleft  + Diff2D(0,  h2),
    00715                            src_upperleft  + Diff2D(w2, h), sa),
    00716               destIter    (dest_upperleft + Diff2D(w1, 0), da));
    00717 }
    00718
    00719 template <class SrcImageIterator, class SrcAccessor,
    00720           class DestImageIterator, class DestAccessor>
    00721 inline void moveDCToCenter(
    00722     triple<SrcImageIterator, SrcImageIterator, SrcAccessor> src,
    00723     pair<DestImageIterator, DestAccessor> dest)
    00724 {
    00725     moveDCToCenter(src.first, src.second, src.third,
    00726                           dest.first, dest.second);
    00727 }
    00728
    00729 /********************************************************/
    00730 /*                                                      */
    00731 /*                   moveDCToUpperLeft                  */
    00732 /*                                                      */
    00733 /********************************************************/
    00734
    00735 /* documentation: see fftw3.hxx
    00736 */
    00737 template <class SrcImageIterator, class SrcAccessor,
    00738           class DestImageIterator, class DestAccessor>
    00739 void moveDCToUpperLeft(SrcImageIterator src_upperleft,
    00740                                SrcImageIterator src_lowerright, SrcAccessor sa,
    00741                                DestImageIterator dest_upperleft, DestAccessor da)
    00742 {
    00743     int w= src_lowerright.x - src_upperleft.x;
    00744     int h= src_lowerright.y - src_upperleft.y;
    00745     int w2 = w/2;
    00746     int h2 = h/2;
    00747     int w1 = (w+1)/2;
    00748     int h1 = (h+1)/2;
    00749
    00750     // 2. Quadrant  zum 4.
    00751     copyImage(srcIterRange(src_upperleft,
    00752                            src_upperleft  + Diff2D(w2, h2), sa),
    00753               destIter    (dest_upperleft + Diff2D(w1, h1), da));
    00754
    00755     // 4. Quadrant zum 2.
    00756     copyImage(srcIterRange(src_upperleft + Diff2D(w2, h2),
    00757                            src_lowerright, sa),
    00758               destIter    (dest_upperleft, da));
    00759
    00760     // 1. Quadrant zum 3.
    00761     copyImage(srcIterRange(src_upperleft  + Diff2D(w2, 0),
    00762                            src_upperleft  + Diff2D(w,  h2), sa),
    00763               destIter    (dest_upperleft + Diff2D(0,  h1), da));
    00764
    00765     // 3. Quadrant zum 1.
    00766     copyImage(srcIterRange(src_upperleft  + Diff2D(0,  h2),
    00767                            src_upperleft  + Diff2D(w2, h), sa),
    00768               destIter    (dest_upperleft + Diff2D(w1, 0), da));
    00769 }
    00770
    00771 template <class SrcImageIterator, class SrcAccessor,
    00772           class DestImageIterator, class DestAccessor>
    00773 inline void moveDCToUpperLeft(
    00774     triple<SrcImageIterator, SrcImageIterator, SrcAccessor> src,
    00775     pair<DestImageIterator, DestAccessor> dest)
    00776 {
    00777     moveDCToUpperLeft(src.first, src.second, src.third,
    00778                                           dest.first, dest.second);
    00779 }
    00780
    00781 /********************************************************/
    00782 /*                                                      */
    00783 /*                   applyFourierFilter                 */
    00784 /*                                                      */
    00785 /********************************************************/
    00786
    00787 /* documentation: see fftw3.hxx
    00788 */
    00789
    00790 // applyFourierFilter versions without fftwnd_plans:
    00791 template <class SrcImageIterator, class SrcAccessor,
    00792           class FilterImageIterator, class FilterAccessor,
    00793           class DestImageIterator, class DestAccessor>
    00794 inline
    00795 void applyFourierFilter(triple<SrcImageIterator, SrcImageIterator, SrcAccessor> src,
    00796                         pair<FilterImageIterator, FilterAccessor> filter,
    00797                         pair<DestImageIterator, DestAccessor> dest)
    00798 {
    00799     applyFourierFilter(src.first, src.second, src.third,
    00800                        filter.first, filter.second,
    00801                        dest.first, dest.second);
    00802 }
    00803
    00804 template <class SrcImageIterator, class SrcAccessor,
    00805           class FilterImageIterator, class FilterAccessor,
    00806           class DestImageIterator, class DestAccessor>
    00807 void applyFourierFilter(SrcImageIterator srcUpperLeft,
    00808                         SrcImageIterator srcLowerRight, SrcAccessor sa,
    00809                         FilterImageIterator filterUpperLeft, FilterAccessor fa,
    00810                         DestImageIterator destUpperLeft, DestAccessor da)
    00811 {
    00812     // copy real input images into a complex one...
    00813     int w= srcLowerRight.x - srcUpperLeft.x;
    00814     int h= srcLowerRight.y - srcUpperLeft.y;
    00815
    00816     FFTWComplexImage workImage(w, h);
    00817     copyImage(srcIterRange(srcUpperLeft, srcLowerRight, sa),
    00818               destImage(workImage, FFTWWriteRealAccessor()));
    00819
    00820     // ...and call the impl
    00821     FFTWComplexImage const & cworkImage = workImage;
    00822     applyFourierFilterImpl(cworkImage.upperLeft(), cworkImage.lowerRight(), cworkImage.accessor(),
    00823                            filterUpperLeft, fa,
    00824                            destUpperLeft, da);
    00825 }
    00826
    00827 typedef FFTWComplexImage::const_traverser FFTWConstTraverser;
    00828
    00829 template <class FilterImageIterator, class FilterAccessor,
    00830           class DestImageIterator, class DestAccessor>
    00831 inline
    00832 void applyFourierFilter(
    00833     FFTWComplexImage::const_traverser srcUpperLeft,
    00834     FFTWComplexImage::const_traverser srcLowerRight,
    00835     FFTWComplexImage::ConstAccessor sa,
    00836     FilterImageIterator filterUpperLeft, FilterAccessor fa,
    00837     DestImageIterator destUpperLeft, DestAccessor da)
    00838 {
    00839     int w= srcLowerRight.x - srcUpperLeft.x;
    00840     int h= srcLowerRight.y - srcUpperLeft.y;
    00841
    00842     // test for right memory layout (fftw expects a 2*width*height floats array)
    00843     if (&(*(srcUpperLeft + Diff2D(w, 0))) == &(*(srcUpperLeft + Diff2D(0, 1))))
    00844         applyFourierFilterImpl(srcUpperLeft, srcLowerRight, sa,
    00845                                filterUpperLeft, fa,
    00846                                destUpperLeft, da);
    00847     else
    00848     {
    00849         FFTWComplexImage workImage(w, h);
    00850         copyImage(srcIterRange(srcUpperLeft, srcLowerRight, sa),
    00851                   destImage(workImage));
    00852
    00853         FFTWComplexImage const & cworkImage = workImage;
    00854         applyFourierFilterImpl(cworkImage.upperLeft(), cworkImage.lowerRight(), cworkImage.accessor(),
    00855                                filterUpperLeft, fa,
    00856                                destUpperLeft, da);
    00857     }
    00858 }
    00859
    00860 template <class FilterImageIterator, class FilterAccessor,
    00861           class DestImageIterator, class DestAccessor>
    00862 void applyFourierFilterImpl(
    00863     FFTWComplexImage::const_traverser srcUpperLeft,
    00864     FFTWComplexImage::const_traverser srcLowerRight,
    00865     FFTWComplexImage::ConstAccessor sa,
    00866     FilterImageIterator filterUpperLeft, FilterAccessor fa,
    00867     DestImageIterator destUpperLeft, DestAccessor da)
    00868 {
    00869     // create plans and call variant with plan parameters
    00870     int w= srcLowerRight.x - srcUpperLeft.x;
    00871     int h= srcLowerRight.y - srcUpperLeft.y;
    00872
    00873     fftwnd_plan forwardPlan=
    00874         fftw2d_create_plan(h, w, FFTW_FORWARD, FFTW_ESTIMATE );
    00875     fftwnd_plan backwardPlan=
    00876         fftw2d_create_plan(h, w, FFTW_BACKWARD, FFTW_ESTIMATE | FFTW_IN_PLACE);
    00877
    00878     applyFourierFilterImpl(srcUpperLeft, srcLowerRight, sa,
    00879                            filterUpperLeft, fa,
    00880                            destUpperLeft, da,
    00881                            forwardPlan, backwardPlan);
    00882
    00883     fftwnd_destroy_plan(forwardPlan);
    00884     fftwnd_destroy_plan(backwardPlan);
    00885 }
    00886
    00887 // applyFourierFilter versions with fftwnd_plans:
    00888 template <class SrcImageIterator, class SrcAccessor,
    00889           class FilterImageIterator, class FilterAccessor,
    00890           class DestImageIterator, class DestAccessor>
    00891 inline
    00892 void applyFourierFilter(triple<SrcImageIterator, SrcImageIterator, SrcAccessor> src,
    00893                         pair<FilterImageIterator, FilterAccessor> filter,
    00894                         pair<DestImageIterator, DestAccessor> dest,
    00895                         const fftwnd_plan &forwardPlan, const fftwnd_plan &backwardPlan)
    00896 {
    00897     applyFourierFilter(src.first, src.second, src.third,
    00898                        filter.first, filter.second,
    00899                        dest.first, dest.second,
    00900                        forwardPlan, backwardPlan);
    00901 }
    00902
    00903 template <class SrcImageIterator, class SrcAccessor,
    00904           class FilterImageIterator, class FilterAccessor,
    00905           class DestImageIterator, class DestAccessor>
    00906 void applyFourierFilter(SrcImageIterator srcUpperLeft,
    00907                         SrcImageIterator srcLowerRight, SrcAccessor sa,
    00908                         FilterImageIterator filterUpperLeft, FilterAccessor fa,
    00909                         DestImageIterator destUpperLeft, DestAccessor da,
    00910                         const fftwnd_plan &forwardPlan, const fftwnd_plan &backwardPlan)
    00911 {
    00912     int w= srcLowerRight.x - srcUpperLeft.x;
    00913     int h= srcLowerRight.y - srcUpperLeft.y;
    00914
    00915     FFTWComplexImage workImage(w, h);
    00916     copyImage(srcIterRange(srcUpperLeft, srcLowerRight, sa),
    00917               destImage(workImage, FFTWWriteRealAccessor()));
    00918
    00919     FFTWComplexImage const & cworkImage = workImage;
    00920     applyFourierFilterImpl(cworkImage.upperLeft(), cworkImage.lowerRight(), cworkImage.accessor(),
    00921                            filterUpperLeft, fa,
    00922                            destUpperLeft, da,
    00923                            forwardPlan, backwardPlan);
    00924 }
    00925
    00926 template <class FilterImageIterator, class FilterAccessor,
    00927           class DestImageIterator, class DestAccessor>
    00928 inline
    00929 void applyFourierFilter(
    00930     FFTWComplexImage::const_traverser srcUpperLeft,
    00931     FFTWComplexImage::const_traverser srcLowerRight,
    00932     FFTWComplexImage::ConstAccessor sa,
    00933     FilterImageIterator filterUpperLeft, FilterAccessor fa,
    00934     DestImageIterator destUpperLeft, DestAccessor da,
    00935     const fftwnd_plan &forwardPlan, const fftwnd_plan &backwardPlan)
    00936 {
    00937     applyFourierFilterImpl(srcUpperLeft, srcLowerRight, sa,
    00938                            filterUpperLeft, fa,
    00939                            destUpperLeft, da,
    00940                            forwardPlan, backwardPlan);
    00941 }
    00942
    00943 template <class FilterImageIterator, class FilterAccessor,
    00944           class DestImageIterator, class DestAccessor>
    00945 void applyFourierFilterImpl(
    00946     FFTWComplexImage::const_traverser srcUpperLeft,
    00947     FFTWComplexImage::const_traverser srcLowerRight,
    00948     FFTWComplexImage::ConstAccessor sa,
    00949     FilterImageIterator filterUpperLeft, FilterAccessor fa,
    00950     DestImageIterator destUpperLeft, DestAccessor da,
    00951     const fftwnd_plan &forwardPlan, const fftwnd_plan &backwardPlan)
    00952 {
    00953     FFTWComplexImage complexResultImg(srcLowerRight - srcUpperLeft);
    00954
    00955     // FFT from srcImage to complexResultImg
    00956     fftwnd_one(forwardPlan, const_cast<FFTWComplex *>(&(*srcUpperLeft)),
    00957                complexResultImg.begin());
    00958
    00959     // convolve in freq. domain (in complexResultImg)
    00960     combineTwoImages(srcImageRange(complexResultImg), srcIter(filterUpperLeft, fa),
    00961                      destImage(complexResultImg), std::multiplies<FFTWComplex>());
    00962
    00963     // FFT back into spatial domain (inplace in complexResultImg)
    00964     fftwnd_one(backwardPlan, complexResultImg.begin(), 0);
    00965
    00966     typedef typename
    00967         NumericTraits<typename DestAccessor::value_type>::isScalar
    00968         isScalarResult;
    00969
    00970     // normalization (after FFTs), maybe stripping imaginary part
    00971     applyFourierFilterImplNormalization(complexResultImg, destUpperLeft, da,
    00972                                         isScalarResult());
    00973 }
    00974
    00975 template <class DestImageIterator, class DestAccessor>
    00976 void applyFourierFilterImplNormalization(FFTWComplexImage const &srcImage,
    00977                                          DestImageIterator destUpperLeft,
    00978                                          DestAccessor da,
    00979                                          VigraFalseType)
    00980 {
    00981     double normFactor= 1.0/(srcImage.width() * srcImage.height());
    00982
    00983     for(int y=0; y<srcImage.height(); y++, destUpperLeft.y++)
    00984     {
    00985         DestImageIterator dIt= destUpperLeft;
    00986         for(int x= 0; x< srcImage.width(); x++, dIt.x++)
    00987         {
    00988             da.setComponent(srcImage(x, y).re*normFactor, dIt, 0);
    00989             da.setComponent(srcImage(x, y).im*normFactor, dIt, 1);
    00990         }
    00991     }
    00992 }
    00993
    00994 inline
    00995 void applyFourierFilterImplNormalization(FFTWComplexImage const & srcImage,
    00996         FFTWComplexImage::traverser destUpperLeft,
    00997         FFTWComplexImage::Accessor da,
    00998         VigraFalseType)
    00999 {
    01000     transformImage(srcImageRange(srcImage), destIter(destUpperLeft, da),
    01001                    linearIntensityTransform<FFTWComplex>(1.0/(srcImage.width() * srcImage.height())));
    01002 }
    01003
    01004 template <class DestImageIterator, class DestAccessor>
    01005 void applyFourierFilterImplNormalization(FFTWComplexImage const & srcImage,
    01006                                          DestImageIterator destUpperLeft,
    01007                                          DestAccessor da,
    01008                                          VigraTrueType)
    01009 {
    01010     double normFactor= 1.0/(srcImage.width() * srcImage.height());
    01011
    01012     for(int y=0; y<srcImage.height(); y++, destUpperLeft.y++)
    01013     {
    01014         DestImageIterator dIt= destUpperLeft;
    01015         for(int x= 0; x< srcImage.width(); x++, dIt.x++)
    01016             da.set(srcImage(x, y).re*normFactor, dIt);
    01017     }
    01018 }
    01019
    01020 /**********************************************************/
    01021 /*                                                        */
    01022 /*                applyFourierFilterFamily                */
    01023 /*                                                        */
    01024 /**********************************************************/
    01025
    01026 /* documentation: see fftw3.hxx
    01027 */
    01028
    01029 // applyFourierFilterFamily versions without fftwnd_plans:
    01030 template <class SrcImageIterator, class SrcAccessor,
    01031           class FilterType, class DestImage>
    01032 inline
    01033 void applyFourierFilterFamily(triple<SrcImageIterator, SrcImageIterator, SrcAccessor> src,
    01034                               const ImageArray<FilterType> &filters,
    01035                               ImageArray<DestImage> &results)
    01036 {
    01037     applyFourierFilterFamily(src.first, src.second, src.third,
    01038                              filters, results);
    01039 }
    01040
    01041 template <class SrcImageIterator, class SrcAccessor,
    01042           class FilterType, class DestImage>
    01043 void applyFourierFilterFamily(SrcImageIterator srcUpperLeft,
    01044                               SrcImageIterator srcLowerRight, SrcAccessor sa,
    01045                               const ImageArray<FilterType> &filters,
    01046                               ImageArray<DestImage> &results)
    01047 {
    01048     int w= srcLowerRight.x - srcUpperLeft.x;
    01049     int h= srcLowerRight.y - srcUpperLeft.y;
    01050
    01051     FFTWComplexImage workImage(w, h);
    01052     copyImage(srcIterRange(srcUpperLeft, srcLowerRight, sa),
    01053               destImage(workImage, FFTWWriteRealAccessor()));
    01054
    01055     FFTWComplexImage const & cworkImage = workImage;
    01056     applyFourierFilterFamilyImpl(cworkImage.upperLeft(), cworkImage.lowerRight(), cworkImage.accessor(),
    01057                                  filters, results);
    01058 }
    01059
    01060 template <class FilterType, class DestImage>
    01061 inline
    01062 void applyFourierFilterFamily(
    01063     FFTWComplexImage::const_traverser srcUpperLeft,
    01064     FFTWComplexImage::const_traverser srcLowerRight,
    01065     FFTWComplexImage::ConstAccessor sa,
    01066     const ImageArray<FilterType> &filters,
    01067     ImageArray<DestImage> &results)
    01068 {
    01069     applyFourierFilterFamilyImpl(srcUpperLeft, srcLowerRight, sa,
    01070                                  filters, results);
    01071 }
    01072
    01073 template <class FilterType, class DestImage>
    01074 void applyFourierFilterFamilyImpl(
    01075     FFTWComplexImage::const_traverser srcUpperLeft,
    01076     FFTWComplexImage::const_traverser srcLowerRight,
    01077     FFTWComplexImage::ConstAccessor sa,
    01078     const ImageArray<FilterType> &filters,
    01079     ImageArray<DestImage> &results)
    01080 {
    01081     int w= srcLowerRight.x - srcUpperLeft.x;
    01082     int h= srcLowerRight.y - srcUpperLeft.y;
    01083
    01084     fftwnd_plan forwardPlan=
    01085         fftw2d_create_plan(h, w, FFTW_FORWARD, FFTW_ESTIMATE );
    01086     fftwnd_plan backwardPlan=
    01087         fftw2d_create_plan(h, w, FFTW_BACKWARD, FFTW_ESTIMATE | FFTW_IN_PLACE);
    01088
    01089     applyFourierFilterFamilyImpl(srcUpperLeft, srcLowerRight, sa,
    01090                                  filters, results,
    01091                                  forwardPlan, backwardPlan);
    01092
    01093     fftwnd_destroy_plan(forwardPlan);
    01094     fftwnd_destroy_plan(backwardPlan);
    01095 }
    01096
    01097 // applyFourierFilterFamily versions with fftwnd_plans:
    01098 template <class SrcImageIterator, class SrcAccessor,
    01099           class FilterType, class DestImage>
    01100 inline
    01101 void applyFourierFilterFamily(triple<SrcImageIterator, SrcImageIterator, SrcAccessor> src,
    01102                               const ImageArray<FilterType> &filters,
    01103                               ImageArray<DestImage> &results,
    01104                               const fftwnd_plan &forwardPlan, const fftwnd_plan &backwardPlan)
    01105 {
    01106     applyFourierFilterFamily(src.first, src.second, src.third,
    01107                                  filters, results,
    01108                                  forwardPlan, backwardPlan);
    01109 }
    01110
    01111 template <class SrcImageIterator, class SrcAccessor,
    01112           class FilterType, class DestImage>
    01113 void applyFourierFilterFamily(SrcImageIterator srcUpperLeft,
    01114                               SrcImageIterator srcLowerRight, SrcAccessor sa,
    01115                               const ImageArray<FilterType> &filters,
    01116                               ImageArray<DestImage> &results,
    01117                               const fftwnd_plan &forwardPlan, const fftwnd_plan &backwardPlan)
    01118 {
    01119     int w= srcLowerRight.x - srcUpperLeft.x;
    01120     int h= srcLowerRight.y - srcUpperLeft.y;
    01121
    01122     FFTWComplexImage workImage(w, h);
    01123     copyImage(srcIterRange(srcUpperLeft, srcLowerRight, sa),
    01124               destImage(workImage, FFTWWriteRealAccessor()));
    01125
    01126     FFTWComplexImage const & cworkImage = workImage;
    01127     applyFourierFilterFamilyImpl(cworkImage.upperLeft(), cworkImage.lowerRight(), cworkImage.accessor(),
    01128                                  filters, results,
    01129                                  forwardPlan, backwardPlan);
    01130 }
    01131
    01132 template <class FilterType, class DestImage>
    01133 inline
    01134 void applyFourierFilterFamily(
    01135     FFTWComplexImage::const_traverser srcUpperLeft,
    01136     FFTWComplexImage::const_traverser srcLowerRight,
    01137     FFTWComplexImage::ConstAccessor sa,
    01138     const ImageArray<FilterType> &filters,
    01139     ImageArray<DestImage> &results,
    01140     const fftwnd_plan &forwardPlan, const fftwnd_plan &backwardPlan)
    01141 {
    01142     int w= srcLowerRight.x - srcUpperLeft.x;
    01143     int h= srcLowerRight.y - srcUpperLeft.y;
    01144
    01145     // test for right memory layout (fftw expects a 2*width*height floats array)
    01146     if (&(*(srcUpperLeft + Diff2D(w, 0))) == &(*(srcUpperLeft + Diff2D(0, 1))))
    01147         applyFourierFilterFamilyImpl(srcUpperLeft, srcLowerRight, sa,
    01148                                      filters, results,
    01149                                      forwardPlan, backwardPlan);
    01150     else
    01151     {
    01152         FFTWComplexImage workImage(w, h);
    01153         copyImage(srcIterRange(srcUpperLeft, srcLowerRight, sa),
    01154                   destImage(workImage));
    01155
    01156         FFTWComplexImage const & cworkImage = workImage;
    01157         applyFourierFilterFamilyImpl(cworkImage.upperLeft(), cworkImage.lowerRight(), cworkImage.accessor(),
    01158                                      filters, results,
    01159                                      forwardPlan, backwardPlan);
    01160     }
    01161 }
    01162
    01163 template <class FilterType, class DestImage>
    01164 void applyFourierFilterFamilyImpl(
    01165     FFTWComplexImage::const_traverser srcUpperLeft,
    01166     FFTWComplexImage::const_traverser srcLowerRight,
    01167     FFTWComplexImage::ConstAccessor sa,
    01168     const ImageArray<FilterType> &filters,
    01169     ImageArray<DestImage> &results,
    01170     const fftwnd_plan &forwardPlan, const fftwnd_plan &backwardPlan)
    01171 {
    01172     // make sure the filter images have the right dimensions
    01173     vigra_precondition((srcLowerRight - srcUpperLeft) == filters.imageSize(),
    01174                        "applyFourierFilterFamily called with src image size != filters.imageSize()!");
    01175
    01176     // make sure the result image array has the right dimensions
    01177     results.resize(filters.size());
    01178     results.resizeImages(filters.imageSize());
    01179
    01180     // FFT from srcImage to freqImage
    01181     int w= srcLowerRight.x - srcUpperLeft.x;
    01182     int h= srcLowerRight.y - srcUpperLeft.y;
    01183
    01184     FFTWComplexImage freqImage(w, h);
    01185     FFTWComplexImage result(w, h);
    01186
    01187     fftwnd_one(forwardPlan, const_cast<FFTWComplex *>(&(*srcUpperLeft)), freqImage.begin());
    01188
    01189     typedef typename
    01190         NumericTraits<typename DestImage::Accessor::value_type>::isScalar
    01191         isScalarResult;
    01192
    01193     // convolve with filters in freq. domain
    01194     for (unsigned int i= 0;  i < filters.size(); i++)
    01195     {
    01196         combineTwoImages(srcImageRange(freqImage), srcImage(filters[i]),
    01197                          destImage(result), std::multiplies<FFTWComplex>());
    01198
    01199         // FFT back into spatial domain (inplace in destImage)
    01200         fftwnd_one(backwardPlan, result.begin(), 0);
    01201
    01202         // normalization (after FFTs), maybe stripping imaginary part
    01203         applyFourierFilterImplNormalization(result,
    01204                                             results[i].upperLeft(), results[i].accessor(),
    01205                                             isScalarResult());
    01206     }
    01207 }
    01208
    01209 } // namespace vigra
    01210
    01211 #endif // VIGRA_FFTW_HXX

© Ullrich Köthe (koethe@informatik.uni-hamburg.de) Cognitive Systems Group, University of Hamburg, Germany | html generated using doxygen and Python VIGRA 1.4.0 (21 Dec 2005)