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| vigra/imageiterator.hxx |
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    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 1.5.0, Dec 07 2006 )                                    */
    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           */
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    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       */
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    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_IMAGEITERATOR_HXX
    00040 #define VIGRA_IMAGEITERATOR_HXX
    00041
    00042 #include "utilities.hxx"
    00043 #include "accessor.hxx"
    00044 #include "iteratortraits.hxx"
    00045 #include "metaprogramming.hxx"
    00046
    00047 namespace vigra {
    00048
    00049 template <class IMAGEITERATOR>
    00050 class StridedIteratorPolicy
    00051 {
    00052   public:
    00053     typedef IMAGEITERATOR                            ImageIterator;
    00054     typedef typename IMAGEITERATOR::value_type       value_type;
    00055     typedef typename IMAGEITERATOR::difference_type::MoveY
    00056                                                      difference_type;
    00057     typedef typename IMAGEITERATOR::reference        reference;
    00058     typedef typename IMAGEITERATOR::index_reference  index_reference;
    00059     typedef typename IMAGEITERATOR::pointer          pointer;
    00060     typedef std::random_access_iterator_tag iterator_category;
    00061
    00062
    00063     struct BaseType
    00064     {
    00065         explicit BaseType(pointer c = 0, difference_type stride = 0)
    00066         : current_(c), stride_(stride)
    00067         {}
    00068
    00069         pointer current_;
    00070         difference_type stride_;
    00071     };
    00072
    00073     static void initialize(BaseType & /* d */) {}
    00074
    00075     static reference dereference(BaseType const & d)
    00076         { return const_cast<reference>(*d.current_); }
    00077
    00078     static index_reference dereference(BaseType const & d, difference_type n)
    00079     {
    00080         return const_cast<index_reference>(d.current_[n*d.stride_]);
    00081     }
    00082
    00083     static bool equal(BaseType const & d1, BaseType const & d2)
    00084         { return d1.current_ == d2.current_; }
    00085
    00086     static bool less(BaseType const & d1, BaseType const & d2)
    00087         { return d1.current_ < d2.current_; }
    00088
    00089     static difference_type difference(BaseType const & d1, BaseType const & d2)
    00090         { return (d1.current_ - d2.current_) / d1.stride_; }
    00091
    00092     static void increment(BaseType & d)
    00093         { d.current_ += d.stride_; }
    00094
    00095     static void decrement(BaseType & d)
    00096         { d.current_ -= d.stride_; }
    00097
    00098     static void advance(BaseType & d, difference_type n)
    00099         { d.current_ += d.stride_*n; }
    00100 };
    00101
    00102 /** \addtogroup ImageIterators  Image Iterators
    00103
    00104     \brief General image iterator definition and implementations.
    00105
    00106 <p>
    00107     The following tables describe the general requirements for image iterators
    00108     and their iterator traits. The iterator implementations provided here
    00109     may be used for any image data type that stores its
    00110     data as a linear array of pixels. The array will be interpreted as a
    00111     row-major matrix with a particular width.
    00112 </p>
    00113 <h3>Requirements for Image Iterators</h3>
    00114 <p>
    00115
    00116 <table border=2 cellspacing=0 cellpadding=2 width="100%">
    00117 <tr><td>
    00118     \htmlonly
    00119     <th colspan=2>
    00120     \endhtmlonly
    00121     Local Types
    00122     \htmlonly
    00123     </th><th>
    00124     \endhtmlonly
    00125     Meaning
    00126     \htmlonly
    00127     </th>
    00128     \endhtmlonly
    00129 </td></tr>
    00130 <tr><td>
    00131     \htmlonly
    00132     <td colspan=2>
    00133     \endhtmlonly
    00134     <tt>ImageIterator::value_type</tt></td><td>the underlying image's pixel type</td>
    00135 </tr>
    00136 <tr>
    00137     <td>
    00138     \htmlonly
    00139     <td colspan=2>
    00140     \endhtmlonly
    00141     <tt>ImageIterator::PixelType</tt></td><td>the underlying image's pixel type</td>
    00142 </tr>
    00143 <tr>
    00144     <td>
    00145     \htmlonly
    00146     <td colspan=2>
    00147     \endhtmlonly
    00148     <tt>ImageIterator::reference</tt></td>
    00149     <td>the iterator's reference type (return type of <TT>*iter</TT>). Will be
    00150     <tt>value_type &</tt> for a mutable iterator, and convertible to
    00151     <tt>value_type const &</tt> for a const iterator.</td>
    00152 </tr>
    00153 <tr>
    00154     <td>
    00155     \htmlonly
    00156     <td colspan=2>
    00157     \endhtmlonly
    00158     <tt>ImageIterator::index_reference</tt></td>
    00159     <td>the iterator's index reference type (return type of <TT>iter[diff]</TT>). Will be
    00160     <tt>value_type &</tt> for a mutable iterator, and convertible to
    00161     <tt>value_type const &</tt> for a const iterator.</td>
    00162 </tr>
    00163 <tr>
    00164     <td>
    00165     \htmlonly
    00166     <td colspan=2>
    00167     \endhtmlonly
    00168     <tt>ImageIterator::pointer</tt></td>
    00169     <td>the iterator's pointer type (return type of <TT>iter.operator->()</TT>). Will be
    00170     <tt>value_type *</tt> for a mutable iterator, and convertible to
    00171     <tt>value_type const *</tt> for a const iterator.</td>
    00172 </tr>
    00173 <tr>
    00174     <td>
    00175     \htmlonly
    00176     <td colspan=2>
    00177     \endhtmlonly
    00178     <tt>ImageIterator::difference_type</tt></td>
    00179     <td>the iterator's difference type (<TT>vigra::Diff2D</TT>)</td>
    00180 </tr>
    00181 <tr>
    00182     <td>
    00183     \htmlonly
    00184     <td colspan=2>
    00185     \endhtmlonly
    00186     <tt>ImageIterator::iterator_category</tt></td>
    00187     <td>the iterator tag (<tt>vigra::image_traverser_tag</tt>)</td>
    00188 </tr>
    00189 <tr>
    00190     <td>
    00191     \htmlonly
    00192     <td colspan=2>
    00193     \endhtmlonly
    00194     <tt>ImageIterator::row_iterator</tt></td><td>the associated row iterator</td>
    00195 </tr>
    00196 <tr>
    00197     <td>
    00198     \htmlonly
    00199     <td colspan=2>
    00200     \endhtmlonly
    00201     <tt>ImageIterator::column_iterator</tt></td><td>the associated column iterator</td>
    00202 </tr>
    00203 <tr>
    00204     <td>
    00205     \htmlonly
    00206     <td colspan=2>
    00207     \endhtmlonly
    00208     <tt>ImageIterator::MoveX</tt></td><td>type of the horizontal navigator</td>
    00209 </tr>
    00210 <tr>
    00211     <td>
    00212     \htmlonly
    00213     <td colspan=2>
    00214     \endhtmlonly
    00215     <tt>ImageIterator::MoveY</tt></td><td>type of the vertical navigator</td>
    00216 </tr>
    00217 <tr><td>
    00218     \htmlonly
    00219     <th>
    00220     \endhtmlonly
    00221     Operation
    00222     \htmlonly
    00223     </th><th>
    00224     \endhtmlonly
    00225     Result
    00226     \htmlonly
    00227     </th><th>
    00228     \endhtmlonly
    00229     Semantics
    00230     \htmlonly
    00231     </th>
    00232     \endhtmlonly
    00233 </td></tr>
    00234 <tr>
    00235     <td><tt>++i.x<br>i.x--</tt></td><td><tt>void</tt></td><td>increment x-coordinate</td>
    00236 </tr>
    00237 <tr>
    00238     <td><tt>--i.x<br>i.x--</tt></td><td><tt>void</tt></td><td>decrement x-coordinate</td>
    00239 </tr>
    00240 <tr>
    00241     <td><tt>i.x += dx</tt></td><td><tt>ImageIterator::MoveX &</tt></td>
    00242     <td>add <tt>dx</tt> to x-coordinate</td>
    00243 </tr>
    00244 <tr>
    00245     <td><tt>i.x -= dx</tt></td><td><tt>ImageIterator::MoveX &</tt></td>
    00246     <td>subtract <tt>dx</tt> from x-coordinate</td>
    00247 </tr>
    00248 <tr>
    00249     <td><tt>i.x - j.x</tt></td><td><tt>int</tt></td>
    00250     <td>difference of the x-coordinates of <tt>i</tt> and <tt>j</tt></td>
    00251 </tr>
    00252 <tr>
    00253     <td><tt>i.x = j.x</tt></td><td><tt>ImageIterator::MoveX &</tt></td><td><tt>i.x += j.x - i.x</tt></td>
    00254 </tr>
    00255 <tr>
    00256     <td><tt>i.x == i.y</tt></td><td><tt>bool</tt></td><td><tt>j.x - i.x == 0</tt></td>
    00257
    00258 </tr>
    00259 <tr>
    00260     <td><tt>i.x < j.x</tt></td><td><tt>bool</tt></td><td><tt>j.x - i.x > 0</tt></td>
    00261
    00262 </tr>
    00263 <tr>
    00264     <td><tt>++i.y<br>i.y++</tt></td><td><tt>void</tt></td><td>increment y-coordinate</td>
    00265 </tr>
    00266 <tr>
    00267     <td><tt>--i.y<br>i.y--</tt></td><td><tt>void</tt></td><td>decrement y-coordinate</td>
    00268 </tr>
    00269 <tr>
    00270     <td><tt>i.y += dy</tt></td><td><tt>ImageIterator::MoveY &</tt></td>
    00271     <td>add <tt>dy</tt> to y-coordinate</td>
    00272 </tr>
    00273 <tr>
    00274     <td><tt>i.y -= dy</tt></td><td><tt>ImageIterator::MoveY &</tt></td>
    00275     <td>subtract <tt>dy</tt> from y-coordinate</td>
    00276 </tr>
    00277 <tr>
    00278     <td><tt>i.y - j.y</tt></td><td><tt>int</tt></td>
    00279     <td>difference of the y-coordinates of <tt>i</tt> and <tt>j</tt></td>
    00280 </tr>
    00281 <tr>
    00282     <td><tt>i.y = j.y</tt></td><td><tt>ImageIterator::MoveY &</tt></td><td><tt>i.y += j.y - i.y</tt></td>
    00283 </tr>
    00284 <tr>
    00285     <td><tt>i.y == j.y</tt></td><td><tt>bool</tt></td><td><tt>j.y - i.y == 0</tt></td>
    00286
    00287 </tr>
    00288 <tr>
    00289     <td><tt>i.y < j.y</tt></td><td><tt>bool</tt></td><td><tt>j.y - i.y > 0</tt></td>
    00290 </tr>
    00291 <tr>
    00292     <td>
    00293     \htmlonly
    00294     <td colspan=2>
    00295     \endhtmlonly
    00296     <tt>ImageIterator k(i)</tt></td><td>copy constructor</td>
    00297 </tr>
    00298 <tr>
    00299     <td><tt>k = i</tt></td><td><tt>ImageIterator &</tt></td><td>assignment</td>
    00300 </tr>
    00301 <tr>
    00302     <td>
    00303     \htmlonly
    00304     <td colspan=2>
    00305     \endhtmlonly
    00306     <tt>ImageIterator k</tt></td><td>default constructor</td>
    00307 </tr>
    00308 <tr>
    00309     <td>
    00310     \htmlonly
    00311     <td colspan=2>
    00312     \endhtmlonly
    00313     <tt>ImageIterator::row_iterator r(i)</tt></td><td>construction of row iterator</td>
    00314 </tr>
    00315 <tr>
    00316     <td>
    00317     \htmlonly
    00318     <td colspan=2>
    00319     \endhtmlonly
    00320     <tt>ImageIterator::column_iterator c(i)</tt></td><td>construction of column iterator</td>
    00321 </tr>
    00322 <tr>
    00323     <td><tt>i += diff</tt></td><td><tt>ImageIterator &</tt></td>
    00324     <td><tt>{ i.x += diff.x<br>i.y += diff.y; }</tt></td>
    00325 </tr>
    00326 <tr>
    00327     <td><tt>i -= diff</tt></td><td><tt>ImageIterator &</tt></td>
    00328     <td><tt>{ i.x -= diff.x<br>i.y -= diff.y; }</tt></td>
    00329 </tr>
    00330 <tr>
    00331     <td><tt>i + diff</tt></td><td><tt>ImageIterator</tt></td>
    00332     <td><tt>{ ImageIterator tmp(i);<br>tmp += diff;<br>return tmp; }</tt></td>
    00333 </tr>
    00334 <tr>
    00335     <td><tt>i - diff</tt></td><td><tt>ImageIterator</tt></td>
    00336     <td><tt>{ ImageIterator tmp(i);<br>tmp -= diff;<br>return tmp; }</tt></td>
    00337 </tr>
    00338 <tr>
    00339     <td><tt>i - j</tt></td><td><tt>ImageIterator::difference_type</tt></td>
    00340     <td><tt>{ ImageIterator::difference_type tmp(i.x - j.x, i.y - j.y);<br>return tmp; }</tt></td>
    00341 </tr>
    00342 <tr>
    00343     <td><tt>i == j</tt></td><td><tt>bool</tt></td>
    00344     <td><tt>i.x == j.x && i.y == j.y</tt></td>
    00345 </tr>
    00346 <tr>
    00347     <td><tt>*i</tt></td><td><tt>ImageIterator::reference</tt></td>
    00348     <td>access the current pixel</td>
    00349 </tr>
    00350 <tr>
    00351     <td><tt>i[diff]</tt></td><td><tt>ImageIterator::index_reference</tt></td>
    00352     <td>access pixel at offset <tt>diff</tt></td>
    00353 </tr>
    00354 <tr>
    00355     <td><tt>i(dx, dy)</tt></td><td><tt>ImageIterator::index_reference</tt></td>
    00356     <td>access pixel at offset <tt>(dx, dy)</tt></td>
    00357 </tr>
    00358 <tr>
    00359     <td><tt>i->member()</tt></td><td>depends on operation</td>
    00360     <td>call member function of underlying pixel type via <tt>operator-></tt> of iterator</td>
    00361 </tr>
    00362 <tr>
    00363     <td>
    00364     \htmlonly
    00365     <td colspan=3>
    00366     \endhtmlonly
    00367        <tt>i, j, k</tt> are of type <tt>ImageIterator</tt><br>
    00368        <tt>diff</tt> is of type <tt>ImageIterator::difference_type</tt><br>
    00369        <tt>dx, dy</tt> are of type <tt>int</tt><br>
    00370     </td>
    00371 </tr>
    00372 </table>
    00373 </p>
    00374 <h3>Requirements for Image Iterator Traits</h3>
    00375 <p>
    00376 The following iterator traits must be defined for an image iterator:
    00377 </p>
    00378 <p>
    00379 <table border=2 cellspacing=0 cellpadding=2 width="100%">
    00380 <tr><td>
    00381     \htmlonly
    00382     <th>
    00383     \endhtmlonly
    00384     Types
    00385     \htmlonly
    00386     </th><th>
    00387     \endhtmlonly
    00388     Meaning
    00389     \htmlonly
    00390     </th>
    00391     \endhtmlonly
    00392 </td></tr>
    00393 <tr>
    00394     <td><tt>IteratorTraits&lt;ImageIterator&gt;::Iterator</tt></td><td>the iterator type the traits are referring to</td>
    00395 </tr>
    00396 <tr>
    00397     <td><tt>IteratorTraits&lt;ImageIterator&gt;::iterator</tt></td><td>the iterator type the traits are referring to</td>
    00398 </tr>
    00399 <tr>
    00400     <td><tt>IteratorTraits&lt;ImageIterator&gt;::value_type</tt></td><td>the underlying image's pixel type</td>
    00401 </tr>
    00402 <tr>
    00403     <td><tt>IteratorTraits&lt;ImageIterator&gt;::reference</tt></td>
    00404     <td>the iterator's reference type (return type of <TT>*iter</TT>)</td>
    00405 </tr>
    00406 <tr>
    00407     <td><tt>IteratorTraits&lt;ImageIterator&gt;::index_reference</tt></td>
    00408     <td>the iterator's index reference type (return type of <TT>iter[diff]</TT>)</td>
    00409 </tr>
    00410 <tr>
    00411     <td><tt>IteratorTraits&lt;ImageIterator&gt;::pointer</tt></td>
    00412     <td>the iterator's pointer type (return type of <TT>iter.operator->()</TT>)</td>
    00413 </tr>
    00414 <tr>
    00415     <td><tt>IteratorTraits&lt;ImageIterator&gt;::difference_type</tt></td>
    00416     <td>the iterator's difference type</td>
    00417 </tr>
    00418 <tr>
    00419     <td><tt>IteratorTraits&lt;ImageIterator&gt;::iterator_category</tt></td>
    00420     <td>the iterator tag (<tt>vigra::image_traverser_tag</tt>)</td>
    00421 </tr>
    00422 <tr>
    00423     <td><tt>IteratorTraits&lt;ImageIterator&gt;::row_iterator</tt></td><td>the associated row iterator</td>
    00424 </tr>
    00425 <tr>
    00426     <td><tt>IteratorTraits&lt;ImageIterator&gt;::column_iterator</tt></td><td>the associated column iterator</td>
    00427 </tr>
    00428 <tr>
    00429     <td><tt>IteratorTraits&lt;ImageIterator&gt;::DefaultAccessor</tt></td>
    00430     <td>the default accessor to be used with the iterator</td>
    00431 </tr>
    00432 <tr>
    00433     <td><tt>IteratorTraits&lt;ImageIterator&gt;::default_accessor</tt></td>
    00434     <td>the default accessor to be used with the iterator</td>
    00435 </tr>
    00436 <tr>
    00437     <td><tt>IteratorTraits&lt;ImageIterator&gt;::hasConstantStrides</tt></td>
    00438     <td>whether the iterator uses constant strides on the underlying memory
    00439         (always <tt>VigraTrueType</tt> for <tt>ImageIterator</tt>s).</td>
    00440 </tr>
    00441 </table>
    00442 </p>
    00443 */
    00444 //@{
    00445
    00446 namespace detail {
    00447
    00448 template <class StridedOrUnstrided>
    00449 class DirectionSelector;
    00450
    00451 template <>
    00452 class DirectionSelector<UnstridedArrayTag>
    00453 {
    00454   public:
    00455
    00456     template <class T>
    00457     class type
    00458     {
    00459       public:
    00460         type(T base)
    00461         : current_(base)
    00462         {}
    00463
    00464         type(type const & rhs)
    00465         : current_(rhs.current_)
    00466         {}
    00467
    00468         type & operator=(type const & rhs)
    00469         {
    00470             current_ = rhs.current_;
    00471             return *this;
    00472         }
    00473
    00474         void operator++() {++current_;}
    00475         void operator++(int) {++current_;}
    00476         void operator--() {--current_;}
    00477         void operator--(int) {--current_;}
    00478         void operator+=(int dx) {current_ += dx; }
    00479         void operator-=(int dx) {current_ -= dx; }
    00480
    00481         bool operator==(type const & rhs) const
    00482          { return current_ == rhs.current_; }
    00483
    00484         bool operator!=(type const & rhs) const
    00485          { return current_ != rhs.current_; }
    00486
    00487         bool operator<(type const & rhs) const
    00488          { return current_ < rhs.current_; }
    00489
    00490         bool operator<=(type const & rhs) const
    00491          { return current_ <= rhs.current_; }
    00492
    00493         bool operator>(type const & rhs) const
    00494          { return current_ > rhs.current_; }
    00495
    00496         bool operator>=(type const & rhs) const
    00497          { return current_ >= rhs.current_; }
    00498
    00499         int operator-(type const & rhs) const
    00500          { return current_ - rhs.current_; }
    00501
    00502         T operator()() const
    00503         { return current_; }
    00504
    00505         T operator()(int d) const
    00506         { return current_ + d; }
    00507
    00508         T current_;
    00509     };
    00510 };
    00511
    00512 template <>
    00513 class DirectionSelector<StridedArrayTag>
    00514 {
    00515   public:
    00516
    00517     template <class T>
    00518     class type
    00519     {
    00520       public:
    00521         type(int stride, T base = 0)
    00522         : stride_(stride),
    00523           current_(base)
    00524         {}
    00525
    00526         type(type const & rhs)
    00527         : stride_(rhs.stride_),
    00528           current_(rhs.current_)
    00529         {}
    00530
    00531         type & operator=(type const & rhs)
    00532         {
    00533             stride_ = rhs.stride_;
    00534             current_ = rhs.current_;
    00535             return *this;
    00536         }
    00537
    00538         void operator++() {current_ += stride_; }
    00539         void operator++(int) {current_ += stride_; }
    00540         void operator--() {current_ -= stride_; }
    00541         void operator--(int) {current_ -= stride_; }
    00542         void operator+=(int dy) {current_ += dy*stride_; }
    00543         void operator-=(int dy) {current_ -= dy*stride_; }
    00544
    00545         bool operator==(type const & rhs) const
    00546          { return (current_ == rhs.current_); }
    00547
    00548         bool operator!=(type const & rhs) const
    00549          { return (current_ != rhs.current_); }
    00550
    00551         bool operator<(type const & rhs) const
    00552          { return (current_ < rhs.current_); }
    00553
    00554         bool operator<=(type const & rhs) const
    00555          { return (current_ <= rhs.current_); }
    00556
    00557         bool operator>(type const & rhs) const
    00558          { return (current_ > rhs.current_); }
    00559
    00560         bool operator>=(type const & rhs) const
    00561          { return (current_ >= rhs.current_); }
    00562
    00563         int operator-(type const & rhs) const
    00564          { return (current_ - rhs.current_) / stride_; }
    00565
    00566         T operator()() const
    00567         { return current_; }
    00568
    00569         T operator()(int d) const
    00570         { return current_ + d*stride_; }
    00571
    00572         int stride_;
    00573         T current_;
    00574     };
    00575 };
    00576
    00577 template <class StridedOrUnstrided>
    00578 class LinearIteratorSelector;
    00579
    00580 template <>
    00581 class LinearIteratorSelector<UnstridedArrayTag>
    00582 {
    00583   public:
    00584     template <class IMAGEITERATOR>
    00585     class type
    00586     {
    00587       public:
    00588         typedef typename IMAGEITERATOR::pointer res;
    00589
    00590         template <class DirSelect>
    00591         static res construct(typename IMAGEITERATOR::pointer data, DirSelect const &)
    00592         {
    00593             return data;
    00594         }
    00595     };
    00596 };
    00597
    00598 template <>
    00599 class LinearIteratorSelector<StridedArrayTag>
    00600 {
    00601   public:
    00602     template <class IMAGEITERATOR>
    00603     class type
    00604     {
    00605       public:
    00606         typedef IteratorAdaptor<StridedIteratorPolicy<IMAGEITERATOR> > res;
    00607
    00608         template <class DirSelect>
    00609         static res construct(typename IMAGEITERATOR::pointer data, DirSelect const & d)
    00610         {
    00611             typedef typename res::BaseType Base;
    00612             return res(Base(data, d.stride_));
    00613         }
    00614     };
    00615 };
    00616
    00617
    00618 } // namespace detail
    00619
    00620 /********************************************************/
    00621 /*                                                      */
    00622 /*                      ImageIteratorBase               */
    00623 /*                                                      */
    00624 /********************************************************/
    00625
    00626 /** \brief Base class for 2D random access iterators.
    00627
    00628     This class contains the navigational part of the iterator.
    00629     It is usually not constructed directly, but via some derived class such as
    00630     \ref ImageIterator or \ref StridedImageIterator.
    00631
    00632     <b>\#include</b> "<a href="imageiterator_8hxx-source.html">vigra/imageiterator.hxx</a>"
    00633
    00634     Namespace: vigra
    00635
    00636     The usage examples assume that you constructed two iterators like
    00637     this:
    00638
    00639     \code
    00640     vigra::ImageIterator<SomePixelType> iterator(base, width);
    00641     vigra::ImageIterator<SomePixelType> iterator1(base, width);
    00642     \endcode
    00643
    00644     See the paper: U. Koethe:
    00645     <a href="documents/GenericProg2D.ps">Reusable Algorithms in Image Processing</a>
    00646     for a discussion of the concepts behind ImageIterators.
    00647
    00648 */
    00649 template <class IMAGEITERATOR,
    00650           class PIXELTYPE, class REFERENCE, class POINTER,
    00651           class StridedOrUnstrided = UnstridedArrayTag>
    00652 class ImageIteratorBase
    00653 {
    00654     typedef typename
    00655         detail::LinearIteratorSelector<StridedOrUnstrided>::template type<ImageIteratorBase>
    00656         RowIteratorSelector;
    00657     typedef typename
    00658         detail::LinearIteratorSelector<StridedArrayTag>::template type<ImageIteratorBase>
    00659         ColumnIteratorSelector;
    00660   public:
    00661     typedef ImageIteratorBase<IMAGEITERATOR,
    00662                  PIXELTYPE, REFERENCE, POINTER, StridedOrUnstrided> self_type;
    00663
    00664         /** The underlying image's pixel type.
    00665         */
    00666     typedef PIXELTYPE value_type;
    00667
    00668         /** deprecated, use <TT>value_type</TT> instead.
    00669         */
    00670     typedef PIXELTYPE PixelType;
    00671
    00672         /** the iterator's reference type (return type of <TT>*iter</TT>)
    00673         */
    00674     typedef REFERENCE            reference;
    00675
    00676         /** the iterator's index reference type (return type of <TT>iter[diff]</TT>)
    00677         */
    00678     typedef REFERENCE            index_reference;
    00679
    00680         /** the iterator's pointer type (return type of <TT>iter.operator->()</TT>)
    00681         */
    00682     typedef POINTER              pointer;
    00683
    00684         /** the iterator's difference type (argument type of <TT>iter[diff]</TT>)
    00685         */
    00686     typedef Diff2D               difference_type;
    00687
    00688         /** the iterator tag (image traverser)
    00689         */
    00690     typedef image_traverser_tag  iterator_category;
    00691
    00692         /** The associated row iterator.
    00693         */
    00694     typedef typename RowIteratorSelector::res row_iterator;
    00695
    00696         /** The associated column iterator.
    00697         */
    00698     typedef typename ColumnIteratorSelector::res column_iterator;
    00699
    00700         /** Let operations act in X direction
    00701         */
    00702     typedef typename
    00703         detail::DirectionSelector<StridedOrUnstrided>::template type<pointer> MoveX;
    00704
    00705         /** Let operations act in Y direction
    00706         */
    00707     typedef typename
    00708         detail::DirectionSelector<StridedArrayTag>::template type<int> MoveY;
    00709
    00710     /** @name Comparison of Iterators */
    00711     //@{
    00712         /** usage: <TT> iterator == iterator1 </TT>
    00713         */
    00714     bool operator==(ImageIteratorBase const & rhs) const
    00715     {
    00716         return (x == rhs.x) && (y == rhs.y);
    00717     }
    00718
    00719         /** usage: <TT> iterator != iterator1 </TT>
    00720         */
    00721     bool operator!=(ImageIteratorBase const & rhs) const
    00722     {
    00723         return (x != rhs.x) || (y != rhs.y);
    00724     }
    00725
    00726         /** usage: <TT> Diff2D dist = iterator - iterator1 </TT>
    00727         */
    00728     difference_type operator-(ImageIteratorBase const & rhs) const
    00729     {
    00730         return difference_type(x - rhs.x, y - rhs.y);
    00731     }
    00732
    00733     //@}
    00734
    00735     /** @name Specify coordinate to operate on */
    00736     //@{
    00737         /** Refer to iterator's x coordinate.
    00738             Usage examples:<br>
    00739             \code
    00740             ++iterator.x;        // move one step to the right
    00741             --iterator.x;        // move one step to the left
    00742             iterator.x += dx;    // move dx steps to the right
    00743             iterator.x -= dx;    // move dx steps to the left
    00744             bool notAtEndOfRow = iterator.x < lowerRight.x;   // compare x coordinates of two iterators
    00745             int width = lowerRight.x - upperLeft.x;           // calculate difference of x coordinates
    00746                                                               // between two iterators
    00747             \endcode
    00748         */
    00749     MoveX x;
    00750         /** Refer to iterator's y coordinate.
    00751             Usage examples:<br>
    00752             \code
    00753             ++iterator.y;        // move one step down
    00754             --iterator.y;        // move one step up
    00755             iterator.y += dy;    // move dy steps down
    00756             iterator.y -= dy;    // move dy steps up
    00757             bool notAtEndOfColumn = iterator.y < lowerRight.y; // compare y coordinates of two iterators
    00758             int height = lowerRight.y - upperLeft.y;           // calculate difference of y coordinates
    00759                                                                // between two iterators
    00760             \endcode
    00761         */
    00762     MoveY y;
    00763     //@}
    00764
    00765   protected:
    00766         /** Construct from raw memory with a vertical stride of <TT>ystride</TT>.
    00767         <TT>ystride</TT> must equal the physical image width (row length),
    00768         even if the iterator will only be used for a sub image. This constructor
    00769         must only be called for unstrided iterators
    00770         (<tt>StridedOrUnstrided == UnstridedArrayTag</tt>)
    00771         */
    00772     ImageIteratorBase(pointer base, int ystride)
    00773     : x(base),
    00774       y(ystride)
    00775     {}
    00776
    00777         /** Construct from raw memory with a horizontal stride of <TT>xstride</TT>
    00778         and a vertical stride of <TT>ystride</TT>. This constructor
    00779         may be used for iterators that shall skip pixels. Thus, it
    00780         must only be called for strided iterators
    00781         (<tt>StridedOrUnstrided == StridedArrayTag</tt>)
    00782         */
    00783     ImageIteratorBase(pointer base, int xstride, int ystride)
    00784     : x(xstride, base),
    00785       y(ystride)
    00786     {}
    00787
    00788         /** Copy constructor */
    00789     ImageIteratorBase(ImageIteratorBase const & rhs)
    00790     : x(rhs.x),
    00791       y(rhs.y)
    00792     {}
    00793
    00794         /** Default constructor */
    00795     ImageIteratorBase()
    00796     : x(0),
    00797       y(0)
    00798     {}
    00799
    00800         /** Copy assignment */
    00801     ImageIteratorBase & operator=(ImageIteratorBase const & rhs)
    00802     {
    00803         if(this != &rhs)
    00804         {
    00805             x = rhs.x;
    00806             y = rhs.y;
    00807         }
    00808         return *this;
    00809     }
    00810
    00811   public:
    00812     /** @name Random navigation */
    00813     //@{
    00814         /** Add offset via Diff2D
    00815         */
    00816     IMAGEITERATOR & operator+=(difference_type const & s)
    00817     {
    00818         x += s.x;
    00819         y += s.y;
    00820         return static_cast<IMAGEITERATOR &>(*this);
    00821     }
    00822         /** Subtract offset via Diff2D
    00823         */
    00824     IMAGEITERATOR & operator-=(difference_type const & s)
    00825     {
    00826         x -= s.x;
    00827         y -= s.y;
    00828         return static_cast<IMAGEITERATOR &>(*this);
    00829     }
    00830
    00831         /** Add a distance
    00832         */
    00833     IMAGEITERATOR operator+(difference_type const & s) const
    00834     {
    00835         IMAGEITERATOR ret(static_cast<IMAGEITERATOR const &>(*this));
    00836
    00837         ret += s;
    00838
    00839         return ret;
    00840     }
    00841
    00842         /** Subtract a distance
    00843         */
    00844     IMAGEITERATOR operator-(difference_type const & s) const
    00845     {
    00846         IMAGEITERATOR ret(static_cast<IMAGEITERATOR const &>(*this));
    00847
    00848         ret -= s;
    00849
    00850         return ret;
    00851     }
    00852    //@}
    00853
    00854     /** @name Access the Pixels */
    00855     //@{
    00856         /** Access current pixel. <br>
    00857             usage: <TT> SomePixelType value = *iterator </TT>
    00858         */
    00859     reference operator*() const
    00860     {
    00861         return *current();
    00862     }
    00863
    00864         /** Call member of current pixel. <br>
    00865             usage: <TT> iterator->pixelMemberFunction() </TT>
    00866         */
    00867     pointer operator->() const
    00868     {
    00869         return current();
    00870     }
    00871
    00872         /** Access pixel at offset from current location. <br>
    00873             usage: <TT> SomePixelType value = iterator[Diff2D(1,1)] </TT>
    00874         */
    00875     index_reference operator[](Diff2D const & d) const
    00876     {
    00877         return *current(d.x, d.y);
    00878     }
    00879
    00880         /** Access pixel at offset (dx, dy) from current location. <br>
    00881             usage: <TT> SomePixelType value = iterator(dx, dy) </TT>
    00882         */
    00883     index_reference operator()(int dx, int dy) const
    00884     {
    00885         return *current(dx, dy);
    00886     }
    00887
    00888         /** Read pixel with offset [dy][dx] from current pixel.
    00889             Note that the 'x' index is the trailing index. <br>
    00890             usage: <TT> SomePixelType value = iterator[dy][dx] </TT>
    00891         */
    00892     pointer operator[](int dy) const
    00893     {
    00894         return x() + y(dy);
    00895     }
    00896     //@}
    00897
    00898     row_iterator rowIterator() const
    00899     {
    00900         return RowIteratorSelector::construct(current(), x);
    00901     }
    00902
    00903     column_iterator columnIterator() const
    00904     {
    00905         return ColumnIteratorSelector::construct(current(), y);
    00906     }
    00907
    00908   private:
    00909
    00910     pointer current() const
    00911         { return x() + y(); }
    00912
    00913     pointer current(int dx, int dy) const
    00914         { return x(dx) + y(dy); }
    00915 };
    00916
    00917 /********************************************************/
    00918 /*                                                      */
    00919 /*                      ImageIterator                   */
    00920 /*                                                      */
    00921 /********************************************************/
    00922
    00923 /** \brief Standard 2D random access iterator for images that store the
    00924     data in a linear array.
    00925
    00926     Most functions and local types are inherited from ImageIteratorBase.
    00927
    00928     See the paper: U. Koethe:
    00929     <a href="documents/GenericProg2D.ps">Reusable Algorithms in Image Processing</a>
    00930     for a discussion of the concepts behind ImageIterators.
    00931
    00932     <b>\#include</b> "<a href="imageiterator_8hxx-source.html">vigra/imageiterator.hxx</a>"
    00933
    00934     Namespace: vigra
    00935
    00936 */
    00937 template <class PIXELTYPE>
    00938 class ImageIterator
    00939 : public ImageIteratorBase<ImageIterator<PIXELTYPE>,
    00940                            PIXELTYPE, PIXELTYPE &, PIXELTYPE *>
    00941 {
    00942   public:
    00943     typedef ImageIteratorBase<ImageIterator<PIXELTYPE>,
    00944                               PIXELTYPE, PIXELTYPE &, PIXELTYPE *> Base;
    00945
    00946     typedef typename Base::pointer         pointer;
    00947     typedef typename Base::difference_type difference_type;
    00948
    00949         /** Construct from raw memory with a vertical stride of <TT>ystride</TT>.
    00950         <TT>ystride</TT> must equal the physical image width (row length),
    00951         even if the iterator will only be used for a sub image.
    00952         If the raw memory is encapsulated in an image object this
    00953         object should have a factory function that constructs the
    00954         iterator.
    00955         */
    00956     ImageIterator(pointer base, int ystride)
    00957     : Base(base, ystride)
    00958     {}
    00959
    00960         /** Default constructor */
    00961     ImageIterator()
    00962     : Base()
    00963     {}
    00964
    00965 };
    00966
    00967 /********************************************************/
    00968 /*                                                      */
    00969 /*                   ConstImageIterator                 */
    00970 /*                                                      */
    00971 /********************************************************/
    00972
    00973 /** \brief Standard 2D random access const iterator for images that
    00974     store the data as a linear array.
    00975
    00976     Most functions are inherited from ImageIteratorBase.
    00977
    00978     <b>\#include</b> "<a href="imageiterator_8hxx-source.html">vigra/imageiterator.hxx</a>"
    00979
    00980     Namespace: vigra
    00981
    00982 */
    00983 template <class PIXELTYPE>
    00984 class ConstImageIterator
    00985 : public ImageIteratorBase<ConstImageIterator<PIXELTYPE>,
    00986                            PIXELTYPE, PIXELTYPE const &, PIXELTYPE const *>
    00987 {
    00988   public:
    00989     typedef ImageIteratorBase<ConstImageIterator<PIXELTYPE>,
    00990                         PIXELTYPE, PIXELTYPE const &, PIXELTYPE const *> Base;
    00991
    00992     typedef typename Base::pointer         pointer;
    00993     typedef typename Base::difference_type difference_type;
    00994
    00995         /** Construct from raw memory with a vertical stride of <TT>ystride</TT>.
    00996         <TT>ystride</TT> must equal the physical image width (row length),
    00997         even if the iterator will only be used for a sub image.
    00998         If the raw memory is encapsulated in an image object this
    00999         object should have a factory function that constructs the
    01000         iterator.
    01001         */
    01002     ConstImageIterator(pointer base, int ystride)
    01003     : Base(base, ystride)
    01004     {}
    01005
    01006     ConstImageIterator(ImageIterator<PIXELTYPE> const & o)
    01007     : Base(o.x, o.y)
    01008     {}
    01009
    01010         /** Default constructor */
    01011     ConstImageIterator()
    01012     : Base()
    01013     {}
    01014
    01015     ConstImageIterator & operator=(ImageIterator<PIXELTYPE> const & o)
    01016     {
    01017         Base::x = o.x;
    01018         Base::y = o.y;
    01019         return *this;
    01020     }
    01021 };
    01022
    01023 /********************************************************/
    01024 /*                                                      */
    01025 /*                 StridedImageIterator                 */
    01026 /*                                                      */
    01027 /********************************************************/
    01028
    01029 /** \brief Iterator to be used when pixels are to be skipped.
    01030
    01031     This iterator can be used when some pixels shall be automatically skipped, for example
    01032     if an image is to be sub-sampled: instead of advancing to the next pixel,
    01033     <tt>++iterator.x</tt> jumps to the pixel at a horizontal offset of <tt>xskip</tt>.
    01034     Likewise with <tt>yskip</tt> in vertical direction. Most functions and local types
    01035     are inherited from ImageIteratorBase.
    01036
    01037     <b> Usage:</b>
    01038
    01039     \code
    01040     BImage img(w,h);
    01041     ...
    01042     int xskip = 2, yskip = 2;
    01043     int wskip = w / xskip + 1, hskip = h / yskip + 1;
    01044
    01045     StridedImageIterator<BImage::value_type> upperLeft(&img(0,0), w, xskip, yskip);
    01046     StridedImageIterator<BImage::value_type> lowerRight = upperLeft + Diff2D(wskip, hskip);
    01047
    01048     // now navigation with upperLeft and lowerRight lets the image appear to have half
    01049     // the original resolution in either dimension
    01050     \endcode
    01051
    01052     <b>\#include</b> "<a href="imageiterator_8hxx-source.html">vigra/imageiterator.hxx</a>"
    01053
    01054     Namespace: vigra
    01055
    01056 */
    01057 template <class PIXELTYPE>
    01058 class StridedImageIterator
    01059 : public ImageIteratorBase<StridedImageIterator<PIXELTYPE>,
    01060                            PIXELTYPE, PIXELTYPE &, PIXELTYPE *, StridedArrayTag>
    01061 {
    01062   public:
    01063     typedef ImageIteratorBase<StridedImageIterator<PIXELTYPE>,
    01064                               PIXELTYPE, PIXELTYPE &, PIXELTYPE *, StridedArrayTag> Base;
    01065
    01066     typedef typename Base::pointer         pointer;
    01067     typedef typename Base::difference_type difference_type;
    01068
    01069         /** Construct from raw memory with a vertical stride of <TT>ystride</TT>,
    01070         jumping by <tt>xskip</tt> horizontally and <tt>yskip</tt> vertically.
    01071         <tt>ystride</tt> must be the physical width (row length) of the image.
    01072         */
    01073     StridedImageIterator(pointer base, int ystride, int xskip, int yskip)
    01074     : Base(base, xskip, ystride*yskip)
    01075     {}
    01076
    01077         /** Default constructor */
    01078     StridedImageIterator()
    01079     : Base()
    01080     {}
    01081
    01082 };
    01083
    01084 /********************************************************/
    01085 /*                                                      */
    01086 /*               ConstStridedImageIterator              */
    01087 /*                                                      */
    01088 /********************************************************/
    01089
    01090 /** \brief Const iterator to be used when pixels are to be skipped.
    01091
    01092     This iterator can be used when some pixels shall be automatically skipped, for example
    01093     if an image is to be sub-sampled: instead of advancing to the next pixel,
    01094     <tt>++iterator.x</tt> jumps to the pixel at a horizontal offset of <tt>xskip</tt>.
    01095     Likewise with <tt>yskip</tt> in vertical direction. Most functions and local types
    01096     are inherited from ImageIteratorBase.
    01097
    01098     <b> Usage:</b>
    01099
    01100     \code
    01101     BImage img(w,h);
    01102     ...
    01103     int xskip = 2, yskip = 2;
    01104     int wskip = w / xskip + 1, hskip = h / yskip + 1;
    01105
    01106     ConstStridedImageIterator<BImage::value_type> upperLeft(&img(0,0), w, xskip, yskip);
    01107     ConstStridedImageIterator<BImage::value_type> lowerRight = upperLeft + Diff2D(wskip, hskip);
    01108
    01109     // now navigation with upperLeft and lowerRight lets the image appear to have half
    01110     // the original resolution in either dimension
    01111     \endcode
    01112
    01113     <b>\#include</b> "<a href="imageiterator_8hxx-source.html">vigra/imageiterator.hxx</a>"
    01114
    01115     Namespace: vigra
    01116
    01117 */
    01118 template <class PIXELTYPE>
    01119 class ConstStridedImageIterator
    01120 : public ImageIteratorBase<ConstStridedImageIterator<PIXELTYPE>,
    01121                            PIXELTYPE, PIXELTYPE const &, PIXELTYPE const *,
    01122                            StridedArrayTag>
    01123 {
    01124   public:
    01125     typedef ImageIteratorBase<ConstStridedImageIterator<PIXELTYPE>,
    01126                         PIXELTYPE, PIXELTYPE const &, PIXELTYPE const *,
    01127                         StridedArrayTag> Base;
    01128
    01129     typedef typename Base::pointer         pointer;
    01130     typedef typename Base::difference_type difference_type;
    01131
    01132         /** Construct from raw memory with a vertical stride of <TT>ystride</TT>,
    01133         jumping by <tt>xskip</tt> horizontally and <tt>yskip</tt> vertically.
    01134         <tt>ystride</tt> must be the physical width (row length) of the image.
    01135         */
    01136     ConstStridedImageIterator(pointer base, int ystride, int xskip, int yskip)
    01137     : Base(base, xskip, ystride*yskip)
    01138     {}
    01139
    01140         /** Copy-construct from mutable iterator */
    01141     ConstStridedImageIterator(StridedImageIterator<PIXELTYPE> const & o)
    01142     : Base(o.x, o.y)
    01143     {}
    01144
    01145         /** Default constructor */
    01146     ConstStridedImageIterator()
    01147     : Base()
    01148     {}
    01149
    01150         /** Assign mutable iterator */
    01151     ConstStridedImageIterator & operator=(StridedImageIterator<PIXELTYPE> const & o)
    01152     {
    01153         Base::x = o.x;
    01154         Base::y = o.y;
    01155         return *this;
    01156     }
    01157 };
    01158
    01159 /********************************************************/
    01160 /*                                                      */
    01161 /*             definition of iterator traits            */
    01162 /*                                                      */
    01163 /********************************************************/
    01164
    01165
    01166 #ifndef NO_PARTIAL_TEMPLATE_SPECIALIZATION
    01167
    01168 template <class T>
    01169 struct IteratorTraits<ImageIterator<T> >
    01170 : public IteratorTraitsBase<ImageIterator<T> >
    01171 {
    01172     typedef ImageIterator<T>                              mutable_iterator;
    01173     typedef ConstImageIterator<T>                         const_iterator;
    01174     typedef typename AccessorTraits<T>::default_accessor  DefaultAccessor;
    01175     typedef DefaultAccessor                               default_accessor;
    01176     typedef VigraTrueType                                 hasConstantStrides;
    01177 };
    01178
    01179 template <class T>
    01180 struct IteratorTraits<ConstImageIterator<T> >
    01181 : public IteratorTraitsBase<ConstImageIterator<T> >
    01182 {
    01183     typedef ImageIterator<T>                              mutable_iterator;
    01184     typedef ConstImageIterator<T>                         const_iterator;
    01185     typedef typename AccessorTraits<T>::default_const_accessor  DefaultAccessor;
    01186     typedef DefaultAccessor                               default_accessor;
    01187     typedef VigraTrueType                                 hasConstantStrides;
    01188 };
    01189
    01190 template <class T>
    01191 struct IteratorTraits<StridedImageIterator<T> >
    01192 : public IteratorTraitsBase<StridedImageIterator<T> >
    01193 {
    01194     typedef StridedImageIterator<T>                       mutable_iterator;
    01195     typedef ConstStridedImageIterator<T>                  const_iterator;
    01196     typedef typename AccessorTraits<T>::default_accessor  DefaultAccessor;
    01197     typedef DefaultAccessor                               default_accessor;
    01198     typedef VigraTrueType                                 hasConstantStrides;
    01199 };
    01200
    01201 template <class T>
    01202 struct IteratorTraits<ConstStridedImageIterator<T> >
    01203 : public IteratorTraitsBase<ConstStridedImageIterator<T> >
    01204 {
    01205     typedef StridedImageIterator<T>                       mutable_iterator;
    01206     typedef ConstStridedImageIterator<T>                  const_iterator;
    01207     typedef typename AccessorTraits<T>::default_const_accessor  DefaultAccessor;
    01208     typedef DefaultAccessor                               default_accessor;
    01209     typedef VigraTrueType                                 hasConstantStrides;
    01210 };
    01211
    01212 #else // NO_PARTIAL_TEMPLATE_SPECIALIZATION
    01213
    01214 #define VIGRA_DEFINE_ITERATORTRAITS(VALUETYPE) \
    01215     template <>  \
    01216     struct IteratorTraits<ImageIterator<VALUETYPE > > \
    01217     : public IteratorTraitsBase<ImageIterator<VALUETYPE > > \
    01218     { \
    01219         typedef ImageIterator<VALUETYPE>                         mutable_iterator; \
    01220         typedef ConstImageIterator<VALUETYPE>                    const_iterator; \
    01221         typedef typename AccessorTraits<VALUETYPE >::default_accessor  DefaultAccessor; \
    01222         typedef DefaultAccessor                               default_accessor; \
    01223         typedef VigraTrueType                                 hasConstantStrides; \
    01224     }; \
    01225     \
    01226     template <>  \
    01227     struct IteratorTraits<ConstImageIterator<VALUETYPE > > \
    01228     : public IteratorTraitsBase<ConstImageIterator<VALUETYPE > > \
    01229     { \
    01230         typedef ImageIterator<VALUETYPE>                         mutable_iterator; \
    01231         typedef ConstImageIterator<VALUETYPE>                    const_iterator; \
    01232         typedef typename AccessorTraits<VALUETYPE >::default_const_accessor  DefaultAccessor; \
    01233         typedef DefaultAccessor                               default_accessor; \
    01234         typedef VigraTrueType                                 hasConstantStrides; \
    01235     }; \
    01236     template <>  \
    01237     struct IteratorTraits<StridedImageIterator<VALUETYPE > > \
    01238     : public IteratorTraitsBase<StridedImageIterator<VALUETYPE > > \
    01239     { \
    01240         typedef StridedImageIterator<VALUETYPE>                         mutable_iterator; \
    01241         typedef ConstStridedImageIterator<VALUETYPE>                    const_iterator; \
    01242         typedef typename AccessorTraits<VALUETYPE >::default_accessor  DefaultAccessor; \
    01243         typedef DefaultAccessor                               default_accessor; \
    01244         typedef VigraTrueType                                 hasConstantStrides; \
    01245     }; \
    01246     \
    01247     template <>  \
    01248     struct IteratorTraits<ConstStridedImageIterator<VALUETYPE > > \
    01249     : public IteratorTraitsBase<ConstStridedImageIterator<VALUETYPE > > \
    01250     { \
    01251         typedef StridedImageIterator<VALUETYPE>                         mutable_iterator; \
    01252         typedef ConstStridedImageIterator<VALUETYPE>                    const_iterator; \
    01253         typedef typename AccessorTraits<VALUETYPE >::default_const_accessor  DefaultAccessor; \
    01254         typedef DefaultAccessor                               default_accessor; \
    01255         typedef VigraTrueType                                 hasConstantStrides; \
    01256     };
    01257
    01258 VIGRA_DEFINE_ITERATORTRAITS(RGBValue<unsigned char>)
    01259 VIGRA_DEFINE_ITERATORTRAITS(RGBValue<short>)
    01260 VIGRA_DEFINE_ITERATORTRAITS(RGBValue<int>)
    01261 VIGRA_DEFINE_ITERATORTRAITS(RGBValue<float>)
    01262 VIGRA_DEFINE_ITERATORTRAITS(RGBValue<double>)
    01263
    01264 #define VIGRA_PIXELTYPE TinyVector<unsigned char, 2>
    01265 VIGRA_DEFINE_ITERATORTRAITS(VIGRA_PIXELTYPE)
    01266 #undef VIGRA_PIXELTYPE
    01267 #define VIGRA_PIXELTYPE TinyVector<unsigned char, 3>
    01268 VIGRA_DEFINE_ITERATORTRAITS(VIGRA_PIXELTYPE)
    01269 #undef VIGRA_PIXELTYPE
    01270 #define VIGRA_PIXELTYPE TinyVector<unsigned char, 4>
    01271 VIGRA_DEFINE_ITERATORTRAITS(VIGRA_PIXELTYPE)
    01272 #undef VIGRA_PIXELTYPE
    01273 #define VIGRA_PIXELTYPE TinyVector<short, 2>
    01274 VIGRA_DEFINE_ITERATORTRAITS(VIGRA_PIXELTYPE)
    01275 #undef VIGRA_PIXELTYPE
    01276 #define VIGRA_PIXELTYPE TinyVector<short, 3>
    01277 VIGRA_DEFINE_ITERATORTRAITS(VIGRA_PIXELTYPE)
    01278 #undef VIGRA_PIXELTYPE
    01279 #define VIGRA_PIXELTYPE TinyVector<short, 4>
    01280 VIGRA_DEFINE_ITERATORTRAITS(VIGRA_PIXELTYPE)
    01281 #undef VIGRA_PIXELTYPE
    01282 #define VIGRA_PIXELTYPE TinyVector<int, 2>
    01283 VIGRA_DEFINE_ITERATORTRAITS(VIGRA_PIXELTYPE)
    01284 #undef VIGRA_PIXELTYPE
    01285 #define VIGRA_PIXELTYPE TinyVector<int, 3>
    01286 VIGRA_DEFINE_ITERATORTRAITS(VIGRA_PIXELTYPE)
    01287 #undef VIGRA_PIXELTYPE
    01288 #define VIGRA_PIXELTYPE TinyVector<int, 4>
    01289 VIGRA_DEFINE_ITERATORTRAITS(VIGRA_PIXELTYPE)
    01290 #undef VIGRA_PIXELTYPE
    01291 #define VIGRA_PIXELTYPE TinyVector<float, 2>
    01292 VIGRA_DEFINE_ITERATORTRAITS(VIGRA_PIXELTYPE)
    01293 #undef VIGRA_PIXELTYPE
    01294 #define VIGRA_PIXELTYPE TinyVector<float, 3>
    01295 VIGRA_DEFINE_ITERATORTRAITS(VIGRA_PIXELTYPE)
    01296 #undef VIGRA_PIXELTYPE
    01297 #define VIGRA_PIXELTYPE TinyVector<float, 4>
    01298 VIGRA_DEFINE_ITERATORTRAITS(VIGRA_PIXELTYPE)
    01299 #undef VIGRA_PIXELTYPE
    01300 #define VIGRA_PIXELTYPE TinyVector<double, 2>
    01301 VIGRA_DEFINE_ITERATORTRAITS(VIGRA_PIXELTYPE)
    01302 #undef VIGRA_PIXELTYPE
    01303 #define VIGRA_PIXELTYPE TinyVector<double, 3>
    01304 VIGRA_DEFINE_ITERATORTRAITS(VIGRA_PIXELTYPE)
    01305 #undef VIGRA_PIXELTYPE
    01306 #define VIGRA_PIXELTYPE TinyVector<double, 4>
    01307 VIGRA_DEFINE_ITERATORTRAITS(VIGRA_PIXELTYPE)
    01308 #undef VIGRA_PIXELTYPE
    01309
    01310 #undef VIGRA_DEFINE_ITERATORTRAITS
    01311
    01312 #endif // NO_PARTIAL_TEMPLATE_SPECIALIZATION
    01313
    01314 template <class PIXELTYPE>
    01315 class ConstValueIteratorPolicy
    01316 {
    01317   public:
    01318
    01319     typedef PIXELTYPE                       value_type;
    01320     typedef int                             difference_type;
    01321     typedef PIXELTYPE const &               reference;
    01322     typedef PIXELTYPE const &               index_reference;
    01323     typedef PIXELTYPE const *               pointer;
    01324     typedef std::random_access_iterator_tag iterator_category;
    01325
    01326     struct BaseType
    01327     {
    01328         BaseType(PIXELTYPE const & v = PIXELTYPE(), int p = 0)
    01329         : value(v), pos(p)
    01330         {}
    01331
    01332         PIXELTYPE value;
    01333         int pos;
    01334     };
    01335
    01336     static void initialize(BaseType & d) {}
    01337
    01338     static reference dereference(BaseType const & d)
    01339         { return d.value; }
    01340
    01341     static index_reference dereference(BaseType d, difference_type)
    01342     {
    01343         return d.value;
    01344     }
    01345
    01346     static bool equal(BaseType const & d1, BaseType const & d2)
    01347         { return d1.pos == d2.pos; }
    01348
    01349     static bool less(BaseType const & d1, BaseType const & d2)
    01350         { return d1.pos < d2.pos; }
    01351
    01352     static difference_type difference(BaseType const & d1, BaseType const & d2)
    01353         { return d1.pos - d2.pos; }
    01354
    01355     static void increment(BaseType & d)
    01356         { ++d.pos; }
    01357
    01358     static void decrement(BaseType & d)
    01359         { --d.pos; }
    01360
    01361     static void advance(BaseType & d, difference_type n)
    01362         { d.pos += n; }
    01363 };
    01364
    01365 /********************************************************/
    01366 /*                                                      */
    01367 /*                 ConstValueIterator                   */
    01368 /*                                                      */
    01369 /********************************************************/
    01370
    01371 /** \brief Iterator that always returns the constant specified in the
    01372     constructor.
    01373
    01374     This iterator can be used to simulate an image that
    01375     does not actually exist.
    01376
    01377     <b>\#include</b> "<a href="imageiterator_8hxx-source.html">vigra/imageiterator.hxx</a>"
    01378
    01379     Namespace: vigra
    01380
    01381 */
    01382 template <class PIXELTYPE>
    01383 class ConstValueIterator
    01384 {
    01385   public:
    01386         /** The type of the constant the iterator holds.
    01387         */
    01388    typedef PIXELTYPE value_type;
    01389
    01390         /** The type of the constant the iterator holds.
    01391         */
    01392     typedef PIXELTYPE PixelType;
    01393
    01394         /** the iterator's reference type (return type of <TT>*iter</TT>)
    01395         */
    01396     typedef PIXELTYPE const &    reference;
    01397
    01398         /** the iterator's index reference type (return type of <TT>iter[diff]</TT>)
    01399         */
    01400     typedef PIXELTYPE const &    index_reference;
    01401
    01402         /** the iterator's pointer type (return type of <TT>iter.operator->()</TT>)
    01403         */
    01404     typedef PIXELTYPE const *    pointer;
    01405
    01406         /** the iterator's difference type (argument type of <TT>iter[diff]</TT>)
    01407         */
    01408     typedef Diff2D               difference_type;
    01409
    01410         /** the iterator tag (image traverser)
    01411         */
    01412     typedef image_traverser_tag  iterator_category;
    01413
    01414         /** The associated row iterator.
    01415         */
    01416     typedef IteratorAdaptor<ConstValueIteratorPolicy<PIXELTYPE> > row_iterator;
    01417
    01418         /** The associated column iterator.
    01419         */
    01420     typedef IteratorAdaptor<ConstValueIteratorPolicy<PIXELTYPE> > column_iterator;
    01421
    01422         /** Let operations act in X direction
    01423         */
    01424     typedef int MoveX;
    01425
    01426         /** Let operations act in Y direction
    01427         */
    01428     typedef int MoveY;
    01429
    01430         /** Default Constructor. (the constant is set to
    01431         <TT>NumericTraits<PIXELTYPE>::zero()</TT> )
    01432         */
    01433     ConstValueIterator()
    01434     : value_(NumericTraits<PIXELTYPE>::zero()), x(0), y(0)
    01435     {}
    01436
    01437         /** Construct with given constant.
    01438         */
    01439     ConstValueIterator(PixelType const & v)
    01440     : value_(v), x(0), y(0)
    01441     {}
    01442
    01443         /** Copy Constructor.
    01444        */
    01445     ConstValueIterator(ConstValueIterator const & v)
    01446     : value_(v.value_), x(v.x), y(v.y)
    01447     {}
    01448
    01449         /** Copy Assigment.
    01450         */
    01451     ConstValueIterator & operator=(ConstValueIterator const & v)
    01452     {
    01453         if(this != &v)
    01454         {
    01455             value_ = v.value_;
    01456             x = v.x;
    01457             y = v.y;
    01458         }
    01459         return *this;
    01460     }
    01461
    01462         /** Move iterator by specified distance.
    01463         */
    01464     ConstValueIterator & operator+=(Diff2D const & d)
    01465     {
    01466         x += d.x;
    01467         y += d.y;
    01468         return *this;
    01469     }
    01470
    01471         /** Move iterator by specified distance.
    01472         */
    01473     ConstValueIterator & operator-=(Diff2D const & d)
    01474     {
    01475         x -= d.x;
    01476         y -= d.y;
    01477         return *this;
    01478     }
    01479
    01480         /** Create iterator at specified distance.
    01481         */
    01482     ConstValueIterator operator+(Diff2D const & d) const
    01483     {
    01484         ConstValueIterator ret(*this);
    01485         ret += d;
    01486         return ret;
    01487     }
    01488
    01489         /** Create iterator at specified distance.
    01490         */
    01491     ConstValueIterator operator-(Diff2D const & d) const
    01492     {
    01493         ConstValueIterator ret(*this);
    01494         ret -= d;
    01495         return ret;
    01496     }
    01497
    01498         /** Compute distance between two iterators
    01499         */
    01500     Diff2D operator-(ConstValueIterator const & r) const
    01501     {
    01502         return Diff2D(x - r.x, y - r.y);
    01503     }
    01504
    01505         /** Equality.
    01506         */
    01507     bool operator==(ConstValueIterator const & r) const
    01508     {
    01509         return (x == r.x) && (y == r.y);
    01510     }
    01511
    01512         /** Inequality.
    01513         */
    01514     bool operator!=(ConstValueIterator const & r) const
    01515     {
    01516         return (x != r.x) || (y != r.y);
    01517     }
    01518
    01519         /** Read current pixel (return specified constant).
    01520         */
    01521     reference operator*() const
    01522     {
    01523         return value_;
    01524     }
    01525
    01526         /** Call member function for stored constant.
    01527         */
    01528     pointer operator->() const
    01529     {
    01530         return &value_;
    01531     }
    01532
    01533         /** Read pixel at a distance (return specified constant).
    01534         */
    01535     index_reference operator()(int const &, int const &) const
    01536     {
    01537         return value_;
    01538     }
    01539
    01540         /** Read pixel at a distance (return specified constant).
    01541         */
    01542     index_reference operator[](Diff2D const &) const
    01543     {
    01544         return value_;
    01545     }
    01546
    01547         /** Get row iterator at current position (which will also hold the constant).
    01548         */
    01549     row_iterator rowIterator() const
    01550         { return row_iterator(typename row_iterator::BaseType(value_, x)); }
    01551
    01552         /** Get column iterator at current position (which will also hold the constant).
    01553         */
    01554     column_iterator columnIterator() const
    01555         { return column_iterator(typename column_iterator::BaseType(value_, y)); }
    01556
    01557     /** @name Specify coordinate direction for navigation commands */
    01558     //@{
    01559         /// refer to x coordinate
    01560     int x;
    01561         /// refer to y coordinate
    01562     int y;
    01563     //@}
    01564
    01565   private:
    01566
    01567     PixelType value_;
    01568 };
    01569
    01570 #ifndef NO_PARTIAL_TEMPLATE_SPECIALIZATION
    01571
    01572 template <class T>
    01573 struct IteratorTraits<ConstValueIterator<T> >
    01574 {
    01575     typedef ConstValueIterator<T>                  Iterator;
    01576     typedef Iterator                               iterator;
    01577     typedef typename iterator::iterator_category   iterator_category;
    01578     typedef typename iterator::value_type          value_type;
    01579     typedef typename iterator::reference           reference;
    01580     typedef typename iterator::index_reference     index_reference;
    01581     typedef typename iterator::pointer             pointer;
    01582     typedef typename iterator::difference_type     difference_type;
    01583     typedef typename iterator::row_iterator        row_iterator;
    01584     typedef typename iterator::column_iterator     column_iterator;
    01585     typedef StandardConstAccessor<T>               DefaultAccessor;
    01586     typedef StandardConstAccessor<T>               default_accessor;
    01587     typedef VigraTrueType                                 hasConstantStrides;
    01588 };
    01589
    01590 #endif
    01591
    01592 typedef Diff2D CoordinateIterator;
    01593
    01594 /** \class CoordinateIterator
    01595
    01596     This used to be a separate class,
    01597     but has now become an alias for \ref vigra::Diff2D. This is possible because
    01598     Diff2D now provides all the necessary functionality.
    01599
    01600     CoordinateIterator behaves like a read-only \ref ImageIterator for
    01601     an image in which each pixel contains its coordinate. This is useful for
    01602     algorithms that need access to the current pixel's location.
    01603     For example, you can use CoordinateIterator/Diff2D to
    01604     find the center of mass of an image region. To implement this,
    01605     we first need a functor for center-of-mass calculations:
    01606
    01607     \code
    01608
    01609     struct CenterOfMassFunctor
    01610     {
    01611         CenterOfMassFunctor()
    01612         : x(0.0), y(0.0), size(0)
    01613         {}
    01614
    01615         void operator()(Diff2d const& diff)
    01616         {
    01617             ++size;
    01618             x += diff.x;
    01619             y += diff.y;
    01620         }
    01621
    01622         float xCenter() const
    01623         {   return x / size; }
    01624
    01625         float yCenter() const
    01626         {   return y / size; }
    01627
    01628         float x;
    01629         float y;
    01630         int size;
    01631     };
    01632     \endcode
    01633
    01634     Using this functor, we find the center of mass like so:
    01635
    01636     \code
    01637     vigra::BImage img(w,h);
    01638     ... // mark a region in the image with '1', background with '0'
    01639
    01640     CenterOfMassFunctor center;
    01641
    01642     vigra::inspectImageIf(
    01643         srcIterRange(Diff2D(), Diff2D() + img.size()),
    01644         srcImage(img),
    01645         center);
    01646
    01647     std::cout << "Center of mass: " << center.xCenter() <<
    01648                                 ", " << center.yCenter() << std::endl;
    01649     \endcode
    01650
    01651     <b>\#include</b> "<a href="imageiterator_8hxx-source.html">vigra/imageiterator.hxx</a>"
    01652
    01653     Namespace: vigra
    01654
    01655     \brief Simulate an image where each pixel contains its coordinate
    01656 */
    01657
    01658 //@}
    01659
    01660 } // namespace vigra
    01661
    01662 #endif // VIGRA_IMAGEITERATOR_HXX

© Ullrich Köthe (koethe@informatik.uni-hamburg.de) Cognitive Systems Group, University of Hamburg, Germany | html generated using doxygen and Python VIGRA 1.5.0 (7 Dec 2006)