This file is indexed.

/usr/include/vigra/combineimages.hxx is in libvigraimpex-dev 1.7.1+dfsg1-2ubuntu4.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
/************************************************************************/
/*                                                                      */
/*               Copyright 1998-2002 by Ullrich Koethe                  */
/*                                                                      */
/*    This file is part of the VIGRA computer vision library.           */
/*    The VIGRA Website is                                              */
/*        http://hci.iwr.uni-heidelberg.de/vigra/                       */
/*    Please direct questions, bug reports, and contributions to        */
/*        ullrich.koethe@iwr.uni-heidelberg.de    or                    */
/*        vigra@informatik.uni-hamburg.de                               */
/*                                                                      */
/*    Permission is hereby granted, free of charge, to any person       */
/*    obtaining a copy of this software and associated documentation    */
/*    files (the "Software"), to deal in the Software without           */
/*    restriction, including without limitation the rights to use,      */
/*    copy, modify, merge, publish, distribute, sublicense, and/or      */
/*    sell copies of the Software, and to permit persons to whom the    */
/*    Software is furnished to do so, subject to the following          */
/*    conditions:                                                       */
/*                                                                      */
/*    The above copyright notice and this permission notice shall be    */
/*    included in all copies or substantial portions of the             */
/*    Software.                                                         */
/*                                                                      */
/*    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND    */
/*    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES   */
/*    OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND          */
/*    NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT       */
/*    HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,      */
/*    WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING      */
/*    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR     */
/*    OTHER DEALINGS IN THE SOFTWARE.                                   */                
/*                                                                      */
/************************************************************************/
 
 
#ifndef VIGRA_COMBINEIMAGES_HXX
#define VIGRA_COMBINEIMAGES_HXX

#include "utilities.hxx"
#include "numerictraits.hxx"
#include "functortraits.hxx"
#include <cmath>

namespace vigra {

/** \addtogroup CombineAlgo Algorithms to Combine Images

    Apply functor to calculate a pixelwise transformation depending on multiple images.
    Note that the binary functors of the STL may be used with these functions.
*/
//@{

/********************************************************/
/*                                                      */
/*                    combine...Lines                   */
/*                                                      */
/********************************************************/

template <class SrcIterator1, class SrcAccessor1,
          class SrcIterator2, class SrcAccessor2,
          class DestIterator, class DestAccessor, class Functor>
void
combineTwoLines(SrcIterator1 s1, 
                SrcIterator1 s1end, SrcAccessor1 src1,
                SrcIterator2 s2, SrcAccessor2 src2,
                DestIterator d, DestAccessor dest,
                Functor const & f)
{
    for(; s1 != s1end; ++s1, ++s2, ++d)
        dest.set(f(src1(s1), src2(s2)), d);
}

template <class SrcIterator1, class SrcAccessor1,
          class SrcIterator2, class SrcAccessor2,
          class MaskIterator, class MaskAccessor, 
          class DestIterator, class DestAccessor, class Functor>
void
combineTwoLinesIf(SrcIterator1 s1, 
                  SrcIterator1 s1end, SrcAccessor1 src1,
                  SrcIterator2 s2, SrcAccessor2 src2,
                  MaskIterator m, MaskAccessor mask,
                  DestIterator d, DestAccessor dest,
                  Functor const & f)
{
    for(; s1 != s1end; ++s1, ++s2, ++m, ++d)
        if(mask(m))
            dest.set(f(src1(s1), src2(s2)), d);
}

template <class SrcIterator1, class SrcAccessor1,
          class SrcIterator2, class SrcAccessor2,
          class SrcIterator3, class SrcAccessor3,
          class DestIterator, class DestAccessor, class Functor>
void
combineThreeLines(SrcIterator1 s1, 
                  SrcIterator1 s1end, SrcAccessor1 src1,
                  SrcIterator2 s2, SrcAccessor2 src2,
                  SrcIterator3 s3, SrcAccessor3 src3,
                  DestIterator d, DestAccessor dest,
                  Functor const & f)
{
    for(; s1 != s1end; ++s1, ++s2, ++s3, ++d)
        dest.set(f(src1(s1), src2(s2), src3(s3)), d);
}

/********************************************************/
/*                                                      */
/*                    combineTwoImages                  */
/*                                                      */
/********************************************************/

/** \brief Combine two source images into destination image.

    The transformation given by the functor is applied to the source 
    pixels and the result written into the corresponding destination pixel.
    This is typically used for operations like add and subtract.
    The function uses accessors to access the pixel data.
    Note that the binary functors of the STL can be used in addition to
    the functors specifically defined in \ref CombineFunctor.
    Creation of new functors is easiest by using \ref FunctorExpressions.
    
    <b> Declarations:</b>
    
    pass arguments explicitly:
    \code
    namespace vigra {
        template <class SrcImageIterator1, class SrcAccessor1,
              class SrcImageIterator2, class SrcAccessor2,
              class DestImageIterator, class DestAccessor,
              class Functor>
        void
        combineTwoImages(SrcImageIterator1 src1_upperleft, 
                 SrcImageIterator1 src1_lowerright, SrcAccessor1 sa1,
                 SrcImageIterator2 src2_upperleft, SrcAccessor2 sa2,
                 DestImageIterator dest_upperleft, DestAccessor da,
                 Functor const & f)
    }
    \endcode
    
    
    use argument objects in conjunction with \ref ArgumentObjectFactories :
    \code
    namespace vigra {
        template <class SrcImageIterator1, class SrcAccessor1,
              class SrcImageIterator2, class SrcAccessor2,
              class DestImageIterator, class DestAccessor,
              class Functor>
        void
        combineTwoImages(triple<SrcImageIterator1, SrcImageIterator1, SrcAccessor1> src1,
                 pair<SrcImageIterator2, SrcAccessor2> src2,
                 pair<DestImageIterator, DestAccessor> dest,
                 Functor const & f)
    }
    \endcode
    
    <b> Usage:</b>
    
        <b>\#include</b> \<<a href="combineimages_8hxx-source.html">vigra/combineimages.hxx</a>\><br>
        Namespace: vigra
    
    \code
    #include <functional>     // for plus

    vigra::combineTwoImages(
                srcIterRange(src1.upperLeft(), src1.lowerRight()), 
                srcIter(src2.upperLeft()), 
                destIter(dest.upperLeft()),  
                std::plus<SrcValueType>());
    
    \endcode
    
    Note that <TT>SrcValueType</TT> must be replaced with the appropriate type (e.g. 
    the promote type of the input images' pixel type, see also 
    \ref NumericPromotionTraits)
    
    <b> Required Interface:</b>
    
    \code
    SrcImageIterator1 src1_upperleft, src1_lowerright;
    SrcImageIterator2 src2_upperleft;
    DestImageIterator dest_upperleft;
    SrcImageIterator1::row_iterator sx1 = src1_upperleft.rowIterator();
    SrcImageIterator2::row_iterator sx2 = src2_upperleft.rowIterator();
    DestImageIterator::row_iterator dx = dest_upperleft.rowIterator();
    
    SrcAccessor1 src1_accessor;
    SrcAccessor2 src2_accessor;
    DestAccessor dest_accessor;
    
    Functor functor;

    dest_accessor.set(
          functor(src1_accessor(sx1), src2_accessor(sx2)), 
          dx);

    \endcode
    
    
*/
doxygen_overloaded_function(template <...> void combineTwoImages)

template <class SrcImageIterator1, class SrcAccessor1,
          class SrcImageIterator2, class SrcAccessor2,
          class DestImageIterator, class DestAccessor,
          class Functor>
void
combineTwoImages(SrcImageIterator1 src1_upperleft, 
                 SrcImageIterator1 src1_lowerright, SrcAccessor1 sa1,
                 SrcImageIterator2 src2_upperleft, SrcAccessor2 sa2,
                 DestImageIterator dest_upperleft, DestAccessor da,
                 Functor const & f)
{
    int w = src1_lowerright.x - src1_upperleft.x;
    
    for(; src1_upperleft.y < src1_lowerright.y; 
            ++src1_upperleft.y, ++src2_upperleft.y, ++dest_upperleft.y)
    {
        combineTwoLines(src1_upperleft.rowIterator(), 
                        src1_upperleft.rowIterator() + w, sa1, 
                        src2_upperleft.rowIterator(), sa2, 
                        dest_upperleft.rowIterator(), da, f);
    }
}
    
template <class SrcImageIterator1, class SrcAccessor1,
          class SrcImageIterator2, class SrcAccessor2,
          class DestImageIterator, class DestAccessor,
          class Functor>
inline
void
combineTwoImages(triple<SrcImageIterator1, SrcImageIterator1, SrcAccessor1> src1,
             pair<SrcImageIterator2, SrcAccessor2> src2,
             pair<DestImageIterator, DestAccessor> dest,
             Functor const & f)
{
    combineTwoImages(src1.first, src1.second, src1.third, 
                     src2.first, src2.second, 
             dest.first, dest.second, f);
}

/********************************************************/
/*                                                      */
/*                  combineTwoImagesIf                  */
/*                                                      */
/********************************************************/

/** \brief Combine ROI of two source images into destination image.

    The transformation given by the functor is applied to all source 
    pixels in the ROI (i.e. whenever the return value of the mask's accessor
    is not zero)
    and the result written into the corresponding destination pixel.
    This is typically used for operations like add and subtract.
    The function uses accessors to access the pixel data.
    Note that the binary functors of the STL can be used in addition to
    the functors specifically defined in \ref CombineFunctor.
    Creation of new functors is easiest by using \ref FunctorExpressions.
    
    <b> Declarations:</b>
    
    pass arguments explicitly:
    \code
    namespace vigra {
        template <class SrcImageIterator1, class SrcAccessor1,
              class SrcImageIterator2, class SrcAccessor2,
              class MaskImageIterator, class MaskAccessor,
              class DestImageIterator, clas DestAccessor,
              class Functor>
        void
        combineTwoImagesIf(SrcImageIterator1 src1_upperleft, 
                   SrcImageIterator1 src1_lowerright, SrcAccessor1 sa1,
                   SrcImageIterator2 src2_upperleft, SrcAccessor2 sa2,
                   MaskImageIterator mask_upperleft, MaskAccessor ma,
                   DestImageIterator dest_upperleft, DestAccessor da,
                   Functor const & f)
    }
    \endcode
    
    
    use argument objects in conjunction with \ref ArgumentObjectFactories :
    \code
    namespace vigra {
        template <class SrcImageIterator1, class SrcAccessor1,
              class SrcImageIterator2, class SrcAccessor2,
              class MaskImageIterator, class MaskAccessor,
              class DestImageIterator, clas DestAccessor,
              class Functor>
        void
        combineTwoImagesIf(triple<SrcImageIterator1, SrcImageIterator1, SrcAccessor1> src1,
                   pair<SrcImageIterator2, SrcAccessor2> src2,
                   pair<MaskImageIterator, MaskAccessor> mask,
                   pair<DestImageIterator, DestAccessor> dest,
                   Functor const & f)
    }
    \endcode
    
    <b> Usage:</b>
    
        <b>\#include</b> \<<a href="combineimages_8hxx-source.html">vigra/combineimages.hxx</a>\><br>
        Namespace: vigra
    
    \code
    #include <functional>     // for plus

    vigra::combineTwoImagesIf(
                srcIterRange(src1.upperLeft(), src1.lowerRight()), 
                srcIter(src2.upperLeft()), 
                maskIter(mask.upperLeft()), 
                destIter(dest.upperLeft()),
                std::plus<SrcValueType>());
    
    \endcode

    Note that <TT>SrcValueType</TT> must be replaced with the appropriate type (e.g. 
    the promote type of the input images' pixel type, see also 
    \ref NumericPromotionTraits)
    
    <b> Required Interface:</b>
    
    \code
    SrcImageIterator1 src1_upperleft, src1_lowerright;
    SrcImageIterator2 src2_upperleft;
    MaskImageIterator mask_upperleft;
    DestImageIterator dest_upperleft;
    SrcImageIterator1::row_iterator sx1 = src1_upperleft.rowIterator();
    SrcImageIterator2::row_iterator sx2 = src2_upperleft.rowIterator();
    MaskImageIterator::row_iterator mx = mask_upperleft.rowIterator();
    DestImageIterator::row_iterator dx = dest_upperleft.rowIterator();
    
    
    SrcAccessor1 src1_accessor;
    SrcAccessor2 src2_accessor;
    MaskAccessor mask_accessor;
    DestAccessor dest_accessor;
    
    Functor functor;
    
    if(mask_accessor(mx))
       dest_accessor.set(
          functor(src1_accessor(sx1), src2_accessor(sx2)), 
          dx);

    \endcode
    
*/
doxygen_overloaded_function(template <...> void combineTwoImagesIf)

template <class SrcImageIterator1, class SrcAccessor1,
          class SrcImageIterator2, class SrcAccessor2,
          class MaskImageIterator, class MaskAccessor,
          class DestImageIterator, class DestAccessor,
          class Functor>
void
combineTwoImagesIf(SrcImageIterator1 src1_upperleft, 
                   SrcImageIterator1 src1_lowerright, SrcAccessor1 sa1,
                   SrcImageIterator2 src2_upperleft, SrcAccessor2 sa2,
                   MaskImageIterator mask_upperleft, MaskAccessor ma,
                   DestImageIterator dest_upperleft, DestAccessor da,
                   Functor const & f)
{
    int w = src1_lowerright.x - src1_upperleft.x;
    
    for(; src1_upperleft.y < src1_lowerright.y;
          ++src1_upperleft.y, ++src2_upperleft.y, 
          ++dest_upperleft.y, ++mask_upperleft.y)
    {
        combineTwoLinesIf(src1_upperleft.rowIterator(), 
                          src1_upperleft.rowIterator() + w, sa1, 
                          src2_upperleft.rowIterator(), sa2, 
                          mask_upperleft.rowIterator(), ma, 
                          dest_upperleft.rowIterator(), da, f);
    }
}
    
template <class SrcImageIterator1, class SrcAccessor1,
          class SrcImageIterator2, class SrcAccessor2,
          class MaskImageIterator, class MaskAccessor,
          class DestImageIterator, class DestAccessor,
          class Functor>
inline
void
combineTwoImagesIf(triple<SrcImageIterator1, SrcImageIterator1, SrcAccessor1> src1,
               pair<SrcImageIterator2, SrcAccessor2> src2,
               pair<MaskImageIterator, MaskAccessor> mask,
               pair<DestImageIterator, DestAccessor> dest,
               Functor const & f)
{
    combineTwoImagesIf(src1.first, src1.second, src1.third, 
                       src2.first, src2.second, 
                       mask.first, mask.second, 
                       dest.first, dest.second, f);
}

/********************************************************/
/*                                                      */
/*                  combineThreeImages                  */
/*                                                      */
/********************************************************/

/** \brief Combine three source images into destination image.

    The transformation given by the functor is applied to the source 
    pixels and the result written into the corresponding destination pixel.
    The function uses accessors to access the pixel data.
    Creation of new functors is easiest by using \ref FunctorExpressions.
    
    <b> Declarations:</b>
    
    pass arguments explicitly:
    \code
    namespace vigra {
        template <class SrcImageIterator1, class SrcAccessor1,
              class SrcImageIterator2, class SrcAccessor2,
              class SrcImageIterator3, class SrcAccessor3,
              class DestImageIterator, class DestAccessor,
              class Functor>
        void
        combineThreeImages(SrcImageIterator1 src1_upperleft, 
                   SrcImageIterator1 src1_lowerright, SrcAccessor1 sa1,
                   SrcImageIterator2 src2_upperleft, SrcAccessor2 sa2,
                   SrcImageIterator3 src2_upperleft, SrcAccessor3 sa3,
                   DestImageIterator dest_upperleft, DestAccessor da,
                   Functor const & f)
    }
    \endcode
    
    
    use argument objects in conjunction with \ref ArgumentObjectFactories :
    \code
    namespace vigra {
        template <class SrcImageIterator1, class SrcAccessor1,
              class SrcImageIterator2, class SrcAccessor2,
              class SrcImageIterator3, class SrcAccessor3,
              class DestImageIterator, class DestAccessor,
              class Functor>
        void
        combineThreeImages(triple<SrcImageIterator1, SrcImageIterator1, SrcAccessor1> src1,
                 pair<SrcImageIterator2, SrcAccessor2> src2,
                 pair<SrcImageIterator3, SrcAccessor3> src3,
                 pair<DestImageIterator, DestAccessor> dest,
                 Functor const & f)
    }
    \endcode
    
    <b> Usage:</b>
    
        <b>\#include</b> \<<a href="combineimages_8hxx-source.html">vigra/combineimages.hxx</a>\><br>
        Namespace: vigra
    
    \code
    vigra::combineThreeImages(
                srcIterRange(src1.upperLeft(), src1.lowerRight()), 
                srcIter(src2.upperLeft()), 
                srcIter(src3.upperLeft()), 
                destIter(dest.upperLeft()),  
                SomeThreeArgumentFunctor());
    
    \endcode

    <b> Required Interface:</b>
    
    \code
    SrcImageIterator1 src1_upperleft, src1_lowerright;
    SrcImageIterator2 src2_upperleft;
    SrcImageIterator3 src3_upperleft;
    DestImageIterator dest_upperleft;
    SrcImageIterator1::row_iterator sx1 = src1_upperleft.rowIterator();
    SrcImageIterator2::row_iterator sx2 = src2_upperleft.rowIterator();
    SrcImageIterator3::row_iterator sx3 = src3_upperleft.rowIterator();
    DestImageIterator::row_iterator dx = dest_upperleft.rowIterator();
    
    SrcAccessor1 src1_accessor;
    SrcAccessor2 src2_accessor;
    SrcAccessor3 src3_accessor;
    DestAccessor dest_accessor;
    
    Functor functor;

    dest_accessor.set(
          functor(src1_accessor(sx1), 
                  src2_accessor(sx2), 
                  src3_accessor(sx3)), 
          dx);

    \endcode
    
    
*/
doxygen_overloaded_function(template <...> void combineThreeImages)

template <class SrcImageIterator1, class SrcAccessor1,
          class SrcImageIterator2, class SrcAccessor2,
          class SrcImageIterator3, class SrcAccessor3,
          class DestImageIterator, class DestAccessor,
          class Functor>
void
combineThreeImages(SrcImageIterator1 src1_upperleft, 
                   SrcImageIterator1 src1_lowerright, SrcAccessor1 sa1,
                   SrcImageIterator2 src2_upperleft, SrcAccessor2 sa2,
                   SrcImageIterator3 src3_upperleft, SrcAccessor3 sa3,
                   DestImageIterator dest_upperleft, DestAccessor da,
                   Functor const & f)
{
    int w = src1_lowerright.x - src1_upperleft.x;
    
    for(; src1_upperleft.y < src1_lowerright.y;
        ++src1_upperleft.y, ++src2_upperleft.y, ++src3_upperleft.y, 
        ++dest_upperleft.y)
    {
        combineThreeLines(src1_upperleft.rowIterator(), 
                          src1_upperleft.rowIterator() + w, sa1, 
                          src2_upperleft.rowIterator(), sa2, 
                          src3_upperleft.rowIterator(), sa3, 
                          dest_upperleft.rowIterator(), da, f);
    }
}
    
template <class SrcImageIterator1, class SrcAccessor1,
          class SrcImageIterator2, class SrcAccessor2,
          class SrcImageIterator3, class SrcAccessor3,
          class DestImageIterator, class DestAccessor,
          class Functor>
inline
void
combineThreeImages(triple<SrcImageIterator1, SrcImageIterator1, SrcAccessor1> src1,
             pair<SrcImageIterator2, SrcAccessor2> src2,
             pair<SrcImageIterator3, SrcAccessor3> src3,
             pair<DestImageIterator, DestAccessor> dest,
             Functor const & f)
{
    combineThreeImages(src1.first, src1.second, src1.third, 
                     src2.first, src2.second, 
                     src3.first, src3.second, 
                     dest.first, dest.second, f);
}

    
//@}

/** \addtogroup CombineFunctor Functors to Combine Images

    Common functors with several arguments
*/
//@{

/********************************************************/
/*                                                      */
/*                    MagnitudeFunctor                  */
/*                                                      */
/********************************************************/

/** Calculate the magnitude from two arguments.
    Can be used in conjunction with \ref gradientBasedTransform().
    
    If the gradient is represented by a vector-valued image instead of 
    a pair of scalar images, use \ref vigra::VectorNormFunctor.

    <b> Traits defined:</b>
    
    <tt>FunctorTraits::isBinaryFunctor</tt> are true (<tt>VigraTrueType</tt>)    
*/
template <class ValueType>
class MagnitudeFunctor
{
  public:
        /** the functor's first argument type
        */
    typedef ValueType first_argument_type;
    
        /** the functor's second argument type
        */
    typedef ValueType second_argument_type;
    
        /** the functor's result type
        */
    typedef typename SquareRootTraits<typename NormTraits<ValueType>::SquaredNormType>::SquareRootResult result_type;
    
        /** \deprecated use first_argument_type, second_argument_type, result_type
        */
    typedef ValueType value_type;
    
        /** calculate transform '<TT>sqrt(squaredNorm(v1) + squaredNorm(v2))</TT>'. 
            
        */
    result_type operator()(first_argument_type const & v1, second_argument_type const & v2) const
    {
        return VIGRA_CSTD::sqrt(squaredNorm(v1) + squaredNorm(v2));
    }
};

template <class T>
class FunctorTraits<MagnitudeFunctor<T> >
: public FunctorTraitsBase<MagnitudeFunctor<T> >
{
public:
    typedef VigraTrueType isBinaryFunctor;
};

/********************************************************/
/*                                                      */
/*             RGBGradientMagnitudeFunctor              */
/*                                                      */
/********************************************************/


/** Calculate the gradient magnitude from RGB arguments.
    Can be used in conjunction with \ref gradientBasedTransform().

    <b> Traits defined:</b>
    
    <tt>FunctorTraits::isBinaryFunctor</tt> are true (<tt>VigraTrueType</tt>)    
*/
template <class ValueType>
class RGBGradientMagnitudeFunctor
{
  public:
        /** the functor's first argument type
        */
    typedef RGBValue<ValueType> first_argument_type;
    
        /** the functor's second argument type
        */
    typedef RGBValue<ValueType> second_argument_type;
    
        /** the functor's result type
        */
    typedef typename NumericTraits<ValueType>::RealPromote result_type;
    
        /** \deprecated use first_argument_type, second_argument_type, result_type
        */
    typedef ValueType value_type;
    
        /** Calculate the gradient magnitude form given RGB components.
            The function returns 
            
            \f[ \sqrt{|\nabla red|^2 + |\nabla green|^2 + |\nabla blue|^2}
            \f]
            
            where \f$|\nabla red|^2\f$ is defined by <TT>gx.red()*gx.red() + gy.red()*gy.red()</TT>.
            
            <TT>ValueType</TT> (the RGB's component type) must support addition, multiplication, 
            abd <TT>sqrt()</TT>.
        */
    result_type 
    operator()(first_argument_type const & gx, second_argument_type const & gy) const
    {
        return VIGRA_CSTD::sqrt(gx.red()*gx.red() + gx.green()*gx.green() +
                    gx.blue()*gx.blue() + gy.red()*gy.red() + 
                    gy.green()*gy.green() + gy.blue()*gy.blue());
    }
};

template <class T>
class FunctorTraits<RGBGradientMagnitudeFunctor<T> >
: public FunctorTraitsBase<RGBGradientMagnitudeFunctor<T> >
{
public:
    typedef VigraTrueType isBinaryFunctor;
};

//@}

} // namespace vigra

#endif // VIGRA_COMBINEIMAGES_HXX