Generic Image Library: image_view_factory.hpp Source File

###  | #  |

- Main Page
- Modules
- Namespaces
- Classes
- Files

- File List
- File Members

image_view_factory.hpp
Go to the documentation of this file.
1 /*
2 Copyright 2005-2007 Adobe Systems Incorporated
3
4 Use, modification and distribution are subject to the Boost Software License,
5 Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
6 http://www.boost.org/LICENSE_1_0.txt).
7
8 See http://opensource.adobe.com/gil for most recent version including documentation.
9 */
10
11 /*************************************************************************************************/
12
13 #ifndef GIL_IMAGE_VIEW_FACTORY_HPP
14 #define GIL_IMAGE_VIEW_FACTORY_HPP
15
25
27 #include <cassert>
28 #include <cstddef>
29 #include "gil_config.hpp"
30 #include "metafunctions.hpp"
31 #include "gray.hpp"
32 #include "color_convert.hpp"
33
37
41
42 namespace boost { namespace gil {
43 struct default_color_converter;
44
45 template <typename T> struct dynamic_x_step_type;
46 template <typename T> struct dynamic_y_step_type;
47 template <typename T> struct transposed_type;
48
51 template <typename View>
52 struct dynamic_xy_step_type : public dynamic_y_step_type<typename dynamic_x_step_type<View>::type> {};
53
56 template <typename View>
57 struct dynamic_xy_step_transposed_type : public dynamic_xy_step_type<typename transposed_type<View>::type> {};
58
59
62 template <typename Iterator>
63 typename type_from_x_iterator<Iterator>::view_t
64 interleaved_view(std::size_t width, std::size_t height,
65 Iterator pixels, std::ptrdiff_t rowsize_in_bytes) {
66 typedef typename type_from_x_iterator<Iterator>::view_t RView;
67 return RView(width, height, typename RView::locator(pixels, rowsize_in_bytes));
68 }
69
72 template <typename Iterator>
73 typename type_from_x_iterator<Iterator>::view_t
74 interleaved_view(point2<std::size_t> dim,
75 Iterator pixels, std::ptrdiff_t rowsize_in_bytes) {
76 typedef typename type_from_x_iterator<Iterator>::view_t RView;
77 return RView(dim, typename RView::locator(pixels, rowsize_in_bytes));
78 }
79
81 // interleaved_view_get_raw_data, planar_view_get_raw_data - return pointers to the raw data (the channels) of a basic homogeneous view.
83
84 namespace detail {
85 template <typename View, bool IsMutable> struct channel_pointer_type_impl;
86
87 template <typename View> struct channel_pointer_type_impl<View, true> {
88 typedef typename channel_type<View>::type* type;
89 };
90 template <typename View> struct channel_pointer_type_impl<View, false> {
91 typedef const typename channel_type<View>::type* type;
92 };
93
94 template <typename View> struct channel_pointer_type
95 : public channel_pointer_type_impl<View, view_is_mutable<View>::value> {};
96 } // namespace detail
97
100 template <typename HomogeneousView>
101 typename detail::channel_pointer_type<HomogeneousView>::type interleaved_view_get_raw_data(const HomogeneousView& view) {
102 BOOST_STATIC_ASSERT((!is_planar<HomogeneousView>::value && view_is_basic<HomogeneousView>::value));
103 BOOST_STATIC_ASSERT((boost::is_pointer<typename HomogeneousView::x_iterator>::value));
104
105 return &gil::at_c<0>(view(0,0));
106 }
107
110 template <typename HomogeneousView>
111 typename detail::channel_pointer_type<HomogeneousView>::type planar_view_get_raw_data(const HomogeneousView& view, int plane_index) {
112 BOOST_STATIC_ASSERT((is_planar<HomogeneousView>::value && view_is_basic<HomogeneousView>::value));
113 return dynamic_at_c(view.row_begin(0),plane_index);
114 }
115
116
120
125 template <typename SrcConstRefP, typename DstP, typename CC=default_color_converter > // const_reference to the source pixel and destination pixel value
126 class color_convert_deref_fn : public deref_base<color_convert_deref_fn<SrcConstRefP,DstP,CC>, DstP, DstP, const DstP&, SrcConstRefP, DstP, false> {
127 private:
128 CC _cc; // color-converter
129 public:
130 color_convert_deref_fn() {}
131 color_convert_deref_fn(CC cc_in) : _cc(cc_in) {}
132
133 DstP operator()(SrcConstRefP srcP) const {
134 DstP dstP;
135 _cc(srcP,dstP);
136 return dstP;
137 }
138 };
139
140 namespace detail {
141 // Add color converter upon dereferencing
142 template <typename SrcView, typename CC, typename DstP, typename SrcP>
143 struct _color_converted_view_type {
144 private:
145 typedef color_convert_deref_fn<typename SrcView::const_t::reference,DstP,CC> deref_t;
146 typedef typename SrcView::template add_deref<deref_t> add_ref_t;
147 public:
148 typedef typename add_ref_t::type type;
149 static type make(const SrcView& sv,CC cc) {return add_ref_t::make(sv,deref_t(cc));}
150 };
151
152 // If the Src view has the same pixel type as the target, there is no need for color conversion
153 template <typename SrcView, typename CC, typename DstP>
154 struct _color_converted_view_type<SrcView,CC,DstP,DstP> {
155 typedef SrcView type;
156 static type make(const SrcView& sv,CC) {return sv;}
157 };
158 } // namespace detail
159
160
163 template <typename SrcView, typename DstP, typename CC=default_color_converter>
164 struct color_converted_view_type : public detail::_color_converted_view_type<SrcView,
165 CC,
166 DstP,
167 typename SrcView::value_type> {
168 GIL_CLASS_REQUIRE(DstP, boost::gil, MutablePixelConcept)//why does it have to be mutable???
169 };
170
171
174 template <typename DstP, typename View, typename CC>
175 inline typename color_converted_view_type<View,DstP,CC>::type color_converted_view(const View& src,CC cc) {
176 return color_converted_view_type<View,DstP,CC>::make(src,cc);
177 }
178
181 template <typename DstP, typename View>
182 inline typename color_converted_view_type<View,DstP>::type
183 color_converted_view(const View& src) {
184 return color_converted_view<DstP>(src,default_color_converter());
185 }
186
190
192 template <typename View>
193 inline typename dynamic_y_step_type<View>::type flipped_up_down_view(const View& src) {
194 typedef typename dynamic_y_step_type<View>::type RView;
195 return RView(src.dimensions(),typename RView::xy_locator(src.xy_at(0,src.height()-1),-1));
196 }
197
201
203 template <typename View>
204 inline typename dynamic_x_step_type<View>::type flipped_left_right_view(const View& src) {
205 typedef typename dynamic_x_step_type<View>::type RView;
206 return RView(src.dimensions(),typename RView::xy_locator(src.xy_at(src.width()-1,0),-1,1));
207 }
208
212
214 template <typename View>
215 inline typename dynamic_xy_step_transposed_type<View>::type transposed_view(const View& src) {
216 typedef typename dynamic_xy_step_transposed_type<View>::type RView;
217 return RView(src.height(),src.width(),typename RView::xy_locator(src.xy_at(0,0),1,1,true));
218 }
219
223
225 template <typename View>
226 inline typename dynamic_xy_step_transposed_type<View>::type rotated90cw_view(const View& src) {
227 typedef typename dynamic_xy_step_transposed_type<View>::type RView;
228 return RView(src.height(),src.width(),typename RView::xy_locator(src.xy_at(0,src.height()-1),-1,1,true));
229 }
230
234
236 template <typename View>
237 inline typename dynamic_xy_step_transposed_type<View>::type rotated90ccw_view(const View& src) {
238 typedef typename dynamic_xy_step_transposed_type<View>::type RView;
239 return RView(src.height(),src.width(),typename RView::xy_locator(src.xy_at(src.width()-1,0),1,-1,true));
240 }
241
245
247 template <typename View>
248 inline typename dynamic_xy_step_type<View>::type rotated180_view(const View& src) {
249 typedef typename dynamic_xy_step_type<View>::type RView;
250 return RView(src.dimensions(),typename RView::xy_locator(src.xy_at(src.width()-1,src.height()-1),-1,-1));
251 }
252
256
258 template <typename View>
259 inline View subimage_view(const View& src, const typename View::point_t& topleft, const typename View::point_t& dimensions) {
260 return View(dimensions,src.xy_at(topleft));
261 }
262
264 template <typename View>
265 inline View subimage_view(const View& src, int xMin, int yMin, int width, int height) {
266 return View(width,height,src.xy_at(xMin,yMin));
267 }
268
272
274 template <typename View>
275 inline typename dynamic_xy_step_type<View>::type subsampled_view(const View& src, typename View::coord_t xStep, typename View::coord_t yStep) {
276 assert(xStep>0 && yStep>0);
277 typedef typename dynamic_xy_step_type<View>::type RView;
278 return RView((src.width()+(xStep-1))/xStep,(src.height()+(yStep-1))/yStep,
279 typename RView::xy_locator(src.xy_at(0,0),xStep,yStep));
280 }
281
283 template <typename View>
284 inline typename dynamic_xy_step_type<View>::type subsampled_view(const View& src, const typename View::point_t& step) {
285 return subsampled_view(src,step.x,step.y);
286 }
287
291
292 namespace detail {
293 template <typename View, bool AreChannelsTogether> struct __nth_channel_view_basic;
294
295 // nth_channel_view when the channels are not adjacent in memory. This can happen for multi-channel interleaved images
296 // or images with a step
297 template <typename View>
298 struct __nth_channel_view_basic<View,false> {
299 typedef typename view_type<typename channel_type<View>::type, gray_layout_t, false, true, view_is_mutable<View>::value>::type type;
300
301 static type make(const View& src, int n) {
302 typedef typename type::xy_locator locator_t;
303 typedef typename type::x_iterator x_iterator_t;
304 typedef typename iterator_adaptor_get_base<x_iterator_t>::type x_iterator_base_t;
305 x_iterator_t sit(x_iterator_base_t(&(src(0,0)[n])),src.pixels().pixel_size());
306 return type(src.dimensions(),locator_t(sit, src.pixels().row_size()));
307 }
308 };
309
310 // nth_channel_view when the channels are together in memory (true for simple grayscale or planar images)
311 template <typename View>
312 struct __nth_channel_view_basic<View,true> {
313 typedef typename view_type<typename channel_type<View>::type, gray_layout_t, false, false, view_is_mutable<View>::value>::type type;
314 static type make(const View& src, int n) {
315 typedef typename type::x_iterator x_iterator_t;
316 return interleaved_view(src.width(),src.height(),(x_iterator_t)&(src(0,0)[n]), src.pixels().row_size());
317 }
318 };
319
320 template <typename View, bool IsBasic> struct __nth_channel_view;
321
322 // For basic (memory-based) views dispatch to __nth_channel_view_basic
323 template <typename View> struct __nth_channel_view<View,true> {
324 private:
325 typedef typename View::x_iterator src_x_iterator;
326
327 // Determines whether the channels of a given pixel iterator are adjacent in memory.
328 // Planar and grayscale iterators have channels adjacent in memory, whereas multi-channel interleaved and iterators with non-fundamental step do not.
329 BOOST_STATIC_CONSTANT(bool, adjacent=
330 !iterator_is_step<src_x_iterator>::value &&
331 (is_planar<src_x_iterator>::value ||
332 num_channels<View>::value==1));
333 public:
334 typedef typename __nth_channel_view_basic<View,adjacent>::type type;
335
336 static type make(const View& src, int n) {
337 return __nth_channel_view_basic<View,adjacent>::make(src,n);
338 }
339 };
340
345 template <typename SrcP> // SrcP is a reference to PixelConcept (could be pixel value or const/non-const reference)
346 // Examples: pixel<T,L>, pixel<T,L>&, const pixel<T,L>&, planar_pixel_reference<T&,L>, planar_pixel_reference<const T&,L>
347 struct nth_channel_deref_fn {
348 BOOST_STATIC_CONSTANT(bool, is_mutable=pixel_is_reference<SrcP>::value && pixel_reference_is_mutable<SrcP>::value);
349 private:
350 typedef typename remove_reference<SrcP>::type src_pixel_t;
351 typedef typename channel_type<src_pixel_t>::type channel_t;
352 typedef typename src_pixel_t::const_reference const_ref_t;
353 typedef typename pixel_reference_type<channel_t,gray_layout_t,false,is_mutable>::type ref_t;
354 public:
355 typedef nth_channel_deref_fn<const_ref_t> const_t;
356 typedef typename pixel_value_type<channel_t,gray_layout_t>::type value_type;
357 typedef typename pixel_reference_type<channel_t,gray_layout_t,false,false>::type const_reference;
358 typedef SrcP argument_type;
359 typedef typename mpl::if_c<is_mutable, ref_t, value_type>::type reference;
360 typedef reference result_type;
361
362 nth_channel_deref_fn(int n=0) : _n(n) {}
363 template <typename P> nth_channel_deref_fn(const nth_channel_deref_fn<P>& d) : _n(d._n) {}
364
365 int _n; // the channel to use
366
367 result_type operator()(argument_type srcP) const {
368 return result_type(srcP[_n]);
369 }
370 };
371
372 template <typename View> struct __nth_channel_view<View,false> {
373 private:
374 typedef nth_channel_deref_fn<typename View::reference> deref_t;
375 typedef typename View::template add_deref<deref_t> AD;
376 public:
377 typedef typename AD::type type;
378 static type make(const View& src, int n) {
379 return AD::make(src, deref_t(n));
380 }
381 };
382 } // namespace detail
383
390 template <typename View>
391 struct nth_channel_view_type {
392 private:
393 GIL_CLASS_REQUIRE(View, boost::gil, ImageViewConcept)
394 typedef detail::__nth_channel_view<View,view_is_basic<View>::value> VB;
395 public:
396 typedef typename VB::type type;
397 static type make(const View& src, int n) { return VB::make(src,n); }
398 };
399
400
402 template <typename View>
403 typename nth_channel_view_type<View>::type nth_channel_view(const View& src, int n) {
404 return nth_channel_view_type<View>::make(src,n);
405 }
406
407
408
409
410
411
412
416
417 namespace detail {
418 template <int K, typename View, bool AreChannelsTogether> struct __kth_channel_view_basic;
419
420 // kth_channel_view when the channels are not adjacent in memory. This can happen for multi-channel interleaved images
421 // or images with a step
422 template <int K, typename View>
423 struct __kth_channel_view_basic<K,View,false> {
424 private:
425 typedef typename kth_element_type<typename View::value_type,K>::type channel_t;
426 public:
427 typedef typename view_type<channel_t, gray_layout_t, false, true, view_is_mutable<View>::value>::type type;
428
429 static type make(const View& src) {
430 typedef typename type::xy_locator locator_t;
431 typedef typename type::x_iterator x_iterator_t;
432 typedef typename iterator_adaptor_get_base<x_iterator_t>::type x_iterator_base_t;
433 x_iterator_t sit(x_iterator_base_t(&gil::at_c<K>(src(0,0))),src.pixels().pixel_size());
434 return type(src.dimensions(),locator_t(sit, src.pixels().row_size()));
435 }
436 };
437
438 // kth_channel_view when the channels are together in memory (true for simple grayscale or planar images)
439 template <int K, typename View>
440 struct __kth_channel_view_basic<K,View,true> {
441 private:
442 typedef typename kth_element_type<typename View::value_type, K>::type channel_t;
443 public:
444 typedef typename view_type<channel_t, gray_layout_t, false, false, view_is_mutable<View>::value>::type type;
445 static type make(const View& src) {
446 typedef typename type::x_iterator x_iterator_t;
447 return interleaved_view(src.width(),src.height(),(x_iterator_t)&gil::at_c<K>(src(0,0)), src.pixels().row_size());
448 }
449 };
450
451 template <int K, typename View, bool IsBasic> struct __kth_channel_view;
452
453 // For basic (memory-based) views dispatch to __kth_channel_view_basic
454 template <int K, typename View> struct __kth_channel_view<K,View,true> {
455 private:
456 typedef typename View::x_iterator src_x_iterator;
457
458 // Determines whether the channels of a given pixel iterator are adjacent in memory.
459 // Planar and grayscale iterators have channels adjacent in memory, whereas multi-channel interleaved and iterators with non-fundamental step do not.
460 BOOST_STATIC_CONSTANT(bool, adjacent=
461 !iterator_is_step<src_x_iterator>::value &&
462 (is_planar<src_x_iterator>::value ||
463 num_channels<View>::value==1));
464 public:
465 typedef typename __kth_channel_view_basic<K,View,adjacent>::type type;
466
467 static type make(const View& src) {
468 return __kth_channel_view_basic<K,View,adjacent>::make(src);
469 }
470 };
471
476 template <int K, typename SrcP> // SrcP is a reference to PixelConcept (could be pixel value or const/non-const reference)
477 // Examples: pixel<T,L>, pixel<T,L>&, const pixel<T,L>&, planar_pixel_reference<T&,L>, planar_pixel_reference<const T&,L>
478 struct kth_channel_deref_fn {
479 BOOST_STATIC_CONSTANT(bool, is_mutable=pixel_is_reference<SrcP>::value && pixel_reference_is_mutable<SrcP>::value);
480 private:
481 typedef typename remove_reference<SrcP>::type src_pixel_t;
482 typedef typename kth_element_type<src_pixel_t, K>::type channel_t;
483 typedef typename src_pixel_t::const_reference const_ref_t;
484 typedef typename pixel_reference_type<channel_t,gray_layout_t,false,is_mutable>::type ref_t;
485 public:
486 typedef kth_channel_deref_fn<K,const_ref_t> const_t;
487 typedef typename pixel_value_type<channel_t,gray_layout_t>::type value_type;
488 typedef typename pixel_reference_type<channel_t,gray_layout_t,false,false>::type const_reference;
489 typedef SrcP argument_type;
490 typedef typename mpl::if_c<is_mutable, ref_t, value_type>::type reference;
491 typedef reference result_type;
492
493 kth_channel_deref_fn() {}
494 template <typename P> kth_channel_deref_fn(const kth_channel_deref_fn<K,P>&) {}
495
496 result_type operator()(argument_type srcP) const {
497 return result_type(gil::at_c<K>(srcP));
498 }
499 };
500
501 template <int K, typename View> struct __kth_channel_view<K,View,false> {
502 private:
503 typedef kth_channel_deref_fn<K,typename View::reference> deref_t;
504 typedef typename View::template add_deref<deref_t> AD;
505 public:
506 typedef typename AD::type type;
507 static type make(const View& src) {
508 return AD::make(src, deref_t());
509 }
510 };
511 } // namespace detail
512
519 template <int K, typename View>
520 struct kth_channel_view_type {
521 private:
522 GIL_CLASS_REQUIRE(View, boost::gil, ImageViewConcept)
523 typedef detail::__kth_channel_view<K,View,view_is_basic<View>::value> VB;
524 public:
525 typedef typename VB::type type;
526 static type make(const View& src) { return VB::make(src); }
527 };
528
530 template <int K, typename View>
531 typename kth_channel_view_type<K,View>::type kth_channel_view(const View& src) {
532 return kth_channel_view_type<K,View>::make(src);
533 }
534
535 } } // namespace boost::gil
536
537 #endif
boost::gil::dynamic_xy_step_transposed_type
Returns the type of a transposed view that has a dynamic step along both X and Y. ...
Definition: image_view_factory.hpp:57
gray.hpp
Support for grayscale color space and variants.
boost::gil::image_view
A lightweight object that interprets memory as a 2D array of pixels. Models ImageViewConcept,PixelBasedConcept,HasDynamicXStepTypeConcept,HasDynamicYStepTypeConcept,HasTransposedTypeConcept.
Definition: image_view.hpp:68
boost::gil::pixel
Represents a pixel value (a container of channels). Models: HomogeneousColorBaseValueConcept, PixelValueConcept, HomogeneousPixelBasedConcept.
Definition: metafunctions.hpp:44
boost::gil::color_convert_deref_fn
Function object that given a source pixel, returns it converted to a given color space and channel de...
Definition: image_view_factory.hpp:126
boost::gil::dynamic_xy_step_type
Returns the type of a view that has a dynamic step along both X and Y.
Definition: image_view_factory.hpp:52
boost::gil::nth_channel_view_type
Given a source image view type View, returns the type of an image view over a single channel of ViewI...
Definition: image_view_factory.hpp:391
boost::gil::deref_base
Helper base class for pixel dereference adaptors.
Definition: utilities.hpp:182
metafunctions.hpp
metafunctions that construct types or return type properties
boost::gil::detail::kth_channel_deref_fn
Function object that returns a grayscale reference of the K-th channel (specified as a template param...
Definition: image_view_factory.hpp:478
boost::gil::interleaved_view
type_from_x_iterator< Iterator >::view_t interleaved_view(point2< std::size_t > dim, Iterator pixels, std::ptrdiff_t rowsize_in_bytes)
Constructing image views from raw interleaved pixel data.
Definition: image_view_factory.hpp:74
boost::gil::color_converted_view_type
Returns the type of a view that does color conversion upon dereferencing its pixels.
Definition: image_view_factory.hpp:164
boost::gil::pixel_reference_is_mutable
Determines if the given pixel reference is mutable (i.e. its channels can be changed) ...
Definition: metafunctions.hpp:184
boost::gil::detail::nth_channel_deref_fn
Function object that returns a grayscale reference of the N-th channel of a given reference...
Definition: image_view_factory.hpp:347
boost::gil::planar_view_get_raw_data
detail::channel_pointer_type< HomogeneousView >::type planar_view_get_raw_data(const HomogeneousView &view, int plane_index)
Returns C pointer to the the channels of a given color plane of a planar homogeneous view...
Definition: image_view_factory.hpp:111
boost::gil::MutablePixelConcept
Pixel concept that allows for changing its channels.
Definition: gil_concept.hpp:921
boost::gil::pixel_reference_type
Returns the type of a homogeneous pixel reference given the channel type, layout, whether it operates...
Definition: metafunctions.hpp:217
boost::gil::interleaved_view_get_raw_data
detail::channel_pointer_type< HomogeneousView >::type interleaved_view_get_raw_data(const HomogeneousView &view)
Returns C pointer to the the channels of an interleaved homogeneous view.
Definition: image_view_factory.hpp:101
boost::gil::ImageViewConcept
GIL's 2-dimensional view over immutable GIL pixels.
Definition: gil_concept.hpp:1942
boost::gil::view
const image< Pixel, IsPlanar, Alloc >::view_t & view(image< Pixel, IsPlanar, Alloc > &img)
Returns the non-constant-pixel view of an image.
Definition: image.hpp:480
boost::gil::color_converted_view
color_converted_view_type< View, DstP >::type color_converted_view(const View &src)
overload of generic color_converted_view with the default color-converter
Definition: image_view_factory.hpp:183
gil_config.hpp
GIL configuration file.
boost::gil::pixel_is_reference
Given a model of a pixel, determines whether the model represents a pixel reference (as opposed to pi...
Definition: metafunctions.hpp:174
boost::gil::point2
2D point both axes of which have the same dimension typeModels: Point2DConcept
Definition: gil_concept.hpp:52
boost::gil::default_color_converter
class for color-converting one pixel to another
Definition: color_convert.hpp:297
boost::gil::view_is_basic
Basic views must be over basic locators.
Definition: metafunctions.hpp:114
boost::gil::kth_channel_view_type
Given a source image view type View, returns the type of an image view over a given channel of View...
Definition: image_view_factory.hpp:520
color_convert.hpp
GIL default color space conversions.