interface/wx/image.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        image.h
   3 // Purpose:     interface of wxImageHandler and wxImage
   4 // Author:      wxWidgets team
   5 // RCS-ID:      $Id$
   6 // Licence:     wxWindows license
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9 /**
  10     Possible values for the image resolution option.
  11
  12     @see wxImage::GetOptionInt().
  13  */
  14 enum wxImageResolution
  15 {
  16     /// Resolution not specified.
  17     wxIMAGE_RESOLUTION_NONE = 0,
  18
  19     /// Resolution specified in inches.
  20     wxIMAGE_RESOLUTION_INCHES = 1,
  21
  22     /// Resolution specified in centimetres.
  23     wxIMAGE_RESOLUTION_CM = 2
  24 };
  25
  26 /**
  27     Possible values for PNG image type option.
  28
  29     @see wxImage::GetOptionInt().
  30  */
  31 enum wxImagePNGType
  32 {
  33     wxPNG_TYPE_COLOUR = 0,      ///< Colour PNG image.
  34     wxPNG_TYPE_GREY = 2,        ///< Greyscale PNG image converted from RGB.
  35     wxPNG_TYPE_GREY_RED = 3     ///< Greyscale PNG image using red as grey.
  36 };
  37
  38 /**
  39     @class wxImageHandler
  40
  41     This is the base class for implementing image file loading/saving, and
  42     image creation from data.
  43     It is used within wxImage and is not normally seen by the application.
  44
  45     If you wish to extend the capabilities of wxImage, derive a class from
  46     wxImageHandler and add the handler using wxImage::AddHandler in your
  47     application initialization.
  48
  49     Note that all wxImageHandlers provided by wxWidgets are part of
  50     the @ref page_libs_wxcore library.
  51     For details about the default handlers, please see the section
  52     @ref image_handlers in the wxImage class documentation.
  53
  54
  55     @section imagehandler_note Note (Legal Issue)
  56
  57     This software is based in part on the work of the Independent JPEG Group.
  58     (Applies when wxWidgets is linked with JPEG support.
  59     wxJPEGHandler uses libjpeg created by IJG.)
  60
  61
  62     @stdobjects
  63     ::wxNullImage
  64
  65     @library{wxcore}
  66     @category{gdi}
  67
  68     @see wxImage, wxInitAllImageHandlers()
  69 */
  70 class wxImageHandler : public wxObject
  71 {
  72 public:
  73     /**
  74         Default constructor.
  75
  76         In your own default constructor, initialise the members
  77         m_name, m_extension and m_type.
  78     */
  79     wxImageHandler();
  80
  81     /**
  82         Destroys the wxImageHandler object.
  83     */
  84     virtual ~wxImageHandler();
  85
  86     /**
  87         Returns @true if this handler supports the image format contained in the
  88         given stream.
  89
  90         This function doesn't modify the current stream position (because it
  91         restores the original position before returning; this however requires the
  92         stream to be seekable; see wxStreamBase::IsSeekable).
  93     */
  94     bool CanRead( wxInputStream& stream );
  95
  96     /**
  97         Returns @true if this handler supports the image format contained in the
  98         file with the given name.
  99
 100         This function doesn't modify the current stream position (because it
 101         restores the original position before returning; this however requires the
 102         stream to be seekable; see wxStreamBase::IsSeekable).
 103     */
 104     bool CanRead( const wxString& filename );
 105
 106     /**
 107         Gets the preferred file extension associated with this handler.
 108
 109         @see GetAltExtensions()
 110     */
 111     const wxString& GetExtension() const;
 112
 113     /**
 114         Returns the other file extensions associated with this handler.
 115
 116         The preferred extension for this handler is returned by GetExtension().
 117
 118         @since 2.9.0
 119     */
 120     const wxArrayString& GetAltExtensions() const;
 121
 122     /**
 123         If the image file contains more than one image and the image handler is capable
 124         of retrieving these individually, this function will return the number of
 125         available images.
 126
 127         @param stream
 128             Opened input stream for reading image data.
 129             This function doesn't modify the current stream position (because it
 130             restores the original position before returning; this however requires the
 131             stream to be seekable; see wxStreamBase::IsSeekable).
 132
 133         @return Number of available images. For most image handlers, this is 1
 134                 (exceptions are TIFF and ICO formats as well as animated GIFs
 135                 for which this function returns the number of frames in the
 136                 animation).
 137     */
 138     virtual int GetImageCount(wxInputStream& stream);
 139
 140     /**
 141         Gets the MIME type associated with this handler.
 142     */
 143     const wxString& GetMimeType() const;
 144
 145     /**
 146         Gets the name of this handler.
 147     */
 148     const wxString& GetName() const;
 149
 150     /**
 151         Gets the image type associated with this handler.
 152     */
 153     wxBitmapType GetType() const;
 154
 155     /**
 156         Loads a image from a stream, putting the resulting data into @a image.
 157
 158         If the image file contains more than one image and the image handler is
 159         capable of retrieving these individually, @a index indicates which image
 160         to read from the stream.
 161
 162         @param image
 163             The image object which is to be affected by this operation.
 164         @param stream
 165             Opened input stream for reading image data.
 166         @param verbose
 167             If set to @true, errors reported by the image handler will produce
 168             wxLogMessages.
 169         @param index
 170             The index of the image in the file (starting from zero).
 171
 172         @return @true if the operation succeeded, @false otherwise.
 173
 174         @see wxImage::LoadFile, wxImage::SaveFile, SaveFile()
 175     */
 176     virtual bool LoadFile(wxImage* image, wxInputStream& stream,
 177                           bool verbose = true, int index = -1);
 178
 179     /**
 180         Saves a image in the output stream.
 181
 182         @param image
 183             The image object which is to be affected by this operation.
 184         @param stream
 185             Opened output stream for writing the data.
 186         @param verbose
 187             If set to @true, errors reported by the image handler will produce
 188             wxLogMessages.
 189
 190         @return @true if the operation succeeded, @false otherwise.
 191
 192         @see wxImage::LoadFile, wxImage::SaveFile, LoadFile()
 193     */
 194     virtual bool SaveFile(wxImage* image, wxOutputStream& stream,
 195                           bool verbose = true);
 196
 197     /**
 198         Sets the preferred file extension associated with this handler.
 199
 200         @param extension
 201             File extension without leading dot.
 202
 203         @see SetAltExtensions()
 204     */
 205     void SetExtension(const wxString& extension);
 206
 207     /**
 208         Sets the alternative file extensions associated with this handler.
 209
 210         @param extensions
 211             Array of file extensions.
 212
 213         @see SetExtension()
 214
 215         @since 2.9.0
 216     */
 217     void SetAltExtensions(const wxArrayString& extensions);
 218
 219     /**
 220         Sets the handler MIME type.
 221
 222         @param mimetype
 223             Handler MIME type.
 224     */
 225     void SetMimeType(const wxString& mimetype);
 226
 227     /**
 228         Sets the handler name.
 229
 230         @param name
 231             Handler name.
 232     */
 233     void SetName(const wxString& name);
 234 };
 235
 236
 237 /**
 238     Constant used to indicate the alpha value conventionally defined as
 239     the complete transparency.
 240 */
 241 const unsigned char wxIMAGE_ALPHA_TRANSPARENT = 0;
 242
 243 /**
 244     Constant used to indicate the alpha value conventionally defined as
 245     the complete opacity.
 246 */
 247 const unsigned char wxIMAGE_ALPHA_OPAQUE = 0xff;
 248
 249 /**
 250     @class wxImage
 251
 252     This class encapsulates a platform-independent image.
 253
 254     An image can be created from data, or using wxBitmap::ConvertToImage.
 255     An image can be loaded from a file in a variety of formats, and is extensible
 256     to new formats via image format handlers. Functions are available to set and
 257     get image bits, so it can be used for basic image manipulation.
 258
 259     A wxImage cannot (currently) be drawn directly to a wxDC.
 260     Instead, a platform-specific wxBitmap object must be created from it using
 261     the wxBitmap::wxBitmap(wxImage,int depth) constructor.
 262     This bitmap can then be drawn in a device context, using wxDC::DrawBitmap.
 263
 264     One colour value of the image may be used as a mask colour which will lead to
 265     the automatic creation of a wxMask object associated to the bitmap object.
 266
 267
 268     @section image_alpha Alpha channel support
 269
 270     Starting from wxWidgets 2.5.0 wxImage supports alpha channel data, that is
 271     in addition to a byte for the red, green and blue colour components for each
 272     pixel it also stores a byte representing the pixel opacity.
 273
 274     An alpha value of 0 corresponds to a transparent pixel (null opacity) while
 275     a value of 255 means that the pixel is 100% opaque.
 276     The constants ::wxIMAGE_ALPHA_TRANSPARENT and ::wxIMAGE_ALPHA_OPAQUE can be
 277     used to indicate those values in a more readable form.
 278
 279     Unlike RGB data, not all images have an alpha channel and before using
 280     wxImage::GetAlpha you should check if this image contains an alpha channel
 281     with wxImage::HasAlpha. Note that currently only the PNG format has full
 282     alpha channel support so only the images loaded from PNG files can have
 283     alpha and, if you initialize the image alpha channel yourself using
 284     wxImage::SetAlpha, you should save it in PNG format to avoid losing it.
 285
 286
 287     @section image_handlers Available image handlers
 288
 289     The following image handlers are available.
 290     wxBMPHandler is always installed by default.
 291     To use other image formats, install the appropriate handler with
 292     wxImage::AddHandler or call ::wxInitAllImageHandlers().
 293
 294     - wxBMPHandler: For loading and saving, always installed.
 295     - wxPNGHandler: For loading (including alpha support) and saving.
 296     - wxJPEGHandler: For loading and saving.
 297     - wxGIFHandler: Only for loading, due to legal issues.
 298     - wxPCXHandler: For loading and saving (see below).
 299     - wxPNMHandler: For loading and saving (see below).
 300     - wxTIFFHandler: For loading and saving.
 301     - wxTGAHandler: For loading only.
 302     - wxIFFHandler: For loading only.
 303     - wxXPMHandler: For loading and saving.
 304     - wxICOHandler: For loading and saving.
 305     - wxCURHandler: For loading and saving.
 306     - wxANIHandler: For loading only.
 307
 308     When saving in PCX format, wxPCXHandler will count the number of different
 309     colours in the image; if there are 256 or less colours, it will save as 8 bit,
 310     else it will save as 24 bit.
 311
 312     Loading PNMs only works for ASCII or raw RGB images.
 313     When saving in PNM format, wxPNMHandler will always save as raw RGB.
 314
 315
 316     @library{wxcore}
 317     @category{gdi}
 318
 319     @stdobjects
 320     ::wxNullImage
 321
 322     @see wxBitmap, wxInitAllImageHandlers(), wxPixelData
 323 */
 324 class wxImage : public wxObject
 325 {
 326 public:
 327     /**
 328         A simple class which stores red, green and blue values as 8 bit unsigned integers
 329         in the range of 0-255.
 330     */
 331     class RGBValue
 332     {
 333     public:
 334         /**
 335             Constructor for RGBValue, an object that contains values for red, green
 336             and blue which represent the value of a color.
 337
 338             It is used by wxImage::HSVtoRGB and wxImage::RGBtoHSV, which convert
 339             between HSV color space and RGB color space.
 340         */
 341         RGBValue(unsigned char r=0, unsigned char g=0, unsigned char b=0);
 342     };
 343
 344     /**
 345         A simple class which stores hue, saturation and value as doubles in the range 0.0-1.0.
 346     */
 347     class HSVValue
 348     {
 349     public:
 350         /**
 351             Constructor for HSVValue, an object that contains values for hue, saturation
 352             and value which represent the value of a color.
 353
 354             It is used by wxImage::HSVtoRGB() and wxImage::RGBtoHSV(), which convert
 355             between HSV color space and RGB color space.
 356         */
 357         HSVValue(double h=0.0, double s=0.0, double v=0.0);
 358     };
 359
 360     /**
 361         Creates an empty wxImage object without an alpha channel.
 362     */
 363     wxImage();
 364
 365     /**
 366         Creates an image with the given size and clears it if requested.
 367
 368         Does not create an alpha channel.
 369
 370         @param width
 371             Specifies the width of the image.
 372         @param height
 373             Specifies the height of the image.
 374         @param clear
 375             If @true, initialize the image to black.
 376     */
 377     wxImage(int width, int height, bool clear = true);
 378
 379     /**
 380         @overload
 381     */
 382     wxImage(const wxSize& sz, bool clear = true);
 383
 384     /**
 385         Creates an image from data in memory. If @a static_data is @false
 386         then the wxImage will take ownership of the data and free it
 387         afterwards. For this, it has to be allocated with @e malloc.
 388
 389         @param width
 390             Specifies the width of the image.
 391         @param height
 392             Specifies the height of the image.
 393         @param data
 394             A pointer to RGB data
 395         @param static_data
 396             Indicates if the data should be free'd after use
 397
 398     */
 399     wxImage(int width, int height, unsigned char* data, bool static_data = false);
 400
 401     /**
 402         @overload
 403     */
 404     wxImage(const wxSize& sz, unsigned char* data, bool static_data = false);
 405
 406     /**
 407         Creates an image from data in memory. If @a static_data is @false
 408         then the wxImage will take ownership of the data and free it
 409         afterwards. For this, it has to be allocated with @e malloc.
 410
 411         @param width
 412             Specifies the width of the image.
 413         @param height
 414             Specifies the height of the image.
 415         @param data
 416             A pointer to RGB data
 417         @param alpha
 418             A pointer to alpha-channel data
 419         @param static_data
 420             Indicates if the data should be free'd after use
 421
 422     */
 423     wxImage(int width, int height, unsigned char* data, unsigned char* alpha,
 424             bool static_data = false );
 425
 426     /**
 427         @overload
 428     */
 429     wxImage(const wxSize& sz, unsigned char* data, unsigned char* data, unsigned char* alpha,
 430             bool static_data = false);
 431
 432     /**
 433         Creates an image from XPM data.
 434
 435         @param xpmData
 436             A pointer to XPM image data.
 437     */
 438     wxImage(const char* const* xpmData);
 439
 440     /**
 441         Creates an image from a file.
 442
 443         @param name
 444             Name of the file from which to load the image.
 445         @param type
 446             May be one of the following:
 447             @li wxBITMAP_TYPE_BMP: Load a Windows bitmap file.
 448             @li wxBITMAP_TYPE_GIF: Load a GIF bitmap file.
 449             @li wxBITMAP_TYPE_JPEG: Load a JPEG bitmap file.
 450             @li wxBITMAP_TYPE_PNG: Load a PNG bitmap file.
 451             @li wxBITMAP_TYPE_PCX: Load a PCX bitmap file.
 452             @li wxBITMAP_TYPE_PNM: Load a PNM bitmap file.
 453             @li wxBITMAP_TYPE_TIF: Load a TIFF bitmap file.
 454             @li wxBITMAP_TYPE_TGA: Load a TGA bitmap file.
 455             @li wxBITMAP_TYPE_XPM: Load a XPM bitmap file.
 456             @li wxBITMAP_TYPE_ICO: Load a Windows icon file (ICO).
 457             @li wxBITMAP_TYPE_CUR: Load a Windows cursor file (CUR).
 458             @li wxBITMAP_TYPE_ANI: Load a Windows animated cursor file (ANI).
 459             @li wxBITMAP_TYPE_ANY: Will try to autodetect the format.
 460         @param index
 461             Index of the image to load in the case that the image file contains
 462             multiple images. This is only used by GIF, ICO and TIFF handlers.
 463             The default value (-1) means "choose the default image" and is
 464             interpreted as the first image (index=0) by the GIF and TIFF handler
 465             and as the largest and most colourful one by the ICO handler.
 466
 467         @remarks Depending on how wxWidgets has been configured and by which
 468                  handlers have been loaded, not all formats may be available.
 469                  Any handler other than BMP must be previously initialized with
 470                 wxImage::AddHandler or wxInitAllImageHandlers.
 471
 472         @note
 473             You can use GetOptionInt() to get the hotspot when loading cursor files:
 474             @code
 475             int hotspot_x = image.GetOptionInt(wxIMAGE_OPTION_CUR_HOTSPOT_X);
 476             int hotspot_y = image.GetOptionInt(wxIMAGE_OPTION_CUR_HOTSPOT_Y);
 477             @endcode
 478
 479         @see LoadFile()
 480     */
 481     wxImage(const wxString& name, wxBitmapType type = wxBITMAP_TYPE_ANY, int index = -1);
 482
 483     /**
 484         Creates an image from a file using MIME-types to specify the type.
 485
 486         @param name
 487             Name of the file from which to load the image.
 488         @param mimetype
 489             MIME type string (for example 'image/jpeg')
 490         @param index
 491             See description in wxImage(const wxString&, wxBitmapType, int) overload.
 492     */
 493     wxImage(const wxString& name, const wxString& mimetype, int index = -1);
 494
 495     /**
 496         Creates an image from a stream.
 497
 498         @param stream
 499             Opened input stream from which to load the image. Currently,
 500             the stream must support seeking.
 501         @param type
 502             See description in wxImage(const wxString&, wxBitmapType, int) overload.
 503         @param index
 504             See description in wxImage(const wxString&, wxBitmapType, int) overload.
 505     */
 506     wxImage(wxInputStream& stream, wxBitmapType type = wxBITMAP_TYPE_ANY, int index = -1);
 507
 508     /**
 509         Creates an image from a stream using MIME-types to specify the type.
 510
 511         @param stream
 512             Opened input stream from which to load the image. Currently,
 513             the stream must support seeking.
 514         @param mimetype
 515             MIME type string (for example 'image/jpeg')
 516         @param index
 517             See description in wxImage(const wxString&, wxBitmapType, int) overload.
 518     */
 519     wxImage(wxInputStream& stream, const wxString& mimetype, int index = -1);
 520
 521     /**
 522         Destructor.
 523
 524         See @ref overview_refcount_destruct "reference-counted object destruction"
 525         for more info.
 526     */
 527     virtual ~wxImage();
 528
 529
 530
 531     /**
 532         @name Image creation, initialization and deletion functions
 533     */
 534     //@{
 535
 536     /**
 537         Returns an identical copy of this image.
 538     */
 539     wxImage Copy() const;
 540
 541     /**
 542         Creates a fresh image.
 543         See wxImage::wxImage(int,int,bool) for more info.
 544
 545         @return @true if the call succeeded, @false otherwise.
 546     */
 547     bool Create(int width, int height, bool clear = true);
 548
 549     /**
 550         @overload
 551     */
 552     bool Create( const wxSize& sz, bool clear = true );
 553
 554     /**
 555         Creates a fresh image.
 556         See wxImage::wxImage(int,int,unsigned char*,bool) for more info.
 557
 558         @return @true if the call succeeded, @false otherwise.
 559     */
 560     bool Create( int width, int height, unsigned char* data, bool static_data = false );
 561
 562     /**
 563         @overload
 564     */
 565     bool Create( const wxSize& sz, unsigned char* data, bool static_data = false );
 566
 567     /**
 568         Creates a fresh image.
 569         See wxImage::wxImage(int,int,unsigned char*,unsigned char*,bool) for more info.
 570
 571         @return @true if the call succeeded, @false otherwise.
 572     */
 573     bool Create( int width, int height, unsigned char* data, unsigned char* alpha, bool static_data = false );
 574
 575     /**
 576         @overload
 577     */
 578     bool Create( const wxSize& sz, unsigned char* data, unsigned char* alpha, bool static_data = false );
 579
 580     /**
 581         Initialize the image data with zeroes (the default) or with the
 582         byte value given as @a value.
 583
 584         @since 2.9.0
 585     */
 586     void Clear(unsigned char value = 0);
 587
 588     /**
 589         Destroys the image data.
 590     */
 591     void Destroy();
 592
 593     /**
 594         Initializes the image alpha channel data.
 595
 596         It is an error to call it if the image already has alpha data.
 597         If it doesn't, alpha data will be by default initialized to all pixels
 598         being fully opaque. But if the image has a mask colour, all mask pixels
 599         will be completely transparent.
 600     */
 601     void InitAlpha();
 602
 603     //@}
 604
 605
 606     /**
 607         @name Image manipulation functions
 608     */
 609     //@{
 610
 611     /**
 612         Blurs the image in both horizontal and vertical directions by the
 613         specified pixel @a blurRadius. This should not be used when using
 614         a single mask colour for transparency.
 615
 616         @see BlurHorizontal(), BlurVertical()
 617     */
 618     wxImage Blur(int blurRadius) const;
 619
 620     /**
 621         Blurs the image in the horizontal direction only. This should not be used
 622         when using a single mask colour for transparency.
 623
 624         @see Blur(), BlurVertical()
 625     */
 626     wxImage BlurHorizontal(int blurRadius) const;
 627
 628     /**
 629         Blurs the image in the vertical direction only. This should not be used
 630         when using a single mask colour for transparency.
 631
 632         @see Blur(), BlurHorizontal()
 633     */
 634     wxImage BlurVertical(int blurRadius) const;
 635
 636     /**
 637         Returns a mirrored copy of the image.
 638         The parameter @a horizontally indicates the orientation.
 639     */
 640     wxImage Mirror(bool horizontally = true) const;
 641
 642     /**
 643         Copy the data of the given @a image to the specified position in this image.
 644     */
 645     void Paste(const wxImage& image, int x, int y);
 646
 647     /**
 648         Replaces the colour specified by @e r1,g1,b1 by the colour @e r2,g2,b2.
 649     */
 650     void Replace(unsigned char r1, unsigned char g1,
 651                  unsigned char b1, unsigned char r2,
 652                  unsigned char g2, unsigned char b2);
 653
 654     /**
 655         Changes the size of the image in-place by scaling it: after a call to this
 656         function,the image will have the given width and height.
 657
 658         For a description of the @a quality parameter, see the Scale() function.
 659         Returns the (modified) image itself.
 660
 661         @see Scale()
 662     */
 663     wxImage& Rescale(int width, int height,
 664                     int quality = wxIMAGE_QUALITY_NORMAL);
 665
 666     /**
 667         Changes the size of the image in-place without scaling it by adding either a
 668         border with the given colour or cropping as necessary.
 669
 670         The image is pasted into a new image with the given @a size and background
 671         colour at the position @a pos relative to the upper left of the new image.
 672
 673         If @a red = green = blue = -1 then use either the  current mask colour
 674         if set or find, use, and set a suitable mask colour for any newly exposed
 675         areas.
 676
 677         @return The (modified) image itself.
 678
 679         @see Size()
 680     */
 681     wxImage& Resize(const wxSize& size, const wxPoint& pos, int red = -1,
 682                     int green = -1, int blue = -1);
 683
 684     /**
 685         Rotates the image about the given point, by @a angle radians.
 686
 687         Passing @true to @a interpolating results in better image quality, but is slower.
 688
 689         If the image has a mask, then the mask colour is used for the uncovered
 690         pixels in the rotated image background. Else, black (rgb 0, 0, 0) will be used.
 691
 692         Returns the rotated image, leaving this image intact.
 693     */
 694     wxImage Rotate(double angle, const wxPoint& rotationCentre,
 695                    bool interpolating = true,
 696                    wxPoint* offsetAfterRotation = NULL) const;
 697
 698     /**
 699         Returns a copy of the image rotated 90 degrees in the direction
 700         indicated by @a clockwise.
 701     */
 702     wxImage Rotate90(bool clockwise = true) const;
 703
 704     /**
 705         Rotates the hue of each pixel in the image by @e angle, which is a double in
 706         the range of -1.0 to +1.0, where -1.0 corresponds to -360 degrees and +1.0
 707         corresponds to +360 degrees.
 708     */
 709     void RotateHue(double angle);
 710
 711     /**
 712         Returns a scaled version of the image.
 713
 714         This is also useful for scaling bitmaps in general as the only other way
 715         to scale bitmaps is to blit a wxMemoryDC into another wxMemoryDC.
 716
 717         The parameter @a quality determines what method to use for resampling the image.
 718         Can be one of the following:
 719         - wxIMAGE_QUALITY_NORMAL: Uses the normal default scaling method of pixel
 720                                   replication
 721         - wxIMAGE_QUALITY_HIGH: Uses bicubic and box averaging resampling methods
 722                                 for upsampling and downsampling respectively
 723
 724         It should be noted that although using @c wxIMAGE_QUALITY_HIGH produces much nicer
 725         looking results it is a slower method. Downsampling will use the box averaging
 726         method which seems to operate very fast. If you are upsampling larger images using
 727         this method you will most likely notice that it is a bit slower and in extreme
 728         cases it will be quite substantially slower as the bicubic algorithm has to process a
 729         lot of data.
 730
 731         It should also be noted that the high quality scaling may not work as expected
 732         when using a single mask colour for transparency, as the scaling will blur the
 733         image and will therefore remove the mask partially. Using the alpha channel
 734         will work.
 735
 736         Example:
 737         @code
 738         // get the bitmap from somewhere
 739         wxBitmap bmp = ...;
 740
 741         // rescale it to have size of 32*32
 742         if ( bmp.GetWidth() != 32 || bmp.GetHeight() != 32 )
 743         {
 744             wxImage image = bmp.ConvertToImage();
 745             bmp = wxBitmap(image.Scale(32, 32));
 746
 747             // another possibility:
 748             image.Rescale(32, 32);
 749             bmp = image;
 750         }
 751         @endcode
 752
 753         @see Rescale()
 754     */
 755     wxImage Scale(int width, int height,
 756                   int quality = wxIMAGE_QUALITY_NORMAL) const;
 757
 758     /**
 759         Returns a resized version of this image without scaling it by adding either a
 760         border with the given colour or cropping as necessary.
 761
 762         The image is pasted into a new image with the given @a size and background
 763         colour at the position @a pos relative to the upper left of the new image.
 764
 765         If @a red = green = blue = -1 then the areas of the larger image not covered
 766         by this image are made transparent by filling them with the image mask colour
 767         (which will be allocated automatically if it isn't currently set).
 768
 769         Otherwise, the areas will be filled with the colour with the specified RGB components.
 770
 771         @see Resize()
 772     */
 773     wxImage Size(const wxSize& size, const wxPoint& pos, int red = -1,
 774                  int green = -1, int blue = -1) const;
 775
 776     //@}
 777
 778
 779     /**
 780         @name Conversion functions
 781     */
 782     //@{
 783
 784     /**
 785         If the image has alpha channel, this method converts it to mask.
 786
 787         If the image has an alpha channel, all pixels with alpha value less
 788         than @a threshold are replaced with the mask colour and the alpha
 789         channel is removed. Otherwise nothing is done.
 790
 791         The mask colour is chosen automatically using
 792         FindFirstUnusedColour() by this function, see the overload below if you
 793         this is not appropriate.
 794
 795         @return @false if FindFirstUnusedColour returns @false, @true otherwise.
 796     */
 797     bool ConvertAlphaToMask(unsigned char threshold = wxIMAGE_ALPHA_THRESHOLD);
 798
 799     /**
 800         If the image has alpha channel, this method converts it to mask using
 801         the specified colour as the mask colour.
 802
 803         If the image has an alpha channel, all pixels with alpha value less
 804         than @a threshold are replaced with the mask colour and the alpha
 805         channel is removed. Otherwise nothing is done.
 806
 807         @since 2.9.0
 808
 809         @param mr
 810             The red component of the mask colour.
 811         @param mg
 812             The green component of the mask colour.
 813         @param mb
 814             The blue component of the mask colour.
 815         @param threshold
 816             Pixels with alpha channel values below the given threshold are
 817             considered to be transparent, i.e. the corresponding mask pixels
 818             are set. Pixels with the alpha values above the threshold are
 819             considered to be opaque.
 820
 821      */
 822     void ConvertAlphaToMask(unsigned char mr, unsigned char mg, unsigned char mb,
 823                             unsigned char threshold = wxIMAGE_ALPHA_THRESHOLD);
 824
 825     /**
 826         Returns a greyscale version of the image.
 827
 828         The returned image uses the luminance component of the original to
 829         calculate the greyscale. Defaults to using the standard ITU-T BT.601
 830         when converting to YUV, where every pixel equals
 831         (R * @a lr) + (G * @a lg) + (B * @a lb).
 832     */
 833     wxImage ConvertToGreyscale(double lr = 0.299, double lg = 0.587, double lb = 1.114) const;
 834
 835     /**
 836         Returns monochromatic version of the image.
 837
 838         The returned image has white colour where the original has @e (r,g,b)
 839         colour and black colour everywhere else.
 840     */
 841     wxImage ConvertToMono(unsigned char r, unsigned char g, unsigned char b) const;
 842
 843     //@}
 844
 845
 846     /**
 847         @name Miscellaneous functions
 848     */
 849     //@{
 850
 851     /**
 852         Computes the histogram of the image. @a histogram is a reference to
 853         wxImageHistogram object. wxImageHistogram is a specialization of
 854         wxHashMap "template" and is defined as follows:
 855
 856         @code
 857         class WXDLLEXPORT wxImageHistogramEntry
 858         {
 859         public:
 860             wxImageHistogramEntry() : index(0), value(0) {}
 861             unsigned long index;
 862             unsigned long value;
 863         };
 864
 865         WX_DECLARE_EXPORTED_HASH_MAP(unsigned long, wxImageHistogramEntry,
 866                                     wxIntegerHash, wxIntegerEqual,
 867                                     wxImageHistogram);
 868         @endcode
 869
 870         @return Returns number of colours in the histogram.
 871     */
 872     unsigned long ComputeHistogram(wxImageHistogram& histogram) const;
 873
 874     /**
 875         Finds the first colour that is never used in the image.
 876         The search begins at given initial colour and continues by increasing
 877         R, G and B components (in this order) by 1 until an unused colour is
 878         found or the colour space exhausted.
 879
 880         The parameters @a r, @a g, @a b are pointers to variables to save the colour.
 881
 882         The parameters @a startR, @a startG, @a startB define the initial values
 883         of the colour.
 884         The returned colour will have RGB values equal to or greater than these.
 885
 886         @return Returns @false if there is no unused colour left, @true on success.
 887
 888         @note
 889             This method involves computing the histogram, which is a
 890             computationally intensive operation.
 891     */
 892     bool FindFirstUnusedColour(unsigned char* r, unsigned char* g,
 893                                unsigned char* b, unsigned char startR = 1,
 894                                unsigned char startG = 0,
 895                                unsigned char startB = 0) const;
 896
 897     /**
 898         Assignment operator, using @ref overview_refcount "reference counting".
 899
 900         @param image
 901             Image to assign.
 902
 903         @return Returns 'this' object.
 904     */
 905     wxImage& operator=(const wxImage& image);
 906
 907     //@}
 908
 909
 910     /**
 911         @name Getters
 912     */
 913     //@{
 914
 915     /**
 916         Returns pointer to the array storing the alpha values for this image.
 917
 918         This pointer is @NULL for the images without the alpha channel. If the image
 919         does have it, this pointer may be used to directly manipulate the alpha values
 920         which are stored as the RGB ones.
 921     */
 922     unsigned char* GetAlpha() const;
 923
 924     /**
 925         Returns the image data as an array.
 926
 927         This is most often used when doing direct image manipulation.
 928         The return value points to an array of characters in RGBRGBRGB... format
 929         in the top-to-bottom, left-to-right order, that is the first RGB triplet
 930         corresponds to the pixel first pixel of the first row, the second one ---
 931         to the second pixel of the first row and so on until the end of the first
 932         row, with second row following after it and so on.
 933
 934         You should not delete the returned pointer nor pass it to SetData().
 935     */
 936     unsigned char* GetData() const;
 937
 938     /**
 939         Return alpha value at given pixel location.
 940     */
 941     unsigned char GetAlpha(int x, int y) const;
 942
 943     /**
 944         Returns the red intensity at the given coordinate.
 945     */
 946     unsigned char GetRed(int x, int y) const;
 947
 948     /**
 949         Returns the green intensity at the given coordinate.
 950     */
 951     unsigned char GetGreen(int x, int y) const;
 952
 953     /**
 954         Returns the blue intensity at the given coordinate.
 955     */
 956     unsigned char GetBlue(int x, int y) const;
 957
 958     /**
 959         Gets the red value of the mask colour.
 960     */
 961     unsigned char GetMaskRed() const;
 962
 963     /**
 964         Gets the green value of the mask colour.
 965     */
 966     unsigned char GetMaskGreen() const;
 967
 968     /**
 969         Gets the blue value of the mask colour.
 970     */
 971     unsigned char GetMaskBlue() const;
 972
 973     /**
 974         Gets the width of the image in pixels.
 975
 976         @see GetHeight(), GetSize()
 977     */
 978     int GetWidth() const;
 979
 980     /**
 981         Gets the height of the image in pixels.
 982
 983         @see GetWidth(), GetSize()
 984     */
 985     int GetHeight() const;
 986
 987     /**
 988         Returns the size of the image in pixels.
 989
 990         @since 2.9.0
 991
 992         @see GetHeight(), GetWidth()
 993     */
 994     wxSize GetSize() const;
 995
 996     /**
 997         Gets a user-defined string-valued option.
 998
 999         Currently the only defined string option is
1000         @li @c wxIMAGE_OPTION_FILENAME: The name of the file from which the image
1001             was loaded.
1002
1003         @param name
1004             The name of the option, case-insensitive.
1005         @return
1006             The value of the option or an empty string if not found. Use
1007             HasOption() if an empty string can be a valid option value.
1008
1009         @see SetOption(), GetOptionInt(), HasOption()
1010     */
1011     wxString GetOption(const wxString& name) const;
1012
1013     /**
1014         Gets a user-defined integer-valued option.
1015
1016         The function is case-insensitive to @a name.
1017         If the given option is not present, the function returns 0.
1018         Use HasOption() is 0 is a possibly valid value for the option.
1019
1020         Generic options:
1021         @li @c wxIMAGE_OPTION_MAX_WIDTH and @c wxIMAGE_OPTION_MAX_HEIGHT: If either
1022             of these options is specified, the loaded image will be scaled down
1023             (preserving its aspect ratio) so that its width is less than the
1024             max width given if it is not 0 @em and its height is less than the
1025             max height given if it is not 0. This is typically used for loading
1026             thumbnails and the advantage of using these options compared to
1027             calling Rescale() after loading is that some handlers (only JPEG
1028             one right now) support rescaling the image during loading which is
1029             vastly more efficient than loading the entire huge image and
1030             rescaling it later (if these options are not supported by the
1031             handler, this is still what happens however). These options must be
1032             set before calling LoadFile() to have any effect.
1033
1034         @li @c wxIMAGE_OPTION_QUALITY: JPEG quality used when saving. This is an
1035             integer in 0..100 range with 0 meaning very poor and 100 excellent
1036             (but very badly compressed). This option is currently ignored for
1037             the other formats.
1038
1039         @li @c wxIMAGE_OPTION_RESOLUTIONUNIT: The value of this option determines
1040             whether the resolution of the image is specified in centimetres or
1041             inches, see wxImageResolution enum elements.
1042
1043         @li @c wxIMAGE_OPTION_RESOLUTION, @c wxIMAGE_OPTION_RESOLUTIONX and
1044             @c wxIMAGE_OPTION_RESOLUTIONY: These options define the resolution of
1045             the image in the units corresponding to @c wxIMAGE_OPTION_RESOLUTIONUNIT
1046             options value. The first option can be set before saving the image
1047             to set both horizontal and vertical resolution to the same value.
1048             The X and Y options are set by the image handlers if they support
1049             the image resolution (currently BMP, JPEG and TIFF handlers do) and
1050             the image provides the resolution information and can be queried
1051             after loading the image.
1052
1053         Options specific to wxPNGHandler:
1054         @li @c wxIMAGE_OPTION_PNG_FORMAT: Format for saving a PNG file, see
1055             wxImagePNGType for the supported values.
1056         @li @c wxIMAGE_OPTION_PNG_BITDEPTH: Bit depth for every channel (R/G/B/A).
1057         @li @c wxIMAGE_OPTION_PNG_FILTER: Filter for saving a PNG file, see libpng
1058             (http://www.libpng.org/pub/png/libpng-1.2.5-manual.html) for possible values
1059             (e.g. PNG_FILTER_NONE, PNG_FILTER_SUB, PNG_FILTER_UP, etc).
1060         @li @c wxIMAGE_OPTION_PNG_COMPRESSION_LEVEL: Compression level (0..9) for
1061             saving a PNG file. An high value creates smaller-but-slower PNG file.
1062             Note that unlike other formats (e.g. JPEG) the PNG format is always
1063             lossless and thus this compression level doesn't tradeoff the image
1064             quality.
1065         @li @c wxIMAGE_OPTION_PNG_COMPRESSION_MEM_LEVEL: Compression memory usage
1066             level (1..9) for saving a PNG file. An high value means the saving
1067             process consumes more memory, but may create smaller PNG file.
1068         @li @c wxIMAGE_OPTION_PNG_COMPRESSION_STRATEGY: Possible values are 0 for
1069             default strategy, 1 for filter, and 2 for Huffman-only.
1070             You can use OptiPNG (http://optipng.sourceforge.net/) to get a suitable
1071             value for your application.
1072         @li @c wxIMAGE_OPTION_PNG_COMPRESSION_BUFFER_SIZE: Internal buffer size
1073             (in bytes) for saving a PNG file. Ideally this should be as big as
1074             the resulting PNG file. Use this option if your application produces
1075             images with small size variation.
1076
1077         @param name
1078             The name of the option, case-insensitive.
1079         @return
1080             The value of the option or 0 if not found.
1081             Use HasOption() if 0 can be a valid option value.
1082
1083         @see SetOption(), GetOption()
1084     */
1085     int GetOptionInt(const wxString& name) const;
1086
1087     /**
1088         Get the current mask colour or find a suitable unused colour that could be
1089         used as a mask colour. Returns @true if the image currently has a mask.
1090     */
1091     bool GetOrFindMaskColour(unsigned char* r, unsigned char* g,
1092                              unsigned char* b) const;
1093
1094     /**
1095         Returns the palette associated with the image.
1096         Currently the palette is only used when converting to wxBitmap under Windows.
1097
1098         Some of the wxImage handlers have been modified to set the palette if
1099         one exists in the image file (usually 256 or less colour images in
1100         GIF or PNG format).
1101     */
1102     const wxPalette& GetPalette() const;
1103
1104     /**
1105         Returns a sub image of the current one as long as the rect belongs entirely
1106         to the image.
1107     */
1108     wxImage GetSubImage(const wxRect& rect) const;
1109
1110     /**
1111         Gets the type of image found by LoadFile() or specified with SaveFile().
1112
1113         @since 2.9.0
1114     */
1115     wxBitmapType GetType() const;
1116
1117     /**
1118         Returns @true if this image has alpha channel, @false otherwise.
1119
1120         @see GetAlpha(), SetAlpha()
1121     */
1122     bool HasAlpha() const;
1123
1124     /**
1125         Returns @true if there is a mask active, @false otherwise.
1126     */
1127     bool HasMask() const;
1128
1129     /**
1130         Returns @true if the given option is present.
1131         The function is case-insensitive to @a name.
1132
1133         The lists of the currently supported options are in GetOption() and
1134         GetOptionInt() function docs.
1135
1136         @see SetOption(), GetOption(), GetOptionInt()
1137     */
1138     bool HasOption(const wxString& name) const;
1139
1140     /**
1141         Returns @true if image data is present.
1142     */
1143     bool IsOk() const;
1144
1145     /**
1146         Returns @true if the given pixel is transparent, i.e. either has the mask
1147         colour if this image has a mask or if this image has alpha channel and alpha
1148         value of this pixel is strictly less than @a threshold.
1149     */
1150     bool IsTransparent(int x, int y,
1151                        unsigned char threshold = wxIMAGE_ALPHA_THRESHOLD) const;
1152
1153     //@}
1154
1155
1156     /**
1157         @name Loading and saving functions
1158     */
1159     //@{
1160
1161     /**
1162         Loads an image from an input stream.
1163
1164         @param stream
1165             Opened input stream from which to load the image.
1166             Currently, the stream must support seeking.
1167         @param type
1168             May be one of the following:
1169             @li wxBITMAP_TYPE_BMP: Load a Windows bitmap file.
1170             @li wxBITMAP_TYPE_GIF: Load a GIF bitmap file.
1171             @li wxBITMAP_TYPE_JPEG: Load a JPEG bitmap file.
1172             @li wxBITMAP_TYPE_PNG: Load a PNG bitmap file.
1173             @li wxBITMAP_TYPE_PCX: Load a PCX bitmap file.
1174             @li wxBITMAP_TYPE_PNM: Load a PNM bitmap file.
1175             @li wxBITMAP_TYPE_TIF: Load a TIFF bitmap file.
1176             @li wxBITMAP_TYPE_TGA: Load a TGA bitmap file.
1177             @li wxBITMAP_TYPE_XPM: Load a XPM bitmap file.
1178             @li wxBITMAP_TYPE_ICO: Load a Windows icon file (ICO).
1179             @li wxBITMAP_TYPE_CUR: Load a Windows cursor file (CUR).
1180             @li wxBITMAP_TYPE_ANI: Load a Windows animated cursor file (ANI).
1181             @li wxBITMAP_TYPE_ANY: Will try to autodetect the format.
1182         @param index
1183             Index of the image to load in the case that the image file contains
1184             multiple images. This is only used by GIF, ICO and TIFF handlers.
1185             The default value (-1) means "choose the default image" and is
1186             interpreted as the first image (index=0) by the GIF and TIFF handler
1187             and as the largest and most colourful one by the ICO handler.
1188
1189         @return @true if the operation succeeded, @false otherwise.
1190                 If the optional index parameter is out of range, @false is
1191                 returned and a call to wxLogError() takes place.
1192
1193         @remarks Depending on how wxWidgets has been configured, not all formats
1194                  may be available.
1195
1196         @note
1197             You can use GetOptionInt() to get the hotspot when loading cursor files:
1198             @code
1199             int hotspot_x = image.GetOptionInt(wxIMAGE_OPTION_CUR_HOTSPOT_X);
1200             int hotspot_y = image.GetOptionInt(wxIMAGE_OPTION_CUR_HOTSPOT_Y);
1201             @endcode
1202
1203         @see SaveFile()
1204     */
1205     virtual bool LoadFile(wxInputStream& stream,
1206                           wxBitmapType type = wxBITMAP_TYPE_ANY,
1207                           int index = -1);
1208
1209     /**
1210         Loads an image from a file.
1211         If no handler type is provided, the library will try to autodetect the format.
1212
1213         @param name
1214             Name of the file from which to load the image.
1215         @param type
1216             See the description in the LoadFile(wxInputStream&, wxBitmapType, int) overload.
1217         @param index
1218             See the description in the LoadFile(wxInputStream&, wxBitmapType, int) overload.
1219     */
1220     virtual bool LoadFile(const wxString& name,
1221                           wxBitmapType type = wxBITMAP_TYPE_ANY,
1222                           int index = -1);
1223
1224     /**
1225         Loads an image from a file.
1226         If no handler type is provided, the library will try to autodetect the format.
1227
1228         @param name
1229             Name of the file from which to load the image.
1230         @param mimetype
1231             MIME type string (for example 'image/jpeg')
1232         @param index
1233             See the description in the LoadFile(wxInputStream&, wxBitmapType, int) overload.
1234     */
1235     virtual bool LoadFile(const wxString& name, const wxString& mimetype,
1236                           int index = -1);
1237
1238     /**
1239         Loads an image from an input stream.
1240
1241         @param stream
1242             Opened input stream from which to load the image.
1243             Currently, the stream must support seeking.
1244         @param mimetype
1245             MIME type string (for example 'image/jpeg')
1246         @param index
1247             See the description in the LoadFile(wxInputStream&, wxBitmapType, int) overload.
1248     */
1249     virtual bool LoadFile(wxInputStream& stream, const wxString& mimetype,
1250                           int index = -1);
1251
1252     /**
1253         Saves an image in the given stream.
1254
1255         @param stream
1256             Opened output stream to save the image to.
1257         @param mimetype
1258             MIME type.
1259
1260         @return @true if the operation succeeded, @false otherwise.
1261
1262         @remarks Depending on how wxWidgets has been configured, not all formats
1263                  may be available.
1264
1265         @note
1266             You can use SetOption() to set the hotspot when saving an image
1267             into a cursor file (default hotspot is in the centre of the image):
1268             @code
1269             image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_X, hotspotX);
1270             image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_Y, hotspotY);
1271             @endcode
1272
1273         @see LoadFile()
1274     */
1275     virtual bool SaveFile(wxOutputStream& stream,
1276                           const wxString& mimetype) const;
1277
1278     /**
1279         Saves an image in the named file.
1280
1281         @param name
1282             Name of the file to save the image to.
1283         @param type
1284             Currently these types can be used:
1285             @li wxBITMAP_TYPE_BMP: Save a BMP image file.
1286             @li wxBITMAP_TYPE_JPEG: Save a JPEG image file.
1287             @li wxBITMAP_TYPE_PNG: Save a PNG image file.
1288             @li wxBITMAP_TYPE_PCX: Save a PCX image file
1289                 (tries to save as 8-bit if possible, falls back to 24-bit otherwise).
1290             @li wxBITMAP_TYPE_PNM: Save a PNM image file (as raw RGB always).
1291             @li wxBITMAP_TYPE_TIFF: Save a TIFF image file.
1292             @li wxBITMAP_TYPE_XPM: Save a XPM image file.
1293             @li wxBITMAP_TYPE_ICO: Save a Windows icon file (ICO).
1294                 The size may be up to 255 wide by 127 high. A single image is saved
1295                 in 8 colors at the size supplied.
1296             @li wxBITMAP_TYPE_CUR: Save a Windows cursor file (CUR).
1297     */
1298     virtual bool SaveFile(const wxString& name, wxBitmapType type) const;
1299
1300     /**
1301         Saves an image in the named file.
1302
1303         @param name
1304             Name of the file to save the image to.
1305         @param mimetype
1306             MIME type.
1307     */
1308     virtual bool SaveFile(const wxString& name, const wxString& mimetype) const;
1309
1310     /**
1311         Saves an image in the named file.
1312
1313         File type is determined from the extension of the file name.
1314         Note that this function may fail if the extension is not recognized!
1315         You can use one of the forms above to save images to files with
1316         non-standard extensions.
1317
1318         @param name
1319             Name of the file to save the image to.
1320     */
1321     virtual bool SaveFile(const wxString& name) const;
1322
1323     /**
1324         Saves an image in the given stream.
1325
1326         @param stream
1327             Opened output stream to save the image to.
1328         @param type
1329             MIME type.
1330     */
1331     virtual bool SaveFile(wxOutputStream& stream, wxBitmapType type) const;
1332
1333     //@}
1334
1335
1336
1337     /**
1338         @name Setters
1339     */
1340     //@{
1341
1342     /**
1343        This function is similar to SetData() and has similar restrictions.
1344
1345         The pointer passed to it may however be @NULL in which case the function
1346         will allocate the alpha array internally -- this is useful to add alpha
1347         channel data to an image which doesn't have any.
1348
1349         If the pointer is not @NULL, it must have one byte for each image pixel
1350         and be allocated with malloc().
1351         wxImage takes ownership of the pointer and will free it unless @a static_data
1352         parameter is set to @true -- in this case the caller should do it.
1353     */
1354     void SetAlpha(unsigned char* alpha = NULL,
1355                   bool static_data = false);
1356
1357     /**
1358         Sets the alpha value for the given pixel.
1359         This function should only be called if the image has alpha channel data,
1360         use HasAlpha() to check for this.
1361     */
1362     void SetAlpha(int x, int y, unsigned char alpha);
1363
1364     /**
1365         Sets the image data without performing checks.
1366
1367         The data given must have the size (width*height*3) or results will be
1368         unexpected. Don't use this method if you aren't sure you know what you
1369         are doing.
1370
1371         The data must have been allocated with @c malloc(), @b NOT with
1372         @c operator new.
1373
1374         If @a static_data is @false, after this call the pointer to the data is
1375         owned by the wxImage object, that will be responsible for deleting it.
1376         Do not pass to this function a pointer obtained through GetData().
1377     */
1378     void SetData(unsigned char* data, bool static_data = false);
1379
1380     /**
1381         @overload
1382     */
1383     void SetData(unsigned char* data, int new_width, int new_height,
1384                  bool static_data = false);
1385
1386     /**
1387         Specifies whether there is a mask or not.
1388
1389         The area of the mask is determined by the current mask colour.
1390     */
1391     void SetMask(bool hasMask = true);
1392
1393     /**
1394         Sets the mask colour for this image (and tells the image to use the mask).
1395     */
1396     void SetMaskColour(unsigned char red, unsigned char green,
1397                        unsigned char blue);
1398
1399     /**
1400         Sets image's mask so that the pixels that have RGB value of mr,mg,mb in
1401         mask will be masked in the image.
1402
1403         This is done by first finding an unused colour in the image, setting
1404         this colour as the mask colour and then using this colour to draw all
1405         pixels in the image who corresponding pixel in mask has given RGB value.
1406
1407         The parameter @a mask is the mask image to extract mask shape from.
1408         It must have the same dimensions as the image.
1409
1410         The parameters @a mr, @a mg, @a mb are the RGB values of the pixels in
1411         mask that will be used to create the mask.
1412
1413         @return Returns @false if mask does not have same dimensions as the image
1414                 or if there is no unused colour left. Returns @true if the mask
1415                 was successfully applied.
1416
1417         @note
1418             Note that this method involves computing the histogram, which is a
1419             computationally intensive operation.
1420     */
1421     bool SetMaskFromImage(const wxImage& mask, unsigned char mr,
1422                           unsigned char mg,
1423                           unsigned char mb);
1424
1425     /**
1426         Sets a user-defined option. The function is case-insensitive to @a name.
1427
1428         For example, when saving as a JPEG file, the option @b quality is
1429         used, which is a number between 0 and 100 (0 is terrible, 100 is very good).
1430
1431         The lists of the currently supported options are in GetOption() and
1432         GetOptionInt() function docs.
1433
1434         @see GetOption(), GetOptionInt(), HasOption()
1435     */
1436     void SetOption(const wxString& name, const wxString& value);
1437
1438     /**
1439         @overload
1440     */
1441     void SetOption(const wxString& name, int value);
1442
1443     /**
1444         Associates a palette with the image.
1445
1446         The palette may be used when converting wxImage to wxBitmap (MSW only at present)
1447         or in file save operations (none as yet).
1448     */
1449     void SetPalette(const wxPalette& palette);
1450
1451     /**
1452         Sets the colour of the pixels within the given rectangle.
1453
1454         This routine performs bounds-checks for the coordinate so it can be considered
1455         a safe way to manipulate the data.
1456     */
1457     void SetRGB(const wxRect& rect,
1458                 unsigned char red,
1459                 unsigned char green,
1460                 unsigned char blue);
1461
1462     /**
1463         Set the type of image returned by GetType().
1464
1465         This method is mostly used internally by the library but can also be
1466         called from the user code if the image was created from data in the
1467         given bitmap format without using LoadFile() (which would set the type
1468         correctly automatically).
1469
1470         Notice that the image must be created before this function is called.
1471
1472         @since 2.9.0
1473
1474         @param type
1475             One of bitmap type constants, @c wxBITMAP_TYPE_INVALID is a valid
1476             value for it and can be used to reset the bitmap type to default
1477             but @c wxBITMAP_TYPE_MAX is not allowed here.
1478     */
1479     void SetType(wxBitmapType type);
1480
1481     //@}
1482
1483
1484
1485     /**
1486         @name Handler management functions
1487     */
1488     //@{
1489
1490     /**
1491         Register an image handler.
1492         See @ref image_handlers for a list of the available handlers.
1493     */
1494     static void AddHandler(wxImageHandler* handler);
1495
1496     /**
1497         Deletes all image handlers.
1498         This function is called by wxWidgets on exit.
1499     */
1500     static void CleanUpHandlers();
1501
1502     /**
1503         Finds the handler with the given name.
1504
1505         @param name
1506             The handler name.
1507
1508         @return A pointer to the handler if found, @NULL otherwise.
1509
1510         @see wxImageHandler
1511     */
1512     static wxImageHandler* FindHandler(const wxString& name);
1513
1514     /**
1515         Finds the handler associated with the given extension and type.
1516
1517         @param extension
1518             The file extension, such as "bmp".
1519         @param imageType
1520             The image type; one of the ::wxBitmapType values.
1521
1522         @return A pointer to the handler if found, @NULL otherwise.
1523
1524         @see wxImageHandler
1525     */
1526     static wxImageHandler* FindHandler(const wxString& extension,
1527                                        wxBitmapType imageType);
1528
1529     /**
1530         Finds the handler associated with the given image type.
1531
1532         @param imageType
1533             The image type; one of the ::wxBitmapType values.
1534
1535         @return A pointer to the handler if found, @NULL otherwise.
1536
1537         @see wxImageHandler
1538     */
1539     static wxImageHandler* FindHandler(wxBitmapType imageType);
1540
1541     /**
1542         Finds the handler associated with the given MIME type.
1543
1544         @param mimetype
1545             MIME type.
1546
1547         @return A pointer to the handler if found, @NULL otherwise.
1548
1549         @see wxImageHandler
1550     */
1551     static wxImageHandler* FindHandlerMime(const wxString& mimetype);
1552
1553     /**
1554         Returns the static list of image format handlers.
1555
1556         @see wxImageHandler
1557     */
1558     static wxList& GetHandlers();
1559
1560     /**
1561         Internal use only. Adds standard image format handlers.
1562         It only install wxBMPHandler for the time being, which is used by wxBitmap.
1563
1564         This function is called by wxWidgets on startup, and shouldn't be called by
1565         the user.
1566
1567         @see wxImageHandler, wxInitAllImageHandlers(), wxQuantize
1568     */
1569     static void InitStandardHandlers();
1570
1571     /**
1572         Adds a handler at the start of the static list of format handlers.
1573
1574         @param handler
1575             A new image format handler object. There is usually only one instance
1576             of a given handler class in an application session.
1577
1578         @see wxImageHandler
1579     */
1580     static void InsertHandler(wxImageHandler* handler);
1581
1582     /**
1583         Finds the handler with the given name, and removes it.
1584         The handler is not deleted.
1585
1586         @param name
1587             The handler name.
1588
1589         @return @true if the handler was found and removed, @false otherwise.
1590
1591         @see wxImageHandler
1592     */
1593     static bool RemoveHandler(const wxString& name);
1594
1595     //@}
1596
1597
1598     /**
1599         Returns @true if at least one of the available image handlers can read
1600         the file with the given name.
1601
1602         See wxImageHandler::CanRead for more info.
1603     */
1604     static bool CanRead(const wxString& filename);
1605
1606     /**
1607         Returns @true if at least one of the available image handlers can read
1608         the data in the given stream.
1609
1610         See wxImageHandler::CanRead for more info.
1611     */
1612     static bool CanRead(wxInputStream& stream);
1613
1614     //@{
1615     /**
1616         If the image file contains more than one image and the image handler is
1617         capable of retrieving these individually, this function will return the
1618         number of available images.
1619
1620         For the overload taking the parameter @a filename, that's the name
1621         of the file to query.
1622         For the overload taking the parameter @a stream, that's the opened input
1623         stream with image data.
1624
1625         See wxImageHandler::GetImageCount() for more info.
1626
1627         The parameter @a type may be one of the following values:
1628         @li wxBITMAP_TYPE_BMP: Load a Windows bitmap file.
1629         @li wxBITMAP_TYPE_GIF: Load a GIF bitmap file.
1630         @li wxBITMAP_TYPE_JPEG: Load a JPEG bitmap file.
1631         @li wxBITMAP_TYPE_PNG: Load a PNG bitmap file.
1632         @li wxBITMAP_TYPE_PCX: Load a PCX bitmap file.
1633         @li wxBITMAP_TYPE_PNM: Load a PNM bitmap file.
1634         @li wxBITMAP_TYPE_TIF: Load a TIFF bitmap file.
1635         @li wxBITMAP_TYPE_TGA: Load a TGA bitmap file.
1636         @li wxBITMAP_TYPE_XPM: Load a XPM bitmap file.
1637         @li wxBITMAP_TYPE_ICO: Load a Windows icon file (ICO).
1638         @li wxBITMAP_TYPE_CUR: Load a Windows cursor file (CUR).
1639         @li wxBITMAP_TYPE_ANI: Load a Windows animated cursor file (ANI).
1640         @li wxBITMAP_TYPE_ANY: Will try to autodetect the format.
1641
1642         @return Number of available images. For most image handlers, this is 1
1643                 (exceptions are TIFF and ICO formats as well as animated GIFs
1644                 for which this function returns the number of frames in the
1645                 animation).
1646     */
1647     static int GetImageCount(const wxString& filename,
1648                              wxBitmapType type = wxBITMAP_TYPE_ANY);
1649     static int GetImageCount(wxInputStream& stream,
1650                              wxBitmapType type = wxBITMAP_TYPE_ANY);
1651     //@}
1652
1653     /**
1654         Iterates all registered wxImageHandler objects, and returns a string containing
1655         file extension masks suitable for passing to file open/save dialog boxes.
1656
1657         @return The format of the returned string is @c "(*.ext1;*.ext2)|*.ext1;*.ext2".
1658                 It is usually a good idea to prepend a description before passing
1659                 the result to the dialog.
1660                 Example:
1661                 @code
1662                 wxFileDialog FileDlg( this, "Choose Image", ::wxGetCwd(), "",
1663                                       _("Image Files ") + wxImage::GetImageExtWildcard(),
1664                                       wxFD_OPEN );
1665                 @endcode
1666
1667         @see wxImageHandler
1668     */
1669     static wxString GetImageExtWildcard();
1670
1671     /**
1672         Converts a color in RGB color space to HSV color space.
1673     */
1674     static wxImage::HSVValue RGBtoHSV(const wxImage::RGBValue& rgb);
1675
1676     /**
1677         Converts a color in HSV color space to RGB color space.
1678     */
1679     static wxImage::RGBValue HSVtoRGB(const wxImage::HSVValue& hsv);
1680 };
1681
1682 /**
1683     An instance of an empty image without an alpha channel.
1684 */
1685 wxImage wxNullImage;
1686
1687
1688 // ============================================================================
1689 // Global functions/macros
1690 // ============================================================================
1691
1692 /** @addtogroup group_funcmacro_appinitterm */
1693 //@{
1694
1695 /**
1696     Initializes all available image handlers. For a list of available handlers,
1697     see wxImage.
1698     If you don't need/want all image handlers loaded
1699
1700     @see wxImage, wxImageHandler
1701
1702     @header{wx/image.h}
1703 */
1704 void wxInitAllImageHandlers();
1705
1706 //@}
1707