1 /////////////////////////////////////////////////////////////////////////////
3 // Purpose: interface of wxImageHandler and wxImage
4 // Author: wxWidgets team
6 // Licence: wxWindows license
7 /////////////////////////////////////////////////////////////////////////////
10 Possible values for the image resolution option.
12 @see wxImage::GetOptionInt().
14 enum wxImageResolution
16 /// Resolution not specified.
17 wxIMAGE_RESOLUTION_NONE
= 0,
19 /// Resolution specified in inches.
20 wxIMAGE_RESOLUTION_INCHES
= 1,
22 /// Resolution specified in centimetres.
23 wxIMAGE_RESOLUTION_CM
= 2
27 Possible values for PNG image type option.
29 @see wxImage::GetOptionInt().
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.
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.
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.
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.
55 @section imagehandler_note Note (Legal Issue)
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.)
68 @see wxImage, wxInitAllImageHandlers()
70 class wxImageHandler
: public wxObject
76 In your own default constructor, initialise the members
77 m_name, m_extension and m_type.
82 Destroys the wxImageHandler object.
84 virtual ~wxImageHandler();
87 Gets the file extension associated with this handler.
89 const wxString
& GetExtension() const;
92 If the image file contains more than one image and the image handler is capable
93 of retrieving these individually, this function will return the number of
97 Opened input stream for reading image data.
98 Currently, the stream must support seeking.
100 @return Number of available images. For most image handlers, this is 1
101 (exceptions are TIFF and ICO formats).
103 virtual int GetImageCount(wxInputStream
& stream
);
106 Gets the MIME type associated with this handler.
108 const wxString
& GetMimeType() const;
111 Gets the name of this handler.
113 const wxString
& GetName() const;
116 Gets the image type associated with this handler.
118 wxBitmapType
GetType() const;
121 Loads a image from a stream, putting the resulting data into @a image.
123 If the image file contains more than one image and the image handler is
124 capable of retrieving these individually, @a index indicates which image
125 to read from the stream.
128 The image object which is to be affected by this operation.
130 Opened input stream for reading image data.
132 If set to @true, errors reported by the image handler will produce
135 The index of the image in the file (starting from zero).
137 @return @true if the operation succeeded, @false otherwise.
139 @see wxImage::LoadFile, wxImage::SaveFile, SaveFile()
141 virtual bool LoadFile(wxImage
* image
, wxInputStream
& stream
,
142 bool verbose
= true, int index
= -1);
145 Saves a image in the output stream.
148 The image object which is to be affected by this operation.
150 Opened output stream for writing the data.
152 If set to @true, errors reported by the image handler will produce
155 @return @true if the operation succeeded, @false otherwise.
157 @see wxImage::LoadFile, wxImage::SaveFile, LoadFile()
159 virtual bool SaveFile(wxImage
* image
, wxOutputStream
& stream
,
160 bool verbose
= true);
163 Sets the handler extension.
168 void SetExtension(const wxString
& extension
);
171 Sets the handler MIME type.
176 void SetMimeType(const wxString
& mimetype
);
179 Sets the handler name.
184 void SetName(const wxString
& name
);
189 Constant used to indicate the alpha value conventionally defined as
190 the complete transparency.
192 const unsigned char wxIMAGE_ALPHA_TRANSPARENT
= 0;
195 Constant used to indicate the alpha value conventionally defined as
196 the complete opacity.
198 const unsigned char wxIMAGE_ALPHA_OPAQUE
= 0xff;
203 This class encapsulates a platform-independent image.
205 An image can be created from data, or using wxBitmap::ConvertToImage.
206 An image can be loaded from a file in a variety of formats, and is extensible
207 to new formats via image format handlers. Functions are available to set and
208 get image bits, so it can be used for basic image manipulation.
210 A wxImage cannot (currently) be drawn directly to a wxDC.
211 Instead, a platform-specific wxBitmap object must be created from it using
212 the wxBitmap::wxBitmap(wxImage,int depth) constructor.
213 This bitmap can then be drawn in a device context, using wxDC::DrawBitmap.
215 One colour value of the image may be used as a mask colour which will lead to
216 the automatic creation of a wxMask object associated to the bitmap object.
219 @section image_alpha Alpha channel support
221 Starting from wxWidgets 2.5.0 wxImage supports alpha channel data, that is
222 in addition to a byte for the red, green and blue colour components for each
223 pixel it also stores a byte representing the pixel opacity.
225 An alpha value of 0 corresponds to a transparent pixel (null opacity) while
226 a value of 255 means that the pixel is 100% opaque.
227 The constants ::wxIMAGE_ALPHA_TRANSPARENT and ::wxIMAGE_ALPHA_OPAQUE can be
228 used to indicate those values in a more readable form.
230 Unlike RGB data, not all images have an alpha channel and before using
231 wxImage::GetAlpha you should check if this image contains an alpha channel
232 with wxImage::HasAlpha. Note that currently only the PNG format has full
233 alpha channel support so only the images loaded from PNG files can have
234 alpha and, if you initialize the image alpha channel yourself using
235 wxImage::SetAlpha, you should save it in PNG format to avoid losing it.
238 @section image_handlers Available image handlers
240 The following image handlers are available.
241 wxBMPHandler is always installed by default.
242 To use other image formats, install the appropriate handler with
243 wxImage::AddHandler or call ::wxInitAllImageHandlers().
245 - wxBMPHandler: For loading and saving, always installed.
246 - wxPNGHandler: For loading (including alpha support) and saving.
247 - wxJPEGHandler: For loading and saving.
248 - wxGIFHandler: Only for loading, due to legal issues.
249 - wxPCXHandler: For loading and saving (see below).
250 - wxPNMHandler: For loading and saving (see below).
251 - wxTIFFHandler: For loading and saving.
252 - wxTGAHandler: For loading only.
253 - wxIFFHandler: For loading only.
254 - wxXPMHandler: For loading and saving.
255 - wxICOHandler: For loading and saving.
256 - wxCURHandler: For loading and saving.
257 - wxANIHandler: For loading only.
259 When saving in PCX format, wxPCXHandler will count the number of different
260 colours in the image; if there are 256 or less colours, it will save as 8 bit,
261 else it will save as 24 bit.
263 Loading PNMs only works for ASCII or raw RGB images.
264 When saving in PNM format, wxPNMHandler will always save as raw RGB.
273 @see wxBitmap, wxInitAllImageHandlers(), wxPixelData
275 class wxImage
: public wxObject
282 Constructor for RGBValue, an object that contains values for red, green
283 and blue which represent the value of a color.
285 It is used by wxImage::HSVtoRGB and wxImage::RGBtoHSV, which converts
286 between HSV color space and RGB color space.
288 RGBValue(unsigned char r
=0, unsigned char g
=0, unsigned char b
=0);
295 Constructor for HSVValue, an object that contains values for hue, saturation
296 and value which represent the value of a color.
298 It is used by wxImage::HSVtoRGB() and wxImage::RGBtoHSV(), which converts
299 between HSV color space and RGB color space.
301 HSVValue(double h
=0.0, double s
=0.0, double v
=0.0);
305 Creates an empty wxImage object without an alpha channel.
310 Creates an image with the given size and clears it if requested.
312 Does not create an alpha channel.
315 Specifies the width of the image.
317 Specifies the height of the image.
319 If @true, initialize the image to black.
321 wxImage(int width
, int height
, bool clear
= true);
324 Creates an image from data in memory. If @a static_data is @false
325 then the wxImage will take ownership of the data and free it
326 afterwards. For this, it has to be allocated with @e malloc.
329 Specifies the width of the image.
331 Specifies the height of the image.
333 A pointer to RGB data
335 Indicates if the data should be free'd after use
338 wxImage(int width
, int height
, unsigned char* data
, bool static_data
= false);
341 Creates an image from data in memory. If @a static_data is @false
342 then the wxImage will take ownership of the data and free it
343 afterwards. For this, it has to be allocated with @e malloc.
346 Specifies the width of the image.
348 Specifies the height of the image.
350 A pointer to RGB data
352 A pointer to alpha-channel data
354 Indicates if the data should be free'd after use
357 wxImage(int width
, int height
, unsigned char* data
, unsigned char* alpha
,
358 bool static_data
= false );
361 Creates an image from XPM data.
364 A pointer to XPM image data.
366 wxImage(const char* const* xpmData
);
369 Creates an image from a file.
372 Name of the file from which to load the image.
374 May be one of the following:
375 @li wxBITMAP_TYPE_BMP: Load a Windows bitmap file.
376 @li wxBITMAP_TYPE_GIF: Load a GIF bitmap file.
377 @li wxBITMAP_TYPE_JPEG: Load a JPEG bitmap file.
378 @li wxBITMAP_TYPE_PNG: Load a PNG bitmap file.
379 @li wxBITMAP_TYPE_PCX: Load a PCX bitmap file.
380 @li wxBITMAP_TYPE_PNM: Load a PNM bitmap file.
381 @li wxBITMAP_TYPE_TIF: Load a TIFF bitmap file.
382 @li wxBITMAP_TYPE_TGA: Load a TGA bitmap file.
383 @li wxBITMAP_TYPE_XPM: Load a XPM bitmap file.
384 @li wxBITMAP_TYPE_ICO: Load a Windows icon file (ICO).
385 @li wxBITMAP_TYPE_CUR: Load a Windows cursor file (CUR).
386 @li wxBITMAP_TYPE_ANI: Load a Windows animated cursor file (ANI).
387 @li wxBITMAP_TYPE_ANY: Will try to autodetect the format.
389 Index of the image to load in the case that the image file contains
390 multiple images. This is only used by GIF, ICO and TIFF handlers.
391 The default value (-1) means "choose the default image" and is
392 interpreted as the first image (index=0) by the GIF and TIFF handler
393 and as the largest and most colourful one by the ICO handler.
395 @remarks Depending on how wxWidgets has been configured and by which
396 handlers have been loaded, not all formats may be available.
397 Any handler other than BMP must be previously initialized with
398 wxImage::AddHandler or wxInitAllImageHandlers.
401 You can use GetOptionInt() to get the hotspot when loading cursor files:
403 int hotspot_x = image.GetOptionInt(wxIMAGE_OPTION_CUR_HOTSPOT_X);
404 int hotspot_y = image.GetOptionInt(wxIMAGE_OPTION_CUR_HOTSPOT_Y);
409 wxImage(const wxString
& name
, wxBitmapType type
= wxBITMAP_TYPE_ANY
, int index
= -1);
412 Creates an image from a file using MIME-types to specify the type.
415 Name of the file from which to load the image.
417 MIME type string (for example 'image/jpeg')
419 See description in wxImage(const wxString&, wxBitmapType, int) overload.
421 wxImage(const wxString
& name
, const wxString
& mimetype
, int index
= -1);
424 Creates an image from a stream.
427 Opened input stream from which to load the image. Currently,
428 the stream must support seeking.
430 See description in wxImage(const wxString&, wxBitmapType, int) overload.
432 See description in wxImage(const wxString&, wxBitmapType, int) overload.
434 wxImage(wxInputStream
& stream
, wxBitmapType type
= wxBITMAP_TYPE_ANY
, int index
= -1);
437 Creates an image from a stream using MIME-types to specify the type.
440 Opened input stream from which to load the image. Currently,
441 the stream must support seeking.
443 MIME type string (for example 'image/jpeg')
445 See description in wxImage(const wxString&, wxBitmapType, int) overload.
447 wxImage(wxInputStream
& stream
, const wxString
& mimetype
, int index
= -1);
453 See @ref overview_refcount_destruct "reference-counted object destruction"
459 Register an image handler.
460 See @ref image_handlers for a list of the available handlers.
462 static void AddHandler(wxImageHandler
* handler
);
465 Blurs the image in both horizontal and vertical directions by the
466 specified pixel @a blurRadius. This should not be used when using
467 a single mask colour for transparency.
469 @see BlurHorizontal(), BlurVertical()
471 wxImage
Blur(int blurRadius
) const;
474 Blurs the image in the horizontal direction only. This should not be used
475 when using a single mask colour for transparency.
477 @see Blur(), BlurVertical()
479 wxImage
BlurHorizontal(int blurRadius
) const;
482 Blurs the image in the vertical direction only. This should not be used
483 when using a single mask colour for transparency.
485 @see Blur(), BlurHorizontal()
487 wxImage
BlurVertical(int blurRadius
) const;
490 Returns @true if the current image handlers can read this file
492 static bool CanRead(const wxString
& filename
);
495 Deletes all image handlers.
496 This function is called by wxWidgets on exit.
498 static void CleanUpHandlers();
501 Computes the histogram of the image. @a histogram is a reference to
502 wxImageHistogram object. wxImageHistogram is a specialization of
503 wxHashMap "template" and is defined as follows:
506 class WXDLLEXPORT wxImageHistogramEntry
509 wxImageHistogramEntry() : index(0), value(0) {}
514 WX_DECLARE_EXPORTED_HASH_MAP(unsigned long, wxImageHistogramEntry,
515 wxIntegerHash, wxIntegerEqual,
519 @return Returns number of colours in the histogram.
521 unsigned long ComputeHistogram(wxImageHistogram
& histogram
) const;
525 If the image has alpha channel, this method converts it to mask.
527 If the image has an alpha channel, all pixels with alpha value less
528 than @a threshold are replaced with the mask colour and the alpha
529 channel is removed. Otherwise nothing is done.
531 The mask colour is chosen automatically using
532 FindFirstUnusedColour() by this function, see the overload below if you
533 this is not appropriate.
535 @return @false if FindFirstUnusedColour returns @false, @true otherwise.
537 bool ConvertAlphaToMask(unsigned char threshold
= wxIMAGE_ALPHA_THRESHOLD
);
540 If the image has alpha channel, this method converts it to mask using
541 the specified colour as the mask colour.
543 If the image has an alpha channel, all pixels with alpha value less
544 than @a threshold are replaced with the mask colour and the alpha
545 channel is removed. Otherwise nothing is done.
550 The red component of the mask colour.
552 The green component of the mask colour.
554 The blue component of the mask colour.
556 Pixels with alpha channel values below the given threshold are
557 considered to be transparent, i.e. the corresponding mask pixels
558 are set. Pixels with the alpha values above the threshold are
559 considered to be opaque.
562 void ConvertAlphaToMask(unsigned char mr
, unsigned char mg
, unsigned char mb
,
563 unsigned char threshold
= wxIMAGE_ALPHA_THRESHOLD
);
567 Returns a greyscale version of the image.
569 The returned image uses the luminance component of the original to
570 calculate the greyscale. Defaults to using the standard ITU-T BT.601
571 when converting to YUV, where every pixel equals
572 (R * @a lr) + (G * @a lg) + (B * @a lb).
574 wxImage
ConvertToGreyscale(double lr
= 0.299, double lg
= 0.587, double lb
= 1.114) const;
577 Returns monochromatic version of the image.
579 The returned image has white colour where the original has @e (r,g,b)
580 colour and black colour everywhere else.
582 wxImage
ConvertToMono(unsigned char r
, unsigned char g
, unsigned char b
) const;
585 Returns an identical copy of the image.
587 wxImage
Copy() const;
590 Creates a fresh image.
592 If @a clear is @true, the new image will be initialized to black.
593 Otherwise, the image data will be uninitialized.
596 The width of the image in pixels.
598 The height of the image in pixels.
600 If @true, initialize the image data with zeroes.
602 @return @true if the call succeeded, @false otherwise.
604 bool Create(int width
, int height
, bool clear
= true);
607 Initialize the image data with zeroes (the default) or with the
608 byte value given as @a value.
612 void Clear(unsigned char value
= 0);
615 Destroys the image data.
620 Finds the first colour that is never used in the image.
621 The search begins at given initial colour and continues by increasing
622 R, G and B components (in this order) by 1 until an unused colour is
623 found or the colour space exhausted.
625 The parameters @a r, @a g, @a b are pointers to variables to save the colour.
627 The parameters @a startR, @a startG, @a startB define the initial values
629 The returned colour will have RGB values equal to or greater than these.
631 @return Returns @false if there is no unused colour left, @true on success.
634 This method involves computing the histogram, which is a
635 computationally intensive operation.
637 bool FindFirstUnusedColour(unsigned char* r
, unsigned char* g
,
638 unsigned char* b
, unsigned char startR
= 1,
639 unsigned char startG
= 0,
640 unsigned char startB
= 0) const;
643 Finds the handler with the given name.
648 @return A pointer to the handler if found, @NULL otherwise.
652 static wxImageHandler
* FindHandler(const wxString
& name
);
655 Finds the handler associated with the given extension and type.
658 The file extension, such as "bmp".
660 The image type; one of the ::wxBitmapType values.
662 @return A pointer to the handler if found, @NULL otherwise.
666 static wxImageHandler
* FindHandler(const wxString
& extension
,
667 wxBitmapType imageType
);
670 Finds the handler associated with the given image type.
673 The image type; one of the ::wxBitmapType values.
675 @return A pointer to the handler if found, @NULL otherwise.
679 static wxImageHandler
* FindHandler(wxBitmapType imageType
);
682 Finds the handler associated with the given MIME type.
687 @return A pointer to the handler if found, @NULL otherwise.
691 static wxImageHandler
* FindHandlerMime(const wxString
& mimetype
);
694 Return alpha value at given pixel location.
696 unsigned char GetAlpha(int x
, int y
) const;
699 Returns pointer to the array storing the alpha values for this image.
701 This pointer is @NULL for the images without the alpha channel. If the image
702 does have it, this pointer may be used to directly manipulate the alpha values
703 which are stored as the RGB ones.
705 unsigned char* GetAlpha() const;
708 Returns the blue intensity at the given coordinate.
710 unsigned char GetBlue(int x
, int y
) const;
713 Returns the image data as an array.
715 This is most often used when doing direct image manipulation.
716 The return value points to an array of characters in RGBRGBRGB... format
717 in the top-to-bottom, left-to-right order, that is the first RGB triplet
718 corresponds to the pixel first pixel of the first row, the second one ---
719 to the second pixel of the first row and so on until the end of the first
720 row, with second row following after it and so on.
722 You should not delete the returned pointer nor pass it to SetData().
724 unsigned char* GetData() const;
727 Returns the green intensity at the given coordinate.
729 unsigned char GetGreen(int x
, int y
) const;
732 Returns the static list of image format handlers.
736 static wxList
& GetHandlers();
739 Gets the height of the image in pixels.
741 @see GetWidth(), GetSize()
743 int GetHeight() const;
747 If the image file contains more than one image and the image handler is
748 capable of retrieving these individually, this function will return the
749 number of available images.
751 For the overload taking the parameter @a filename, that's the name
752 of the file to query.
753 For the overload taking the parameter @a stream, that's the ppened input
754 stream with image data. Currently, the stream must support seeking.
756 The parameter @a type may be one of the following values:
757 @li wxBITMAP_TYPE_BMP: Load a Windows bitmap file.
758 @li wxBITMAP_TYPE_GIF: Load a GIF bitmap file.
759 @li wxBITMAP_TYPE_JPEG: Load a JPEG bitmap file.
760 @li wxBITMAP_TYPE_PNG: Load a PNG bitmap file.
761 @li wxBITMAP_TYPE_PCX: Load a PCX bitmap file.
762 @li wxBITMAP_TYPE_PNM: Load a PNM bitmap file.
763 @li wxBITMAP_TYPE_TIF: Load a TIFF bitmap file.
764 @li wxBITMAP_TYPE_TGA: Load a TGA bitmap file.
765 @li wxBITMAP_TYPE_XPM: Load a XPM bitmap file.
766 @li wxBITMAP_TYPE_ICO: Load a Windows icon file (ICO).
767 @li wxBITMAP_TYPE_CUR: Load a Windows cursor file (CUR).
768 @li wxBITMAP_TYPE_ANI: Load a Windows animated cursor file (ANI).
769 @li wxBITMAP_TYPE_ANY: Will try to autodetect the format.
771 @return Number of available images. For most image handlers, this is 1
772 (exceptions are TIFF and ICO formats).
774 static int GetImageCount(const wxString
& filename
,
775 wxBitmapType type
= wxBITMAP_TYPE_ANY
);
776 static int GetImageCount(wxInputStream
& stream
,
777 wxBitmapType type
= wxBITMAP_TYPE_ANY
);
781 Iterates all registered wxImageHandler objects, and returns a string containing
782 file extension masks suitable for passing to file open/save dialog boxes.
784 @return The format of the returned string is @c "(*.ext1;*.ext2)|*.ext1;*.ext2".
785 It is usually a good idea to prepend a description before passing
786 the result to the dialog.
789 wxFileDialog FileDlg( this, "Choose Image", ::wxGetCwd(), "",
790 _("Image Files ") + wxImage::GetImageExtWildcard(),
796 static wxString
GetImageExtWildcard();
799 Gets the blue value of the mask colour.
801 unsigned char GetMaskBlue() const;
804 Gets the green value of the mask colour.
806 unsigned char GetMaskGreen() const;
809 Gets the red value of the mask colour.
811 unsigned char GetMaskRed() const;
814 Gets a user-defined string-valued option.
816 Currently the only defined string option is
817 @li @c wxIMAGE_OPTION_FILENAME: The name of the file from which the image
821 The name of the option, case-insensitive.
823 The value of the option or an empty string if not found. Use
824 HasOption() if an empty string can be a valid option value.
826 @see SetOption(), GetOptionInt(), HasOption()
828 wxString
GetOption(const wxString
& name
) const;
831 Gets a user-defined integer-valued option.
833 The function is case-insensitive to @a name.
834 If the given option is not present, the function returns 0.
835 Use HasOption() is 0 is a possibly valid value for the option.
838 @li @c wxIMAGE_OPTION_MAX_WIDTH and @c wxIMAGE_OPTION_MAX_HEIGHT: If either
839 of these options is specified, the loaded image will be scaled down
840 (preserving its aspect ratio) so that its width is less than the
841 max width given if it is not 0 @em and its height is less than the
842 max height given if it is not 0. This is typically used for loading
843 thumbnails and the advantage of using these options compared to
844 calling Rescale() after loading is that some handlers (only JPEG
845 one right now) support rescaling the image during loading which is
846 vastly more efficient than loading the entire huge image and
847 rescaling it later (if these options are not supported by the
848 handler, this is still what happens however). These options must be
849 set before calling LoadFile() to have any effect.
851 @li @c wxIMAGE_OPTION_QUALITY: JPEG quality used when saving. This is an
852 integer in 0..100 range with 0 meaning very poor and 100 excellent
853 (but very badly compressed). This option is currently ignored for
856 @li @c wxIMAGE_OPTION_RESOLUTIONUNIT: The value of this option determines
857 whether the resolution of the image is specified in centimetres or
858 inches, see wxImageResolution enum elements.
860 @li @c wxIMAGE_OPTION_RESOLUTION, @c wxIMAGE_OPTION_RESOLUTIONX and
861 @c wxIMAGE_OPTION_RESOLUTIONY: These options define the resolution of
862 the image in the units corresponding to @c wxIMAGE_OPTION_RESOLUTIONUNIT
863 options value. The first option can be set before saving the image
864 to set both horizontal and vertical resolution to the same value.
865 The X and Y options are set by the image handlers if they support
866 the image resolution (currently BMP, JPEG and TIFF handlers do) and
867 the image provides the resolution information and can be queried
868 after loading the image.
870 Options specific to wxPNGHandler:
871 @li @c wxIMAGE_OPTION_PNG_FORMAT: Format for saving a PNG file, see
872 wxImagePNGType for the supported values.
873 @li @c wxIMAGE_OPTION_PNG_BITDEPTH: Bit depth for every channel (R/G/B/A).
874 @li @c wxIMAGE_OPTION_PNG_FILTER: Filter for saving a PNG file, see libpng
875 (http://www.libpng.org/pub/png/libpng-1.2.5-manual.html) for possible values
876 (e.g. PNG_FILTER_NONE, PNG_FILTER_SUB, PNG_FILTER_UP, etc).
877 @li @c wxIMAGE_OPTION_PNG_COMPRESSION_LEVEL: Compression level (0..9) for
878 saving a PNG file. An high value creates smaller-but-slower PNG file.
879 Note that unlike other formats (e.g. JPEG) the PNG format is always
880 lossless and thus this compression level doesn't tradeoff the image
882 @li @c wxIMAGE_OPTION_PNG_COMPRESSION_MEM_LEVEL: Compression memory usage
883 level (1..9) for saving a PNG file. An high value means the saving
884 process consumes more memory, but may create smaller PNG file.
885 @li @c wxIMAGE_OPTION_PNG_COMPRESSION_STRATEGY: Possible values are 0 for
886 default strategy, 1 for filter, and 2 for Huffman-only.
887 You can use OptiPNG (http://optipng.sourceforge.net/) to get a suitable
888 value for your application.
889 @li @c wxIMAGE_OPTION_PNG_COMPRESSION_BUFFER_SIZE: Internal buffer size
890 (in bytes) for saving a PNG file. Ideally this should be as big as
891 the resulting PNG file. Use this option if your application produces
892 images with small size variation.
895 The name of the option, case-insensitive.
897 The value of the option or 0 if not found.
898 Use HasOption() if 0 can be a valid option value.
900 @see SetOption(), GetOption()
902 int GetOptionInt(const wxString
& name
) const;
905 Get the current mask colour or find a suitable unused colour that could be
906 used as a mask colour. Returns @true if the image currently has a mask.
908 bool GetOrFindMaskColour(unsigned char* r
, unsigned char* g
,
909 unsigned char* b
) const;
912 Returns the palette associated with the image.
913 Currently the palette is only used when converting to wxBitmap under Windows.
915 Some of the wxImage handlers have been modified to set the palette if
916 one exists in the image file (usually 256 or less colour images in
919 const wxPalette
& GetPalette() const;
922 Returns the red intensity at the given coordinate.
924 unsigned char GetRed(int x
, int y
) const;
927 Returns a sub image of the current one as long as the rect belongs entirely
930 wxImage
GetSubImage(const wxRect
& rect
) const;
933 Returns the size of the image in pixels.
937 @see GetHeight(), GetWidth()
939 wxSize
GetSize() const;
942 Gets the type of image found by LoadFile() or specified with SaveFile().
946 wxBitmapType
GetType() const;
949 Gets the width of the image in pixels.
951 @see GetHeight(), GetSize()
953 int GetWidth() const;
956 Converts a color in HSV color space to RGB color space.
958 static wxImage::RGBValue
HSVtoRGB(const wxImage::HSVValue
& hsv
);
961 Returns @true if this image has alpha channel, @false otherwise.
963 @see GetAlpha(), SetAlpha()
965 bool HasAlpha() const;
968 Returns @true if there is a mask active, @false otherwise.
970 bool HasMask() const;
973 Returns @true if the given option is present.
974 The function is case-insensitive to @a name.
976 The lists of the currently supported options are in GetOption() and
977 GetOptionInt() function docs.
979 @see SetOption(), GetOption(), GetOptionInt()
981 bool HasOption(const wxString
& name
) const;
984 Initializes the image alpha channel data.
986 It is an error to call it if the image already has alpha data.
987 If it doesn't, alpha data will be by default initialized to all pixels
988 being fully opaque. But if the image has a mask colour, all mask pixels
989 will be completely transparent.
994 Internal use only. Adds standard image format handlers.
995 It only install wxBMPHandler for the time being, which is used by wxBitmap.
997 This function is called by wxWidgets on startup, and shouldn't be called by
1000 @see wxImageHandler, wxInitAllImageHandlers(), wxQuantize
1002 static void InitStandardHandlers();
1005 Adds a handler at the start of the static list of format handlers.
1008 A new image format handler object. There is usually only one instance
1009 of a given handler class in an application session.
1013 static void InsertHandler(wxImageHandler
* handler
);
1016 Returns @true if image data is present.
1021 Returns @true if the given pixel is transparent, i.e. either has the mask
1022 colour if this image has a mask or if this image has alpha channel and alpha
1023 value of this pixel is strictly less than @a threshold.
1025 bool IsTransparent(int x
, int y
,
1026 unsigned char threshold
= wxIMAGE_ALPHA_THRESHOLD
) const;
1029 Loads an image from an input stream.
1032 Opened input stream from which to load the image.
1033 Currently, the stream must support seeking.
1035 May be one of the following:
1036 @li wxBITMAP_TYPE_BMP: Load a Windows bitmap file.
1037 @li wxBITMAP_TYPE_GIF: Load a GIF bitmap file.
1038 @li wxBITMAP_TYPE_JPEG: Load a JPEG bitmap file.
1039 @li wxBITMAP_TYPE_PNG: Load a PNG bitmap file.
1040 @li wxBITMAP_TYPE_PCX: Load a PCX bitmap file.
1041 @li wxBITMAP_TYPE_PNM: Load a PNM bitmap file.
1042 @li wxBITMAP_TYPE_TIF: Load a TIFF bitmap file.
1043 @li wxBITMAP_TYPE_TGA: Load a TGA bitmap file.
1044 @li wxBITMAP_TYPE_XPM: Load a XPM bitmap file.
1045 @li wxBITMAP_TYPE_ICO: Load a Windows icon file (ICO).
1046 @li wxBITMAP_TYPE_CUR: Load a Windows cursor file (CUR).
1047 @li wxBITMAP_TYPE_ANI: Load a Windows animated cursor file (ANI).
1048 @li wxBITMAP_TYPE_ANY: Will try to autodetect the format.
1050 Index of the image to load in the case that the image file contains
1051 multiple images. This is only used by GIF, ICO and TIFF handlers.
1052 The default value (-1) means "choose the default image" and is
1053 interpreted as the first image (index=0) by the GIF and TIFF handler
1054 and as the largest and most colourful one by the ICO handler.
1056 @return @true if the operation succeeded, @false otherwise.
1057 If the optional index parameter is out of range, @false is
1058 returned and a call to wxLogError() takes place.
1060 @remarks Depending on how wxWidgets has been configured, not all formats
1064 You can use GetOptionInt() to get the hotspot when loading cursor files:
1066 int hotspot_x = image.GetOptionInt(wxIMAGE_OPTION_CUR_HOTSPOT_X);
1067 int hotspot_y = image.GetOptionInt(wxIMAGE_OPTION_CUR_HOTSPOT_Y);
1072 virtual bool LoadFile(wxInputStream
& stream
,
1073 wxBitmapType type
= wxBITMAP_TYPE_ANY
,
1077 Loads an image from a file.
1078 If no handler type is provided, the library will try to autodetect the format.
1081 Name of the file from which to load the image.
1083 See the description in the LoadFile(wxInputStream&, wxBitmapType, int) overload.
1085 See the description in the LoadFile(wxInputStream&, wxBitmapType, int) overload.
1087 virtual bool LoadFile(const wxString
& name
,
1088 wxBitmapType type
= wxBITMAP_TYPE_ANY
,
1092 Loads an image from a file.
1093 If no handler type is provided, the library will try to autodetect the format.
1096 Name of the file from which to load the image.
1098 MIME type string (for example 'image/jpeg')
1100 See the description in the LoadFile(wxInputStream&, wxBitmapType, int) overload.
1102 virtual bool LoadFile(const wxString
& name
, const wxString
& mimetype
,
1107 Loads an image from an input stream.
1110 Opened input stream from which to load the image.
1111 Currently, the stream must support seeking.
1113 MIME type string (for example 'image/jpeg')
1115 See the description in the LoadFile(wxInputStream&, wxBitmapType, int) overload.
1117 virtual bool LoadFile(wxInputStream
& stream
, const wxString
& mimetype
,
1121 Returns a mirrored copy of the image.
1122 The parameter @a horizontally indicates the orientation.
1124 wxImage
Mirror(bool horizontally
= true) const;
1127 Copy the data of the given @a image to the specified position in this image.
1129 void Paste(const wxImage
& image
, int x
, int y
);
1132 Converts a color in RGB color space to HSV color space.
1134 static wxImage::HSVValue
RGBtoHSV(const wxImage::RGBValue
& rgb
);
1137 Finds the handler with the given name, and removes it.
1138 The handler is not deleted.
1143 @return @true if the handler was found and removed, @false otherwise.
1147 static bool RemoveHandler(const wxString
& name
);
1150 Replaces the colour specified by @e r1,g1,b1 by the colour @e r2,g2,b2.
1152 void Replace(unsigned char r1
, unsigned char g1
,
1153 unsigned char b1
, unsigned char r2
,
1154 unsigned char g2
, unsigned char b2
);
1157 Changes the size of the image in-place by scaling it: after a call to this
1158 function,the image will have the given width and height.
1160 For a description of the @a quality parameter, see the Scale() function.
1161 Returns the (modified) image itself.
1165 wxImage
& Rescale(int width
, int height
,
1166 int quality
= wxIMAGE_QUALITY_NORMAL
);
1169 Changes the size of the image in-place without scaling it by adding either a
1170 border with the given colour or cropping as necessary.
1172 The image is pasted into a new image with the given @a size and background
1173 colour at the position @a pos relative to the upper left of the new image.
1175 If @a red = green = blue = -1 then use either the current mask colour
1176 if set or find, use, and set a suitable mask colour for any newly exposed
1179 @return The (modified) image itself.
1183 wxImage
& Resize(const wxSize
& size
, const wxPoint
& pos
, int red
= -1,
1184 int green
= -1, int blue
= -1);
1187 Rotates the image about the given point, by @a angle radians.
1189 Passing @true to @a interpolating results in better image quality, but is slower.
1191 If the image has a mask, then the mask colour is used for the uncovered
1192 pixels in the rotated image background. Else, black (rgb 0, 0, 0) will be used.
1194 Returns the rotated image, leaving this image intact.
1196 wxImage
Rotate(double angle
, const wxPoint
& rotationCentre
,
1197 bool interpolating
= true,
1198 wxPoint
* offsetAfterRotation
= NULL
) const;
1201 Returns a copy of the image rotated 90 degrees in the direction
1202 indicated by @a clockwise.
1204 wxImage
Rotate90(bool clockwise
= true) const;
1207 Rotates the hue of each pixel in the image by @e angle, which is a double in
1208 the range of -1.0 to +1.0, where -1.0 corresponds to -360 degrees and +1.0
1209 corresponds to +360 degrees.
1211 void RotateHue(double angle
);
1214 Saves an image in the given stream.
1217 Opened output stream to save the image to.
1221 @return @true if the operation succeeded, @false otherwise.
1223 @remarks Depending on how wxWidgets has been configured, not all formats
1227 You can use SetOption() to set the hotspot when saving an image
1228 into a cursor file (default hotspot is in the centre of the image):
1230 image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_X, hotspotX);
1231 image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_Y, hotspotY);
1236 virtual bool SaveFile(wxOutputStream
& stream
,
1237 const wxString
& mimetype
) const;
1240 Saves an image in the named file.
1243 Name of the file to save the image to.
1245 Currently these types can be used:
1246 @li wxBITMAP_TYPE_BMP: Save a BMP image file.
1247 @li wxBITMAP_TYPE_JPEG: Save a JPEG image file.
1248 @li wxBITMAP_TYPE_PNG: Save a PNG image file.
1249 @li wxBITMAP_TYPE_PCX: Save a PCX image file
1250 (tries to save as 8-bit if possible, falls back to 24-bit otherwise).
1251 @li wxBITMAP_TYPE_PNM: Save a PNM image file (as raw RGB always).
1252 @li wxBITMAP_TYPE_TIFF: Save a TIFF image file.
1253 @li wxBITMAP_TYPE_XPM: Save a XPM image file.
1254 @li wxBITMAP_TYPE_ICO: Save a Windows icon file (ICO).
1255 The size may be up to 255 wide by 127 high. A single image is saved
1256 in 8 colors at the size supplied.
1257 @li wxBITMAP_TYPE_CUR: Save a Windows cursor file (CUR).
1259 virtual bool SaveFile(const wxString
& name
, wxBitmapType type
) const;
1262 Saves an image in the named file.
1265 Name of the file to save the image to.
1269 virtual bool SaveFile(const wxString
& name
, const wxString
& mimetype
) const;
1272 Saves an image in the named file.
1274 File type is determined from the extension of the file name.
1275 Note that this function may fail if the extension is not recognized!
1276 You can use one of the forms above to save images to files with
1277 non-standard extensions.
1280 Name of the file to save the image to.
1282 virtual bool SaveFile(const wxString
& name
) const;
1285 Saves an image in the given stream.
1288 Opened output stream to save the image to.
1292 virtual bool SaveFile(wxOutputStream
& stream
, wxBitmapType type
) const;
1295 Returns a scaled version of the image.
1297 This is also useful for scaling bitmaps in general as the only other way
1298 to scale bitmaps is to blit a wxMemoryDC into another wxMemoryDC.
1300 The parameter @a quality determines what method to use for resampling the image.
1301 Can be one of the following:
1302 - wxIMAGE_QUALITY_NORMAL: Uses the normal default scaling method of pixel
1304 - wxIMAGE_QUALITY_HIGH: Uses bicubic and box averaging resampling methods
1305 for upsampling and downsampling respectively
1307 It should be noted that although using @c wxIMAGE_QUALITY_HIGH produces much nicer
1308 looking results it is a slower method. Downsampling will use the box averaging
1309 method which seems to operate very fast. If you are upsampling larger images using
1310 this method you will most likely notice that it is a bit slower and in extreme
1311 cases it will be quite substantially slower as the bicubic algorithm has to process a
1314 It should also be noted that the high quality scaling may not work as expected
1315 when using a single mask colour for transparency, as the scaling will blur the
1316 image and will therefore remove the mask partially. Using the alpha channel
1321 // get the bitmap from somewhere
1324 // rescale it to have size of 32*32
1325 if ( bmp.GetWidth() != 32 || bmp.GetHeight() != 32 )
1327 wxImage image = bmp.ConvertToImage();
1328 bmp = wxBitmap(image.Scale(32, 32));
1330 // another possibility:
1331 image.Rescale(32, 32);
1338 wxImage
Scale(int width
, int height
,
1339 int quality
= wxIMAGE_QUALITY_NORMAL
) const;
1342 This function is similar to SetData() and has similar restrictions.
1344 The pointer passed to it may however be @NULL in which case the function
1345 will allocate the alpha array internally -- this is useful to add alpha
1346 channel data to an image which doesn't have any.
1348 If the pointer is not @NULL, it must have one byte for each image pixel
1349 and be allocated with malloc().
1350 wxImage takes ownership of the pointer and will free it unless @a static_data
1351 parameter is set to @true -- in this case the caller should do it.
1353 void SetAlpha(unsigned char* alpha
= NULL
,
1354 bool static_data
= false);
1357 Sets the alpha value for the given pixel.
1358 This function should only be called if the image has alpha channel data,
1359 use HasAlpha() to check for this.
1361 void SetAlpha(int x
, int y
, unsigned char alpha
);
1365 Sets the image data without performing checks.
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
1371 The data must have been allocated with @c malloc(), @b NOT with
1374 After this call the pointer to the data is owned by the wxImage object,
1375 that will be responsible for deleting it.
1376 Do not pass to this function a pointer obtained through GetData().
1378 void SetData(unsigned char* data
, bool static_data
= false);
1379 void SetData(unsigned char* data
, int new_width
, int new_height
,
1380 bool static_data
= false);
1384 Specifies whether there is a mask or not.
1386 The area of the mask is determined by the current mask colour.
1388 void SetMask(bool hasMask
= true);
1391 Sets the mask colour for this image (and tells the image to use the mask).
1393 void SetMaskColour(unsigned char red
, unsigned char green
,
1394 unsigned char blue
);
1397 Sets image's mask so that the pixels that have RGB value of mr,mg,mb in
1398 mask will be masked in the image.
1400 This is done by first finding an unused colour in the image, setting
1401 this colour as the mask colour and then using this colour to draw all
1402 pixels in the image who corresponding pixel in mask has given RGB value.
1404 The parameter @a mask is the mask image to extract mask shape from.
1405 It must have the same dimensions as the image.
1407 The parameters @a mr, @a mg, @a mb are the RGB values of the pixels in
1408 mask that will be used to create the mask.
1410 @return Returns @false if mask does not have same dimensions as the image
1411 or if there is no unused colour left. Returns @true if the mask
1412 was successfully applied.
1415 Note that this method involves computing the histogram, which is a
1416 computationally intensive operation.
1418 bool SetMaskFromImage(const wxImage
& mask
, unsigned char mr
,
1424 Sets a user-defined option. The function is case-insensitive to @a name.
1426 For example, when saving as a JPEG file, the option @b quality is
1427 used, which is a number between 0 and 100 (0 is terrible, 100 is very good).
1429 The lists of the currently supported options are in GetOption() and
1430 GetOptionInt() function docs.
1432 @see GetOption(), GetOptionInt(), HasOption()
1434 void SetOption(const wxString
& name
, const wxString
& value
);
1435 void SetOption(const wxString
& name
, int value
);
1439 Associates a palette with the image.
1441 The palette may be used when converting wxImage to wxBitmap (MSW only at present)
1442 or in file save operations (none as yet).
1444 void SetPalette(const wxPalette
& palette
);
1447 Sets the colour of the pixels within the given rectangle.
1449 This routine performs bounds-checks for the coordinate so it can be considered
1450 a safe way to manipulate the data.
1452 void SetRGB(const wxRect
& rect
,
1454 unsigned char green
,
1455 unsigned char blue
);
1458 Set the type of image returned by GetType().
1460 This method is mostly used internally by the library but can also be
1461 called from the user code if the image was created from data in the
1462 given bitmap format without using LoadFile() (which would set the type
1463 correctly automatically).
1465 Notice that the image must be created before this function is called.
1470 One of bitmap type constants, @c wxBITMAP_TYPE_INVALID is a valid
1471 value for it and can be used to reset the bitmap type to default
1472 but @c wxBITMAP_TYPE_MAX is not allowed here.
1474 void SetType(wxBitmapType type
);
1477 Returns a resized version of this image without scaling it by adding either a
1478 border with the given colour or cropping as necessary.
1480 The image is pasted into a new image with the given @a size and background
1481 colour at the position @a pos relative to the upper left of the new image.
1483 If @a red = green = blue = -1 then the areas of the larger image not covered
1484 by this image are made transparent by filling them with the image mask colour
1485 (which will be allocated automatically if it isn't currently set).
1487 Otherwise, the areas will be filled with the colour with the specified RGB components.
1491 wxImage
Size(const wxSize
& size
, const wxPoint
& pos
, int red
= -1,
1492 int green
= -1, int blue
= -1) const;
1495 Assignment operator, using @ref overview_refcount "reference counting".
1500 @return Returns 'this' object.
1502 wxImage
& operator=(const wxImage
& image
);
1506 An instance of an empty image without an alpha channel.
1508 wxImage wxNullImage
;
1511 // ============================================================================
1512 // Global functions/macros
1513 // ============================================================================
1515 /** @addtogroup group_funcmacro_appinitterm */
1519 Initializes all available image handlers. For a list of available handlers,
1521 If you don't need/want all image handlers loaded
1523 @see wxImage, wxImageHandler
1527 void wxInitAllImageHandlers();