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 initialisation.
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.
461 static void AddHandler(wxImageHandler
* handler
);
464 Blurs the image in both horizontal and vertical directions by the
465 specified pixel @a blurRadius. This should not be used when using
466 a single mask colour for transparency.
468 @see BlurHorizontal(), BlurVertical()
470 wxImage
Blur(int blurRadius
) const;
473 Blurs the image in the horizontal direction only. This should not be used
474 when using a single mask colour for transparency.
476 @see Blur(), BlurVertical()
478 wxImage
BlurHorizontal(int blurRadius
) const;
481 Blurs the image in the vertical direction only. This should not be used
482 when using a single mask colour for transparency.
484 @see Blur(), BlurHorizontal()
486 wxImage
BlurVertical(int blurRadius
) const;
489 Returns @true if the current image handlers can read this file
491 static bool CanRead(const wxString
& filename
);
494 Deletes all image handlers.
495 This function is called by wxWidgets on exit.
497 static void CleanUpHandlers();
500 Computes the histogram of the image. @a histogram is a reference to
501 wxImageHistogram object. wxImageHistogram is a specialization of
502 wxHashMap "template" and is defined as follows:
505 class WXDLLEXPORT wxImageHistogramEntry
508 wxImageHistogramEntry() : index(0), value(0) {}
513 WX_DECLARE_EXPORTED_HASH_MAP(unsigned long, wxImageHistogramEntry,
514 wxIntegerHash, wxIntegerEqual,
518 @return Returns number of colours in the histogram.
520 unsigned long ComputeHistogram(wxImageHistogram
& histogram
) const;
524 If the image has alpha channel, this method converts it to mask.
526 If the image has an alpha channel, all pixels with alpha value less
527 than @a threshold are replaced with the mask colour and the alpha
528 channel is removed. Otherwise nothing is done.
530 The mask colour is chosen automatically using
531 FindFirstUnusedColour() by this function, see the overload below if you
532 this is not appropriate.
534 @return @false if FindFirstUnusedColour returns @false, @true otherwise.
536 bool ConvertAlphaToMask(unsigned char threshold
= wxIMAGE_ALPHA_THRESHOLD
);
539 If the image has alpha channel, this method converts it to mask using
540 the specified colour as the mask colour.
542 If the image has an alpha channel, all pixels with alpha value less
543 than @a threshold are replaced with the mask colour and the alpha
544 channel is removed. Otherwise nothing is done.
549 The red component of the mask colour.
551 The green component of the mask colour.
553 The blue component of the mask colour.
555 Pixels with alpha channel values below the given threshold are
556 considered to be transparent, i.e. the corresponding mask pixels
557 are set. Pixels with the alpha values above the threshold are
558 considered to be opaque.
561 void ConvertAlphaToMask(unsigned char mr
, unsigned char mg
, unsigned char mb
,
562 unsigned char threshold
= wxIMAGE_ALPHA_THRESHOLD
);
566 Returns a greyscale version of the image.
568 The returned image uses the luminance component of the original to
569 calculate the greyscale. Defaults to using the standard ITU-T BT.601
570 when converting to YUV, where every pixel equals
571 (R * @a lr) + (G * @a lg) + (B * @a lb).
573 wxImage
ConvertToGreyscale(double lr
= 0.299, double lg
= 0.587, double lb
= 1.114) const;
576 Returns monochromatic version of the image.
578 The returned image has white colour where the original has @e (r,g,b)
579 colour and black colour everywhere else.
581 wxImage
ConvertToMono(unsigned char r
, unsigned char g
, unsigned char b
) const;
584 Returns an identical copy of the image.
586 wxImage
Copy() const;
589 Creates a fresh image.
591 If @a clear is @true, the new image will be initialized to black.
592 Otherwise, the image data will be uninitialized.
595 The width of the image in pixels.
597 The height of the image in pixels.
599 If @true, initialize the image data with zeroes.
601 @return @true if the call succeeded, @false otherwise.
603 bool Create(int width
, int height
, bool clear
= true);
606 Initialize the image data with zeroes (the default) or with the
607 byte value given as @a value.
611 void Clear(unsigned char value
= 0);
614 Destroys the image data.
619 Finds the first colour that is never used in the image.
620 The search begins at given initial colour and continues by increasing
621 R, G and B components (in this order) by 1 until an unused colour is
622 found or the colour space exhausted.
624 The parameters @a r, @a g, @a b are pointers to variables to save the colour.
626 The parameters @a startR, @a startG, @a startB define the initial values
628 The returned colour will have RGB values equal to or greater than these.
630 @return Returns @false if there is no unused colour left, @true on success.
633 This method involves computing the histogram, which is a
634 computationally intensive operation.
636 bool FindFirstUnusedColour(unsigned char* r
, unsigned char* g
,
637 unsigned char* b
, unsigned char startR
= 1,
638 unsigned char startG
= 0,
639 unsigned char startB
= 0) const;
642 Finds the handler with the given name.
647 @return A pointer to the handler if found, @NULL otherwise.
651 static wxImageHandler
* FindHandler(const wxString
& name
);
654 Finds the handler associated with the given extension and type.
657 The file extension, such as "bmp".
659 The image type; one of the ::wxBitmapType values.
661 @return A pointer to the handler if found, @NULL otherwise.
665 static wxImageHandler
* FindHandler(const wxString
& extension
,
666 wxBitmapType imageType
);
669 Finds the handler associated with the given image type.
672 The image type; one of the ::wxBitmapType values.
674 @return A pointer to the handler if found, @NULL otherwise.
678 static wxImageHandler
* FindHandler(wxBitmapType imageType
);
681 Finds the handler associated with the given MIME type.
686 @return A pointer to the handler if found, @NULL otherwise.
690 static wxImageHandler
* FindHandlerMime(const wxString
& mimetype
);
693 Return alpha value at given pixel location.
695 unsigned char GetAlpha(int x
, int y
) const;
698 Returns pointer to the array storing the alpha values for this image.
700 This pointer is @NULL for the images without the alpha channel. If the image
701 does have it, this pointer may be used to directly manipulate the alpha values
702 which are stored as the RGB ones.
704 unsigned char* GetAlpha() const;
707 Returns the blue intensity at the given coordinate.
709 unsigned char GetBlue(int x
, int y
) const;
712 Returns the image data as an array.
714 This is most often used when doing direct image manipulation.
715 The return value points to an array of characters in RGBRGBRGB... format
716 in the top-to-bottom, left-to-right order, that is the first RGB triplet
717 corresponds to the pixel first pixel of the first row, the second one ---
718 to the second pixel of the first row and so on until the end of the first
719 row, with second row following after it and so on.
721 You should not delete the returned pointer nor pass it to SetData().
723 unsigned char* GetData() const;
726 Returns the green intensity at the given coordinate.
728 unsigned char GetGreen(int x
, int y
) const;
731 Returns the static list of image format handlers.
735 static wxList
& GetHandlers();
738 Gets the height of the image in pixels.
740 @see GetWidth(), GetSize()
742 int GetHeight() const;
746 If the image file contains more than one image and the image handler is
747 capable of retrieving these individually, this function will return the
748 number of available images.
750 For the overload taking the parameter @a filename, that's the name
751 of the file to query.
752 For the overload taking the parameter @a stream, that's the ppened input
753 stream with image data. Currently, the stream must support seeking.
755 The parameter @a type may be one of the following values:
756 @li wxBITMAP_TYPE_BMP: Load a Windows bitmap file.
757 @li wxBITMAP_TYPE_GIF: Load a GIF bitmap file.
758 @li wxBITMAP_TYPE_JPEG: Load a JPEG bitmap file.
759 @li wxBITMAP_TYPE_PNG: Load a PNG bitmap file.
760 @li wxBITMAP_TYPE_PCX: Load a PCX bitmap file.
761 @li wxBITMAP_TYPE_PNM: Load a PNM bitmap file.
762 @li wxBITMAP_TYPE_TIF: Load a TIFF bitmap file.
763 @li wxBITMAP_TYPE_TGA: Load a TGA bitmap file.
764 @li wxBITMAP_TYPE_XPM: Load a XPM bitmap file.
765 @li wxBITMAP_TYPE_ICO: Load a Windows icon file (ICO).
766 @li wxBITMAP_TYPE_CUR: Load a Windows cursor file (CUR).
767 @li wxBITMAP_TYPE_ANI: Load a Windows animated cursor file (ANI).
768 @li wxBITMAP_TYPE_ANY: Will try to autodetect the format.
770 @return Number of available images. For most image handlers, this is 1
771 (exceptions are TIFF and ICO formats).
773 static int GetImageCount(const wxString
& filename
,
774 wxBitmapType type
= wxBITMAP_TYPE_ANY
);
775 static int GetImageCount(wxInputStream
& stream
,
776 wxBitmapType type
= wxBITMAP_TYPE_ANY
);
780 Iterates all registered wxImageHandler objects, and returns a string containing
781 file extension masks suitable for passing to file open/save dialog boxes.
783 @return The format of the returned string is @c "(*.ext1;*.ext2)|*.ext1;*.ext2".
784 It is usually a good idea to prepend a description before passing
785 the result to the dialog.
788 wxFileDialog FileDlg( this, "Choose Image", ::wxGetCwd(), "",
789 _("Image Files ") + wxImage::GetImageExtWildcard(),
795 static wxString
GetImageExtWildcard();
798 Gets the blue value of the mask colour.
800 unsigned char GetMaskBlue() const;
803 Gets the green value of the mask colour.
805 unsigned char GetMaskGreen() const;
808 Gets the red value of the mask colour.
810 unsigned char GetMaskRed() const;
813 Gets a user-defined string-valued option.
815 Currently the only defined string option is
816 @li @c wxIMAGE_OPTION_FILENAME: The name of the file from which the image
820 The name of the option, case-insensitive.
822 The value of the option or an empty string if not found. Use
823 HasOption() if an empty string can be a valid option value.
825 @see SetOption(), GetOptionInt(), HasOption()
827 wxString
GetOption(const wxString
& name
) const;
830 Gets a user-defined integer-valued option.
832 The function is case-insensitive to @a name.
833 If the given option is not present, the function returns 0.
834 Use HasOption() is 0 is a possibly valid value for the option.
837 @li @c wxIMAGE_OPTION_MAX_WIDTH and @c wxIMAGE_OPTION_MAX_HEIGHT: If either
838 of these options is specified, the loaded image will be scaled down
839 (preserving its aspect ratio) so that its width is less than the
840 max width given if it is not 0 @em and its height is less than the
841 max height given if it is not 0. This is typically used for loading
842 thumbnails and the advantage of using these options compared to
843 calling Rescale() after loading is that some handlers (only JPEG
844 one right now) support rescaling the image during loading which is
845 vastly more efficient than loading the entire huge image and
846 rescaling it later (if these options are not supported by the
847 handler, this is still what happens however). These options must be
848 set before calling LoadFile() to have any effect.
850 @li @c wxIMAGE_OPTION_QUALITY: JPEG quality used when saving. This is an
851 integer in 0..100 range with 0 meaning very poor and 100 excellent
852 (but very badly compressed). This option is currently ignored for
855 @li @c wxIMAGE_OPTION_RESOLUTIONUNIT: The value of this option determines
856 whether the resolution of the image is specified in centimetres or
857 inches, see wxImageResolution enum elements.
859 @li @c wxIMAGE_OPTION_RESOLUTION, @c wxIMAGE_OPTION_RESOLUTIONX and
860 @c wxIMAGE_OPTION_RESOLUTIONY: These options define the resolution of
861 the image in the units corresponding to @c wxIMAGE_OPTION_RESOLUTIONUNIT
862 options value. The first option can be set before saving the image
863 to set both horizontal and vertical resolution to the same value.
864 The X and Y options are set by the image handlers if they support
865 the image resolution (currently BMP, JPEG and TIFF handlers do) and
866 the image provides the resolution information and can be queried
867 after loading the image.
869 Options specific to wxPNGHandler:
870 @li @c wxIMAGE_OPTION_PNG_FORMAT: Format for saving a PNG file, see
871 wxImagePNGType for the supported values.
872 @li @c wxIMAGE_OPTION_PNG_BITDEPTH: Bit depth for every channel (R/G/B/A).
873 @li @c wxIMAGE_OPTION_PNG_FILTER: Filter for saving a PNG file, see libpng
874 (http://www.libpng.org/pub/png/libpng-1.2.5-manual.html) for possible values
875 (e.g. PNG_FILTER_NONE, PNG_FILTER_SUB, PNG_FILTER_UP, etc).
876 @li @c wxIMAGE_OPTION_PNG_COMPRESSION_LEVEL: Compression level (0..9) for
877 saving a PNG file. An high value creates smaller-but-slower PNG file.
878 Note that unlike other formats (e.g. JPEG) the PNG format is always
879 lossless and thus this compression level doesn't tradeoff the image
881 @li @c wxIMAGE_OPTION_PNG_COMPRESSION_MEM_LEVEL: Compression memory usage
882 level (1..9) for saving a PNG file. An high value means the saving
883 process consumes more memory, but may create smaller PNG file.
884 @li @c wxIMAGE_OPTION_PNG_COMPRESSION_STRATEGY: Possible values are 0 for
885 default strategy, 1 for filter, and 2 for Huffman-only.
886 You can use OptiPNG (http://optipng.sourceforge.net/) to get a suitable
887 value for your application.
888 @li @c wxIMAGE_OPTION_PNG_COMPRESSION_BUFFER_SIZE: Internal buffer size
889 (in bytes) for saving a PNG file. Ideally this should be as big as
890 the resulting PNG file. Use this option if your application produces
891 images with small size variation.
894 The name of the option, case-insensitive.
896 The value of the option or 0 if not found.
897 Use HasOption() if 0 can be a valid option value.
899 @see SetOption(), GetOption()
901 int GetOptionInt(const wxString
& name
) const;
904 Get the current mask colour or find a suitable unused colour that could be
905 used as a mask colour. Returns @true if the image currently has a mask.
907 bool GetOrFindMaskColour(unsigned char* r
, unsigned char* g
,
908 unsigned char* b
) const;
911 Returns the palette associated with the image.
912 Currently the palette is only used when converting to wxBitmap under Windows.
914 Some of the wxImage handlers have been modified to set the palette if
915 one exists in the image file (usually 256 or less colour images in
918 const wxPalette
& GetPalette() const;
921 Returns the red intensity at the given coordinate.
923 unsigned char GetRed(int x
, int y
) const;
926 Returns a sub image of the current one as long as the rect belongs entirely
929 wxImage
GetSubImage(const wxRect
& rect
) const;
932 Returns the size of the image in pixels.
936 @see GetHeight(), GetWidth()
938 wxSize
GetSize() const;
941 Gets the type of image found by LoadFile() or specified with SaveFile().
945 wxBitmapType
GetType() const;
948 Gets the width of the image in pixels.
950 @see GetHeight(), GetSize()
952 int GetWidth() const;
955 Converts a color in HSV color space to RGB color space.
957 static wxImage::RGBValue
HSVtoRGB(const wxImage::HSVValue
& hsv
);
960 Returns @true if this image has alpha channel, @false otherwise.
962 @see GetAlpha(), SetAlpha()
964 bool HasAlpha() const;
967 Returns @true if there is a mask active, @false otherwise.
969 bool HasMask() const;
972 Returns @true if the given option is present.
973 The function is case-insensitive to @a name.
975 The lists of the currently supported options are in GetOption() and
976 GetOptionInt() function docs.
978 @see SetOption(), GetOption(), GetOptionInt()
980 bool HasOption(const wxString
& name
) const;
983 Initializes the image alpha channel data.
985 It is an error to call it if the image already has alpha data.
986 If it doesn't, alpha data will be by default initialized to all pixels
987 being fully opaque. But if the image has a mask colour, all mask pixels
988 will be completely transparent.
993 Internal use only. Adds standard image format handlers.
994 It only install wxBMPHandler for the time being, which is used by wxBitmap.
996 This function is called by wxWidgets on startup, and shouldn't be called by
999 @see wxImageHandler, wxInitAllImageHandlers(), wxQuantize
1001 static void InitStandardHandlers();
1004 Adds a handler at the start of the static list of format handlers.
1007 A new image format handler object. There is usually only one instance
1008 of a given handler class in an application session.
1012 static void InsertHandler(wxImageHandler
* handler
);
1015 Returns @true if image data is present.
1020 Returns @true if the given pixel is transparent, i.e. either has the mask
1021 colour if this image has a mask or if this image has alpha channel and alpha
1022 value of this pixel is strictly less than @a threshold.
1024 bool IsTransparent(int x
, int y
,
1025 unsigned char threshold
= wxIMAGE_ALPHA_THRESHOLD
) const;
1028 Loads an image from an input stream.
1031 Opened input stream from which to load the image.
1032 Currently, the stream must support seeking.
1034 May be one of the following:
1035 @li wxBITMAP_TYPE_BMP: Load a Windows bitmap file.
1036 @li wxBITMAP_TYPE_GIF: Load a GIF bitmap file.
1037 @li wxBITMAP_TYPE_JPEG: Load a JPEG bitmap file.
1038 @li wxBITMAP_TYPE_PNG: Load a PNG bitmap file.
1039 @li wxBITMAP_TYPE_PCX: Load a PCX bitmap file.
1040 @li wxBITMAP_TYPE_PNM: Load a PNM bitmap file.
1041 @li wxBITMAP_TYPE_TIF: Load a TIFF bitmap file.
1042 @li wxBITMAP_TYPE_TGA: Load a TGA bitmap file.
1043 @li wxBITMAP_TYPE_XPM: Load a XPM bitmap file.
1044 @li wxBITMAP_TYPE_ICO: Load a Windows icon file (ICO).
1045 @li wxBITMAP_TYPE_CUR: Load a Windows cursor file (CUR).
1046 @li wxBITMAP_TYPE_ANI: Load a Windows animated cursor file (ANI).
1047 @li wxBITMAP_TYPE_ANY: Will try to autodetect the format.
1049 Index of the image to load in the case that the image file contains
1050 multiple images. This is only used by GIF, ICO and TIFF handlers.
1051 The default value (-1) means "choose the default image" and is
1052 interpreted as the first image (index=0) by the GIF and TIFF handler
1053 and as the largest and most colourful one by the ICO handler.
1055 @return @true if the operation succeeded, @false otherwise.
1056 If the optional index parameter is out of range, @false is
1057 returned and a call to wxLogError() takes place.
1059 @remarks Depending on how wxWidgets has been configured, not all formats
1063 You can use GetOptionInt() to get the hotspot when loading cursor files:
1065 int hotspot_x = image.GetOptionInt(wxIMAGE_OPTION_CUR_HOTSPOT_X);
1066 int hotspot_y = image.GetOptionInt(wxIMAGE_OPTION_CUR_HOTSPOT_Y);
1071 virtual bool LoadFile(wxInputStream
& stream
,
1072 wxBitmapType type
= wxBITMAP_TYPE_ANY
,
1076 Loads an image from a file.
1077 If no handler type is provided, the library will try to autodetect the format.
1080 Name of the file from which to load the image.
1082 See the description in the LoadFile(wxInputStream&, wxBitmapType, int) overload.
1084 See the description in the LoadFile(wxInputStream&, wxBitmapType, int) overload.
1086 virtual bool LoadFile(const wxString
& name
,
1087 wxBitmapType type
= wxBITMAP_TYPE_ANY
,
1091 Loads an image from a file.
1092 If no handler type is provided, the library will try to autodetect the format.
1095 Name of the file from which to load the image.
1097 MIME type string (for example 'image/jpeg')
1099 See the description in the LoadFile(wxInputStream&, wxBitmapType, int) overload.
1101 virtual bool LoadFile(const wxString
& name
, const wxString
& mimetype
,
1106 Loads an image from an input stream.
1109 Opened input stream from which to load the image.
1110 Currently, the stream must support seeking.
1112 MIME type string (for example 'image/jpeg')
1114 See the description in the LoadFile(wxInputStream&, wxBitmapType, int) overload.
1116 virtual bool LoadFile(wxInputStream
& stream
, const wxString
& mimetype
,
1120 Returns a mirrored copy of the image.
1121 The parameter @a horizontally indicates the orientation.
1123 wxImage
Mirror(bool horizontally
= true) const;
1126 Copy the data of the given @a image to the specified position in this image.
1128 void Paste(const wxImage
& image
, int x
, int y
);
1131 Converts a color in RGB color space to HSV color space.
1133 static wxImage::HSVValue
RGBtoHSV(const wxImage::RGBValue
& rgb
);
1136 Finds the handler with the given name, and removes it.
1137 The handler is not deleted.
1142 @return @true if the handler was found and removed, @false otherwise.
1146 static bool RemoveHandler(const wxString
& name
);
1149 Replaces the colour specified by @e r1,g1,b1 by the colour @e r2,g2,b2.
1151 void Replace(unsigned char r1
, unsigned char g1
,
1152 unsigned char b1
, unsigned char r2
,
1153 unsigned char g2
, unsigned char b2
);
1156 Changes the size of the image in-place by scaling it: after a call to this
1157 function,the image will have the given width and height.
1159 For a description of the @a quality parameter, see the Scale() function.
1160 Returns the (modified) image itself.
1164 wxImage
& Rescale(int width
, int height
,
1165 int quality
= wxIMAGE_QUALITY_NORMAL
);
1168 Changes the size of the image in-place without scaling it by adding either a
1169 border with the given colour or cropping as necessary.
1171 The image is pasted into a new image with the given @a size and background
1172 colour at the position @a pos relative to the upper left of the new image.
1174 If @a red = green = blue = -1 then use either the current mask colour
1175 if set or find, use, and set a suitable mask colour for any newly exposed
1178 @return The (modified) image itself.
1182 wxImage
& Resize(const wxSize
& size
, const wxPoint
& pos
, int red
= -1,
1183 int green
= -1, int blue
= -1);
1186 Rotates the image about the given point, by @a angle radians.
1188 Passing @true to @a interpolating results in better image quality, but is slower.
1190 If the image has a mask, then the mask colour is used for the uncovered
1191 pixels in the rotated image background. Else, black (rgb 0, 0, 0) will be used.
1193 Returns the rotated image, leaving this image intact.
1195 wxImage
Rotate(double angle
, const wxPoint
& rotationCentre
,
1196 bool interpolating
= true,
1197 wxPoint
* offsetAfterRotation
= NULL
) const;
1200 Returns a copy of the image rotated 90 degrees in the direction
1201 indicated by @a clockwise.
1203 wxImage
Rotate90(bool clockwise
= true) const;
1206 Rotates the hue of each pixel in the image by @e angle, which is a double in
1207 the range of -1.0 to +1.0, where -1.0 corresponds to -360 degrees and +1.0
1208 corresponds to +360 degrees.
1210 void RotateHue(double angle
);
1213 Saves an image in the given stream.
1216 Opened output stream to save the image to.
1220 @return @true if the operation succeeded, @false otherwise.
1222 @remarks Depending on how wxWidgets has been configured, not all formats
1226 You can use SetOption() to set the hotspot when saving an image
1227 into a cursor file (default hotspot is in the centre of the image):
1229 image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_X, hotspotX);
1230 image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_Y, hotspotY);
1235 virtual bool SaveFile(wxOutputStream
& stream
,
1236 const wxString
& mimetype
) const;
1239 Saves an image in the named file.
1242 Name of the file to save the image to.
1244 Currently these types can be used:
1245 @li wxBITMAP_TYPE_BMP: Save a BMP image file.
1246 @li wxBITMAP_TYPE_JPEG: Save a JPEG image file.
1247 @li wxBITMAP_TYPE_PNG: Save a PNG image file.
1248 @li wxBITMAP_TYPE_PCX: Save a PCX image file
1249 (tries to save as 8-bit if possible, falls back to 24-bit otherwise).
1250 @li wxBITMAP_TYPE_PNM: Save a PNM image file (as raw RGB always).
1251 @li wxBITMAP_TYPE_TIFF: Save a TIFF image file.
1252 @li wxBITMAP_TYPE_XPM: Save a XPM image file.
1253 @li wxBITMAP_TYPE_ICO: Save a Windows icon file (ICO).
1254 The size may be up to 255 wide by 127 high. A single image is saved
1255 in 8 colors at the size supplied.
1256 @li wxBITMAP_TYPE_CUR: Save a Windows cursor file (CUR).
1258 virtual bool SaveFile(const wxString
& name
, wxBitmapType type
) const;
1261 Saves an image in the named file.
1264 Name of the file to save the image to.
1268 virtual bool SaveFile(const wxString
& name
, const wxString
& mimetype
) const;
1271 Saves an image in the named file.
1273 File type is determined from the extension of the file name.
1274 Note that this function may fail if the extension is not recognized!
1275 You can use one of the forms above to save images to files with
1276 non-standard extensions.
1279 Name of the file to save the image to.
1281 virtual bool SaveFile(const wxString
& name
) const;
1284 Saves an image in the given stream.
1287 Opened output stream to save the image to.
1291 virtual bool SaveFile(wxOutputStream
& stream
, wxBitmapType type
) const;
1294 Returns a scaled version of the image.
1296 This is also useful for scaling bitmaps in general as the only other way
1297 to scale bitmaps is to blit a wxMemoryDC into another wxMemoryDC.
1299 The parameter @a quality determines what method to use for resampling the image.
1300 Can be one of the following:
1301 - wxIMAGE_QUALITY_NORMAL: Uses the normal default scaling method of pixel
1303 - wxIMAGE_QUALITY_HIGH: Uses bicubic and box averaging resampling methods
1304 for upsampling and downsampling respectively
1306 It should be noted that although using @c wxIMAGE_QUALITY_HIGH produces much nicer
1307 looking results it is a slower method. Downsampling will use the box averaging
1308 method which seems to operate very fast. If you are upsampling larger images using
1309 this method you will most likely notice that it is a bit slower and in extreme
1310 cases it will be quite substantially slower as the bicubic algorithm has to process a
1313 It should also be noted that the high quality scaling may not work as expected
1314 when using a single mask colour for transparency, as the scaling will blur the
1315 image and will therefore remove the mask partially. Using the alpha channel
1320 // get the bitmap from somewhere
1323 // rescale it to have size of 32*32
1324 if ( bmp.GetWidth() != 32 || bmp.GetHeight() != 32 )
1326 wxImage image = bmp.ConvertToImage();
1327 bmp = wxBitmap(image.Scale(32, 32));
1329 // another possibility:
1330 image.Rescale(32, 32);
1337 wxImage
Scale(int width
, int height
,
1338 int quality
= wxIMAGE_QUALITY_NORMAL
) const;
1341 This function is similar to SetData() and has similar restrictions.
1343 The pointer passed to it may however be @NULL in which case the function
1344 will allocate the alpha array internally -- this is useful to add alpha
1345 channel data to an image which doesn't have any.
1347 If the pointer is not @NULL, it must have one byte for each image pixel
1348 and be allocated with malloc().
1349 wxImage takes ownership of the pointer and will free it unless @a static_data
1350 parameter is set to @true -- in this case the caller should do it.
1352 void SetAlpha(unsigned char* alpha
= NULL
,
1353 bool static_data
= false);
1356 Sets the alpha value for the given pixel.
1357 This function should only be called if the image has alpha channel data,
1358 use HasAlpha() to check for this.
1360 void SetAlpha(int x
, int y
, unsigned char alpha
);
1364 Sets the image data without performing checks.
1366 The data given must have the size (width*height*3) or results will be
1367 unexpected. Don't use this method if you aren't sure you know what you
1370 The data must have been allocated with @c malloc(), @b NOT with
1373 After this call the pointer to the data is owned by the wxImage object,
1374 that will be responsible for deleting it.
1375 Do not pass to this function a pointer obtained through GetData().
1377 void SetData(unsigned char* data
, bool static_data
= false);
1378 void SetData(unsigned char* data
, int new_width
, int new_height
,
1379 bool static_data
= false);
1383 Specifies whether there is a mask or not.
1385 The area of the mask is determined by the current mask colour.
1387 void SetMask(bool hasMask
= true);
1390 Sets the mask colour for this image (and tells the image to use the mask).
1392 void SetMaskColour(unsigned char red
, unsigned char green
,
1393 unsigned char blue
);
1396 Sets image's mask so that the pixels that have RGB value of mr,mg,mb in
1397 mask will be masked in the image.
1399 This is done by first finding an unused colour in the image, setting
1400 this colour as the mask colour and then using this colour to draw all
1401 pixels in the image who corresponding pixel in mask has given RGB value.
1403 The parameter @a mask is the mask image to extract mask shape from.
1404 It must have the same dimensions as the image.
1406 The parameters @a mr, @a mg, @a mb are the RGB values of the pixels in
1407 mask that will be used to create the mask.
1409 @return Returns @false if mask does not have same dimensions as the image
1410 or if there is no unused colour left. Returns @true if the mask
1411 was successfully applied.
1414 Note that this method involves computing the histogram, which is a
1415 computationally intensive operation.
1417 bool SetMaskFromImage(const wxImage
& mask
, unsigned char mr
,
1423 Sets a user-defined option. The function is case-insensitive to @a name.
1425 For example, when saving as a JPEG file, the option @b quality is
1426 used, which is a number between 0 and 100 (0 is terrible, 100 is very good).
1428 The lists of the currently supported options are in GetOption() and
1429 GetOptionInt() function docs.
1431 @see GetOption(), GetOptionInt(), HasOption()
1433 void SetOption(const wxString
& name
, const wxString
& value
);
1434 void SetOption(const wxString
& name
, int value
);
1438 Associates a palette with the image.
1440 The palette may be used when converting wxImage to wxBitmap (MSW only at present)
1441 or in file save operations (none as yet).
1443 void SetPalette(const wxPalette
& palette
);
1446 Sets the colour of the pixels within the given rectangle.
1448 This routine performs bounds-checks for the coordinate so it can be considered
1449 a safe way to manipulate the data.
1451 void SetRGB(const wxRect
& rect
,
1453 unsigned char green
,
1454 unsigned char blue
);
1457 Set the type of image returned by GetType().
1459 This method is mostly used internally by the library but can also be
1460 called from the user code if the image was created from data in the
1461 given bitmap format without using LoadFile() (which would set the type
1462 correctly automatically).
1464 Notice that the image must be created before this function is called.
1469 One of bitmap type constants, @c wxBITMAP_TYPE_INVALID is a valid
1470 value for it and can be used to reset the bitmap type to default
1471 but @c wxBITMAP_TYPE_MAX is not allowed here.
1473 void SetType(wxBitmapType type
);
1476 Returns a resized version of this image without scaling it by adding either a
1477 border with the given colour or cropping as necessary.
1479 The image is pasted into a new image with the given @a size and background
1480 colour at the position @a pos relative to the upper left of the new image.
1482 If @a red = green = blue = -1 then the areas of the larger image not covered
1483 by this image are made transparent by filling them with the image mask colour
1484 (which will be allocated automatically if it isn't currently set).
1486 Otherwise, the areas will be filled with the colour with the specified RGB components.
1490 wxImage
Size(const wxSize
& size
, const wxPoint
& pos
, int red
= -1,
1491 int green
= -1, int blue
= -1) const;
1494 Assignment operator, using @ref overview_refcount "reference counting".
1499 @return Returns 'this' object.
1501 wxImage
& operator=(const wxImage
& image
);
1505 An instance of an empty image without an alpha channel.
1507 wxImage wxNullImage
;
1510 // ============================================================================
1511 // Global functions/macros
1512 // ============================================================================
1514 /** @addtogroup group_funcmacro_appinitterm */
1518 Initializes all available image handlers. For a list of available handlers,
1521 @see wxImage, wxImageHandler
1525 void wxInitAllImageHandlers();