Fix wrong use of EVT_COMMAND in the example in wxThread documentation.

[wxWidgets.git] / interface / wx / image.h

diff --git a/interface/wx/image.h b/interface/wx/image.h
index fa58c8cf25e390a362eb1d360e43f72181281454..1a2ae82c79a5ab1580398ad9936c13e5120c2838 100644 (file)
--- a/interface/wx/image.h
+++ b/interface/wx/image.h
@@ -39,10 +39,25 @@ enum wxImageResizeQuality
     /// Highest quality but slowest execution time.
     wxIMAGE_QUALITY_BICUBIC,
 
     /// Highest quality but slowest execution time.
     wxIMAGE_QUALITY_BICUBIC,
 

-    /// Default image resizing algorithm used by wxImage::Scale().
+    /**
+    Use surrounding pixels to calculate an average that will be used for
+    new pixels. This method is typically used when reducing the size of
+    an image.
+    */
+    wxIMAGE_QUALITY_BOX_AVERAGE,
+
+    /**
+    Default image resizing algorithm used by wxImage::Scale(). Currently
+    the same as wxIMAGE_QUALITY_NEAREST.
+    */

     wxIMAGE_QUALITY_NORMAL,
 
     wxIMAGE_QUALITY_NORMAL,
 

-    /// Best image resizing algorithm, currently same as wxIMAGE_QUALITY_BICUBIC.
+    /**
+    Best image resizing algorithm. Since version 2.9.2 this results in
+    wxIMAGE_QUALITY_BOX_AVERAGE being used when reducing the size of the
+    image (meaning that both the new width and height will be smaller than
+    the original size). Otherwise wxIMAGE_QUALITY_BICUBIC is used.
+    */

     wxIMAGE_QUALITY_HIGH
 };
 
     wxIMAGE_QUALITY_HIGH
 };
 


@@ -55,9 +70,61 @@ enum wxImagePNGType
 {
     wxPNG_TYPE_COLOUR = 0,      ///< Colour PNG image.
     wxPNG_TYPE_GREY = 2,        ///< Greyscale PNG image converted from RGB.
 {
     wxPNG_TYPE_COLOUR = 0,      ///< Colour PNG image.
     wxPNG_TYPE_GREY = 2,        ///< Greyscale PNG image converted from RGB.

-    wxPNG_TYPE_GREY_RED = 3     ///< Greyscale PNG image using red as grey.
+    wxPNG_TYPE_GREY_RED = 3,    ///< Greyscale PNG image using red as grey.
+    wxPNG_TYPE_PALETTE = 4      ///< Palette encoding.

 };
 
 };
 

+
+/**
+   Image option names.
+*/
+#define wxIMAGE_OPTION_QUALITY                          wxString("quality")
+#define wxIMAGE_OPTION_FILENAME                         wxString("FileName")
+#define wxIMAGE_OPTION_RESOLUTION                       wxString("Resolution")
+#define wxIMAGE_OPTION_RESOLUTIONX                      wxString("ResolutionX")
+#define wxIMAGE_OPTION_RESOLUTIONY                      wxString("ResolutionY")
+#define wxIMAGE_OPTION_RESOLUTIONUNIT                   wxString("ResolutionUnit")
+#define wxIMAGE_OPTION_MAX_WIDTH                        wxString("MaxWidth")
+#define wxIMAGE_OPTION_MAX_HEIGHT                       wxString("MaxHeight")
+#define wxIMAGE_OPTION_ORIGINAL_WIDTH                   wxString("OriginalWidth")
+#define wxIMAGE_OPTION_ORIGINAL_HEIGHT                  wxString("OriginalHeight")
+
+#define wxIMAGE_OPTION_BMP_FORMAT                       wxString("wxBMP_FORMAT")
+#define wxIMAGE_OPTION_CUR_HOTSPOT_X                    wxString("HotSpotX")
+#define wxIMAGE_OPTION_CUR_HOTSPOT_Y                    wxString("HotSpotY")
+
+#define wxIMAGE_OPTION_GIF_COMMENT                      wxString("GifComment")
+
+#define wxIMAGE_OPTION_PNG_FORMAT                       wxString("PngFormat")
+#define wxIMAGE_OPTION_PNG_BITDEPTH                     wxString("PngBitDepth")
+#define wxIMAGE_OPTION_PNG_FILTER                       wxString("PngF")
+#define wxIMAGE_OPTION_PNG_COMPRESSION_LEVEL            wxString("PngZL")
+#define wxIMAGE_OPTION_PNG_COMPRESSION_MEM_LEVEL        wxString("PngZM")
+#define wxIMAGE_OPTION_PNG_COMPRESSION_STRATEGY         wxString("PngZS")
+#define wxIMAGE_OPTION_PNG_COMPRESSION_BUFFER_SIZE      wxString("PngZB")
+
+#define wxIMAGE_OPTION_TIFF_BITSPERSAMPLE               wxString("BitsPerSample")
+#define wxIMAGE_OPTION_TIFF_SAMPLESPERPIXEL             wxString("SamplesPerPixel")
+#define wxIMAGE_OPTION_TIFF_COMPRESSION                 wxString("Compression")
+#define wxIMAGE_OPTION_TIFF_PHOTOMETRIC                 wxString("Photometric")
+#define wxIMAGE_OPTION_TIFF_IMAGEDESCRIPTOR             wxString("ImageDescriptor")
+
+
+enum
+{
+    wxBMP_24BPP        = 24, // default, do not need to set
+    //wxBMP_16BPP      = 16, // wxQuantize can only do 236 colors?
+    wxBMP_8BPP         =  8, // 8bpp, quantized colors
+    wxBMP_8BPP_GREY    =  9, // 8bpp, rgb averaged to greys
+    wxBMP_8BPP_GRAY    =  wxBMP_8BPP_GREY,
+    wxBMP_8BPP_RED     = 10, // 8bpp, red used as greyscale
+    wxBMP_8BPP_PALETTE = 11, // 8bpp, use the wxImage's palette
+    wxBMP_4BPP         =  4, // 4bpp, quantized colors
+    wxBMP_1BPP         =  1, // 1bpp, quantized "colors"
+    wxBMP_1BPP_BW      =  2  // 1bpp, black & white from red
+};
+
+

 /**
     @class wxImageHandler
 
 /**
     @class wxImageHandler
 


@@ -254,6 +321,38 @@ public:
             Handler name.
     */
     void SetName(const wxString& name);
             Handler name.
     */
     void SetName(const wxString& name);

+
+    /**
+        Retrieve the version information about the image library used by this
+        handler.
+
+        This method is not present in wxImageHandler class itself but is
+        present in a few of the classes deriving from it, currently
+        wxJPEGHandler, wxPNGHandler and wxTIFFHandler. It returns the
+        information about the version of the image library being used for the
+        corresponding handler implementation.
+
+        @since 2.9.2
+     */
+     static wxVersionInfo GetLibraryVersionInfo();
+
+protected:
+    /**
+       Called to get the number of images available in a multi-image file
+       type, if supported.
+       
+       NOTE: this function is allowed to change the current stream position
+             since GetImageCount() will take care of restoring it later
+    */
+    virtual int DoGetImageCount( wxInputStream& stream );
+
+    /**
+       Called to test if this handler can read an image from the given stream.
+       
+       NOTE: this function is allowed to change the current stream position
+             since CallDoCanRead() will take care of restoring it later
+    */
+    virtual bool DoCanRead( wxInputStream& stream ) = 0;

 };
 
 
 };
 
 


@@ -269,6 +368,9 @@ const unsigned char wxIMAGE_ALPHA_TRANSPARENT = 0;
 */
 const unsigned char wxIMAGE_ALPHA_OPAQUE = 0xff;
 
 */
 const unsigned char wxIMAGE_ALPHA_OPAQUE = 0xff;
 

+const unsigned char wxIMAGE_ALPHA_THRESHOLD = 0x80;
+
+

 /**
     @class wxImage
 
 /**
     @class wxImage
 


@@ -284,6 +386,17 @@ const unsigned char wxIMAGE_ALPHA_OPAQUE = 0xff;
     the wxBitmap::wxBitmap(wxImage,int depth) constructor.
     This bitmap can then be drawn in a device context, using wxDC::DrawBitmap.
 
     the wxBitmap::wxBitmap(wxImage,int depth) constructor.
     This bitmap can then be drawn in a device context, using wxDC::DrawBitmap.
 

+    More on the difference between wxImage and wxBitmap: wxImage is just a
+    buffer of RGB bytes with an optional buffer for the alpha bytes. It is all
+    generic, platform independent and image file format independent code. It
+    includes generic code for scaling, resizing, clipping, and other manipulations
+    of the image data. OTOH, wxBitmap is intended to be a wrapper of whatever is
+    the native image format that is quickest/easiest to draw to a DC or to be the
+    target of the drawing operations performed on a wxMemoryDC. By splitting the
+    responsibilities between wxImage/wxBitmap like this then it's easier to use
+    generic code shared by all platforms and image types for generic operations and
+    platform specific code where performance or compatibility is needed.
+

     One colour value of the image may be used as a mask colour which will lead to
     the automatic creation of a wxMask object associated to the bitmap object.
 
     One colour value of the image may be used as a mask colour which will lead to
     the automatic creation of a wxMask object associated to the bitmap object.
 


@@ -301,10 +414,12 @@ const unsigned char wxIMAGE_ALPHA_OPAQUE = 0xff;
 
     While all images have RGB data, not all images have an alpha channel. Before
     using wxImage::GetAlpha you should check if this image contains an alpha
 
     While all images have RGB data, not all images have an alpha channel. Before
     using wxImage::GetAlpha you should check if this image contains an alpha

-    channel with wxImage::HasAlpha. Note that currently only the PNG format has
-    full alpha channel support so only the images loaded from PNG files can have
-    alpha and, if you initialize the image alpha channel yourself using
-    wxImage::SetAlpha, you should save it in PNG format to avoid losing it.
+    channel with wxImage::HasAlpha. Currently the BMP, PNG, TGA, and TIFF format
+    handlers have full alpha channel support for loading so if you want to use
+    alpha you have to use one of these formats. If you initialize the image
+    alpha channel yourself using wxImage::SetAlpha, you should save it in
+    either PNG, TGA, or TIFF format to avoid losing it as these are the only
+    handlers that currently support saving with alpha.

 
 
     @section image_handlers Available image handlers
 
 
     @section image_handlers Available image handlers


@@ -314,14 +429,14 @@ const unsigned char wxIMAGE_ALPHA_OPAQUE = 0xff;
     To use other image formats, install the appropriate handler with
     wxImage::AddHandler or call ::wxInitAllImageHandlers().
 
     To use other image formats, install the appropriate handler with
     wxImage::AddHandler or call ::wxInitAllImageHandlers().
 

-    - wxBMPHandler: For loading and saving, always installed.
-    - wxPNGHandler: For loading (including alpha support) and saving.
+    - wxBMPHandler: For loading (including alpha support) and saving, always installed.
+    - wxPNGHandler: For loading and saving. Includes alpha support.

     - wxJPEGHandler: For loading and saving.
     - wxJPEGHandler: For loading and saving.

-    - wxGIFHandler: Only for loading, due to legal issues.
+    - wxGIFHandler: For loading and saving (see below).

     - wxPCXHandler: For loading and saving (see below).
     - wxPNMHandler: For loading and saving (see below).
     - wxPCXHandler: For loading and saving (see below).
     - wxPNMHandler: For loading and saving (see below).

-    - wxTIFFHandler: For loading and saving.
-    - wxTGAHandler: For loading only.
+    - wxTIFFHandler: For loading and saving. Includes alpha support.
+    - wxTGAHandler: For loading and saving. Includes alpha support.

     - wxIFFHandler: For loading only.
     - wxXPMHandler: For loading and saving.
     - wxICOHandler: For loading and saving.
     - wxIFFHandler: For loading only.
     - wxXPMHandler: For loading and saving.
     - wxICOHandler: For loading and saving.


@@ -335,6 +450,8 @@ const unsigned char wxIMAGE_ALPHA_OPAQUE = 0xff;
     Loading PNMs only works for ASCII or raw RGB images.
     When saving in PNM format, wxPNMHandler will always save as raw RGB.
 
     Loading PNMs only works for ASCII or raw RGB images.
     When saving in PNM format, wxPNMHandler will always save as raw RGB.
 

+    Saving GIFs requires images of maximum 8 bpp (see wxQuantize), and the alpha channel converted to a mask (see wxImage::ConvertAlphaToMask).
+    Saving an animated GIF requires images of the same size (see wxGIFHandler::SaveAnimation)

 
     @library{wxcore}
     @category{gdi}
 
     @library{wxcore}
     @category{gdi}


@@ -362,6 +479,10 @@ public:
             between HSV color space and RGB color space.
         */
         RGBValue(unsigned char r=0, unsigned char g=0, unsigned char b=0);
             between HSV color space and RGB color space.
         */
         RGBValue(unsigned char r=0, unsigned char g=0, unsigned char b=0);

+
+        unsigned char red;
+        unsigned char green;
+        unsigned char blue;

     };
 
     /**
     };
 
     /**


@@ -378,6 +499,10 @@ public:
             between HSV color space and RGB color space.
         */
         HSVValue(double h=0.0, double s=0.0, double v=0.0);
             between HSV color space and RGB color space.
         */
         HSVValue(double h=0.0, double s=0.0, double v=0.0);

+
+        double hue;
+        double saturation;
+        double value;        

     };
 
     /**
     };
 
     /**


@@ -449,7 +574,7 @@ public:
     /**
         @overload
     */
     /**
         @overload
     */

-    wxImage(const wxSize& sz, unsigned char* data, unsigned char* data, unsigned char* alpha,
+    wxImage(const wxSize& sz, unsigned char* data, unsigned char* alpha,

             bool static_data = false);
 
     /**
             bool static_data = false);
 
     /**


@@ -477,7 +602,7 @@ public:
             @li wxBITMAP_TYPE_PNG: Load a PNG bitmap file.
             @li wxBITMAP_TYPE_PCX: Load a PCX bitmap file.
             @li wxBITMAP_TYPE_PNM: Load a PNM bitmap file.
             @li wxBITMAP_TYPE_PNG: Load a PNG bitmap file.
             @li wxBITMAP_TYPE_PCX: Load a PCX bitmap file.
             @li wxBITMAP_TYPE_PNM: Load a PNM bitmap file.

-            @li wxBITMAP_TYPE_TIF: Load a TIFF bitmap file.
+            @li wxBITMAP_TYPE_TIFF: Load a TIFF bitmap file.

             @li wxBITMAP_TYPE_TGA: Load a TGA bitmap file.
             @li wxBITMAP_TYPE_XPM: Load a XPM bitmap file.
             @li wxBITMAP_TYPE_ICO: Load a Windows icon file (ICO).
             @li wxBITMAP_TYPE_TGA: Load a TGA bitmap file.
             @li wxBITMAP_TYPE_XPM: Load a XPM bitmap file.
             @li wxBITMAP_TYPE_ICO: Load a Windows icon file (ICO).


@@ -970,7 +1095,7 @@ public:
         This is most often used when doing direct image manipulation.
         The return value points to an array of characters in RGBRGBRGB... format
         in the top-to-bottom, left-to-right order, that is the first RGB triplet
         This is most often used when doing direct image manipulation.
         The return value points to an array of characters in RGBRGBRGB... format
         in the top-to-bottom, left-to-right order, that is the first RGB triplet

-        corresponds to the pixel first pixel of the first row, the second one ---
+        corresponds to the first pixel of the first row, the second one ---

         to the second pixel of the first row and so on until the end of the first
         row, with second row following after it and so on.
 
         to the second pixel of the first row and so on until the end of the first
         row, with second row following after it and so on.
 


@@ -1039,10 +1164,16 @@ public:
     /**
         Gets a user-defined string-valued option.
 
     /**
         Gets a user-defined string-valued option.
 

-        Currently the only defined string option is
+        Generic options:

         @li @c wxIMAGE_OPTION_FILENAME: The name of the file from which the image
             was loaded.
 
         @li @c wxIMAGE_OPTION_FILENAME: The name of the file from which the image
             was loaded.
 

+        Options specific to wxGIFHandler:
+        @li @c wxIMAGE_OPTION_GIF_COMMENT: The comment text that is read from
+            or written to the GIF file. In an animated GIF each frame can have
+            its own comment. If there is only a comment in the first frame of
+            a GIF it will not be repeated in other frames.
+

         @param name
             The name of the option, case-insensitive.
         @return
         @param name
             The name of the option, case-insensitive.
         @return


@@ -1058,7 +1189,7 @@ public:
 
         The function is case-insensitive to @a name.
         If the given option is not present, the function returns 0.
 
         The function is case-insensitive to @a name.
         If the given option is not present, the function returns 0.

-        Use HasOption() is 0 is a possibly valid value for the option.
+        Use HasOption() if 0 is a possibly valid value for the option.

 
         Generic options:
         @li @c wxIMAGE_OPTION_MAX_WIDTH and @c wxIMAGE_OPTION_MAX_HEIGHT: If either
 
         Generic options:
         @li @c wxIMAGE_OPTION_MAX_WIDTH and @c wxIMAGE_OPTION_MAX_HEIGHT: If either


@@ -1074,6 +1205,12 @@ public:
             handler, this is still what happens however). These options must be
             set before calling LoadFile() to have any effect.
 
             handler, this is still what happens however). These options must be
             set before calling LoadFile() to have any effect.
 

+        @li @c wxIMAGE_OPTION_ORIGINAL_WIDTH and @c wxIMAGE_OPTION_ORIGINAL_HEIGHT:
+            These options will return the original size of the image if either
+            @c wxIMAGE_OPTION_MAX_WIDTH or @c wxIMAGE_OPTION_MAX_HEIGHT is
+            specified.
+            @since 2.9.3
+

         @li @c wxIMAGE_OPTION_QUALITY: JPEG quality used when saving. This is an
             integer in 0..100 range with 0 meaning very poor and 100 excellent
             (but very badly compressed). This option is currently ignored for
         @li @c wxIMAGE_OPTION_QUALITY: JPEG quality used when saving. This is an
             integer in 0..100 range with 0 meaning very poor and 100 excellent
             (but very badly compressed). This option is currently ignored for


@@ -1117,6 +1254,39 @@ public:
             the resulting PNG file. Use this option if your application produces
             images with small size variation.
 
             the resulting PNG file. Use this option if your application produces
             images with small size variation.
 

+        Options specific to wxTIFFHandler:
+        @li @c wxIMAGE_OPTION_TIFF_BITSPERSAMPLE: Number of bits per
+            sample (channel). Currently values of 1 and 8 are supported. A
+            value of 1 results in a black and white image. A value of 8 (the
+            default) can mean greyscale or RGB, depending on the value of
+            @c wxIMAGE_OPTION_TIFF_SAMPLESPERPIXEL.
+        @li @c wxIMAGE_OPTION_TIFF_SAMPLESPERPIXEL: Number of samples
+            (channels) per pixel. Currently values of 1 and 3 are supported.
+            A value of 1 results in either a greyscale (by default) or black and
+            white image, depending on the value of
+            @c wxIMAGE_OPTION_TIFF_BITSPERSAMPLE. A value of 3 (the default)
+            will result in an RGB image.
+        @li @c wxIMAGE_OPTION_TIFF_COMPRESSION: Compression type. By default
+            it is set to 1 (COMPRESSION_NONE). Typical other values are
+            5 (COMPRESSION_LZW) and 7 (COMPRESSION_JPEG). See tiff.h for more
+            options.
+        @li @c wxIMAGE_OPTION_TIFF_PHOTOMETRIC: Specifies the photometric
+            interpretation. By default it is set to 2 (PHOTOMETRIC_RGB) for RGB
+            images and 0 (PHOTOMETRIC_MINISWHITE) for greyscale or black and
+            white images. It can also be set to 1 (PHOTOMETRIC_MINISBLACK) to
+            treat the lowest value as black and highest as white.
+            If you want a greyscale image it is also sufficient to only specify
+            @c wxIMAGE_OPTION_TIFF_PHOTOMETRIC and set it to either
+            PHOTOMETRIC_MINISWHITE or PHOTOMETRIC_MINISBLACK. The other values
+            are taken care of.
+
+        @note
+        Be careful when combining the options @c wxIMAGE_OPTION_TIFF_SAMPLESPERPIXEL,
+        @c wxIMAGE_OPTION_TIFF_BITSPERSAMPLE, and @c wxIMAGE_OPTION_TIFF_PHOTOMETRIC.
+        While some measures are taken to prevent illegal combinations and/or
+        values, it is still easy to abuse them and come up with invalid
+        results in the form of either corrupted images or crashes.
+

         @param name
             The name of the option, case-insensitive.
         @return
         @param name
             The name of the option, case-insensitive.
         @return


@@ -1186,7 +1356,7 @@ public:
     bool IsOk() const;
 
     /**
     bool IsOk() const;
 
     /**

-        Returns @true if the given pixel is transparent, i.e. either has the mask
+        Returns @true if the given pixel is transparent, i.e.\ either has the mask

         colour if this image has a mask or if this image has alpha channel and alpha
         value of this pixel is strictly less than @a threshold.
     */
         colour if this image has a mask or if this image has alpha channel and alpha
         value of this pixel is strictly less than @a threshold.
     */


@@ -1215,7 +1385,7 @@ public:
             @li wxBITMAP_TYPE_PNG: Load a PNG bitmap file.
             @li wxBITMAP_TYPE_PCX: Load a PCX bitmap file.
             @li wxBITMAP_TYPE_PNM: Load a PNM bitmap file.
             @li wxBITMAP_TYPE_PNG: Load a PNG bitmap file.
             @li wxBITMAP_TYPE_PCX: Load a PCX bitmap file.
             @li wxBITMAP_TYPE_PNM: Load a PNM bitmap file.

-            @li wxBITMAP_TYPE_TIF: Load a TIFF bitmap file.
+            @li wxBITMAP_TYPE_TIFF: Load a TIFF bitmap file.

             @li wxBITMAP_TYPE_TGA: Load a TGA bitmap file.
             @li wxBITMAP_TYPE_XPM: Load a XPM bitmap file.
             @li wxBITMAP_TYPE_ICO: Load a Windows icon file (ICO).
             @li wxBITMAP_TYPE_TGA: Load a TGA bitmap file.
             @li wxBITMAP_TYPE_XPM: Load a XPM bitmap file.
             @li wxBITMAP_TYPE_ICO: Load a Windows icon file (ICO).


@@ -1542,7 +1712,19 @@ public:
 
     /**
         Register an image handler.
 
     /**
         Register an image handler.

-        See @ref image_handlers for a list of the available handlers.
+
+        Typical example of use:
+        @code
+            wxImage::AddHandler(new wxPNGHandler);
+        @endcode
+
+        See @ref image_handlers for a list of the available handlers. You can
+        also use ::wxInitAllImageHandlers() to add handlers for all the image
+        formats supported by wxWidgets at once.
+
+        @param handler
+            A heap-allocated handler object which will be deleted by wxImage
+            if it is removed later by RemoveHandler() or at program shutdown.

     */
     static void AddHandler(wxImageHandler* handler);
 
     */
     static void AddHandler(wxImageHandler* handler);
 


@@ -1634,7 +1816,8 @@ public:
 
     /**
         Finds the handler with the given name, and removes it.
 
     /**
         Finds the handler with the given name, and removes it.

-        The handler is not deleted.
+
+        The handler is also deleted.

 
         @param name
             The handler name.
 
         @param name
             The handler name.


@@ -1684,7 +1867,7 @@ public:
         @li wxBITMAP_TYPE_PNG: Load a PNG bitmap file.
         @li wxBITMAP_TYPE_PCX: Load a PCX bitmap file.
         @li wxBITMAP_TYPE_PNM: Load a PNM bitmap file.
         @li wxBITMAP_TYPE_PNG: Load a PNG bitmap file.
         @li wxBITMAP_TYPE_PCX: Load a PCX bitmap file.
         @li wxBITMAP_TYPE_PNM: Load a PNM bitmap file.

-        @li wxBITMAP_TYPE_TIF: Load a TIFF bitmap file.
+        @li wxBITMAP_TYPE_TIFF: Load a TIFF bitmap file.

         @li wxBITMAP_TYPE_TGA: Load a TGA bitmap file.
         @li wxBITMAP_TYPE_XPM: Load a XPM bitmap file.
         @li wxBITMAP_TYPE_ICO: Load a Windows icon file (ICO).
         @li wxBITMAP_TYPE_TGA: Load a TGA bitmap file.
         @li wxBITMAP_TYPE_XPM: Load a XPM bitmap file.
         @li wxBITMAP_TYPE_ICO: Load a Windows icon file (ICO).


@@ -1732,6 +1915,30 @@ public:
     static wxImage::RGBValue HSVtoRGB(const wxImage::HSVValue& hsv);
 };
 
     static wxImage::RGBValue HSVtoRGB(const wxImage::HSVValue& hsv);
 };
 

+
+class wxImageHistogram : public wxImageHistogramBase
+{
+public:
+    wxImageHistogram();
+
+    // get the key in the histogram for the given RGB values
+    static unsigned long MakeKey(unsigned char r,
+                                 unsigned char g,
+                                 unsigned char b);
+
+    // find first colour that is not used in the image and has higher
+    // RGB values than RGB(startR, startG, startB)
+    //
+    // returns true and puts this colour in r, g, b (each of which may be NULL)
+    // on success or returns false if there are no more free colours
+    bool FindFirstUnusedColour(unsigned char *r,
+                               unsigned char *g,
+                               unsigned char *b,
+                               unsigned char startR = 1,
+                               unsigned char startG = 0,
+                               unsigned char startB = 0 ) const;
+};
+

 /**
     An instance of an empty image without an alpha channel.
 */
 /**
     An instance of an empty image without an alpha channel.
 */


@@ -1746,9 +1953,14 @@ wxImage wxNullImage;
 //@{
 
 /**
 //@{
 
 /**

-    Initializes all available image handlers. For a list of available handlers,
-    see wxImage.
-    If you don't need/want all image handlers loaded
+    Initializes all available image handlers.
+
+    This function calls wxImage::AddHandler() for all the available image
+    handlers (see @ref image_handlers for the full list). Calling it is the
+    simplest way to initialize wxImage but it creates and registers even the
+    handlers your program may not use. If you want to avoid the overhead of
+    doing this you need to call wxImage::AddHandler() manually just for the
+    handlers that you do want to use.

 
     @see wxImage, wxImageHandler
 
 
     @see wxImage, wxImageHandler