#include <wx/image.h>

Inheritance diagram for wxImage:

Detailed Description

This class encapsulates a platform-independent image.

An image can be created from data, or using wxBitmap::ConvertToImage. An image can be loaded from a file in a variety of formats, and is extensible to new formats via image format handlers. Functions are available to set and get image bits, so it can be used for basic image manipulation.

A wxImage cannot (currently) be drawn directly to a wxDC. Instead, a platform-specific wxBitmap object must be created from it using 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.

Alpha channel support

Starting from wxWidgets 2.5.0 wxImage supports alpha channel data, that is in addition to a byte for the red, green and blue colour components for each pixel it also stores a byte representing the pixel opacity.

An alpha value of 0 corresponds to a transparent pixel (null opacity) while a value of 255 means that the pixel is 100% opaque. The constants wxIMAGE_ALPHA_TRANSPARENT and wxIMAGE_ALPHA_OPAQUE can be used to indicate those values in a more readable form.

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. 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.

Available image handlers

The following image handlers are available. wxBMPHandler is always installed by default. To use other image formats, install the appropriate handler with wxImage::AddHandler or call wxInitAllImageHandlers().

wxBMPHandler: For loading (including alpha support) and saving, always installed.
wxPNGHandler: For loading and saving. Includes alpha support.
wxJPEGHandler: For loading and saving.
wxGIFHandler: 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. 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.
wxCURHandler: For loading and saving.
wxANIHandler: For loading only.

When saving in PCX format, wxPCXHandler will count the number of different colours in the image; if there are 256 or less colours, it will save as 8 bit, else it will save as 24 bit.

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: Graphics Device Interface (GDI)

Predefined objects/pointers: wxNullImage

See also: wxBitmap, wxInitAllImageHandlers(), wxPixelData

Setters
void	SetAlpha (unsigned char *alpha=NULL, bool static_data=false)
	This function is similar to SetData() and has similar restrictions. More...

void	SetAlpha (int x, int y, unsigned char alpha)
	Sets the alpha value for the given pixel. More...

void	ClearAlpha ()
	Removes the alpha channel from the image. More...

void	SetData (unsigned char *data, bool static_data=false)
	Sets the image data without performing checks. More...

void	SetData (unsigned char *data, int new_width, int new_height, bool static_data=false)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...

void	SetLoadFlags (int flags)
	Sets the flags used for loading image files by this object. More...

void	SetMask (bool hasMask=true)
	Specifies whether there is a mask or not. More...

void	SetMaskColour (unsigned char red, unsigned char green, unsigned char blue)
	Sets the mask colour for this image (and tells the image to use the mask). More...

bool	SetMaskFromImage (const wxImage &mask, unsigned char mr, unsigned char mg, unsigned char mb)
	Sets image's mask so that the pixels that have RGB value of mr,mg,mb in mask will be masked in the image. More...

void	SetOption (const wxString &name, const wxString &value)
	Sets a user-defined option. More...

void	SetOption (const wxString &name, int value)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...

void	SetPalette (const wxPalette &palette)
	Associates a palette with the image. More...

void	SetRGB (int x, int y, unsigned char r, unsigned char g, unsigned char b)
	Set the color of the pixel at the given x and y coordinate. More...

void	SetRGB (const wxRect &rect, unsigned char red, unsigned char green, unsigned char blue)
	Sets the colour of the pixels within the given rectangle. More...

void	SetType (wxBitmapType type)
	Set the type of image returned by GetType(). More...

static void	SetDefaultLoadFlags (int flags)
	Sets the default value for the flags used for loading image files. More...

Classes
class	HSVValue
	A simple class which stores hue, saturation and value as doubles in the range 0.0-1.0. More...

class	RGBValue
	A simple class which stores red, green and blue values as 8 bit unsigned integers in the range of 0-255. More...

Public Member Functions
	wxImage ()
	Creates an empty wxImage object without an alpha channel. More...

	wxImage (int width, int height, bool clear=true)
	Creates an image with the given size and clears it if requested. More...

	wxImage (const wxSize &sz, bool clear=true)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...

	wxImage (int width, int height, unsigned char *data, bool static_data=false)
	Creates an image from data in memory. More...

	wxImage (const wxSize &sz, unsigned char *data, bool static_data=false)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...

	wxImage (int width, int height, unsigned char data, unsigned char alpha, bool static_data=false)
	Creates an image from data in memory. More...

	wxImage (const wxSize &sz, unsigned char data, unsigned char alpha, bool static_data=false)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...

	wxImage (const char const xpmData)
	Creates an image from XPM data. More...

	wxImage (const wxString &name, wxBitmapType type=wxBITMAP_TYPE_ANY, int index=-1)
	Creates an image from a file. More...

	wxImage (const wxString &name, const wxString &mimetype, int index=-1)
	Creates an image from a file using MIME-types to specify the type. More...

	wxImage (wxInputStream &stream, wxBitmapType type=wxBITMAP_TYPE_ANY, int index=-1)
	Creates an image from a stream. More...

	wxImage (wxInputStream &stream, const wxString &mimetype, int index=-1)
	Creates an image from a stream using MIME-types to specify the type. More...

virtual	~wxImage ()
	Destructor. More...

int	GetLoadFlags () const
	Returns the file load flags used for this object. More...

Image creation, initialization and deletion functions
wxImage	Copy () const
	Returns an identical copy of this image. More...

bool	Create (int width, int height, bool clear=true)
	Creates a fresh image. More...

bool	Create (const wxSize &sz, bool clear=true)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...

bool	Create (int width, int height, unsigned char *data, bool static_data=false)
	Creates a fresh image. More...

bool	Create (const wxSize &sz, unsigned char *data, bool static_data=false)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...

bool	Create (int width, int height, unsigned char data, unsigned char alpha, bool static_data=false)
	Creates a fresh image. More...

bool	Create (const wxSize &sz, unsigned char data, unsigned char alpha, bool static_data=false)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...

void	Clear (unsigned char value=0)
	Initialize the image data with zeroes (the default) or with the byte value given as value. More...

void	Destroy ()
	Destroys the image data. More...

void	InitAlpha ()
	Initializes the image alpha channel data. More...

Image manipulation functions
wxImage	Blur (int blurRadius) const
	Blurs the image in both horizontal and vertical directions by the specified pixel blurRadius. More...

wxImage	BlurHorizontal (int blurRadius) const
	Blurs the image in the horizontal direction only. More...

wxImage	BlurVertical (int blurRadius) const
	Blurs the image in the vertical direction only. More...

wxImage	Mirror (bool horizontally=true) const
	Returns a mirrored copy of the image. More...

void	Paste (const wxImage &image, int x, int y)
	Copy the data of the given image to the specified position in this image. More...

void	Replace (unsigned char r1, unsigned char g1, unsigned char b1, unsigned char r2, unsigned char g2, unsigned char b2)
	Replaces the colour specified by r1,g1,b1 by the colour r2,g2,b2. More...

wxImage &	Rescale (int width, int height, wxImageResizeQuality quality=wxIMAGE_QUALITY_NORMAL)
	Changes the size of the image in-place by scaling it: after a call to this function,the image will have the given width and height. More...

wxImage &	Resize (const wxSize &size, const wxPoint &pos, int red=-1, int green=-1, int blue=-1)
	Changes the size of the image in-place without scaling it by adding either a border with the given colour or cropping as necessary. More...

wxImage	Rotate (double angle, const wxPoint &rotationCentre, bool interpolating=true, wxPoint *offsetAfterRotation=NULL) const
	Rotates the image about the given point, by angle radians. More...

wxImage	Rotate90 (bool clockwise=true) const
	Returns a copy of the image rotated 90 degrees in the direction indicated by clockwise. More...

wxImage	Rotate180 () const
	Returns a copy of the image rotated by 180 degrees. More...

void	RotateHue (double angle)
	Rotates the hue of each pixel in the image by angle, which is a double in the range of -1.0 to +1.0, where -1.0 corresponds to -360 degrees and +1.0 corresponds to +360 degrees. More...

wxImage	Scale (int width, int height, wxImageResizeQuality quality=wxIMAGE_QUALITY_NORMAL) const
	Returns a scaled version of the image. More...

wxImage	Size (const wxSize &size, const wxPoint &pos, int red=-1, int green=-1, int blue=-1) const
	Returns a resized version of this image without scaling it by adding either a border with the given colour or cropping as necessary. More...

Conversion functions
bool	ConvertAlphaToMask (unsigned char threshold=wxIMAGE_ALPHA_THRESHOLD)
	If the image has alpha channel, this method converts it to mask. More...

bool	ConvertAlphaToMask (unsigned char mr, unsigned char mg, unsigned char mb, unsigned char threshold=wxIMAGE_ALPHA_THRESHOLD)
	If the image has alpha channel, this method converts it to mask using the specified colour as the mask colour. More...

wxImage	ConvertToGreyscale (double weight_r, double weight_g, double weight_b) const
	Returns a greyscale version of the image. More...

wxImage	ConvertToGreyscale () const
	Returns a greyscale version of the image. More...

wxImage	ConvertToMono (unsigned char r, unsigned char g, unsigned char b) const
	Returns monochromatic version of the image. More...

wxImage	ConvertToDisabled (unsigned char brightness=255) const
	Returns disabled (dimmed) version of the image. More...

Miscellaneous functions
unsigned long	ComputeHistogram (wxImageHistogram &histogram) const
	Computes the histogram of the image. More...

bool	FindFirstUnusedColour (unsigned char r, unsigned char g, unsigned char *b, unsigned char startR=1, unsigned char startG=0, unsigned char startB=0) const
	Finds the first colour that is never used in the image. More...

wxImage &	operator= (const wxImage &image)
	Assignment operator, using reference counting. More...

Getters
unsigned char *	GetAlpha () const
	Returns pointer to the array storing the alpha values for this image. More...

unsigned char *	GetData () const
	Returns the image data as an array. More...

unsigned char	GetAlpha (int x, int y) const
	Return alpha value at given pixel location. More...

unsigned char	GetRed (int x, int y) const
	Returns the red intensity at the given coordinate. More...

unsigned char	GetGreen (int x, int y) const
	Returns the green intensity at the given coordinate. More...

unsigned char	GetBlue (int x, int y) const
	Returns the blue intensity at the given coordinate. More...

unsigned char	GetMaskRed () const
	Gets the red value of the mask colour. More...

unsigned char	GetMaskGreen () const
	Gets the green value of the mask colour. More...

unsigned char	GetMaskBlue () const
	Gets the blue value of the mask colour. More...

int	GetWidth () const
	Gets the width of the image in pixels. More...

int	GetHeight () const
	Gets the height of the image in pixels. More...

wxSize	GetSize () const
	Returns the size of the image in pixels. More...

wxString	GetOption (const wxString &name) const
	Gets a user-defined string-valued option. More...

int	GetOptionInt (const wxString &name) const
	Gets a user-defined integer-valued option. More...

bool	GetOrFindMaskColour (unsigned char r, unsigned char g, unsigned char *b) const
	Get the current mask colour or find a suitable unused colour that could be used as a mask colour. More...

const wxPalette &	GetPalette () const
	Returns the palette associated with the image. More...

wxImage	GetSubImage (const wxRect &rect) const
	Returns a sub image of the current one as long as the rect belongs entirely to the image. More...

wxBitmapType	GetType () const
	Gets the type of image found by LoadFile() or specified with SaveFile(). More...

bool	HasAlpha () const
	Returns true if this image has alpha channel, false otherwise. More...

bool	HasMask () const
	Returns true if there is a mask active, false otherwise. More...

bool	HasOption (const wxString &name) const
	Returns true if the given option is present. More...

bool	IsOk () const
	Returns true if image data is present. More...

bool	IsTransparent (int x, int y, unsigned char threshold=wxIMAGE_ALPHA_THRESHOLD) const
	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 threshold. More...

Loading and saving functions
virtual bool	LoadFile (wxInputStream &stream, wxBitmapType type=wxBITMAP_TYPE_ANY, int index=-1)
	Loads an image from an input stream. More...

virtual bool	LoadFile (const wxString &name, wxBitmapType type=wxBITMAP_TYPE_ANY, int index=-1)
	Loads an image from a file. More...

virtual bool	LoadFile (const wxString &name, const wxString &mimetype, int index=-1)
	Loads an image from a file. More...

virtual bool	LoadFile (wxInputStream &stream, const wxString &mimetype, int index=-1)
	Loads an image from an input stream. More...

virtual bool	SaveFile (wxOutputStream &stream, const wxString &mimetype) const
	Saves an image in the given stream. More...

virtual bool	SaveFile (const wxString &name, wxBitmapType type) const
	Saves an image in the named file. More...

virtual bool	SaveFile (const wxString &name, const wxString &mimetype) const
	Saves an image in the named file. More...

virtual bool	SaveFile (const wxString &name) const
	Saves an image in the named file. More...

virtual bool	SaveFile (wxOutputStream &stream, wxBitmapType type) const
	Saves an image in the given stream. More...

Public Member Functions inherited from wxObject
	wxObject ()
	Default ctor; initializes to NULL the internal reference data. More...

	wxObject (const wxObject &other)
	Copy ctor. More...

virtual	~wxObject ()
	Destructor. More...

virtual wxClassInfo *	GetClassInfo () const
	This virtual function is redefined for every class that requires run-time type information, when using the wxDECLARE_CLASS macro (or similar). More...

wxObjectRefData *	GetRefData () const
	Returns the wxObject::m_refData pointer, i.e. the data referenced by this object. More...

bool	IsKindOf (const wxClassInfo *info) const
	Determines whether this class is a subclass of (or the same class as) the given class. More...

bool	IsSameAs (const wxObject &obj) const
	Returns true if this object has the same data pointer as obj. More...

void	Ref (const wxObject &clone)
	Makes this object refer to the data in clone. More...

void	SetRefData (wxObjectRefData *data)
	Sets the wxObject::m_refData pointer. More...

void	UnRef ()
	Decrements the reference count in the associated data, and if it is zero, deletes the data. More...

void	UnShare ()
	This is the same of AllocExclusive() but this method is public. More...

void	operator delete (void *buf)
	The delete operator is defined for debugging versions of the library only, when the identifier `WXDEBUG` is defined. More...

void *	operator new (size_t size, const wxString &filename=NULL, int lineNum=0)
	The new operator is defined for debugging versions of the library only, when the identifier `WXDEBUG` is defined. More...

Static Public Member Functions
static bool	CanRead (const wxString &filename)
	Returns true if at least one of the available image handlers can read the file with the given name. More...

static bool	CanRead (wxInputStream &stream)
	Returns true if at least one of the available image handlers can read the data in the given stream. More...

static int	GetDefaultLoadFlags ()
	Returns the currently used default file load flags. More...

static wxString	GetImageExtWildcard ()
	Iterates all registered wxImageHandler objects, and returns a string containing file extension masks suitable for passing to file open/save dialog boxes. More...

static wxImage::HSVValue	RGBtoHSV (const wxImage::RGBValue &rgb)
	Converts a color in RGB color space to HSV color space. More...

static wxImage::RGBValue	HSVtoRGB (const wxImage::HSVValue &hsv)
	Converts a color in HSV color space to RGB color space. More...

Handler management functions
static void	AddHandler (wxImageHandler *handler)
	Register an image handler. More...

static void	CleanUpHandlers ()
	Deletes all image handlers. More...

static wxImageHandler *	FindHandler (const wxString &name)
	Finds the handler with the given name. More...

static wxImageHandler *	FindHandler (const wxString &extension, wxBitmapType imageType)
	Finds the handler associated with the given extension and type. More...

static wxImageHandler *	FindHandler (wxBitmapType imageType)
	Finds the handler associated with the given image type. More...

static wxImageHandler *	FindHandlerMime (const wxString &mimetype)
	Finds the handler associated with the given MIME type. More...

static wxList &	GetHandlers ()
	Returns the static list of image format handlers. More...

static void	InitStandardHandlers ()
	Internal use only. More...

static void	InsertHandler (wxImageHandler *handler)
	Adds a handler at the start of the static list of format handlers. More...

static bool	RemoveHandler (const wxString &name)
	Finds the handler with the given name, and removes it. More...


static int	GetImageCount (const wxString &filename, wxBitmapType type=wxBITMAP_TYPE_ANY)
	If the image file contains more than one image and the image handler is capable of retrieving these individually, this function will return the number of available images. More...

static int	GetImageCount (wxInputStream &stream, wxBitmapType type=wxBITMAP_TYPE_ANY)
	If the image file contains more than one image and the image handler is capable of retrieving these individually, this function will return the number of available images. More...

Additional Inherited Members
Protected Member Functions inherited from wxObject
void	AllocExclusive ()
	Ensure that this object's data is not shared with any other object. More...

virtual wxObjectRefData *	CreateRefData () const
	Creates a new instance of the wxObjectRefData-derived class specific to this object and returns it. More...

virtual wxObjectRefData *	CloneRefData (const wxObjectRefData *data) const
	Creates a new instance of the wxObjectRefData-derived class specific to this object and initializes it copying data. More...

Protected Attributes inherited from wxObject
wxObjectRefData *	m_refData
	Pointer to an object which is the object's reference-counted data. More...

Constructor & Destructor Documentation

wxImage::wxImage ( )

Creates an empty wxImage object without an alpha channel.

wxImage::wxImage	(	int	width,
		int	height,
		bool	clear = `true`
	)

Creates an image with the given size and clears it if requested.

Does not create an alpha channel.

Parameters

width	Specifies the width of the image.
height	Specifies the height of the image.
clear	If true, initialize the image to black.

wxImage::wxImage	(	const wxSize &	sz,
		bool	clear = `true`
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

wxImage::wxImage	(	int	width,
		int	height,
		unsigned char *	data,
		bool	static_data = `false`
	)

Creates an image from data in memory.

If static_data is false then the wxImage will take ownership of the data and free it afterwards. For this, it has to be allocated with malloc.

Parameters

width	Specifies the width of the image.
height	Specifies the height of the image.
data	A pointer to RGB data
static_data	Indicates if the data should be free'd after use

wxImage::wxImage	(	const wxSize &	sz,
		unsigned char *	data,
		bool	static_data = `false`
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

wxImage::wxImage	(	int	width,
		int	height,
		unsigned char *	data,
		unsigned char *	alpha,
		bool	static_data = `false`
	)

Creates an image from data in memory.

If static_data is false then the wxImage will take ownership of the data and free it afterwards. For this, it has to be allocated with malloc.

Parameters

width	Specifies the width of the image.
height	Specifies the height of the image.
data	A pointer to RGB data
alpha	A pointer to alpha-channel data
static_data	Indicates if the data should be free'd after use

wxImage::wxImage	(	const wxSize &	sz,
		unsigned char *	data,
		unsigned char *	alpha,
		bool	static_data = `false`
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

wxImage::wxImage ( const char *const * xpmData )

Creates an image from XPM data.

Parameters

xpmData A pointer to XPM image data.

wxPerl Note: Not supported by wxPerl.

wxImage::wxImage	(	const wxString &	name,
		wxBitmapType	type = `wxBITMAP_TYPE_ANY`,
		int	index = `-1`
	)

Creates an image from a file.

Parameters

name	Name of the file from which to load the image.
type	May be one of the following: wxBITMAP_TYPE_BMP: Load a Windows bitmap file. wxBITMAP_TYPE_GIF: Load a GIF bitmap file. wxBITMAP_TYPE_JPEG: Load a JPEG bitmap file. wxBITMAP_TYPE_PNG: Load a PNG bitmap file. wxBITMAP_TYPE_PCX: Load a PCX bitmap file. wxBITMAP_TYPE_PNM: Load a PNM bitmap file. wxBITMAP_TYPE_TIFF: Load a TIFF bitmap file. wxBITMAP_TYPE_TGA: Load a TGA bitmap file. wxBITMAP_TYPE_XPM: Load a XPM bitmap file. wxBITMAP_TYPE_ICO: Load a Windows icon file (ICO). wxBITMAP_TYPE_CUR: Load a Windows cursor file (CUR). wxBITMAP_TYPE_ANI: Load a Windows animated cursor file (ANI). wxBITMAP_TYPE_ANY: Will try to autodetect the format.
index	Index of the image to load in the case that the image file contains multiple images. This is only used by GIF, ICO and TIFF handlers. The default value (-1) means "choose the default image" and is interpreted as the first image (index=0) by the GIF and TIFF handler and as the largest and most colourful one by the ICO handler.

Remarks: Depending on how wxWidgets has been configured and by which handlers have been loaded, not all formats may be available. Any handler other than BMP must be previously initialized with wxImage::AddHandler or wxInitAllImageHandlers.

Note: You can use GetOptionInt() to get the hotspot when loading cursor files:
int hotspot_x = image.GetOptionInt(wxIMAGE_OPTION_CUR_HOTSPOT_X);
int hotspot_y = image.GetOptionInt(wxIMAGE_OPTION_CUR_HOTSPOT_Y);

See also: LoadFile()

wxImage::wxImage	(	const wxString &	name,
		const wxString &	mimetype,
		int	index = `-1`
	)

Creates an image from a file using MIME-types to specify the type.

Parameters

name	Name of the file from which to load the image.
mimetype	MIME type string (for example 'image/jpeg')
index	See description in wxImage(const wxString&, wxBitmapType, int) overload.

wxImage::wxImage	(	wxInputStream &	stream,
		wxBitmapType	type = `wxBITMAP_TYPE_ANY`,
		int	index = `-1`
	)

Creates an image from a stream.

Parameters

stream	Opened input stream from which to load the image. Currently, the stream must support seeking.
type	See description in wxImage(const wxString&, wxBitmapType, int) overload.
index	See description in wxImage(const wxString&, wxBitmapType, int) overload.

wxImage::wxImage	(	wxInputStream &	stream,
		const wxString &	mimetype,
		int	index = `-1`
	)

Creates an image from a stream using MIME-types to specify the type.

Parameters

stream	Opened input stream from which to load the image. Currently, the stream must support seeking.
mimetype	MIME type string (for example 'image/jpeg')
index	See description in wxImage(const wxString&, wxBitmapType, int) overload.

virtual wxImage::~wxImage ( )

virtual

Destructor.

See reference-counted object destruction for more info.

Member Function Documentation

static void wxImage::AddHandler ( wxImageHandler * handler )

static

Register an image handler.

Typical example of use:

wxImage::AddHandler(new wxPNGHandler);

See Available 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.

Parameters

handler A heap-allocated handler object which will be deleted by wxImage if it is removed later by RemoveHandler() or at program shutdown.

wxImage wxImage::Blur ( int blurRadius ) const

Blurs the image in both horizontal and vertical directions by the specified pixel blurRadius.

This should not be used when using a single mask colour for transparency.

See also: BlurHorizontal(), BlurVertical()

wxImage wxImage::BlurHorizontal ( int blurRadius ) const

Blurs the image in the horizontal direction only.

This should not be used when using a single mask colour for transparency.

See also: Blur(), BlurVertical()

wxImage wxImage::BlurVertical ( int blurRadius ) const

Blurs the image in the vertical direction only.

This should not be used when using a single mask colour for transparency.

See also: Blur(), BlurHorizontal()

static bool wxImage::CanRead ( const wxString & filename )

static

Returns true if at least one of the available image handlers can read the file with the given name.

See wxImageHandler::CanRead for more info.

static bool wxImage::CanRead ( wxInputStream & stream )

static

Returns true if at least one of the available image handlers can read the data in the given stream.

See wxImageHandler::CanRead for more info.

static void wxImage::CleanUpHandlers ( )

static

Deletes all image handlers.

This function is called by wxWidgets on exit.

void wxImage::Clear ( unsigned char value = 0 )

Initialize the image data with zeroes (the default) or with the byte value given as value.

Since: 2.9.0

void wxImage::ClearAlpha ( )

Removes the alpha channel from the image.

This function should only be called if the image has alpha channel data, use HasAlpha() to check for this.

Since: 2.9.1

unsigned long wxImage::ComputeHistogram ( wxImageHistogram & histogram ) const

Computes the histogram of the image.

histogram is a reference to wxImageHistogram object. wxImageHistogram is a specialization of wxHashMap "template" and is defined as follows:

class WXDLLEXPORT wxImageHistogramEntry
{
public:
    wxImageHistogramEntry() : index(0), value(0) {}
    unsigned long index;
    unsigned long value;
};
WX_DECLARE_EXPORTED_HASH_MAP(unsigned long, wxImageHistogramEntry,
                            wxIntegerHash, wxIntegerEqual,
                            wxImageHistogram);

Returns: Returns number of colours in the histogram.

bool wxImage::ConvertAlphaToMask ( unsigned char threshold = wxIMAGE_ALPHA_THRESHOLD )

If the image has alpha channel, this method converts it to mask.

If the image has an alpha channel, all pixels with alpha value less than threshold are replaced with the mask colour and the alpha channel is removed. Otherwise nothing is done.

The mask colour is chosen automatically using FindFirstUnusedColour() by this function, see the overload below if you this is not appropriate.

Returns: Returns true on success, false on error.

bool wxImage::ConvertAlphaToMask	(	unsigned char	mr,
		unsigned char	mg,
		unsigned char	mb,
		unsigned char	threshold = `wxIMAGE_ALPHA_THRESHOLD`
	)

If the image has alpha channel, this method converts it to mask using the specified colour as the mask colour.

If the image has an alpha channel, all pixels with alpha value less than threshold are replaced with the mask colour and the alpha channel is removed. Otherwise nothing is done.

Since: 2.9.0

Parameters

mr	The red component of the mask colour.
mg	The green component of the mask colour.
mb	The blue component of the mask colour.
threshold	Pixels with alpha channel values below the given threshold are considered to be transparent, i.e. the corresponding mask pixels are set. Pixels with the alpha values above the threshold are considered to be opaque.

Returns: Returns true on success, false on error.

wxImage wxImage::ConvertToDisabled ( unsigned char brightness = 255 ) const

Returns disabled (dimmed) version of the image.

Since: 2.9.0

wxImage wxImage::ConvertToGreyscale	(	double	weight_r,
		double	weight_g,
		double	weight_b
	)		const

Returns a greyscale version of the image.

The returned image uses the luminance component of the original to calculate the greyscale. Defaults to using the standard ITU-T BT.601 when converting to YUV, where every pixel equals (R * weight_r) + (G * weight_g) + (B * weight_b).

wxImage wxImage::ConvertToGreyscale ( ) const

Returns a greyscale version of the image.

Since: 2.9.0

wxImage wxImage::ConvertToMono	(	unsigned char	r,
		unsigned char	g,
		unsigned char	b
	)		const

Returns monochromatic version of the image.

The returned image has white colour where the original has (r,g,b) colour and black colour everywhere else.

wxImage wxImage::Copy ( ) const

Returns an identical copy of this image.

bool wxImage::Create	(	int	width,
		int	height,
		bool	clear = `true`
	)

Creates a fresh image.

See wxImage::wxImage(int,int,bool) for more info.

Returns: true if the call succeeded, false otherwise.

bool wxImage::Create	(	const wxSize &	sz,
		bool	clear = `true`
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

bool wxImage::Create	(	int	width,
		int	height,
		unsigned char *	data,
		bool	static_data = `false`
	)

Creates a fresh image.

See wxImage::wxImage(int,int,unsigned char*,bool) for more info.

Returns: true if the call succeeded, false otherwise.

bool wxImage::Create	(	const wxSize &	sz,
		unsigned char *	data,
		bool	static_data = `false`
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

bool wxImage::Create	(	int	width,
		int	height,
		unsigned char *	data,
		unsigned char *	alpha,
		bool	static_data = `false`
	)

Creates a fresh image.

See wxImage::wxImage(int,int,unsigned char*,unsigned char*,bool) for more info.

Returns: true if the call succeeded, false otherwise.

bool wxImage::Create	(	const wxSize &	sz,
		unsigned char *	data,
		unsigned char *	alpha,
		bool	static_data = `false`
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

void wxImage::Destroy ( )

Destroys the image data.

bool wxImage::FindFirstUnusedColour	(	unsigned char *	r,
		unsigned char *	g,
		unsigned char *	b,
		unsigned char	startR = `1`,
		unsigned char	startG = `0`,
		unsigned char	startB = `0`
	)		const

Finds the first colour that is never used in the image.

The search begins at given initial colour and continues by increasing R, G and B components (in this order) by 1 until an unused colour is found or the colour space exhausted.

The parameters r, g, b are pointers to variables to save the colour.

The parameters startR, startG, startB define the initial values of the colour. The returned colour will have RGB values equal to or greater than these.

Returns: Returns false if there is no unused colour left, true on success.

Note: This method involves computing the histogram, which is a computationally intensive operation.

static wxImageHandler* wxImage::FindHandler ( const wxString & name )

static

Finds the handler with the given name.

Parameters

name	The handler name.

Returns: A pointer to the handler if found, NULL otherwise.

See also: wxImageHandler

static wxImageHandler* wxImage::FindHandler	(	const wxString &	extension,
		wxBitmapType	imageType
	)

static

Finds the handler associated with the given extension and type.

Parameters

extension	The file extension, such as "bmp".
imageType	The image type; one of the wxBitmapType values.

Returns: A pointer to the handler if found, NULL otherwise.

See also: wxImageHandler

static wxImageHandler* wxImage::FindHandler ( wxBitmapType imageType )

static

Finds the handler associated with the given image type.

Parameters

imageType The image type; one of the wxBitmapType values.

Returns: A pointer to the handler if found, NULL otherwise.

See also: wxImageHandler

static wxImageHandler* wxImage::FindHandlerMime ( const wxString & mimetype )

static

Finds the handler associated with the given MIME type.

Parameters

mimetype MIME type.

Returns: A pointer to the handler if found, NULL otherwise.

See also: wxImageHandler

unsigned char* wxImage::GetAlpha ( ) const

Returns pointer to the array storing the alpha values for this image.

This pointer is NULL for the images without the alpha channel. If the image does have it, this pointer may be used to directly manipulate the alpha values which are stored as the RGB ones.

unsigned char wxImage::GetAlpha	(	int	x,
		int	y
	)		const

Return alpha value at given pixel location.

unsigned char wxImage::GetBlue	(	int	x,
		int	y
	)		const

Returns the blue intensity at the given coordinate.

unsigned char* wxImage::GetData ( ) const

Returns the image data as an array.

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 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.

You should not delete the returned pointer nor pass it to SetData().

static int wxImage::GetDefaultLoadFlags ( )

static

Returns the currently used default file load flags.

See SetDefaultLoadFlags() for more information about these flags.

Since: 3.1.0

unsigned char wxImage::GetGreen	(	int	x,
		int	y
	)		const

Returns the green intensity at the given coordinate.

static wxList& wxImage::GetHandlers ( )

static

Returns the static list of image format handlers.

See also: wxImageHandler

int wxImage::GetHeight ( ) const

Gets the height of the image in pixels.

See also: GetWidth(), GetSize()

static int wxImage::GetImageCount	(	const wxString &	filename,
		wxBitmapType	type = `wxBITMAP_TYPE_ANY`
	)

static

If the image file contains more than one image and the image handler is capable of retrieving these individually, this function will return the number of available images.

For the overload taking the parameter filename, that's the name of the file to query. For the overload taking the parameter stream, that's the opened input stream with image data.

See wxImageHandler::GetImageCount() for more info.

The parameter type may be one of the following values:

wxBITMAP_TYPE_BMP: Load a Windows bitmap file.
wxBITMAP_TYPE_GIF: Load a GIF bitmap file.
wxBITMAP_TYPE_JPEG: Load a JPEG bitmap file.
wxBITMAP_TYPE_PNG: Load a PNG bitmap file.
wxBITMAP_TYPE_PCX: Load a PCX bitmap file.
wxBITMAP_TYPE_PNM: Load a PNM bitmap file.
wxBITMAP_TYPE_TIFF: Load a TIFF bitmap file.
wxBITMAP_TYPE_TGA: Load a TGA bitmap file.
wxBITMAP_TYPE_XPM: Load a XPM bitmap file.
wxBITMAP_TYPE_ICO: Load a Windows icon file (ICO).
wxBITMAP_TYPE_CUR: Load a Windows cursor file (CUR).
wxBITMAP_TYPE_ANI: Load a Windows animated cursor file (ANI).
wxBITMAP_TYPE_ANY: Will try to autodetect the format.

Returns: Number of available images. For most image handlers, this is 1 (exceptions are TIFF and ICO formats as well as animated GIFs for which this function returns the number of frames in the animation).

static int wxImage::GetImageCount	(	wxInputStream &	stream,
		wxBitmapType	type = `wxBITMAP_TYPE_ANY`
	)

static

If the image file contains more than one image and the image handler is capable of retrieving these individually, this function will return the number of available images.

For the overload taking the parameter filename, that's the name of the file to query. For the overload taking the parameter stream, that's the opened input stream with image data.

See wxImageHandler::GetImageCount() for more info.

The parameter type may be one of the following values:

wxBITMAP_TYPE_BMP: Load a Windows bitmap file.
wxBITMAP_TYPE_GIF: Load a GIF bitmap file.
wxBITMAP_TYPE_JPEG: Load a JPEG bitmap file.
wxBITMAP_TYPE_PNG: Load a PNG bitmap file.
wxBITMAP_TYPE_PCX: Load a PCX bitmap file.
wxBITMAP_TYPE_PNM: Load a PNM bitmap file.
wxBITMAP_TYPE_TIFF: Load a TIFF bitmap file.
wxBITMAP_TYPE_TGA: Load a TGA bitmap file.
wxBITMAP_TYPE_XPM: Load a XPM bitmap file.
wxBITMAP_TYPE_ICO: Load a Windows icon file (ICO).
wxBITMAP_TYPE_CUR: Load a Windows cursor file (CUR).
wxBITMAP_TYPE_ANI: Load a Windows animated cursor file (ANI).
wxBITMAP_TYPE_ANY: Will try to autodetect the format.

Returns: Number of available images. For most image handlers, this is 1 (exceptions are TIFF and ICO formats as well as animated GIFs for which this function returns the number of frames in the animation).

static wxString wxImage::GetImageExtWildcard ( )

static

Iterates all registered wxImageHandler objects, and returns a string containing file extension masks suitable for passing to file open/save dialog boxes.

Returns: The format of the returned string is "(*.ext1;*.ext2)|*.ext1;*.ext2". It is usually a good idea to prepend a description before passing the result to the dialog. Example:
wxFileDialog FileDlg( this, "Choose Image", ::wxGetCwd(), "",
_("Image Files ") + wxImage::GetImageExtWildcard(),
wxFD_OPEN );

See also: wxImageHandler

int wxImage::GetLoadFlags ( ) const

Returns the file load flags used for this object.

See SetLoadFlags() for more information about these flags.

Since: 3.1.0

unsigned char wxImage::GetMaskBlue ( ) const

Gets the blue value of the mask colour.

unsigned char wxImage::GetMaskGreen ( ) const

Gets the green value of the mask colour.

unsigned char wxImage::GetMaskRed ( ) const

Gets the red value of the mask colour.

wxString wxImage::GetOption ( const wxString & name ) const

Gets a user-defined string-valued option.

Generic options:

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

Options specific to wxGIFHandler:

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.

Parameters

name	The name of the option, case-insensitive.

Returns: The value of the option or an empty string if not found. Use HasOption() if an empty string can be a valid option value.

See also: SetOption(), GetOptionInt(), HasOption()

int wxImage::GetOptionInt ( const wxString & name ) const

Gets a user-defined integer-valued option.

The function is case-insensitive to name. If the given option is not present, the function returns 0. Use HasOption() if 0 is a possibly valid value for the option.

Generic options:

wxIMAGE_OPTION_MAX_WIDTH and wxIMAGE_OPTION_MAX_HEIGHT: If either of these options is specified, the loaded image will be scaled down (preserving its aspect ratio) so that its width is less than the max width given if it is not 0 and its height is less than the max height given if it is not 0. This is typically used for loading thumbnails and the advantage of using these options compared to calling Rescale() after loading is that some handlers (only JPEG one right now) support rescaling the image during loading which is vastly more efficient than loading the entire huge image and rescaling it later (if these options are not supported by the handler, this is still what happens however). These options must be set before calling LoadFile() to have any effect.

wxIMAGE_OPTION_ORIGINAL_WIDTH and wxIMAGE_OPTION_ORIGINAL_HEIGHT: These options will return the original size of the image if either wxIMAGE_OPTION_MAX_WIDTH or wxIMAGE_OPTION_MAX_HEIGHT is specified.
Since
2.9.3
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 the other formats.

wxIMAGE_OPTION_RESOLUTIONUNIT: The value of this option determines whether the resolution of the image is specified in centimetres or inches, see wxImageResolution enum elements.

wxIMAGE_OPTION_RESOLUTION, wxIMAGE_OPTION_RESOLUTIONX and wxIMAGE_OPTION_RESOLUTIONY: These options define the resolution of the image in the units corresponding to wxIMAGE_OPTION_RESOLUTIONUNIT options value. The first option can be set before saving the image to set both horizontal and vertical resolution to the same value. The X and Y options are set by the image handlers if they support the image resolution (currently BMP, JPEG and TIFF handlers do) and the image provides the resolution information and can be queried after loading the image.

Options specific to wxPNGHandler:

wxIMAGE_OPTION_PNG_FORMAT: Format for saving a PNG file, see wxImagePNGType for the supported values.
wxIMAGE_OPTION_PNG_BITDEPTH: Bit depth for every channel (R/G/B/A).
wxIMAGE_OPTION_PNG_FILTER: Filter for saving a PNG file, see libpng (http://www.libpng.org/pub/png/libpng-1.2.5-manual.html) for possible values (e.g. PNG_FILTER_NONE, PNG_FILTER_SUB, PNG_FILTER_UP, etc).
wxIMAGE_OPTION_PNG_COMPRESSION_LEVEL: Compression level (0..9) for saving a PNG file. An high value creates smaller-but-slower PNG file. Note that unlike other formats (e.g. JPEG) the PNG format is always lossless and thus this compression level doesn't tradeoff the image quality.
wxIMAGE_OPTION_PNG_COMPRESSION_MEM_LEVEL: Compression memory usage level (1..9) for saving a PNG file. An high value means the saving process consumes more memory, but may create smaller PNG file.
wxIMAGE_OPTION_PNG_COMPRESSION_STRATEGY: Possible values are 0 for default strategy, 1 for filter, and 2 for Huffman-only. You can use OptiPNG (http://optipng.sourceforge.net/) to get a suitable value for your application.
wxIMAGE_OPTION_PNG_COMPRESSION_BUFFER_SIZE: Internal buffer size (in bytes) for saving a PNG file. Ideally this should be as big as the resulting PNG file. Use this option if your application produces images with small size variation.

Options specific to wxTIFFHandler:

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 wxIMAGE_OPTION_TIFF_SAMPLESPERPIXEL.
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 wxIMAGE_OPTION_TIFF_BITSPERSAMPLE. A value of 3 (the default) will result in an RGB image.
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.
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 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 wxIMAGE_OPTION_TIFF_SAMPLESPERPIXEL, wxIMAGE_OPTION_TIFF_BITSPERSAMPLE, and 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.

Parameters

name	The name of the option, case-insensitive.

Returns: The value of the option or 0 if not found. Use HasOption() if 0 can be a valid option value.

See also: SetOption(), GetOption()

bool wxImage::GetOrFindMaskColour	(	unsigned char *	r,
		unsigned char *	g,
		unsigned char *	b
	)		const

Get the current mask colour or find a suitable unused colour that could be used as a mask colour.

Returns true if the image currently has a mask.

const wxPalette& wxImage::GetPalette ( ) const

Returns the palette associated with the image.

Currently the palette is only used when converting to wxBitmap under Windows.

Some of the wxImage handlers have been modified to set the palette if one exists in the image file (usually 256 or less colour images in GIF or PNG format).

unsigned char wxImage::GetRed	(	int	x,
		int	y
	)		const

Returns the red intensity at the given coordinate.

wxSize wxImage::GetSize ( ) const

Returns the size of the image in pixels.

Since: 2.9.0

See also: GetHeight(), GetWidth()

wxImage wxImage::GetSubImage ( const wxRect & rect ) const

Returns a sub image of the current one as long as the rect belongs entirely to the image.

wxBitmapType wxImage::GetType ( ) const

Gets the type of image found by LoadFile() or specified with SaveFile().

Since: 2.9.0

int wxImage::GetWidth ( ) const

Gets the width of the image in pixels.

See also: GetHeight(), GetSize()

bool wxImage::HasAlpha ( ) const

Returns true if this image has alpha channel, false otherwise.

See also: GetAlpha(), SetAlpha()

bool wxImage::HasMask ( ) const

Returns true if there is a mask active, false otherwise.

bool wxImage::HasOption ( const wxString & name ) const

Returns true if the given option is present.

The function is case-insensitive to name.

The lists of the currently supported options are in GetOption() and GetOptionInt() function docs.

See also: SetOption(), GetOption(), GetOptionInt()

static wxImage::RGBValue wxImage::HSVtoRGB ( const wxImage::HSVValue & hsv )

static

Converts a color in HSV color space to RGB color space.

void wxImage::InitAlpha ( )

Initializes the image alpha channel data.

It is an error to call it if the image already has alpha data. If it doesn't, alpha data will be by default initialized to all pixels being fully opaque. But if the image has a mask colour, all mask pixels will be completely transparent.

static void wxImage::InitStandardHandlers ( )

static

Internal use only.

Adds standard image format handlers. It only install wxBMPHandler for the time being, which is used by wxBitmap.

This function is called by wxWidgets on startup, and shouldn't be called by the user.

See also: wxImageHandler, wxInitAllImageHandlers(), wxQuantize

static void wxImage::InsertHandler ( wxImageHandler * handler )

static

Adds a handler at the start of the static list of format handlers.

Parameters

handler A new image format handler object. There is usually only one instance of a given handler class in an application session.

See also: wxImageHandler

bool wxImage::IsOk ( ) const

Returns true if image data is present.

bool wxImage::IsTransparent	(	int	x,
		int	y,
		unsigned char	threshold = `wxIMAGE_ALPHA_THRESHOLD`
	)		const

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 threshold.

virtual bool wxImage::LoadFile	(	wxInputStream &	stream,
		wxBitmapType	type = `wxBITMAP_TYPE_ANY`,
		int	index = `-1`
	)

virtual

Loads an image from an input stream.

If the file can't be loaded, this function returns false and logs an error using wxLogError(). If the file can be loaded but some problems were detected while doing it, it can also call wxLogWarning() to notify about these problems. If this is undesirable, use SetLoadFlags() to reset Load_Verbose flag and suppress these warnings.

Parameters

stream	Opened input stream from which to load the image. Currently, the stream must support seeking.
type	May be one of the following: wxBITMAP_TYPE_BMP: Load a Windows bitmap file. wxBITMAP_TYPE_GIF: Load a GIF bitmap file. wxBITMAP_TYPE_JPEG: Load a JPEG bitmap file. wxBITMAP_TYPE_PNG: Load a PNG bitmap file. wxBITMAP_TYPE_PCX: Load a PCX bitmap file. wxBITMAP_TYPE_PNM: Load a PNM bitmap file. wxBITMAP_TYPE_TIFF: Load a TIFF bitmap file. wxBITMAP_TYPE_TGA: Load a TGA bitmap file. wxBITMAP_TYPE_XPM: Load a XPM bitmap file. wxBITMAP_TYPE_ICO: Load a Windows icon file (ICO). wxBITMAP_TYPE_CUR: Load a Windows cursor file (CUR). wxBITMAP_TYPE_ANI: Load a Windows animated cursor file (ANI). wxBITMAP_TYPE_ANY: Will try to autodetect the format.
index	Index of the image to load in the case that the image file contains multiple images. This is only used by GIF, ICO and TIFF handlers. The default value (-1) means "choose the default image" and is interpreted as the first image (index=0) by the GIF and TIFF handler and as the largest and most colourful one by the ICO handler.

Returns: true if the operation succeeded, false otherwise. If the optional index parameter is out of range, false is returned and a call to wxLogError() takes place.

Remarks: Depending on how wxWidgets has been configured, not all formats may be available.

Note: You can use GetOptionInt() to get the hotspot when loading cursor files:
int hotspot_x = image.GetOptionInt(wxIMAGE_OPTION_CUR_HOTSPOT_X);
int hotspot_y = image.GetOptionInt(wxIMAGE_OPTION_CUR_HOTSPOT_Y);

See also: SaveFile()

virtual bool wxImage::LoadFile	(	const wxString &	name,
		wxBitmapType	type = `wxBITMAP_TYPE_ANY`,
		int	index = `-1`
	)

virtual

Loads an image from a file.

If no handler type is provided, the library will try to autodetect the format.

Parameters

name	Name of the file from which to load the image.
type	See the description in the LoadFile(wxInputStream&, wxBitmapType, int) overload.
index	See the description in the LoadFile(wxInputStream&, wxBitmapType, int) overload.

virtual bool wxImage::LoadFile	(	const wxString &	name,
		const wxString &	mimetype,
		int	index = `-1`
	)

virtual

Loads an image from a file.

If no handler type is provided, the library will try to autodetect the format.

Parameters

name	Name of the file from which to load the image.
mimetype	MIME type string (for example 'image/jpeg')
index	See the description in the LoadFile(wxInputStream&, wxBitmapType, int) overload.

virtual bool wxImage::LoadFile	(	wxInputStream &	stream,
		const wxString &	mimetype,
		int	index = `-1`
	)

virtual

Loads an image from an input stream.

Parameters

stream	Opened input stream from which to load the image. Currently, the stream must support seeking.
mimetype	MIME type string (for example 'image/jpeg')
index	See the description in the LoadFile(wxInputStream&, wxBitmapType, int) overload.

wxImage wxImage::Mirror ( bool horizontally = true ) const

Returns a mirrored copy of the image.

The parameter horizontally indicates the orientation.

wxImage& wxImage::operator= ( const wxImage & image )

Assignment operator, using reference counting.

Parameters

image Image to assign.

Returns: Returns 'this' object.

void wxImage::Paste	(	const wxImage &	image,
		int	x,
		int	y
	)

Copy the data of the given image to the specified position in this image.

static bool wxImage::RemoveHandler ( const wxString & name )

static

Finds the handler with the given name, and removes it.

The handler is also deleted.

Parameters

name	The handler name.

Returns: true if the handler was found and removed, false otherwise.

See also: wxImageHandler

void wxImage::Replace	(	unsigned char	r1,
		unsigned char	g1,
		unsigned char	b1,
		unsigned char	r2,
		unsigned char	g2,
		unsigned char	b2
	)

Replaces the colour specified by r1,g1,b1 by the colour r2,g2,b2.

wxImage& wxImage::Rescale	(	int	width,
		int	height,
		wxImageResizeQuality	quality = `wxIMAGE_QUALITY_NORMAL`
	)

Changes the size of the image in-place by scaling it: after a call to this function,the image will have the given width and height.

For a description of the quality parameter, see the Scale() function. Returns the (modified) image itself.

See also: Scale()

wxImage& wxImage::Resize	(	const wxSize &	size,
		const wxPoint &	pos,
		int	red = `-1`,
		int	green = `-1`,
		int	blue = `-1`
	)

Changes the size of the image in-place without scaling it by adding either a border with the given colour or cropping as necessary.

The image is pasted into a new image with the given size and background colour at the position pos relative to the upper left of the new image.

If red = green = blue = -1 then use either the current mask colour if set or find, use, and set a suitable mask colour for any newly exposed areas.

Returns: The (modified) image itself.

See also: Size()

static wxImage::HSVValue wxImage::RGBtoHSV ( const wxImage::RGBValue & rgb )

static

Converts a color in RGB color space to HSV color space.

wxImage wxImage::Rotate	(	double	angle,
		const wxPoint &	rotationCentre,
		bool	interpolating = `true`,
		wxPoint *	offsetAfterRotation = `NULL`
	)		const

Rotates the image about the given point, by angle radians.

Passing true to interpolating results in better image quality, but is slower.

If the image has a mask, then the mask colour is used for the uncovered pixels in the rotated image background. Else, black (rgb 0, 0, 0) will be used.

Returns the rotated image, leaving this image intact.

wxImage wxImage::Rotate180 ( ) const

Returns a copy of the image rotated by 180 degrees.

Since: 2.9.2

wxImage wxImage::Rotate90 ( bool clockwise = true ) const

Returns a copy of the image rotated 90 degrees in the direction indicated by clockwise.

void wxImage::RotateHue ( double angle )

Rotates the hue of each pixel in the image by angle, which is a double in the range of -1.0 to +1.0, where -1.0 corresponds to -360 degrees and +1.0 corresponds to +360 degrees.

virtual bool wxImage::SaveFile	(	wxOutputStream &	stream,
		const wxString &	mimetype
	)		const

virtual

Saves an image in the given stream.

Parameters

stream	Opened output stream to save the image to.
mimetype	MIME type.

Returns: true if the operation succeeded, false otherwise.

Remarks: Depending on how wxWidgets has been configured, not all formats may be available.

Note: You can use SetOption() to set the hotspot when saving an image into a cursor file (default hotspot is in the centre of the image):
image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_X, hotspotX);
image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_Y, hotspotY);

See also: LoadFile()

virtual bool wxImage::SaveFile	(	const wxString &	name,
		wxBitmapType	type
	)		const

virtual

Saves an image in the named file.

Parameters

name Name of the file to save the image to.

type

Currently these types can be used:

wxBITMAP_TYPE_BMP: Save a BMP image file.
wxBITMAP_TYPE_JPEG: Save a JPEG image file.
wxBITMAP_TYPE_PNG: Save a PNG image file.
wxBITMAP_TYPE_PCX: Save a PCX image file (tries to save as 8-bit if possible, falls back to 24-bit otherwise).
wxBITMAP_TYPE_PNM: Save a PNM image file (as raw RGB always).
wxBITMAP_TYPE_TIFF: Save a TIFF image file.
wxBITMAP_TYPE_XPM: Save a XPM image file.
wxBITMAP_TYPE_ICO: Save a Windows icon file (ICO). The size may be up to 255 wide by 127 high. A single image is saved in 8 colors at the size supplied.
wxBITMAP_TYPE_CUR: Save a Windows cursor file (CUR).

virtual bool wxImage::SaveFile	(	const wxString &	name,
		const wxString &	mimetype
	)		const

virtual

Saves an image in the named file.

Parameters

name	Name of the file to save the image to.
mimetype	MIME type.

virtual bool wxImage::SaveFile ( const wxString & name ) const

virtual

Saves an image in the named file.

File type is determined from the extension of the file name. Note that this function may fail if the extension is not recognized! You can use one of the forms above to save images to files with non-standard extensions.

Parameters

name	Name of the file to save the image to.

virtual bool wxImage::SaveFile	(	wxOutputStream &	stream,
		wxBitmapType	type
	)		const

virtual

Saves an image in the given stream.

Parameters

stream	Opened output stream to save the image to.
type	MIME type.

wxImage wxImage::Scale	(	int	width,
		int	height,
		wxImageResizeQuality	quality = `wxIMAGE_QUALITY_NORMAL`
	)		const

Returns a scaled version of the image.

This is also useful for scaling bitmaps in general as the only other way to scale bitmaps is to blit a wxMemoryDC into another wxMemoryDC.

The parameter quality determines what method to use for resampling the image, see wxImageResizeQuality documentation.

It should be noted that although using wxIMAGE_QUALITY_HIGH produces much nicer looking results it is a slower method. Downsampling will use the box averaging method which seems to operate very fast. If you are upsampling larger images using this method you will most likely notice that it is a bit slower and in extreme cases it will be quite substantially slower as the bicubic algorithm has to process a lot of data.

It should also be noted that the high quality scaling may not work as expected when using a single mask colour for transparency, as the scaling will blur the image and will therefore remove the mask partially. Using the alpha channel will work.

Example:

// get the bitmap from somewhere
wxBitmap bmp = ...;
// rescale it to have size of 32*32
if ( bmp.GetWidth() != 32 || bmp.GetHeight() != 32 )
{
    wxImage image = bmp.ConvertToImage();
    bmp = wxBitmap(image.Scale(32, 32));
    // another possibility:
    image.Rescale(32, 32);
    bmp = image;
}

See also: Rescale()

void wxImage::SetAlpha	(	unsigned char *	alpha = `NULL`,
		bool	static_data = `false`
	)

This function is similar to SetData() and has similar restrictions.

The pointer passed to it may however be NULL in which case the function will allocate the alpha array internally – this is useful to add alpha channel data to an image which doesn't have any.

If the pointer is not NULL, it must have one byte for each image pixel and be allocated with malloc(). wxImage takes ownership of the pointer and will free it unless static_data parameter is set to true – in this case the caller should do it.

void wxImage::SetAlpha	(	int	x,
		int	y,
		unsigned char	alpha
	)

Sets the alpha value for the given pixel.

This function should only be called if the image has alpha channel data, use HasAlpha() to check for this.

void wxImage::SetData	(	unsigned char *	data,
		bool	static_data = `false`
	)

Sets the image data without performing checks.

The data given must have the size (width*height*3) or results will be unexpected. Don't use this method if you aren't sure you know what you are doing.

The data must have been allocated with malloc(), NOT with operator new.

If static_data is false, after this call the pointer to the data is owned by the wxImage object, that will be responsible for deleting it. Do not pass to this function a pointer obtained through GetData().

void wxImage::SetData	(	unsigned char *	data,
		int	new_width,
		int	new_height,
		bool	static_data = `false`
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

static void wxImage::SetDefaultLoadFlags ( int flags )

static

Sets the default value for the flags used for loading image files.

This method changes the global value of the flags used for all the subsequently created wxImage objects by default. It doesn't affect the already existing objects.

By default, the global flags include Load_Verbose flag value.

See also: LoadFile(), SetLoadFlags(), GetDefaultLoadFlags()

Since: 3.1.0

void wxImage::SetLoadFlags ( int flags )

Sets the flags used for loading image files by this object.

The flags will affect any future calls to LoadFile() for this object. To change the flags for all image objects, call SetDefaultLoadFlags() before creating any of them.

Currently the only defined flag is Load_Verbose which determines if the non-fatal (i.e. not preventing the file from being loaded completely) problems should result in the calls to wxLogWarning() function. It is recommended to customize handling of these warnings by e.g. defining a custom log target (see Logging Overview), but if such warnings should be completely suppressed, clearing this flag provides a simple way to do it, for example:

wxImage image;
image.SetLoadFlags(image.GetLoadFlags() & ~wxImage::Load_Verbose);
image.LoadFile(...);

See also: LoadFile(), SetLoadFlags(), GetLoadFlags()

Since: 3.1.0

void wxImage::SetMask ( bool hasMask = true )

Specifies whether there is a mask or not.

The area of the mask is determined by the current mask colour.

void wxImage::SetMaskColour	(	unsigned char	red,
		unsigned char	green,
		unsigned char	blue
	)

Sets the mask colour for this image (and tells the image to use the mask).

bool wxImage::SetMaskFromImage	(	const wxImage &	mask,
		unsigned char	mr,
		unsigned char	mg,
		unsigned char	mb
	)

Sets image's mask so that the pixels that have RGB value of mr,mg,mb in mask will be masked in the image.

This is done by first finding an unused colour in the image, setting this colour as the mask colour and then using this colour to draw all pixels in the image who corresponding pixel in mask has given RGB value.

The parameter mask is the mask image to extract mask shape from. It must have the same dimensions as the image.

The parameters mr, mg, mb are the RGB values of the pixels in mask that will be used to create the mask.

Returns: Returns false if mask does not have same dimensions as the image or if there is no unused colour left. Returns true if the mask was successfully applied.

Note: Note that this method involves computing the histogram, which is a computationally intensive operation.

void wxImage::SetOption	(	const wxString &	name,
		const wxString &	value
	)

Sets a user-defined option.

The function is case-insensitive to name.

For example, when saving as a JPEG file, the option quality is used, which is a number between 0 and 100 (0 is terrible, 100 is very good).

The lists of the currently supported options are in GetOption() and GetOptionInt() function docs.

See also: GetOption(), GetOptionInt(), HasOption()

void wxImage::SetOption	(	const wxString &	name,
		int	value
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

void wxImage::SetPalette ( const wxPalette & palette )

Associates a palette with the image.

The palette may be used when converting wxImage to wxBitmap (MSW only at present) or in file save operations (none as yet).

void wxImage::SetRGB	(	int	x,
		int	y,
		unsigned char	r,
		unsigned char	g,
		unsigned char	b
	)

Set the color of the pixel at the given x and y coordinate.

void wxImage::SetRGB	(	const wxRect &	rect,
		unsigned char	red,
		unsigned char	green,
		unsigned char	blue
	)

Sets the colour of the pixels within the given rectangle.

This routine performs bounds-checks for the coordinate so it can be considered a safe way to manipulate the data.

void wxImage::SetType ( wxBitmapType type )

Set the type of image returned by GetType().

This method is mostly used internally by the library but can also be called from the user code if the image was created from data in the given bitmap format without using LoadFile() (which would set the type correctly automatically).

Notice that the image must be created before this function is called.

Since: 2.9.0

Parameters

type	One of bitmap type constants, `wxBITMAP_TYPE_INVALID` is a valid value for it and can be used to reset the bitmap type to default but `wxBITMAP_TYPE_MAX` is not allowed here.

wxImage wxImage::Size	(	const wxSize &	size,
		const wxPoint &	pos,
		int	red = `-1`,
		int	green = `-1`,
		int	blue = `-1`
	)		const

Returns a resized version of this image without scaling it by adding either a border with the given colour or cropping as necessary.

The image is pasted into a new image with the given size and background colour at the position pos relative to the upper left of the new image.

If red = green = blue = -1 then the areas of the larger image not covered by this image are made transparent by filling them with the image mask colour (which will be allocated automatically if it isn't currently set).

Otherwise, the areas will be filled with the colour with the specified RGB components.

See also: Resize()

Detailed Description

Alpha channel support

Available image handlers

Setters

Classes

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Constructor & Destructor Documentation

Member Function Documentation