1 \section{\class{wxImage
}}\label{wximage
}
3 This class encapsulates a platform-independent image. An image can be created
4 from data, or using
\helpref{wxBitmap::ConvertToImage
}{wxbitmapconverttoimage
}. An image
5 can be loaded from a file in a variety of formats, and is extensible to new formats
6 via image format handlers. Functions are available to set and get image bits, so
7 it can be used for basic image manipulation.
9 A wxImage cannot (currently) be drawn directly to a
\helpref{wxDC
}{wxdc
}. Instead,
10 a platform-specific
\helpref{wxBitmap
}{wxbitmap
} object must be created from it using
11 the
\helpref{wxBitmap::wxBitmap(wxImage,int depth)
}{wxbitmapconstr
} constructor.
13 be drawn in a device context, using
\helpref{wxDC::DrawBitmap
}{wxdcdrawbitmap
}.
15 One colour value of the image may be used as a mask colour which will lead to the automatic
16 creation of a
\helpref{wxMask
}{wxmask
} object associated to the bitmap object.
18 \wxheading{Alpha channel support
}
20 Starting from wxWindows
2.5.0 wxImage supports alpha channel data, that is in
21 addition to a byte for the red, green and blue colour components for each pixel
22 it also stores a byte representing the pixel opacity. The alpha value of $
0$
23 corresponds to a transparent pixel (null opacity) while the value of $
255$
24 means that the pixel is
100\% opaque.
26 Unlike the RGB data, not all images have the alpha channel and before using
27 \helpref{GetAlpha
}{wximagegetalpha
} you should check if this image contains
28 alpha value with
\helpref{HasAlpha
}{wximagehasalpha
}. In fact, currently only
29 images loaded from PNG files with transparency information will have alpha
30 channel but support for it will be added to the other formats as well (as well
31 as support for saving images with alpha channel which is not still implemented
34 \wxheading{Available image handlers
}
36 The following image handlers are available.
{\bf wxBMPHandler
} is always
37 installed by default. To use other image formats, install the appropriate
38 handler with
\helpref{wxImage::AddHandler
}{wximageaddhandler
} or
39 \helpref{wxInitAllImageHandlers
}{wxinitallimagehandlers
}.
43 \twocolitem{\indexit{wxBMPHandler
}}{For loading and saving, always installed.
}
44 \twocolitem{\indexit{wxPNGHandler
}}{For loading (including alpha support) and saving.
}
45 \twocolitem{\indexit{wxJPEGHandler
}}{For loading and saving.
}
46 \twocolitem{\indexit{wxGIFHandler
}}{Only for loading, due to legal issues.
}
47 \twocolitem{\indexit{wxPCXHandler
}}{For loading and saving (see below).
}
48 \twocolitem{\indexit{wxPNMHandler
}}{For loading and saving (see below).
}
49 \twocolitem{\indexit{wxTIFFHandler
}}{For loading and saving.
}
50 \twocolitem{\indexit{wxIFFHandler
}}{For loading only.
}
51 \twocolitem{\indexit{wxXPMHandler
}}{For loading and saving.
}
52 \twocolitem{\indexit{wxICOHandler
}}{For loading and saving.
}
53 \twocolitem{\indexit{wxCURHandler
}}{For loading and saving.
}
54 \twocolitem{\indexit{wxANIHandler
}}{For loading only.
}
57 When saving in PCX format,
{\bf wxPCXHandler
} will count the number of
58 different colours in the image; if there are
256 or less colours, it will
59 save as
8 bit, else it will save as
24 bit.
61 Loading PNMs only works for ASCII or raw RGB images. When saving in
62 PNM format,
{\bf wxPNMHandler
} will always save as raw RGB.
64 \wxheading{Derived from
}
66 \helpref{wxObject
}{wxobject
}
68 \wxheading{Include files
}
74 \helpref{wxBitmap
}{wxbitmap
},
75 \helpref{wxInitAllImageHandlers
}{wxinitallimagehandlers
}
77 \latexignore{\rtfignore{\wxheading{Members
}}}
79 \membersection{wxImage::wxImage
}\label{wximageconstr
}
81 \func{}{wxImage
}{\void}
85 \func{}{wxImage
}{\param{const wxImage\&
}{image
}}
89 \func{}{wxImage
}{\param{const wxBitmap\&
}{ bitmap
}}
91 (Deprecated form, use
\helpref{wxBitmap::ConvertToImage
}{wxbitmapconverttoimage
}
92 instead.) Constructs an image from a platform-dependent bitmap. This preserves
93 mask information so that bitmaps and images can be converted back
94 and forth without loss in that respect.
96 \func{}{wxImage
}{\param{int
}{ width
},
\param{int
}{ height
}}
98 Creates an image with the given width and height.
100 \func{}{wxImage
}{\param{int
}{ width
},
\param{int
}{ height
},
\param{unsigned char*
}{ data
},
\param{bool
}{ static
\_data=false
}}
102 Creates an image from given data with the given width and height. If
103 {\it static
\_data} is true, then wxImage will not delete the actual
104 image data in its destructor, otherwise it will free it by calling
107 \func{}{wxImage
}{\param{const wxString\&
}{name
},
\param{long
}{ type = wxBITMAP
\_TYPE\_ANY},
\param{int
}{ index = -
1}}
109 \func{}{wxImage
}{\param{const wxString\&
}{name
},
\param{const wxString\&
}{ mimetype
},
\param{int
}{ index = -
1}}
111 Loads an image from a file.
113 \func{}{wxImage
}{\param{wxInputStream\&
}{stream
},
\param{long
}{ type = wxBITMAP
\_TYPE\_ANY},
\param{int
}{ index = -
1}}
115 \func{}{wxImage
}{\param{wxInputStream\&
}{stream
},
\param{const wxString\&
}{ mimetype
},
\param{int
}{ index = -
1}}
117 Loads an image from an input stream.
119 \wxheading{Parameters
}
121 \docparam{width
}{Specifies the width of the image.
}
123 \docparam{height
}{Specifies the height of the image.
}
125 \docparam{name
}{Name of the file from which to load the image.
}
127 \docparam{stream
}{Opened input stream from which to load the image. Currently, the stream must support seeking.
}
129 \docparam{type
}{May be one of the following:
133 \twocolitem{\indexit{wxBITMAP
\_TYPE\_BMP}}{Load a Windows bitmap file.
}
134 \twocolitem{\indexit{wxBITMAP
\_TYPE\_GIF}}{Load a GIF bitmap file.
}
135 \twocolitem{\indexit{wxBITMAP
\_TYPE\_JPEG}}{Load a JPEG bitmap file.
}
136 \twocolitem{\indexit{wxBITMAP
\_TYPE\_PNG}}{Load a PNG bitmap file.
}
137 \twocolitem{\indexit{wxBITMAP
\_TYPE\_PCX}}{Load a PCX bitmap file.
}
138 \twocolitem{\indexit{wxBITMAP
\_TYPE\_PNM}}{Load a PNM bitmap file.
}
139 \twocolitem{\indexit{wxBITMAP
\_TYPE\_TIF}}{Load a TIFF bitmap file.
}
140 \twocolitem{\indexit{wxBITMAP
\_TYPE\_XPM}}{Load a XPM bitmap file.
}
141 \twocolitem{\indexit{wxBITMAP
\_TYPE\_ICO}}{Load a Windows icon file (ICO).
}
142 \twocolitem{\indexit{wxBITMAP
\_TYPE\_CUR}}{Load a Windows cursor file (CUR).
}
143 \twocolitem{\indexit{wxBITMAP
\_TYPE\_ANI}}{Load a Windows animated cursor file (ANI).
}
144 \twocolitem{\indexit{wxBITMAP
\_TYPE\_ANY}}{Will try to autodetect the format.
}
147 \docparam{mimetype
}{MIME type string (for example 'image/jpeg')
}
149 \docparam{index
}{Index of the image to load in the case that the image file contains multiple images.
150 This is only used by GIF, ICO and TIFF handlers. The default value (-
1) means
151 "choose the default image" and is interpreted as the first image (index=
0) by
152 the GIF and TIFF handler and as the largest and most colourful one by the ICO handler.
}
156 Depending on how wxWindows has been configured, not all formats may be available.
158 Note: any handler other than BMP must be previously
159 initialized with
\helpref{wxImage::AddHandler
}{wximageaddhandler
} or
160 \helpref{wxInitAllImageHandlers
}{wxinitallimagehandlers
}.
162 Note: you can use
\helpref{GetOptionInt
}{wximagegetoptionint
} to get the
163 hotspot for loaded cursor file:
165 int hotspot_x = image.GetOptionInt(wxIMAGE_OPTION_CUR_HOTSPOT_X);
166 int hotspot_y = image.GetOptionInt(wxIMAGE_OPTION_CUR_HOTSPOT_Y);
172 \helpref{wxImage::LoadFile
}{wximageloadfile
}
174 \pythonnote{Constructors supported by wxPython are:
\par
175 \indented{2cm
}{\begin{twocollist
}
176 \twocolitem{{\bf wxImage(name, flag)
}}{Loads an image from a file
}
177 \twocolitem{{\bf wxNullImage()
}}{Create a null image (has no size or
179 \twocolitem{{\bf wxEmptyImage(width, height)
}}{Creates an empty image
181 \twocolitem{{\bf wxImageFromMime(name, mimetype
}}{Creates an image from
182 the given file of the given mimetype
}
183 \twocolitem{{\bf wxImageFromBitmap(bitmap)
}}{Creates an image from a
184 platform-dependent bitmap
}
188 \perlnote{Constructors supported by wxPerl are:
\par
190 \item{Wx::Image->new( bitmap )
}
191 \item{Wx::Image->new( width, height )
}
192 \item{Wx::Image->new( name, type )
}
193 \item{Wx::Image->new( name, mimetype )
}
197 \membersection{wxImage::
\destruct{wxImage
}}
199 \func{}{\destruct{wxImage
}}{\void}
203 \membersection{wxImage::AddHandler
}\label{wximageaddhandler
}
205 \func{static void
}{AddHandler
}{\param{wxImageHandler*
}{ handler
}}
207 Adds a handler to the end of the static list of format handlers.
209 \docparam{handler
}{A new image format handler object. There is usually only one instance
210 of a given handler class in an application session.
}
214 \helpref{wxImageHandler
}{wximagehandler
}
216 \func{bool
}{CanRead
}{\param{const wxString\&
}{ filename
}}
218 returns true if the current image handlers can read this file
220 \pythonnote{In wxPython this static method is named
{\tt wxImage
\_AddHandler}.
}
221 \membersection{wxImage::CleanUpHandlers
}
223 \func{static void
}{CleanUpHandlers
}{\void}
225 Deletes all image handlers.
227 This function is called by wxWindows on exit.
229 \membersection{wxImage::ComputeHistogram
}\label{wximagecomputehistogram
}
231 \constfunc{unsigned long
}{ComputeHistogram
}{\param{wxImageHistogram\&
}{histogram
}}
233 Computes the histogram of the image.
{\it histogram
} is a reference to
234 wxImageHistogram object. wxImageHistogram is a specialization of
235 \helpref{wxHashMap
}{wxhashmap
} "template" and is defined as follows:
238 class WXDLLEXPORT wxImageHistogramEntry
241 wxImageHistogramEntry() : index(
0), value(
0)
{}
246 WX_DECLARE_EXPORTED_HASH_MAP(unsigned long, wxImageHistogramEntry,
247 wxIntegerHash, wxIntegerEqual,
251 \wxheading{Return value
}
253 Returns number of colours in the histogram.
255 \membersection{wxImage::ConvertToBitmap
}\label{wximageconverttobitmap
}
257 \constfunc{wxBitmap
}{ConvertToBitmap
}{\void}
259 Deprecated, use equivalent
\helpref{wxBitmap constructor
}{wxbitmapconstr
}
260 (which takes wxImage and depth as its arguments) instead.
262 \membersection{wxImage::ConvertToMono
}\label{wxbitmapconverttomono
}
264 \constfunc{wxImage
}{ConvertToMono
}{\param{unsigned char
}{ r
},
\param{unsigned char
}{ g
},
\param{unsigned char
}{ b
}}
266 Returns monochromatic version of the image. The returned image has white
267 colour where the original has
{\it (r,g,b)
} colour and black colour
270 \membersection{wxImage::Copy
}\label{wximagecopy
}
272 \constfunc{wxImage
}{Copy
}{\void}
274 Returns an identical copy of the image.
276 \membersection{wxImage::Create
}\label{wximagecreate
}
278 \func{bool
}{Create
}{\param{int
}{ width
},
\param{int
}{ height
}}
280 Creates a fresh image.
282 \wxheading{Parameters
}
284 \docparam{width
}{The width of the image in pixels.
}
286 \docparam{height
}{The height of the image in pixels.
}
288 \wxheading{Return value
}
290 true if the call succeeded, false otherwise.
292 \membersection{wxImage::Destroy
}\label{wximagedestroy
}
294 \func{bool
}{Destroy
}{\void}
296 Destroys the image data.
298 \membersection{wxImage::FindFirstUnusedColour
}\label{wximagefindfirstunusedcolour
}
300 \func{bool
}{FindFirstUnusedColour
}{\param{unsigned char *
}{ r
},
\param{unsigned char *
}{ g
},
\param{unsigned char *
}{ b
},
\param{unsigned char
}{ startR =
1},
\param{unsigned char
}{ startG =
0},
\param{unsigned char
}{ startB =
0}}
302 \wxheading{Parameters
}
304 \docparam{r,g,b
}{Pointers to variables to save the colour.
}
306 \docparam{startR,startG,startB
}{Initial values of the colour. Returned colour
307 will have RGB values equal to or greater than these.
}
309 Finds the first colour that is never used in the image. The search begins at
310 given initial colour and continues by increasing R, G and B components (in this
311 order) by
1 until an unused colour is found or the colour space exhausted.
313 \wxheading{Return value
}
315 Returns false if there is no unused colour left, true on success.
319 Note that this method involves computing the histogram, which is
320 computationally intensive operation.
322 \membersection{wxImage::FindHandler
}
324 \func{static wxImageHandler*
}{FindHandler
}{\param{const wxString\&
}{name
}}
326 Finds the handler with the given name.
328 \func{static wxImageHandler*
}{FindHandler
}{\param{const wxString\&
}{extension
},
\param{long
}{ imageType
}}
330 Finds the handler associated with the given extension and type.
332 \func{static wxImageHandler*
}{FindHandler
}{\param{long
}{imageType
}}
334 Finds the handler associated with the given image type.
336 \func{static wxImageHandler*
}{FindHandlerMime
}{\param{const wxString\&
}{mimetype
}}
338 Finds the handler associated with the given MIME type.
340 \docparam{name
}{The handler name.
}
342 \docparam{extension
}{The file extension, such as ``bmp".
}
344 \docparam{imageType
}{The image type, such as wxBITMAP
\_TYPE\_BMP.
}
346 \docparam{mimetype
}{MIME type.
}
348 \wxheading{Return value
}
350 A pointer to the handler if found, NULL otherwise.
354 \helpref{wxImageHandler
}{wximagehandler
}
356 \membersection{wxImage::GetAlpha
}\label{wximagegetalpha
}
358 \constfunc{unsigned char
}{GetAlpha
}{\param{int
}{ x
},
\param{int
}{ y
}}
360 Returns the alpha value for the given pixel. This function may only be called
361 for the images with alpha channel, use
\helpref{HasAlpha
}{wximagehasalpha
} to
364 The returned value is the
{\it opacity
} of the image, i.e. the value of $
0$
365 corresponds to the transparent pixels while the value of $
255$ -- to the opaque
368 \constfunc{unsigned char *
}{GetAlpha
}{\void}
370 Returns pointer to the array storing the alpha values for this image. This
371 pointer is
{\tt NULL
} for the images without the alpha channel. If the image
372 does have it, this pointer may be used to directly manipulate the alpha values
373 which are stored as the
\helpref{RGB
}{wximagegetdata
} ones.
375 \membersection{wxImage::GetBlue
}\label{wximagegetblue
}
377 \constfunc{unsigned char
}{GetBlue
}{\param{int
}{ x
},
\param{int
}{ y
}}
379 Returns the blue intensity at the given coordinate.
381 \membersection{wxImage::GetData
}\label{wximagegetdata
}
383 \constfunc{unsigned char*
}{GetData
}{\void}
385 Returns the image data as an array. This is most often used when doing
386 direct image manipulation. The return value points to an array of
387 characters in RGBRGBRGB$
\ldots$ format in the top-to-bottom, left-to-right
388 order, that is the first RGB triplet corresponds to the pixel $(
0,
0)$, the
389 second one --- to $(
0,
1)$ and so on.
391 You should not delete the returned pointer nor pass it to
392 \helpref{wxImage::SetData
}{wximagesetdata
}.
394 \membersection{wxImage::GetGreen
}\label{wximagegetgreen
}
396 \constfunc{unsigned char
}{GetGreen
}{\param{int
}{ x
},
\param{int
}{ y
}}
398 Returns the green intensity at the given coordinate.
400 \membersection{wxImage::GetImageCount
}\label{wximagegetimagecount
}
402 \func{static int
}{GetImageCount
}{\param{const wxString\&
}{ filename
},
\param{long
}{ type = wxBITMAP
\_TYPE\_ANY}}
404 \func{static int
}{GetImageCount
}{\param{wxInputStream\&
}{ stream
},
\param{long
}{ type = wxBITMAP
\_TYPE\_ANY}}
406 If the image file contains more than one image and the image handler is capable
407 of retrieving these individually, this function will return the number of
410 \docparam{name
}{Name of the file to query.
}
412 \docparam{stream
}{Opened input stream with image data. Currently, the stream must support seeking.
}
414 \docparam{type
}{May be one of the following:
418 \twocolitem{\indexit{wxBITMAP
\_TYPE\_BMP}}{Load a Windows bitmap file.
}
419 \twocolitem{\indexit{wxBITMAP
\_TYPE\_GIF}}{Load a GIF bitmap file.
}
420 \twocolitem{\indexit{wxBITMAP
\_TYPE\_JPEG}}{Load a JPEG bitmap file.
}
421 \twocolitem{\indexit{wxBITMAP
\_TYPE\_PNG}}{Load a PNG bitmap file.
}
422 \twocolitem{\indexit{wxBITMAP
\_TYPE\_PCX}}{Load a PCX bitmap file.
}
423 \twocolitem{\indexit{wxBITMAP
\_TYPE\_PNM}}{Load a PNM bitmap file.
}
424 \twocolitem{\indexit{wxBITMAP
\_TYPE\_TIF}}{Load a TIFF bitmap file.
}
425 \twocolitem{\indexit{wxBITMAP
\_TYPE\_XPM}}{Load a XPM bitmap file.
}
426 \twocolitem{\indexit{wxBITMAP
\_TYPE\_ICO}}{Load a Windows icon file (ICO).
}
427 \twocolitem{\indexit{wxBITMAP
\_TYPE\_CUR}}{Load a Windows cursor file (CUR).
}
428 \twocolitem{\indexit{wxBITMAP
\_TYPE\_ANI}}{Load a Windows animated cursor file (ANI).
}
429 \twocolitem{\indexit{wxBITMAP
\_TYPE\_ANY}}{Will try to autodetect the format.
}
432 \wxheading{Return value
}
434 Number of available images. For most image handlers, this is
1 (exceptions
435 are TIFF and ICO formats).
437 \membersection{wxImage::GetHandlers
}
439 \func{static wxList\&
}{GetHandlers
}{\void}
441 Returns the static list of image format handlers.
445 \helpref{wxImageHandler
}{wximagehandler
}
447 \membersection{wxImage::GetHeight
}\label{wximagegetheight
}
449 \constfunc{int
}{GetHeight
}{\void}
451 Gets the height of the image in pixels.
453 \membersection{wxImage::GetMaskBlue
}\label{wximagegetmaskblue
}
455 \constfunc{unsigned char
}{GetMaskBlue
}{\void}
457 Gets the blue value of the mask colour.
459 \membersection{wxImage::GetMaskGreen
}\label{wximagegetmaskgreen
}
461 \constfunc{unsigned char
}{GetMaskGreen
}{\void}
463 Gets the green value of the mask colour.
465 \membersection{wxImage::GetMaskRed
}\label{wximagegetmaskred
}
467 \constfunc{unsigned char
}{GetMaskRed
}{\void}
469 Gets the red value of the mask colour.
471 \membersection{wxImage::GetPalette
}\label{wximagegetpalette
}
473 \constfunc{const wxPalette\&
}{GetPalette
}{\void}
475 Returns the palette associated with the image. Currently the palette is only
476 used when converting to wxBitmap under Windows.
478 Eventually wxImage handlers will set the palette if one exists in the image file.
480 \membersection{wxImage::GetRed
}\label{wximagegetred
}
482 \constfunc{unsigned char
}{GetRed
}{\param{int
}{ x
},
\param{int
}{ y
}}
484 Returns the red intensity at the given coordinate.
486 \membersection{wxImage::GetSubImage
}\label{wximagegetsubimage
}
488 \constfunc{wxImage
}{GetSubImage
}{\param{const wxRect\&
}{ rect
}}
490 Returns a sub image of the current one as long as the rect belongs entirely to
493 \membersection{wxImage::GetWidth
}\label{wximagegetwidth
}
495 \constfunc{int
}{GetWidth
}{\void}
497 Gets the width of the image in pixels.
501 \helpref{wxImage::GetHeight
}{wximagegetheight
}
503 \membersection{wxImage::HasAlpha
}\label{wximagehasalpha
}
505 \constfunc{bool
}{HasAlpha
}{\void}
507 Returns true if this image has alpha channel, false otherwise.
511 \helpref{GetAlpha
}{wximagegetalpha
},
\helpref{SetAlpha
}{wximagesetalpha
}
513 \membersection{wxImage::HasMask
}\label{wximagehasmask
}
515 \constfunc{bool
}{HasMask
}{\void}
517 Returns true if there is a mask active, false otherwise.
519 \membersection{wxImage::GetOption
}\label{wximagegetoption
}
521 \constfunc{wxString
}{GetOption
}{\param{const wxString\&
}{ name
}}
523 Gets a user-defined option. The function is case-insensitive to
{\it name
}.
525 For example, when saving as a JPEG file, the option
{\bf quality
} is
526 used, which is a number between
0 and
100 (
0 is terrible,
100 is very good).
530 \helpref{wxImage::SetOption
}{wximagesetoption
},
\rtfsp
531 \helpref{wxImage::GetOptionInt
}{wximagegetoptionint
},
\rtfsp
532 \helpref{wxImage::HasOption
}{wximagehasoption
}
534 \membersection{wxImage::GetOptionInt
}\label{wximagegetoptionint
}
536 \constfunc{int
}{GetOptionInt
}{\param{const wxString\&
}{ name
}}
538 Gets a user-defined option as an integer. The function is case-insensitive to
{\it name
}.
542 \helpref{wxImage::SetOption
}{wximagesetoption
},
\rtfsp
543 \helpref{wxImage::GetOption
}{wximagegetoption
},
\rtfsp
544 \helpref{wxImage::HasOption
}{wximagehasoption
}
546 \membersection{wxImage::HasOption
}\label{wximagehasoption
}
548 \constfunc{bool
}{HasOption
}{\param{const wxString\&
}{ name
}}
550 Returns true if the given option is present. The function is case-insensitive to
{\it name
}.
554 \helpref{wxImage::SetOption
}{wximagesetoption
},
\rtfsp
555 \helpref{wxImage::GetOption
}{wximagegetoption
},
\rtfsp
556 \helpref{wxImage::GetOptionInt
}{wximagegetoptionint
}
558 \membersection{wxImage::InitStandardHandlers
}
560 \func{static void
}{InitStandardHandlers
}{\void}
562 Internal use only. Adds standard image format handlers. It only install BMP
563 for the time being, which is used by wxBitmap.
565 This function is called by wxWindows on startup, and shouldn't be called by
570 \helpref{wxImageHandler
}{wximagehandler
},
571 \helpref{wxInitAllImageHandlers
}{wxinitallimagehandlers
}
573 \membersection{wxImage::InsertHandler
}
575 \func{static void
}{InsertHandler
}{\param{wxImageHandler*
}{ handler
}}
577 Adds a handler at the start of the static list of format handlers.
579 \docparam{handler
}{A new image format handler object. There is usually only one instance
580 of a given handler class in an application session.
}
584 \helpref{wxImageHandler
}{wximagehandler
}
586 \membersection{wxImage::LoadFile
}\label{wximageloadfile
}
588 \func{bool
}{LoadFile
}{\param{const wxString\&
}{ name
},
\param{long
}{ type = wxBITMAP
\_TYPE\_ANY},
\param{int
}{ index = -
1}}
590 \func{bool
}{LoadFile
}{\param{const wxString\&
}{ name
},
\param{const wxString\&
}{ mimetype
},
\param{int
}{ index = -
1}}
592 Loads an image from a file. If no handler type is provided, the library will
593 try to autodetect the format.
595 \func{bool
}{LoadFile
}{\param{wxInputStream\&
}{ stream
},
\param{long
}{ type
},
\param{int
}{ index = -
1}}
597 \func{bool
}{LoadFile
}{\param{wxInputStream\&
}{ stream
},
\param{const wxString\&
}{ mimetype
},
\param{int
}{ index = -
1}}
599 Loads an image from an input stream.
601 \wxheading{Parameters
}
603 \docparam{name
}{Name of the file from which to load the image.
}
605 \docparam{stream
}{Opened input stream from which to load the image. Currently, the stream must support seeking.
}
607 \docparam{type
}{One of the following values:
611 \twocolitem{{\bf wxBITMAP
\_TYPE\_BMP}}{Load a Windows image file.
}
612 \twocolitem{{\bf wxBITMAP
\_TYPE\_GIF}}{Load a GIF image file.
}
613 \twocolitem{{\bf wxBITMAP
\_TYPE\_JPEG}}{Load a JPEG image file.
}
614 \twocolitem{{\bf wxBITMAP
\_TYPE\_PCX}}{Load a PCX image file.
}
615 \twocolitem{{\bf wxBITMAP
\_TYPE\_PNG}}{Load a PNG image file.
}
616 \twocolitem{{\bf wxBITMAP
\_TYPE\_PNM}}{Load a PNM image file.
}
617 \twocolitem{{\bf wxBITMAP
\_TYPE\_TIF}}{Load a TIFF image file.
}
618 \twocolitem{{\bf wxBITMAP
\_TYPE\_XPM}}{Load a XPM image file.
}
619 \twocolitem{{\bf wxBITMAP
\_TYPE\_ICO}}{Load a Windows icon file (ICO).
}
620 \twocolitem{{\bf wxBITMAP
\_TYPE\_CUR}}{Load a Windows cursor file (CUR).
}
621 \twocolitem{\indexit{wxBITMAP
\_TYPE\_ANI}}{Load a Windows animated cursor file (ANI).
}
622 \twocolitem{{\bf wxBITMAP
\_TYPE\_ANY}}{Will try to autodetect the format.
}
625 \docparam{mimetype
}{MIME type string (for example 'image/jpeg')
}
627 \docparam{index
}{Index of the image to load in the case that the image file contains multiple images.
628 This is only used by GIF, ICO and TIFF handlers. The default value (-
1) means
629 "choose the default image" and is interpreted as the first image (index=
0) by
630 the GIF and TIFF handler and as the largest and most colourful one by the ICO handler.
}
634 Depending on how wxWindows has been configured, not all formats may be available.
636 Note: you can use
\helpref{GetOptionInt
}{wximagegetoptionint
} to get the
637 hotspot for loaded cursor file:
639 int hotspot_x = image.GetOptionInt(wxIMAGE_OPTION_CUR_HOTSPOT_X);
640 int hotspot_y = image.GetOptionInt(wxIMAGE_OPTION_CUR_HOTSPOT_Y);
644 \wxheading{Return value
}
646 true if the operation succeeded, false otherwise. If the optional index parameter is out of range,
647 false is returned and a call to wxLogError() takes place.
651 \helpref{wxImage::SaveFile
}{wximagesavefile
}
653 \pythonnote{In place of a single overloaded method name, wxPython
654 implements the following methods:
\par
655 \indented{2cm
}{\begin{twocollist
}
656 \twocolitem{{\bf LoadFile(filename, type)
}}{Loads an image of the given
658 \twocolitem{{\bf LoadMimeFile(filename, mimetype)
}}{Loads an image of the given
659 mimetype from a file
}
663 \perlnote{Methods supported by wxPerl are:
\par
665 \item{bitmap->LoadFile( name, type )
}
666 \item{bitmap->LoadFile( name, mimetype )
}
671 \membersection{wxImage::Ok
}\label{wximageok
}
673 \constfunc{bool
}{Ok
}{\void}
675 Returns true if image data is present.
677 \membersection{wxImage::RemoveHandler
}
679 \func{static bool
}{RemoveHandler
}{\param{const wxString\&
}{name
}}
681 Finds the handler with the given name, and removes it. The handler
684 \docparam{name
}{The handler name.
}
686 \wxheading{Return value
}
688 true if the handler was found and removed, false otherwise.
692 \helpref{wxImageHandler
}{wximagehandler
}
694 \membersection{wxImage::SaveFile
}\label{wximagesavefile
}
696 \constfunc{bool
}{SaveFile
}{\param{const wxString\&
}{name
},
\param{int
}{ type
}}
698 \constfunc{bool
}{SaveFile
}{\param{const wxString\&
}{name
},
\param{const wxString\&
}{ mimetype
}}
700 Saves an image in the named file.
702 \constfunc{bool
}{SaveFile
}{\param{const wxString\&
}{name
}}
704 Saves an image in the named file. File type is determined from the extension of the
705 file name. Note that this function may fail if the extension is not recognized! You
706 can use one of the forms above to save images to files with non-standard extensions.
708 \constfunc{bool
}{SaveFile
}{\param{wxOutputStream\&
}{stream
},
\param{int
}{ type
}}
710 \constfunc{bool
}{SaveFile
}{\param{wxOutputStream\&
}{stream
},
\param{const wxString\&
}{ mimetype
}}
712 Saves an image in the given stream.
714 \wxheading{Parameters
}
716 \docparam{name
}{Name of the file to save the image to.
}
718 \docparam{stream
}{Opened output stream to save the image to.
}
720 \docparam{type
}{Currently these types can be used:
724 \twocolitem{{\bf wxBITMAP
\_TYPE\_BMP}}{Save a BMP image file.
}
725 \twocolitem{{\bf wxBITMAP
\_TYPE\_JPEG}}{Save a JPEG image file.
}
726 \twocolitem{{\bf wxBITMAP
\_TYPE\_PNG}}{Save a PNG image file.
}
727 \twocolitem{{\bf wxBITMAP
\_TYPE\_PCX}}{Save a PCX image file (tries to save as
8-bit if possible, falls back to
24-bit otherwise).
}
728 \twocolitem{{\bf wxBITMAP
\_TYPE\_PNM}}{Save a PNM image file (as raw RGB always).
}
729 \twocolitem{{\bf wxBITMAP
\_TYPE\_TIFF}}{Save a TIFF image file.
}
730 \twocolitem{{\bf wxBITMAP
\_TYPE\_XPM}}{Save a XPM image file.
}
731 \twocolitem{{\bf 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).
}
732 \twocolitem{{\bf wxBITMAP
\_TYPE\_CUR}}{Save a Windows cursor file (CUR).
}
735 \docparam{mimetype
}{MIME type.
}
737 \wxheading{Return value
}
739 true if the operation succeeded, false otherwise.
743 Depending on how wxWindows has been configured, not all formats may be available.
745 Note: you can use
\helpref{GetOptionInt
}{wximagegetoptionint
} to set the
746 hotspot before saving an image into a cursor file (default hotspot is in
747 the centre of the image):
749 image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_X, hotspotX);
750 image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_Y, hotspotY);
756 \helpref{wxImage::LoadFile
}{wximageloadfile
}
758 \pythonnote{In place of a single overloaded method name, wxPython
759 implements the following methods:
\par
760 \indented{2cm
}{\begin{twocollist
}
761 \twocolitem{{\bf SaveFile(filename, type)
}}{Saves the image using the given
762 type to the named file
}
763 \twocolitem{{\bf SaveMimeFile(filename, mimetype)
}}{Saves the image using the given
764 mimetype to the named file
}
768 \perlnote{Methods supported by wxPerl are:
\par
770 \item{bitmap->SaveFile( name, type )
}
771 \item{bitmap->SaveFile( name, mimetype )
}
775 \membersection{wxImage::Mirror
}\label{wximagemirror
}
777 \constfunc{wxImage
}{Mirror
}{\param{bool
}{ horizontally = true
}}
779 Returns a mirrored copy of the image. The parameter
{\it horizontally
}
780 indicates the orientation.
782 \membersection{wxImage::Replace
}\label{wximagereplace
}
784 \func{void
}{Replace
}{\param{unsigned char
}{ r1
},
\param{unsigned char
}{ g1
},
\param{unsigned char
}{ b1
},
785 \param{unsigned char
}{ r2
},
\param{unsigned char
}{ g2
},
\param{unsigned char
}{ b2
}}
787 Replaces the colour specified by
{\it r1,g1,b1
} by the colour
{\it r2,g2,b2
}.
789 \membersection{wxImage::Rescale
}\label{wximagerescale
}
791 \func{wxImage \&
}{Rescale
}{\param{int
}{ width
},
\param{int
}{ height
}}
793 Changes the size of the image in-place: after a call to this function, the
794 image will have the given width and height.
796 Returns the (modified) image itself.
800 \helpref{Scale
}{wximagescale
}
802 \membersection{wxImage::Rotate
}\label{wximagerotate
}
804 \func{wxImage
}{Rotate
}{\param{double
}{ angle
},
\param{const wxPoint\&
}{rotationCentre
},
805 \param{bool
}{ interpolating = true
},
\param{wxPoint*
}{ offsetAfterRotation = NULL
}}
807 Rotates the image about the given point, by
{\it angle
} radians. Passing true
808 to
{\it interpolating
} results in better image quality, but is slower. If the
809 image has a mask, then the mask colour is used for the uncovered pixels in the
810 rotated image background. Else, black (rgb
0,
0,
0) will be used.
812 Returns the rotated image, leaving this image intact.
814 \membersection{wxImage::Rotate90
}\label{wximagerotate90
}
816 \constfunc{wxImage
}{Rotate90
}{\param{bool
}{ clockwise = true
}}
818 Returns a copy of the image rotated
90 degrees in the direction
819 indicated by
{\it clockwise
}.
821 \membersection{wxImage::Scale
}\label{wximagescale
}
823 \constfunc{wxImage
}{Scale
}{\param{int
}{ width
},
\param{int
}{ height
}}
825 Returns a scaled version of the image. This is also useful for
826 scaling bitmaps in general as the only other way to scale bitmaps
827 is to blit a wxMemoryDC into another wxMemoryDC.
829 It may be mentioned that the GTK port uses this function internally
830 to scale bitmaps when using mapping modes in wxDC.
835 // get the bitmap from somewhere
838 // rescale it to have size of
32*
32
839 if ( bmp.GetWidth() !=
32 || bmp.GetHeight() !=
32 )
841 wxImage image = bmp.ConvertToImage();
842 bmp = wxBitmap(image.Scale(
32,
32));
844 // another possibility:
845 image.Rescale(
32,
32);
853 \helpref{Rescale
}{wximagerescale
}
855 \membersection{wxImage::SetAlpha
}\label{wximagesetalpha
}
857 \func{void
}{SetAlpha
}{\param{unsigned char *
}{alpha =
{\tt NULL
}}}
859 This function is similar to
\helpref{SetData
}{wximagesetdata
} and has similar
860 restrictions. The pointer passed to it may however be
{\tt NULL
} in which case
861 the function will allocate the alpha array internally -- this is useful to add
862 alpha channel data to an image which doesn't have any. If the pointer is not
863 {\tt NULL
}, it must have one byte for each image pixel and be allocated with
864 {\tt malloc()
}. wxImage takes ownership of the pointer and will free it.
866 \func{void
}{SetAlpha
}{\param{int
}{x
},
\param{int
}{y
},
\param{unsigned char
}{alpha
}}
868 Sets the alpha value for the given pixel. This function should only be called
869 if the image has alpha channel data, use
\helpref{HasAlpha
}{wximagehasalpha
} to
872 \membersection{wxImage::SetData
}\label{wximagesetdata
}
874 \func{void
}{SetData
}{\param{unsigned char*
}{data
}}
876 Sets the image data without performing checks. The data given must have
877 the size (width*height*
3) or results will be unexpected. Don't use this
878 method if you aren't sure you know what you are doing.
880 The data must have been allocated with
{\tt malloc()
},
{\large \bf NOT
} with
883 After this call the pointer to the data is owned by the wxImage object,
884 that will be responsible for deleting it.
885 Do not pass to this function a pointer obtained through
886 \helpref{wxImage::GetData
}{wximagegetdata
}.
888 \membersection{wxImage::SetMask
}\label{wximagesetmask
}
890 \func{void
}{SetMask
}{\param{bool
}{ hasMask = true
}}
892 Specifies whether there is a mask or not. The area of the mask is determined by the current mask colour.
894 \membersection{wxImage::SetMaskColour
}\label{wximagesetmaskcolour
}
896 \func{void
}{SetMaskColour
}{\param{unsigned char
}{red
},
\param{unsigned char
}{green
},
\param{unsigned char
}{blue
}}
898 Sets the mask colour for this image (and tells the image to use the mask).
900 \membersection{wxImage::SetMaskFromImage
}\label{wximagesetmaskfromimage
}
902 \func{bool
}{SetMaskFromImage
}{\param{const wxImage\&
}{ mask
},
\param{unsigned char
}{ mr
},
\param{unsigned char
}{ mg
},
\param{unsigned char
}{ mb
}}
904 \wxheading{Parameters
}
906 \docparam{mask
}{The mask image to extract mask shape from. Must have same dimensions as the image.
}
908 \docparam{mr,mg,mb
}{RGB value of pixels in
{\it mask
} that will be used to create the mask.
}
910 Sets image's mask so that the pixels that have RGB value of
{\it mr,mg,mb
}
911 in
{\it mask
} will be masked in the image. This is done by first finding an
912 unused colour in the image, setting this colour as the mask colour and then
913 using this colour to draw all pixels in the image who corresponding pixel
914 in
{\it mask
} has given RGB value.
916 \wxheading{Return value
}
918 Returns false if
{\it mask
} does not have same dimensions as the image or if
919 there is no unused colour left. Returns true if the mask was successfully
924 Note that this method involves computing the histogram, which is
925 computationally intensive operation.
927 \membersection{wxImage::SetOption
}\label{wximagesetoption
}
929 \func{void
}{SetOption
}{\param{const wxString\&
}{ name
},
\param{const wxString\&
}{ value
}}
931 \func{void
}{SetOption
}{\param{const wxString\&
}{ name
},
\param{int
}{ value
}}
933 Sets a user-defined option. The function is case-insensitive to
{\it name
}.
935 For example, when saving as a JPEG file, the option
{\bf quality
} is
936 used, which is a number between
0 and
100 (
0 is terrible,
100 is very good).
940 \helpref{wxImage::GetOption
}{wximagegetoption
},
\rtfsp
941 \helpref{wxImage::GetOptionInt
}{wximagegetoptionint
},
\rtfsp
942 \helpref{wxImage::HasOption
}{wximagehasoption
}
944 \membersection{wxImage::SetPalette
}\label{wximagesetpalette
}
946 \func{void
}{SetPalette
}{\param{const wxPalette\&
}{ palette
}}
948 Associates a palette with the image. The palette may be used when converting
949 wxImage to wxBitmap (MSW only at present) or in file save operations (none as yet).
951 \membersection{wxImage::SetRGB
}\label{wximagesetrgb
}
953 \func{void
}{SetRGB
}{\param{int
}{x
},
\param{int
}{y
},
\param{unsigned char
}{red
},
\param{unsigned char
}{green
},
\param{unsigned char
}{blue
}}
955 Sets the pixel at the given coordinate. This routine performs bounds-checks
956 for the coordinate so it can be considered a safe way to manipulate the
957 data, but in some cases this might be too slow so that the data will have to
958 be set directly. In that case you will have to get access to the image data
959 using the
\helpref{GetData
}{wximagegetdata
} method.
961 \membersection{wxImage::operator $=$
}
963 \func{wxImage\&
}{operator $=$
}{\param{const wxImage\&
}{image
}}
965 Assignment operator. This operator does not copy any data, but instead
966 passes a pointer to the data in
{\it image
} and increments a reference
967 counter. It is a fast operation.
969 \wxheading{Parameters
}
971 \docparam{image
}{Image to assign.
}
973 \wxheading{Return value
}
975 Returns 'this' object.
977 \membersection{wxImage::operator $==$
}
979 \constfunc{bool
}{operator $==$
}{\param{const wxImage\&
}{image
}}
981 Equality operator. This operator tests whether the internal data pointers are
984 \wxheading{Parameters
}
986 \docparam{image
}{Image to compare with 'this'
}
988 \wxheading{Return value
}
990 Returns true if the images were effectively equal, false otherwise.
992 \membersection{wxImage::operator $!=$
}
994 \constfunc{bool
}{operator $!=$
}{\param{const wxImage\&
}{image
}}
996 Inequality operator. This operator tests whether the internal data pointers are
997 unequal (a fast test).
999 \wxheading{Parameters
}
1001 \docparam{image
}{Image to compare with 'this'
}
1003 \wxheading{Return value
}
1005 Returns true if the images were unequal, false otherwise.
1007 \section{\class{wxImageHandler
}}\label{wximagehandler
}
1009 This is the base class for implementing image file loading/saving, and image creation from data.
1010 It is used within wxImage and is not normally seen by the application.
1012 If you wish to extend the capabilities of wxImage, derive a class from wxImageHandler
1013 and add the handler using
\helpref{wxImage::AddHandler
}{wximageaddhandler
} in your
1014 application initialisation.
1016 \wxheading{Note (Legal Issue)
}
1018 This software is based in part on the work of the Independent JPEG Group.
1020 (Applies when wxWindows is linked with JPEG support. wxJPEGHandler uses libjpeg
1023 \wxheading{Derived from
}
1025 \helpref{wxObject
}{wxobject
}
1027 \wxheading{Include files
}
1031 \wxheading{See also
}
1033 \helpref{wxImage
}{wximage
},
1034 \helpref{wxInitAllImageHandlers
}{wxinitallimagehandlers
}
1036 \latexignore{\rtfignore{\wxheading{Members
}}}
1038 \membersection{wxImageHandler::wxImageHandler
}\label{wximagehandlerconstr
}
1040 \func{}{wxImageHandler
}{\void}
1042 Default constructor. In your own default constructor, initialise the members
1043 m
\_name, m
\_extension and m
\_type.
1045 \membersection{wxImageHandler::
\destruct{wxImageHandler
}}
1047 \func{}{\destruct{wxImageHandler
}}{\void}
1049 Destroys the wxImageHandler object.
1051 \membersection{wxImageHandler::GetName
}
1053 \constfunc{wxString
}{GetName
}{\void}
1055 Gets the name of this handler.
1057 \membersection{wxImageHandler::GetExtension
}
1059 \constfunc{wxString
}{GetExtension
}{\void}
1061 Gets the file extension associated with this handler.
1063 \membersection{wxImageHandler::GetImageCount
}\label{wximagehandlergetimagecount
}
1065 \func{int
}{GetImageCount
}{\param{wxInputStream\&
}{ stream
}}
1067 If the image file contains more than one image and the image handler is capable
1068 of retrieving these individually, this function will return the number of
1071 \docparam{stream
}{Opened input stream for reading image data. Currently, the stream must support seeking.
}
1073 \wxheading{Return value
}
1075 Number of available images. For most image handlers, this is
1 (exceptions
1076 are TIFF and ICO formats).
1078 \membersection{wxImageHandler::GetType
}
1080 \constfunc{long
}{GetType
}{\void}
1082 Gets the image type associated with this handler.
1084 \membersection{wxImageHandler::GetMimeType
}
1086 \constfunc{wxString
}{GetMimeType
}{\void}
1088 Gets the MIME type associated with this handler.
1090 \membersection{wxImageHandler::LoadFile
}\label{wximagehandlerloadfile
}
1092 \func{bool
}{LoadFile
}{\param{wxImage*
}{image
},
\param{wxInputStream\&
}{ stream
},
\param{bool
}{ verbose=true
},
\param{int
}{ index=
0}}
1094 Loads a image from a stream, putting the resulting data into
{\it image
}. If the image file contains
1095 more than one image and the image handler is capable of retrieving these individually,
{\it index
}
1096 indicates which image to read from the stream.
1098 \wxheading{Parameters
}
1100 \docparam{image
}{The image object which is to be affected by this operation.
}
1102 \docparam{stream
}{Opened input stream for reading image data.
}
1104 \docparam{verbose
}{If set to true, errors reported by the image handler will produce wxLogMessages.
}
1106 \docparam{index
}{The index of the image in the file (starting from zero).
}
1108 \wxheading{Return value
}
1110 true if the operation succeeded, false otherwise.
1112 \wxheading{See also
}
1114 \helpref{wxImage::LoadFile
}{wximageloadfile
},
1115 \helpref{wxImage::SaveFile
}{wximagesavefile
},
1116 \helpref{wxImageHandler::SaveFile
}{wximagehandlersavefile
}
1118 \membersection{wxImageHandler::SaveFile
}\label{wximagehandlersavefile
}
1120 \func{bool
}{SaveFile
}{\param{wxImage*
}{image
},
\param{wxOutputStream\&
}{stream
}}
1122 Saves a image in the output stream.
1124 \wxheading{Parameters
}
1126 \docparam{image
}{The image object which is to be affected by this operation.
}
1128 \docparam{stream
}{Opened output stream for writing the data.
}
1130 \wxheading{Return value
}
1132 true if the operation succeeded, false otherwise.
1134 \wxheading{See also
}
1136 \helpref{wxImage::LoadFile
}{wximageloadfile
},
1137 \helpref{wxImage::SaveFile
}{wximagesavefile
},
1138 \helpref{wxImageHandler::LoadFile
}{wximagehandlerloadfile
}
1140 \membersection{wxImageHandler::SetName
}
1142 \func{void
}{SetName
}{\param{const wxString\&
}{name
}}
1144 Sets the handler name.
1146 \wxheading{Parameters
}
1148 \docparam{name
}{Handler name.
}
1150 \membersection{wxImageHandler::SetExtension
}
1152 \func{void
}{SetExtension
}{\param{const wxString\&
}{extension
}}
1154 Sets the handler extension.
1156 \wxheading{Parameters
}
1158 \docparam{extension
}{Handler extension.
}
1160 \membersection{wxImageHandler::SetMimeType
}\label{wximagehandlersetmimetype
}
1162 \func{void
}{SetMimeType
}{\param{const wxString\&
}{mimetype
}}
1164 Sets the handler MIME type.
1166 \wxheading{Parameters
}
1168 \docparam{mimename
}{Handler MIME type.
}
1170 \membersection{wxImageHandler::SetType
}
1172 \func{void
}{SetType
}{\param{long
}{type
}}
1174 Sets the handler type.
1176 \wxheading{Parameters
}
1178 \docparam{name
}{Handler type.
}