Unlike RGB data, not all images have an alpha channel and before using
\helpref{GetAlpha}{wximagegetalpha} you should check if this image contains
-an alpha channel with \helpref{HasAlpha}{wximagehasalpha}. Note that currently only
-images loaded from PNG files with transparency information will have an alpha
-channel but alpha support will be added to the other formats as well (as well
-as support for saving images with alpha channel which also isn't implemented).
+an alpha channel with \helpref{HasAlpha}{wximagehasalpha}. Note that currently
+only the PNG format has full alpha channel support so only the images loaded
+from PNG files can have alpha and, if you initialize the image alpha channel
+yourself using \helpref{SetAlpha}{wximagesetalpha}, you should save it in PNG
+format to avoid losing it.
+
\wxheading{Available image handlers}
The following image handlers are available. {\bf wxBMPHandler} is always
installed by default. To use other image formats, install the appropriate
-handler with \helpref{wxImage::AddHandler}{wximageaddhandler} or
+handler with \helpref{wxImage::AddHandler}{wximageaddhandler} or call
\helpref{wxInitAllImageHandlers}{wxinitallimagehandlers}.
\twocolwidtha{5cm}%
\twocolitem{\indexit{wxPCXHandler}}{For loading and saving (see below).}
\twocolitem{\indexit{wxPNMHandler}}{For loading and saving (see below).}
\twocolitem{\indexit{wxTIFFHandler}}{For loading and saving.}
+\twocolitem{\indexit{wxTGAHandler}}{For loading only.}
\twocolitem{\indexit{wxIFFHandler}}{For loading only.}
\twocolitem{\indexit{wxXPMHandler}}{For loading and saving.}
\twocolitem{\indexit{wxICOHandler}}{For loading and saving.}
<wx/image.h>
+\wxheading{Library}
+
+\helpref{wxCore}{librarieslist}
+
\wxheading{See also}
\helpref{wxBitmap}{wxbitmap},
\func{}{wxImage}{\param{const wxImage\& }{image}}
-Copy constructor.
+Copy constructor, uses \helpref{reference counting}{trefcount}.
\func{}{wxImage}{\param{const wxBitmap\&}{ bitmap}}
Loads an image from an input stream.
-\func{}{wxImage}{\param{const char** }{xpmData}}
+\func{}{wxImage}{\param{const char* const* }{xpmData}}
Creates an image from XPM data.
\twocolitem{\indexit{wxBITMAP\_TYPE\_PCX}}{Load a PCX bitmap file.}
\twocolitem{\indexit{wxBITMAP\_TYPE\_PNM}}{Load a PNM bitmap file.}
\twocolitem{\indexit{wxBITMAP\_TYPE\_TIF}}{Load a TIFF bitmap file.}
+\twocolitem{\indexit{wxBITMAP\_TYPE\_TGA}}{Load a TGA bitmap file.}
\twocolitem{\indexit{wxBITMAP\_TYPE\_XPM}}{Load a XPM bitmap file.}
\twocolitem{\indexit{wxBITMAP\_TYPE\_ICO}}{Load a Windows icon file (ICO).}
\twocolitem{\indexit{wxBITMAP\_TYPE\_CUR}}{Load a Windows cursor file (CUR).}
\func{}{\destruct{wxImage}}{\void}
Destructor.
+See \helpref{reference-counted object destruction}{refcountdestruct} for more info.
\membersection{wxImage::AddHandler}\label{wximageaddhandler}
\pythonnote{In wxPython this static method is named {\tt wxImage\_AddHandler}.}
+
+\membersection{wxImage::Blur}\label{wximageblur}
+
+\func{wxImage}{Blur}{\param{int}{ blurRadius}}
+
+Blurs the image in both horizontal and vertical directions by the specified pixel
+{\it blurRadius}. This should not be used when using a single mask colour
+for transparency.
+
+\wxheading{See also}
+
+\helpref{BlurHorizontal}{wximagehorzblur}
+\helpref{BlurVertical}{wximagevertblur}
+
+
+\membersection{wxImage::BlurHorizontal}\label{wximagehorzblur}
+
+\func{wxImage}{BlurHorizontal}{\param{int}{ blurRadius}}
+
+Blurs the image in the horizontal direction only. This should not be used
+when using a single mask colour for transparency.
+\wxheading{See also}
+
+\helpref{Blur}{wximageblur}
+\helpref{BlurVertical}{wximagevertblur}
+
+
+\membersection{wxImage::BlurVertical}\label{wximagevertblur}
+
+\func{wxImage}{BlurVertical}{\param{int}{ blurRadius}}
+
+Blurs the image in the vertical direction only. This should not be used
+when using a single mask colour for transparency.
+
+\wxheading{See also}
+
+\helpref{Blur}{wximageblur}
+\helpref{BlurHorizontal}{wximagehorzblur}
+
+
\membersection{wxImage::CleanUpHandlers}\label{wximagecleanuphandlers}
\func{static void}{CleanUpHandlers}{\void}
(which takes wxImage and depth as its arguments) instead.
+\membersection{wxImage::ConvertToGreyscale}\label{wximageconverttogreyscale}
+
+\constfunc{wxImage}{ConvertToGreyscale}{\param{double}{ lr = 0.299}, \param{double}{ lg = 0.587}, \param{double}{ lb = 0.114}}
+
+Returns a greyscale version of the image. The returned image uses the luminance
+component of the original to calculate the greyscale. Defaults to using
+ITU-T BT.601 when converting to YUV, where every pixel equals
+(R * {\it lr}) + (G * {\it lg}) + (B * {\it lb}).
+
+
\membersection{wxImage::ConvertToMono}\label{wxbitmapconverttomono}
\constfunc{wxImage}{ConvertToMono}{\param{unsigned char}{ r}, \param{unsigned char}{ g}, \param{unsigned char}{ b}}
Example:
\begin{verbatim}
- wxFileDialog FileDlg( this, "Choose Image", ::wxGetCwd(), "", _("Image Files ") + wxImage::GetImageExtWildcard(), wxOPEN );
+ wxFileDialog FileDlg( this, "Choose Image", ::wxGetCwd(), "", _("Image Files ") + wxImage::GetImageExtWildcard(), wxFD_OPEN );
\end{verbatim}
\wxheading{See also}
\constfunc{const wxPalette\&}{GetPalette}{\void}
Returns the palette associated with the image. Currently the palette is only
-used when converting to wxBitmap under Windows.
-
-Eventually wxImage handlers will set the palette if one exists in the image file.
+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).
\membersection{wxImage::GetRed}\label{wximagegetred}
-\membersection{wxImage::Ok}\label{wximageok}
+\membersection{wxImage::IsOk}\label{wximageisok}
-\constfunc{bool}{Ok}{\void}
+\constfunc{bool}{IsOk}{\void}
Returns true if image data is present.
\func{}{RGBValue}{\param{unsigned char }{r = 0}, \param{unsigned char }{g = 0}, \param{unsigned char }{b = 0}}
-Constructor for RGBValue, an object that contains values for red, green and blud which
+Constructor for RGBValue, an object that contains values for red, green and blue which
represent the value of a color. It is used by \helpref{wxImage::HSVtoRGB}{wximagehsvtorgb}
and \helpref{wxImage::RGBtoHSV}{wximagergbtohsv}, which
converts between HSV color space and RGB color space.
\membersection{wxImage::Rescale}\label{wximagerescale}
-\func{wxImage \&}{Rescale}{\param{int}{ width}, \param{int}{ height}}
+\func{wxImage \&}{Rescale}{\param{int}{ width}, \param{int}{ height}, \param{int}{ 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 {\it quality} parameter, see the \helpref{Scale}{wximagescale} function.
+
Returns the (modified) image itself.
\wxheading{See also}
\membersection{wxImage::Scale}\label{wximagescale}
-\constfunc{wxImage}{Scale}{\param{int}{ width}, \param{int}{ height}}
+\constfunc{wxImage}{Scale}{\param{int}{ width}, \param{int}{ height}, \param{int}{ quality = wxIMAGE\_QUALITY\_NORMAL}}
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.
-It may be mentioned that the GTK port uses this function internally
-to scale bitmaps when using mapping modes in wxDC.
+\docparam{quality}{Determines what method to use for resampling the image. Can be one of the following:
+
+\twocolwidtha{5cm}%
+\begin{twocollist}
+\twocolitem{{\bf wxIMAGE\_QUALITY\_NORMAL}}{Uses the normal default scaling method of pixel replication}
+\twocolitem{{\bf wxIMAGE\_QUALITY\_HIGH}}{Uses bicubic and box averaging resampling methods for upsampling and downsampling respectively}
+\end{twocollist}}
+
+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:
alpha channel data to an image which doesn't have any. If the pointer is not
{\tt NULL}, it must have one byte for each image pixel and be allocated with
{\tt malloc()}. wxImage takes ownership of the pointer and will free it unless
-\arg{static\_data} parameter is set.to \true -- in this case the caller should
+\arg{static\_data} parameter is set to \true -- in this case the caller should
do it.
\func{void}{SetAlpha}{\param{int }{x}, \param{int }{y}, \param{unsigned char }{alpha}}
\func{wxImage\& }{operator $=$}{\param{const wxImage\& }{image}}
-Assignment operator. This operator does not copy any data, but instead
-passes a pointer to the data in {\it image} and increments a reference
-counter. It is a fast operation.
+Assignment operator, using \helpref{reference counting}{trefcount}.
\wxheading{Parameters}
Returns 'this' object.
-\membersection{wxImage::operator $==$}\label{wximageequal}
-
-\constfunc{bool}{operator $==$}{\param{const wxImage\& }{image}}
-
-Equality operator. This operator tests whether the internal data pointers are
-equal (a fast test).
-
-\wxheading{Parameters}
-
-\docparam{image}{Image to compare with 'this'}
-
-\wxheading{Return value}
-
-Returns true if the images were effectively equal, false otherwise.
-
-
-\membersection{wxImage::operator $!=$}\label{wximagenotequal}
-
-\constfunc{bool}{operator $!=$}{\param{const wxImage\& }{image}}
-
-Inequality operator. This operator tests whether the internal data pointers are
-unequal (a fast test).
-
-\wxheading{Parameters}
-
-\docparam{image}{Image to compare with 'this'}
-
-\wxheading{Return value}
-
-Returns true if the images were unequal, false otherwise.
\section{\class{wxImageHandler}}\label{wximagehandler}
<wx/image.h>
+\wxheading{Library}
+
+\helpref{wxCore}{librarieslist}
+
\wxheading{See also}
\helpref{wxImage}{wximage},
\membersection{wxImageHandler::GetName}\label{wximagehandlergetname}
-\constfunc{wxString}{GetName}{\void}
+\constfunc{const wxString\&}{GetName}{\void}
Gets the name of this handler.
\membersection{wxImageHandler::GetExtension}\label{wximagehandlergetextension}
-\constfunc{wxString}{GetExtension}{\void}
+\constfunc{const wxString\&}{GetExtension}{\void}
Gets the file extension associated with this handler.
\membersection{wxImageHandler::GetMimeType}\label{wximagehandlergetmimetype}
-\constfunc{wxString}{GetMimeType}{\void}
+\constfunc{const wxString\&}{GetMimeType}{\void}
Gets the MIME type associated with this handler.
projects / wxWidgets.git / blobdiff