X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/6be663cf0d9c0ce48dea6c1c2f628ed376f128c0..a294c6d53ed8be5b92c31e1eb7e3366ba1642fa7:/docs/latex/wx/image.tex?ds=sidebyside diff --git a/docs/latex/wx/image.tex b/docs/latex/wx/image.tex index 2037c9e7db..6199e3ec2d 100644 --- a/docs/latex/wx/image.tex +++ b/docs/latex/wx/image.tex @@ -6,19 +6,50 @@ can be loaded from a file in a variety of formats, and is extensible to new form 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, and that bitmap drawn on the wxDC, using -wxDC::DrawBitmap. +A wxImage cannot (currently) be drawn directly to a \helpref{wxDC}{wxdc}. Instead, +a platform-specific \helpref{wxBitmap}{wxbitmap} object must be created from it using +the \helpref{ConvertToBitmap}{wximageconverttobitmap} function. This bitmap can then +be drawn in a device context, using \helpref{wxDC::DrawBitmap}{wxdcdrawbitmap}. -This class is currently only available under GTK and Windows. +One colour value of the image may be used as a mask colour which will lead to the automatic +creation of a \helpref{wxMask}{wxmask} object associated to the bitmap object. + +\wxheading{Available image handlers} + +The following image handlers are available. {\bf wxBMPHandler} is always +installed by default. To use other image formats, install the appropiate +handler with \helpref{wxImage::AddHandler}{wximageaddhandler} or +\helpref{wxInitAllImageHandlers}{wxinitallimagehandlers}. + +\twocolwidtha{5cm}% +\begin{twocollist} +\twocolitem{{\bf \indexit{wxBMPHandler}}}{Only for loading, always installed.} +\twocolitem{{\bf \indexit{wxPNGHandler}}}{For loading and saving.} +\twocolitem{{\bf \indexit{wxJPEGHandler}}}{For loading and saving.} +\twocolitem{{\bf \indexit{wxGIFHandler}}}{Only for loading, due to legal issues.} +\twocolitem{{\bf \indexit{wxPCXHandler}}}{For loading and saving (see below).} +\twocolitem{{\bf \indexit{wxPNMHandler}}}{For loading and saving (see below).} +\end{twocollist} + +When saving in PCX format, {\bf 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, {\bf wxPNMHandler} will always save as raw RGB. \wxheading{Derived from} \helpref{wxObject}{wxobject} +\wxheading{Include files} + + + \wxheading{See also} \helpref{wxBitmap}{wxbitmap} +\helpref{wxInitAllImageHandlers}{wxinitallimagehandlers} \latexignore{\rtfignore{\wxheading{Members}}} @@ -42,11 +73,15 @@ and forth without loss in that respect. Creates an image with the given width and height. -\func{}{wxImage}{\param{const wxString\& }{name}, \param{long}{ type = wxBITMAP\_TYPE\_PNG}} +\func{}{wxImage}{\param{const wxString\& }{name}, \param{long}{ type = wxBITMAP\_TYPE\_ANY}} + +\func{}{wxImage}{\param{const wxString\& }{name}, \param{const wxString\&}{ mimetype}} Loads an image from a file. -\func{}{wxImage}{\param{wxInputStream\& }{stream}, \param{long}{ type = wxBITMAP\_TYPE\_PNG}} +\func{}{wxImage}{\param{wxInputStream\& }{stream}, \param{long}{ type = wxBITMAP\_TYPE\_ANY}} + +\func{}{wxImage}{\param{wxInputStream\& }{stream}, \param{const wxString\&}{ mimetype}} Loads an image from an input stream. @@ -66,17 +101,41 @@ Loads an image from an input stream. \begin{twocollist} \twocolitem{{\bf \indexit{wxBITMAP\_TYPE\_BMP}}}{Load a Windows bitmap file.} \twocolitem{{\bf \indexit{wxBITMAP\_TYPE\_PNG}}}{Load a PNG bitmap file.} +\twocolitem{{\bf \indexit{wxBITMAP\_TYPE\_JPEG}}}{Load a JPEG bitmap file.} +\twocolitem{{\bf \indexit{wxBITMAP\_TYPE\_GIF}}}{Load a GIF bitmap file.} +\twocolitem{{\bf \indexit{wxBITMAP\_TYPE\_PCX}}}{Load a PCX bitmap file.} +\twocolitem{{\bf \indexit{wxBITMAP\_TYPE\_PNM}}}{Load a PNM bitmap file.} +\twocolitem{{\bf \indexit{wxBITMAP\_TYPE\_ANY}}}{Will try to autodetect the format.} \end{twocollist} The validity of these flags depends on the platform and wxWindows configuration. -If all possible wxWindows settings are used, the loading a BMP (Windows bitmap) file -and a PNG (portable network graphics) file is supported on all platforms that +If all possible wxWindows settings are used, the loading a BMP (Windows bitmap) file, +a PNG (portable network graphics) file and a JPEG file is supported on all platforms that implement wxImage.} +\docparam{mimetype}{MIME type string (for example 'image/jpeg')} + +Note : you must call wxImage::AddHandler(new wxJPEGHandler) during application +initialization in order to work with JPEGs. + \wxheading{See also} \helpref{wxImage::LoadFile}{wximageloadfile} +\pythonnote{Constructors supported by wxPython are:\par +\indented{2cm}{\begin{twocollist} +\twocolitem{{\bf wxImage(name, flag)}}{Loads an image from a file} +\twocolitem{{\bf wxNullImage()}}{Create a null image (has no size or +image data)} +\twocolitem{{\bf wxEmptyImage(width, height)}}{Creates an empty image +of the given size} +\twocolitem{{\bf wxImageFromMime(name, mimetype}}{Creates an image from +the given file of the given mimetype} +\twocolitem{{\bf wxImageFromBitmap(bitmap)}}{Creates an image from a +platform-dependent bitmap} +\end{twocollist}} +} + \membersection{wxImage::\destruct{wxImage}} \func{}{\destruct{wxImage}}{\void} @@ -96,6 +155,7 @@ of a given handler class in an application session.} \helpref{wxImageHandler}{wximagehandler} +\pythonnote{In wxPython this static method is named {\tt wxImage_AddHandler}.} \membersection{wxImage::CleanUpHandlers} \func{static void}{CleanUpHandlers}{\void} @@ -111,9 +171,12 @@ This function is called by wxWindows on exit. Converts the image to a platform-specific bitmap object. This has to be done to actually display an image as you cannot draw an image directly on a window. The resulting bitmap will use the colour depth of the current system which entails -that a (crude) colour reduction has to take place. When in 8-bit mode, this -routine will use a color cube created on program start-up to look up colors. -Still, the image quality won't be perfect for photo images. +that a colour reduction has to take place. + +When in 8-bit mode (PseudoColour mode), the GTK port will use a color cube created +on program start-up to look up colors. This ensures a very fast conversion, but +the image quality won't be perfect (and could be better for photo images using more +sophisticated dithering algorithms). \membersection{wxImage::Create}\label{wximagecreate} @@ -151,12 +214,18 @@ Finds the handler associated with the given extension and type. Finds the handler associated with the given image type. +\func{static wxImageHandler*}{FindHandlerMime}{\param{const wxString\& }{mimetype}} + +Finds the handler associated with the given MIME type. + \docparam{name}{The handler name.} \docparam{extension}{The file extension, such as ``bmp".} \docparam{imageType}{The image type, such as wxBITMAP\_TYPE\_BMP.} +\docparam{mimetype}{MIME type.} + \wxheading{Return value} A pointer to the handler if found, NULL otherwise. @@ -225,6 +294,13 @@ Gets the green value of the mask colour. Gets the red value of the mask colour. +\membersection{wxImage::GetSubImage}\label{wximagegetsubimage} + +\constfunc{wxImage}{GetSubImage}{\param{const wxRect\&}{ rect}} + +Returns a sub image of the current one as long as the rect belongs entirely to +the image. + \membersection{wxImage::GetWidth}\label{wximagegetwidth} \constfunc{int}{GetWidth}{\void} @@ -245,15 +321,16 @@ Returns TRUE if there is a mask active, FALSE otherwise. \func{static void}{InitStandardHandlers}{\void} -Adds the standard image format handlers, which, depending on wxWindows -configuration, can be handlers for Windows BMP (loading) and PNG -(loading and saving) file formats. +Internal use only. Adds standard image format handlers. It only install BMP +for the time being, which is use by wxBitmap. -This function is called by wxWindows on startup. +This function is called by wxWindows on startup, and shouldn't be called by +the user. \wxheading{See also} \helpref{wxImageHandler}{wximagehandler} +\helpref{wxInitAllImageHandlers}{wxinitallimagehandlers} \membersection{wxImage::InsertHandler} @@ -270,12 +347,17 @@ of a given handler class in an application session.} \membersection{wxImage::LoadFile}\label{wximageloadfile} -\func{bool}{LoadFile}{\param{const wxString\&}{ name}, \param{long}{ type}} +\func{bool}{LoadFile}{\param{const wxString\&}{ name}, \param{long}{ type = wxBITMAP\_TYPE\_ANY}} -Loads an image from a file. +\func{bool}{LoadFile}{\param{const wxString\&}{ name}, \param{const wxString\&}{ mimetype}} + +Loads an image from a file. If no handler type is provided, the library will +try to use wxBITMAP\_TYPE\_BMP. \func{bool}{LoadFile}{\param{wxInputStream\&}{ stream}, \param{long}{ type}} +\func{bool}{LoadFile}{\param{wxInputStream\&}{ stream}, \param{const wxString\&}{ mimetype}} + Loads an image from an input stream. \wxheading{Parameters} @@ -291,11 +373,18 @@ The meaning of {\it stream} data is determined by the {\it type} parameter.} \twocolwidtha{5cm}% \begin{twocollist} \twocolitem{{\bf wxBITMAP\_TYPE\_BMP}}{Load a Windows image file.} +\twocolitem{{\bf wxBITMAP\_TYPE\_GIF}}{Load a GIF image file.} +\twocolitem{{\bf wxBITMAP\_TYPE\_TIF}}{Load a TIFF image file.} +\twocolitem{{\bf wxBITMAP\_TYPE\_JPEG}}{Load a JPEG image file.} +\twocolitem{{\bf wxBITMAP\_TYPE\_PCX}}{Load a PCX image file.} \twocolitem{{\bf wxBITMAP\_TYPE\_PNG}}{Load a PNG image file.} +\twocolitem{{\bf wxBITMAP\_TYPE\_PNM}}{Load a PNM image file.} \end{twocollist} The validity of these flags depends on the platform and wxWindows configuration.} +\docparam{mimetype}{MIME type string (for example 'image/jpeg')} + \wxheading{Return value} TRUE if the operation succeeded, FALSE otherwise. @@ -304,6 +393,17 @@ TRUE if the operation succeeded, FALSE otherwise. \helpref{wxImage::SaveFile}{wximagesavefile} +\pythonnote{In place of a single overloaded method name, wxPython +implements the following methods:\par +\indented{2cm}{\begin{twocollist} +\twocolitem{{\bf LoadFile(filename, type)}}{Loads an image of the given +type from a file} +\twocolitem{{\bf LoadMimeFile(filename, mimetype)}}{Loads an image of the given +mimetype from a file} +\end{twocollist}} +} + + \membersection{wxImage::Ok}\label{wximageok} \constfunc{bool}{Ok}{\void} @@ -331,10 +431,14 @@ TRUE if the handler was found and removed, FALSE otherwise. \func{bool}{SaveFile}{\param{const wxString\& }{name}, \param{int}{ type}} +\func{bool}{SaveFile}{\param{const wxString\& }{name}, \param{const wxString\&}{ mimetype}} + Saves a image in the named file. \func{bool}{SaveFile}{\param{wxOutputStream\& }{stream}, \param{int}{ type}} +\func{bool}{SaveFile}{\param{wxOutputStream\& }{stream}, \param{const wxString\&}{ mimetype}} + Saves a image in the given stream. \wxheading{Parameters} @@ -343,16 +447,20 @@ Saves a image in the given stream. \docparam{stream}{An output stream. The meaning of {\it stream} is determined by the {\it type} parameter.} -\docparam{type}{Currently only one type can be used: +\docparam{type}{Currently three types can be used: \twocolwidtha{5cm}% \begin{twocollist} \twocolitem{{\bf wxBITMAP\_TYPE\_PNG}}{Save a PNG image file.} +\twocolitem{{\bf wxBITMAP\_TYPE\_JPEG}}{Save a JPEG image file.} +\twocolitem{{\bf wxBITMAP\_TYPE\_PCX}}{Save a PCX image file.} \end{twocollist} The validity of these flags depends on the platform and wxWindows configuration as well as user-added handlers.} +\docparam{mimetype}{MIME type.} + \wxheading{Return value} TRUE if the operation succeeded, FALSE otherwise. @@ -365,21 +473,75 @@ Depending on how wxWindows has been configured, not all formats may be available \helpref{wxImage::LoadFile}{wximageloadfile} +\pythonnote{In place of a single overloaded method name, wxPython +implements the following methods:\par +\indented{2cm}{\begin{twocollist} +\twocolitem{{\bf SaveFile(filename, type)}}{Saves the image using the given +type to the named file} +\twocolitem{{\bf SaveMimeFile(filename, mimetype)}}{Saves the image using the given +mimetype to the named file} +\end{twocollist}} +} + +\membersection{wxImage::Replace}\label{wximagereplace} + +\func{void}{Replace}{\param{unsigned char}{ r1}, \param{unsigned char}{ g1}, \param{unsigned char}{ b1}, +\param{unsigned char}{ r2}, \param{unsigned char}{ g2}, \param{unsigned char}{ b2}} + +Replaces the colour specified by {\it r1,g1,b1} by the colour {\it r2,g2,b2}. + +\membersection{wxImage::Rescale}\label{wximagerescale} + +\func{wxImage \&}{Rescale}{\param{int}{ width}, \param{int}{ height}} + +Changes the size of the image in-place: after a call to this function, the +image will have the given width and height. + +Returns the (modified) image itself. + +\wxheading{See also} + +\helpref{Scale}{wximagescale} + \membersection{wxImage::Scale}\label{wximagescale} -\func{wxImage}{Scale}{\param{int}{ width}, \param{int}{ height}} +\constfunc{wxImage}{Scale}{\param{int}{ width}, \param{int}{ height}} 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 do blit a wxMemoryDC into another wxMemoryDC. Windows can such scaling -itself, but on GTK scaling bitmaps is done using this routine -internally. +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 mode in wxDC. + +Example: + +\begin{verbatim} + // 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); + bmp = image.Scale(32, 32).ConvertToBitmap(); + + // another possibility: + image.Rescale(32, 32); + bmp = image; + } + +\end{verbatim} + +\wxheading{See also} + +\helpref{Rescale}{wximagerescale} \membersection{wxImage::SetData}\label{wximagesetdata} \func{void}{SetData}{\param{unsigned char*}{data}} -Sets the image data without performing checks. The data given must have +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. @@ -393,7 +555,7 @@ Specifies whether there is a mask or not. The area of the mask is determined by \func{void}{SetMaskColour}{\param{unsigned char }{red}, \param{unsigned char }{blue}, \param{unsigned char }{green}} -Sets the mask colour for this image. +Sets the mask colour for this image (and tells the image to use the mask). \membersection{wxImage::SetRGB}\label{wximagesetrgb} @@ -402,7 +564,8 @@ Sets the mask colour for this image. Sets the pixel at the given coordinate. This routine performs bounds-checks for the coordinate so it can be considered a safe way to manipulate the data, but in some cases this might be too slow so that the data will have to -be set directly. In that case you have to get that data by calling GetData(). +be set directly. In that case you will have to get access to the image data +using the \helpref{GetData}{wximagegetdata} method. \membersection{wxImage::operator $=$} @@ -459,13 +622,25 @@ If you wish to extend the capabilities of wxImage, derive a class from wxImageHa and add the handler using \helpref{wxImage::AddHandler}{wximageaddhandler} in your application initialisation. +\wxheading{Note (Legal Issue)} + +This software is based in part on the work of the Independent JPEG Group. + +(Applies when wxWindows is linked with JPEG support. wxJPEGHandler uses libjpeg +created by IJG.) + \wxheading{Derived from} \helpref{wxObject}{wxobject} +\wxheading{Include files} + + + \wxheading{See also} \helpref{wxImage}{wximage} +\helpref{wxInitAllImageHandlers}{wxinitallimagehandlers} \latexignore{\rtfignore{\wxheading{Members}}} @@ -494,24 +669,49 @@ Gets the name of this handler. Gets the file extension associated with this handler. +\membersection{wxImageHandler::GetImageCount}\label{wximagehandlergetimagecount} + +\func{int}{GetImageCount}{\param{wxInputStream\&}{ stream}} + +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. + +\docparam{stream}{Opened input stream for reading image file.} + +\wxheading{Return value} + +Number of available images. For most image handles, this defaults to 1. + \membersection{wxImageHandler::GetType} \constfunc{long}{GetType}{\void} Gets the image type associated with this handler. +\membersection{wxImageHandler::GetMimeType} + +\constfunc{wxString}{GetMimeType}{\void} + +Gets the MIME type associated with this handler. + \membersection{wxImageHandler::LoadFile}\label{wximagehandlerloadfile} -\func{bool}{LoadFile}{\param{wxImage* }{image}, \param{wxInputStream\&}{ stream}} +\func{bool}{LoadFile}{\param{wxImage* }{image}, \param{wxInputStream\&}{ stream}, \param{bool}{ verbose=TRUE}, \param{int}{ index=0}} -Loads a image from a stream, putting the resulting data into {\it image}. +Loads a image from a stream, putting the resulting data into {\it image}. If the image file contains +more than one image and the image handler is capable of retrieving these individually, {\it index} +indicates which image to read from the stream. \wxheading{Parameters} \docparam{image}{The image object which is to be affected by this operation.} -\docparam{stream}{Opened input stream. -The meaning of {\it stream} is determined by the {\it type} parameter.} +\docparam{stream}{Opened input stream for reading images.} + +\docparam{verbose}{If set to TRUE, errors reported by the image handler will produce wxLogMessages.} + +\docparam{index}{The index of the image in the file (starting from zero).} \wxheading{Return value} @@ -533,7 +733,7 @@ Saves a image in the output stream. \docparam{image}{The image object which is to be affected by this operation.} -\docparam{stream}{A stream. The meaning of {\it stream} is determined by the {\it type} parameter.} +\docparam{stream}{An opened stream for writing images.} \wxheading{Return value} @@ -575,3 +775,14 @@ Sets the handler type. \docparam{name}{Handler type.} + +\membersection{wxImageHandler::SetMimeType} + +\func{void}{SetMimeType}{\param{const wxString\& }{mimetype}} + +Sets the handler MIME type. + +\wxheading{Parameters} + +\docparam{mimename}{Handler MIME type.} +