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<td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>QImage Class Reference</h1>
<p>The QImage class provides a hardware-independent pixmap
representation with direct access to the pixel data.
<a href="#details">More...</a>
<p><tt>#include <<a href="qimage-h.html">qimage.h</a>></tt>
<p><a href="qimage-members.html">List of all member functions.</a>
<h2>Public Members</h2>
<ul>
<li><div class=fn>enum <a href="#Endian-enum"><b>Endian</b></a> { IgnoreEndian, BigEndian, LittleEndian }</div></li>
<li><div class=fn><a href="#QImage"><b>QImage</b></a> ()</div></li>
<li><div class=fn><a href="#QImage-2"><b>QImage</b></a> ( int w, int h, int depth, int numColors = 0, Endian bitOrder = IgnoreEndian )</div></li>
<li><div class=fn><a href="#QImage-3"><b>QImage</b></a> ( const QSize & size, int depth, int numColors = 0, Endian bitOrder = IgnoreEndian )</div></li>
<li><div class=fn><a href="#QImage-4"><b>QImage</b></a> ( const QString & fileName, const char * format = 0 )</div></li>
<li><div class=fn><a href="#QImage-5"><b>QImage</b></a> ( const char * const xpm[] )</div></li>
<li><div class=fn><a href="#QImage-6"><b>QImage</b></a> ( const QByteArray & array )</div></li>
<li><div class=fn><a href="#QImage-7"><b>QImage</b></a> ( uchar * yourdata, int w, int h, int depth, QRgb * colortable, int numColors, Endian bitOrder )</div></li>
<li><div class=fn><a href="#QImage-8"><b>QImage</b></a> ( uchar * yourdata, int w, int h, int depth, int bpl, QRgb * colortable, int numColors, Endian bitOrder )</div></li>
<li><div class=fn><a href="#QImage-9"><b>QImage</b></a> ( const QImage & image )</div></li>
<li><div class=fn><a href="#~QImage"><b>~QImage</b></a> ()</div></li>
<li><div class=fn>QImage & <a href="#operator-eq"><b>operator=</b></a> ( const QImage & image )</div></li>
<li><div class=fn>QImage & <a href="#operator-eq-2"><b>operator=</b></a> ( const QPixmap & pixmap )</div></li>
<li><div class=fn>bool <a href="#operator-eq-eq"><b>operator==</b></a> ( const QImage & i ) const</div></li>
<li><div class=fn>bool <a href="#operator!-eq"><b>operator!=</b></a> ( const QImage & i ) const</div></li>
<li><div class=fn>void <a href="#detach"><b>detach</b></a> ()</div></li>
<li><div class=fn>QImage <a href="#copy"><b>copy</b></a> () const</div></li>
<li><div class=fn>QImage <a href="#copy-2"><b>copy</b></a> ( int x, int y, int w, int h, int conversion_flags = 0 ) const</div></li>
<li><div class=fn>QImage <a href="#copy-3"><b>copy</b></a> ( const QRect & r ) const</div></li>
<li><div class=fn>bool <a href="#isNull"><b>isNull</b></a> () const</div></li>
<li><div class=fn>int <a href="#width"><b>width</b></a> () const</div></li>
<li><div class=fn>int <a href="#height"><b>height</b></a> () const</div></li>
<li><div class=fn>QSize <a href="#size"><b>size</b></a> () const</div></li>
<li><div class=fn>QRect <a href="#rect"><b>rect</b></a> () const</div></li>
<li><div class=fn>int <a href="#depth"><b>depth</b></a> () const</div></li>
<li><div class=fn>int <a href="#numColors"><b>numColors</b></a> () const</div></li>
<li><div class=fn>Endian <a href="#bitOrder"><b>bitOrder</b></a> () const</div></li>
<li><div class=fn>QRgb <a href="#color"><b>color</b></a> ( int i ) const</div></li>
<li><div class=fn>void <a href="#setColor"><b>setColor</b></a> ( int i, QRgb c )</div></li>
<li><div class=fn>void <a href="#setNumColors"><b>setNumColors</b></a> ( int numColors )</div></li>
<li><div class=fn>bool <a href="#hasAlphaBuffer"><b>hasAlphaBuffer</b></a> () const</div></li>
<li><div class=fn>void <a href="#setAlphaBuffer"><b>setAlphaBuffer</b></a> ( bool enable )</div></li>
<li><div class=fn>bool <a href="#allGray"><b>allGray</b></a> () const</div></li>
<li><div class=fn>bool <a href="#isGrayscale"><b>isGrayscale</b></a> () const</div></li>
<li><div class=fn>uchar * <a href="#bits"><b>bits</b></a> () const</div></li>
<li><div class=fn>uchar * <a href="#scanLine"><b>scanLine</b></a> ( int i ) const</div></li>
<li><div class=fn>uchar ** <a href="#jumpTable"><b>jumpTable</b></a> () const</div></li>
<li><div class=fn>QRgb * <a href="#colorTable"><b>colorTable</b></a> () const</div></li>
<li><div class=fn>int <a href="#numBytes"><b>numBytes</b></a> () const</div></li>
<li><div class=fn>int <a href="#bytesPerLine"><b>bytesPerLine</b></a> () const</div></li>
<li><div class=fn>QGfx * <b>graphicsContext</b> ()</div></li>
<li><div class=fn>bool <a href="#create"><b>create</b></a> ( int width, int height, int depth, int numColors = 0, Endian bitOrder = IgnoreEndian )</div></li>
<li><div class=fn>bool <a href="#create-2"><b>create</b></a> ( const QSize &, int depth, int numColors = 0, Endian bitOrder = IgnoreEndian )</div></li>
<li><div class=fn>void <a href="#reset"><b>reset</b></a> ()</div></li>
<li><div class=fn>void <a href="#fill"><b>fill</b></a> ( uint pixel )</div></li>
<li><div class=fn>void <a href="#invertPixels"><b>invertPixels</b></a> ( bool invertAlpha = TRUE )</div></li>
<li><div class=fn>QImage <a href="#convertDepth-2"><b>convertDepth</b></a> ( int depth ) const</div></li>
<li><div class=fn>QImage <a href="#convertDepthWithPalette"><b>convertDepthWithPalette</b></a> ( int d, QRgb * palette, int palette_count, int conversion_flags = 0 ) const</div></li>
<li><div class=fn>QImage <a href="#convertDepth"><b>convertDepth</b></a> ( int depth, int conversion_flags ) const</div></li>
<li><div class=fn>QImage <a href="#convertBitOrder"><b>convertBitOrder</b></a> ( Endian bitOrder ) const</div></li>
<li><div class=fn>enum <a href="#ScaleMode-enum"><b>ScaleMode</b></a> { ScaleFree, ScaleMin, ScaleMax }</div></li>
<li><div class=fn>QImage <a href="#smoothScale"><b>smoothScale</b></a> ( int w, int h, ScaleMode mode = ScaleFree ) const</div></li>
<li><div class=fn>QImage <a href="#smoothScale-2"><b>smoothScale</b></a> ( const QSize & s, ScaleMode mode = ScaleFree ) const</div></li>
<li><div class=fn>QImage <a href="#scale"><b>scale</b></a> ( int w, int h, ScaleMode mode = ScaleFree ) const</div></li>
<li><div class=fn>QImage <a href="#scale-2"><b>scale</b></a> ( const QSize & s, ScaleMode mode = ScaleFree ) const</div></li>
<li><div class=fn>QImage <a href="#scaleWidth"><b>scaleWidth</b></a> ( int w ) const</div></li>
<li><div class=fn>QImage <a href="#scaleHeight"><b>scaleHeight</b></a> ( int h ) const</div></li>
<li><div class=fn>QImage <a href="#xForm"><b>xForm</b></a> ( const QWMatrix & matrix ) const</div></li>
<li><div class=fn>QImage <a href="#createAlphaMask"><b>createAlphaMask</b></a> ( int conversion_flags = 0 ) const</div></li>
<li><div class=fn>QImage <a href="#createHeuristicMask"><b>createHeuristicMask</b></a> ( bool clipTight = TRUE ) const</div></li>
<li><div class=fn>QImage <a href="#mirror"><b>mirror</b></a> () const</div></li>
<li><div class=fn>QImage <a href="#mirror-2"><b>mirror</b></a> ( bool horizontal, bool vertical ) const</div></li>
<li><div class=fn>QImage <a href="#swapRGB"><b>swapRGB</b></a> () const</div></li>
<li><div class=fn>bool <a href="#load"><b>load</b></a> ( const QString & fileName, const char * format = 0 )</div></li>
<li><div class=fn>bool <a href="#loadFromData"><b>loadFromData</b></a> ( const uchar * buf, uint len, const char * format = 0 )</div></li>
<li><div class=fn>bool <a href="#loadFromData-2"><b>loadFromData</b></a> ( QByteArray buf, const char * format = 0 )</div></li>
<li><div class=fn>bool <a href="#save"><b>save</b></a> ( const QString & fileName, const char * format, int quality = -1 ) const</div></li>
<li><div class=fn>bool <a href="#valid"><b>valid</b></a> ( int x, int y ) const</div></li>
<li><div class=fn>int <a href="#pixelIndex"><b>pixelIndex</b></a> ( int x, int y ) const</div></li>
<li><div class=fn>QRgb <a href="#pixel"><b>pixel</b></a> ( int x, int y ) const</div></li>
<li><div class=fn>void <a href="#setPixel"><b>setPixel</b></a> ( int x, int y, uint index_or_rgb )</div></li>
<li><div class=fn>int <a href="#dotsPerMeterX"><b>dotsPerMeterX</b></a> () const</div></li>
<li><div class=fn>int <a href="#dotsPerMeterY"><b>dotsPerMeterY</b></a> () const</div></li>
<li><div class=fn>void <a href="#setDotsPerMeterX"><b>setDotsPerMeterX</b></a> ( int x )</div></li>
<li><div class=fn>void <a href="#setDotsPerMeterY"><b>setDotsPerMeterY</b></a> ( int y )</div></li>
<li><div class=fn>QPoint <a href="#offset"><b>offset</b></a> () const</div></li>
<li><div class=fn>void <a href="#setOffset"><b>setOffset</b></a> ( const QPoint & p )</div></li>
<li><div class=fn>QValueList<QImageTextKeyLang> <a href="#textList"><b>textList</b></a> () const</div></li>
<li><div class=fn>QStringList <a href="#textLanguages"><b>textLanguages</b></a> () const</div></li>
<li><div class=fn>QStringList <a href="#textKeys"><b>textKeys</b></a> () const</div></li>
<li><div class=fn>QString <a href="#text"><b>text</b></a> ( const char * key, const char * lang = 0 ) const</div></li>
<li><div class=fn>QString <a href="#text-2"><b>text</b></a> ( const QImageTextKeyLang & kl ) const</div></li>
<li><div class=fn>void <a href="#setText"><b>setText</b></a> ( const char * key, const char * lang, const QString & s )</div></li>
</ul>
<h2>Static Public Members</h2>
<ul>
<li><div class=fn>Endian <a href="#systemBitOrder"><b>systemBitOrder</b></a> ()</div></li>
<li><div class=fn>Endian <a href="#systemByteOrder"><b>systemByteOrder</b></a> ()</div></li>
<li><div class=fn>const char * <a href="#imageFormat"><b>imageFormat</b></a> ( const QString & fileName )</div></li>
<li><div class=fn>QStrList <a href="#inputFormats"><b>inputFormats</b></a> ()</div></li>
<li><div class=fn>QStrList <a href="#outputFormats"><b>outputFormats</b></a> ()</div></li>
<li><div class=fn>QStringList <a href="#inputFormatList"><b>inputFormatList</b></a> ()</div></li>
<li><div class=fn>QStringList <a href="#outputFormatList"><b>outputFormatList</b></a> ()</div></li>
</ul>
<h2>Related Functions</h2>
<ul>
<li><div class=fn>QDataStream & <a href="#operator-lt-lt"><b>operator<<</b></a> ( QDataStream & s, const QImage & image )</div></li>
<li><div class=fn>QDataStream & <a href="#operator-gt-gt"><b>operator>></b></a> ( QDataStream & s, QImage & image )</div></li>
</ul>
<hr><a name="details"></a><h2>Detailed Description</h2>
The QImage class provides a hardware-independent pixmap
representation with direct access to the pixel data.
<p>
<p> It is one of the two classes Qt provides for dealing with images,
the other being <a href="qpixmap.html">QPixmap</a>. QImage is designed and optimized for I/O
and for direct pixel access/manipulation. QPixmap is designed and
optimized for drawing. There are (slow) functions to convert
between QImage and QPixmap: <a href="qpixmap.html#convertToImage">QPixmap::convertToImage</a>() and
<a href="qpixmap.html#convertFromImage">QPixmap::convertFromImage</a>().
<p> An image has the parameters <a href="#width">width</a>, <a href="#height">height</a> and <a href="#depth">depth</a> (bits per pixel, bpp), a
color table and the actual <a href="#bits">pixels</a>. QImage supports
1-bpp, 8-bpp and 32-bpp image data. 1-bpp and 8-bpp images use a color
lookup table; the pixel value is a color table index.
<p> 32-bpp images encode an RGB value in 24 bits and ignore the color table.
The most significant byte is used for the <a href="#setAlphaBuffer">alpha
buffer</a>.
<p> An entry in the color table is an RGB triplet encoded as <tt>uint</tt>. Use
the qRed, qGreen and qBlue functions (qcolor.h) to access the
components, and qRgb to make an RGB triplet (see the <a href="qcolor.html">QColor</a> class
documentation).
<p> 1-bpp (monochrome) images have a color table with maximum two colors.
There are two different formats: big endian (MSB first) or little endian
(LSB first) bit order. To access a single bit you will have to do some
bit shifts:
<p> <pre>
QImage image;
// sets bit at (x,y) to 1
if ( image.<a href="#bitOrder">bitOrder</a>() == QImage::<a href="#Endian-enum">LittleEndian</a> )
*(image.<a href="#scanLine">scanLine</a>(y) + (x >> 3)) |= 1 << (x & 7);
else
*(image.<a href="#scanLine">scanLine</a>(y) + (x >> 3)) |= 1 << (7 -(x & 7));
</pre>
<p> If this looks complicated, it might be a good idea to convert the 1-bpp
image to an 8-bpp image using <a href="#convertDepth">convertDepth</a>().
<p> 8-bpp images are much easier to work with than 1-bpp images because they
have a single byte per pixel:
<p> <pre>
QImage image;
// set entry 19 in the color table to yellow
image.<a href="#setColor">setColor</a>( 19, qRgb(255,255,0) );
// set 8 bit pixel at (x,y) to value yellow (in color table)
*(image.<a href="#scanLine">scanLine</a>(y) + x) = 19;
</pre>
<p> 32-bpp images ignore the color table; instead, each pixel contains the
RGB triplet. 24 bits contain the RGB value; the most significant
byte is reserved for the alpha buffer.
<p> <pre>
QImage image;
// sets 32 bit pixel at (x,y) to yellow.
uint *p = (uint *)image.<a href="#scanLine">scanLine</a>(y) + x;
*p = <a href="qcolor.html#qRgb">qRgb</a>(255,255,0);
</pre>
<p> On Qt/Embedded, scanlines are aligned to the pixel depth and may be padded
to any degree, while on all other platforms, the scanlines are 32-bit aligned
for all depths. The constructor taking a <pre> uchar*</pre>
argument
always expects 32-bit aligned data. On Qt/Embedded, an additional
constructor allows the number of byte-per-line to be specified.
<p> QImage supports a variety of methods for getting information about
the image, for example, <a href="#colorTable">colorTable</a>(), <a href="#allGray">allGray</a>(), <a href="#isGrayscale">isGrayscale</a>(),
<a href="#bitOrder">bitOrder</a>(), <a href="#bytesPerLine">bytesPerLine</a>(), <a href="#depth">depth</a>(), <a href="#dotsPerMeterX">dotsPerMeterX</a>() and
<a href="#dotsPerMeterY">dotsPerMeterY</a>(), <a href="#hasAlphaBuffer">hasAlphaBuffer</a>(), <a href="#numBytes">numBytes</a>(), <a href="#numColors">numColors</a>(), and
<a href="#width">width</a>() and <a href="#height">height</a>().
<p> Pixel colors are retrieved with <a href="#pixel">pixel</a>() and set with <a href="#setPixel">setPixel</a>().
<p> QImage also supports a number of functions for creating a new
image that is a transformed version of the original. For example,
<a href="#copy">copy</a>(),
<a href="#convertBitOrder">convertBitOrder</a>(), <a href="#convertDepth">convertDepth</a>(), <a href="#createAlphaMask">createAlphaMask</a>(),
<a href="#createHeuristicMask">createHeuristicMask</a>(), <a href="#mirror">mirror</a>(), <a href="#scale">scale</a>(), <a href="#smoothScale">smoothScale</a>(), <a href="#swapRGB">swapRGB</a>()
and <a href="#xForm">xForm</a>(). There are also functions for changing attributes of
an image in-place, for example, <a href="#setAlphaBuffer">setAlphaBuffer</a>(), <a href="#setColor">setColor</a>(),
<a href="#setDotsPerMeterX">setDotsPerMeterX</a>() and <a href="#setDotsPerMeterY">setDotsPerMeterY</a>() and <a href="#setNumColors">setNumColors</a>().
<p> Images can be loaded and saved in the supported formats.
Images are saved to a file with <a href="#save">save</a>(). Images are loaded from a
file with <a href="#load">load</a>() (or in the constructor) or from an array of data
with <a href="#loadFromData">loadFromData</a>(). The lists of supported formats are available
from <a href="#inputFormatList">inputFormatList</a>() and <a href="#outputFormatList">outputFormatList</a>().
<p> Strings of text may be added to images using <a href="#setText">setText</a>().
<p> The QImage class uses explicit <a href="shclass.html">sharing</a>,
similar to that used by <a href="qmemarray.html">QMemArray</a>.
<p> New image formats can be added as <a href="plugins-howto.html">plugins</a>.
<p> <p>See also <a href="qimageio.html">QImageIO</a>, <a href="qpixmap.html">QPixmap</a>, <a href="shclass.html">Shared Classes</a>, <a href="graphics.html">Graphics Classes</a>, <a href="images.html">Image Processing Classes</a> and <a href="shared.html">Implicitly and Explicitly Shared Classes</a>.
<hr><h2>Member Type Documentation</h2>
<h3 class=fn><a name="Endian-enum"></a>QImage::Endian</h3>
<p> This enum type is used to describe the endianness of the CPU and
graphics hardware.
<p> The current values are:
<ul>
<li><tt>QImage::IgnoreEndian</tt> - Endianness does not matter. Useful for some operations
that are independent of endianness.
<li><tt>QImage::BigEndian</tt> - Network byte order, as on SPARC and Motorola CPUs.
<li><tt>QImage::LittleEndian</tt> - PC/Alpha byte order.
</ul>
<h3 class=fn><a name="ScaleMode-enum"></a>QImage::ScaleMode</h3>
<p> The functions <a href="#scale">scale</a>() and <a href="#smoothScale">smoothScale</a>() use different modes for scaling the
image. The purpose of these modes is to retain the ratio of the image if
this is required.
<ul>
<li><tt>QImage::ScaleFree</tt> - The image is scaled freely: the resulting image fits exactly
into the specified size; the ratio will not necessarily be preserved.
<li><tt>QImage::ScaleMin</tt> - The ratio of the image is preserved and the resulting image
is guaranteed to fit into the specified size (it is as large as possible
within these constraints) - the image might be smaller than the
requested size.
<li><tt>QImage::ScaleMax</tt> - The ratio of the image is preserved and the resulting image
fills the whole specified rectangle (it is as small as possible within
these constraints) - the image might be larger than the requested size.
</ul>
<hr><h2>Member Function Documentation</h2>
<h3 class=fn><a name="QImage"></a>QImage::QImage ()
</h3>
Constructs a null image.
<p> <p>See also <a href="#isNull">isNull</a>().
<h3 class=fn><a name="QImage-2"></a>QImage::QImage ( int w, int h, int depth, int numColors = 0, <a href="qimage.html#Endian-enum">Endian</a> bitOrder = IgnoreEndian )
</h3>
Constructs an image with <em>w</em> width, <em>h</em> height, <em>depth</em> bits per
pixel, <em>numColors</em> colors and bit order <em>bitOrder</em>.
<p> Using this constructor is the same as first constructing a null image and
then calling the <a href="#create">create</a>() function.
<p> <p>See also <a href="#create">create</a>().
<h3 class=fn><a name="QImage-3"></a>QImage::QImage ( const <a href="qsize.html">QSize</a> & size, int depth, int numColors = 0, <a href="qimage.html#Endian-enum">Endian</a> bitOrder = IgnoreEndian )
</h3>
Constructs an image with size <em>size</em> pixels, depth <em>depth</em>
bits, <em>numColors</em> and <em>bitOrder</em> endianness.
<p> Using this constructor is the same as first constructing a null image and
then calling the <a href="#create">create</a>() function.
<p> <p>See also <a href="#create">create</a>().
<h3 class=fn><a name="QImage-4"></a>QImage::QImage ( const <a href="qstring.html">QString</a> & fileName, const char * format = 0 )
</h3>
Constructs an image and tries to load it image from the file <em>fileName</em>.
<p> If <em>format</em> is specified, the loader attempts to read the image using the
specified format. If <em>format</em> is not specified (which is the default),
the loader reads a few bytes from the header to guess the file format.
<p> If the loading of the image failed, this object is a null image.
<p> The <a href="qimageio.html">QImageIO</a> documentation lists the supported image formats and
explains how to add extra formats.
<p> <p>See also <a href="#load">load</a>(), <a href="#isNull">isNull</a>() and <a href="qimageio.html">QImageIO</a>.
<h3 class=fn><a name="QImage-5"></a>QImage::QImage ( const char * const xpm[] )
</h3>
Constructs an image from <em>xpm</em>, which must be a valid XPM image.
<p> Errors are silently ignored.
<p> Note that it's possible to squeeze the XPM variable a little bit by
using an unusual declaration:
<p> <pre>
static const char * const start_xpm[]={
"16 15 8 1",
"a c #cec6bd",
....
</pre>
<p> The extra <tt>const</tt> makes the entire definition read-only, which is
slightly more efficient (e.g., when the code is in a shared library)
and ROMable when the application is to be stored in ROM.
<h3 class=fn><a name="QImage-6"></a>QImage::QImage ( const <a href="qbytearray.html">QByteArray</a> & array )
</h3>
Constructs an image from the binary data <em>array</em>. It tries to guess the
file format.
<p> If the loading of the image failed, this object is a null image.
<p> <p>See also <a href="#loadFromData">loadFromData</a>(), <a href="#isNull">isNull</a>() and <a href="#imageFormat">imageFormat</a>().
<h3 class=fn><a name="QImage-7"></a>QImage::QImage ( uchar * yourdata, int w, int h, int depth, QRgb * colortable, int numColors, <a href="qimage.html#Endian-enum">Endian</a> bitOrder )
</h3>
Constructs an image <em>w</em> pixels wide, <em>h</em> pixels high with a
color depth of <em>depth</em>, that uses an existing memory buffer, <em>yourdata</em>. The buffer must remain valid throughout the life of the
QImage. The image does not delete the buffer at destruction.
<p> If <em>colortable</em> is 0, a color table sufficient for <em>numColors</em> will be
allocated (and destructed later).
<p> Note that <em>yourdata</em> must be 32-bit aligned.
<p> The endianness is given in <em>bitOrder</em>.
<h3 class=fn><a name="QImage-8"></a>QImage::QImage ( uchar * yourdata, int w, int h, int depth, int bpl, QRgb * colortable, int numColors, <a href="qimage.html#Endian-enum">Endian</a> bitOrder )
</h3>
Constructs an image that uses an existing memory buffer.
The buffer must remain valid for the life of the QImage. The image
does not delete the buffer at destruction.
<p> <em>bpl</em> specifies the number of bytes per line.
<p> If colortable is 0, a color table sufficient for <em>numColors</em> will be
allocated (and destructed later).
<h3 class=fn><a name="QImage-9"></a>QImage::QImage ( const <a href="qimage.html">QImage</a> & image )
</h3>
Constructs a
<a href="shclass.html">shallow copy</a> of <em>image</em>.
<h3 class=fn><a name="~QImage"></a>QImage::~QImage ()
</h3>
Destroys the image and cleans up.
<h3 class=fn>bool <a name="allGray"></a>QImage::allGray () const
</h3>
Returns TRUE if all the colors in the image are shades of
gray (i.e., their red, green and blue components are equal).
<p> This function is slow for large 16-bit and 32-bit images.
<p> <p>See also <a href="#isGrayscale">isGrayscale</a>().
<h3 class=fn><a href="qimage.html#Endian-enum">Endian</a> <a name="bitOrder"></a>QImage::bitOrder () const
</h3>
Returns the bit order for the image.
<p> If it is a 1-bpp image, this function returns either QImage::BigEndian or
QImage::LittleEndian.
<p> If it is not a 1-bpp image, this function returns QImage::IgnoreEndian.
<p> <p>See also <a href="#depth">depth</a>().
<h3 class=fn>uchar * <a name="bits"></a>QImage::bits () const
</h3>
<p> Returns a pointer to the first pixel data. This is equivalent to <a href="#scanLine">scanLine</a>(0).
<p> <p>See also <a href="#numBytes">numBytes</a>(), <a href="#scanLine">scanLine</a>() and <a href="#jumpTable">jumpTable</a>().
<p>Example: <a href="qglwidget.html#x22">opengl/texture/gltexobj.cpp</a>.
<h3 class=fn>int <a name="bytesPerLine"></a>QImage::bytesPerLine () const
</h3>
Returns the number of bytes per image scanline.
This is equivalent to <a href="#numBytes">numBytes</a>()/height().
<p> <p>See also <a href="#numBytes">numBytes</a>() and <a href="#scanLine">scanLine</a>().
<h3 class=fn>QRgb <a name="color"></a>QImage::color ( int i ) const
</h3>
<p> Returns the color in the color table at index <em>i</em>. The first color is at
index 0.
<p> A color value is an RGB triplet. Use the <a href="qcolor.html#qRed">qRed</a>(), <a href="qcolor.html#qGreen">qGreen</a>() and <a href="qcolor.html#qBlue">qBlue</a>()
functions (defined in qcolor.h) to get the color value components.
<p> <p>See also <a href="#setColor">setColor</a>(), <a href="#numColors">numColors</a>() and <a href="qcolor.html">QColor</a>.
<p>Example: <a href="themes-example.html#x222">themes/wood.cpp</a>.
<h3 class=fn>QRgb * <a name="colorTable"></a>QImage::colorTable () const
</h3>
Returns a pointer to the color table.
<p> <p>See also <a href="#numColors">numColors</a>().
<h3 class=fn><a href="qimage.html">QImage</a> <a name="convertBitOrder"></a>QImage::convertBitOrder ( <a href="qimage.html#Endian-enum">Endian</a> bitOrder ) const
</h3>
Converts the bit order of the image to <em>bitOrder</em> and returns the converted
image. The original image is not changed.
<p> Returns <tt>*this</tt> if the <em>bitOrder</em> is equal to the image bit order, or a
null image if this image cannot be converted.
<p> <p>See also <a href="#bitOrder">bitOrder</a>(), <a href="#systemBitOrder">systemBitOrder</a>() and <a href="#isNull">isNull</a>().
<h3 class=fn><a href="qimage.html">QImage</a> <a name="convertDepth"></a>QImage::convertDepth ( int depth, int conversion_flags ) const
</h3>
Converts the depth (bpp) of the image to <em>depth</em> and returns the
converted image. The original image is not changed.
<p> The <em>depth</em> argument must be 1, 8, 16 or 32.
<p> Returns <tt>*this</tt> if <em>depth</em> is equal to the image depth, or a null
image if this image cannot be converted.
<p> If the image needs to be modified to fit in a lower-resolution
result (eg. converting from 32-bit to 8-bit), use the <em>conversion_flags</em> to specify how you'd prefer this to happen.
<p> <p>See also <a href="qt.html#ImageConversionFlags-enum">Qt::ImageConversionFlags</a>, <a href="#depth">depth</a>() and <a href="#isNull">isNull</a>().
<h3 class=fn><a href="qimage.html">QImage</a> <a name="convertDepth-2"></a>QImage::convertDepth ( int depth ) const
</h3> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p>
<h3 class=fn><a href="qimage.html">QImage</a> <a name="convertDepthWithPalette"></a>QImage::convertDepthWithPalette ( int d, QRgb * palette, int palette_count, int conversion_flags = 0 ) const
</h3>
Note: currently no closest-color search is made. If colors are
found that are not in the palette, the palette may not be used at
all. This result should not be considered valid because it may
change in future implementations.
<p> Currently inefficient for non-32-bit images.
<p> Returns an image with depth <em>d</em>, using the <em>palette_count</em> colors
pointed to by <em>palette</em>. If <em>d</em> is 1 or 8, the returned image will
have its color table ordered the same as <em>palette</em>.
<p> If the image needs to be modified to fit in a lower-resolution
result (eg. converting from 32-bit to 8-bit), use the <em>conversion_flags</em> to specify how you'd prefer this to happen.
<p> <p>See also <a href="qt.html#ImageConversionFlags-enum">Qt::ImageConversionFlags</a>.
<h3 class=fn><a href="qimage.html">QImage</a> <a name="copy"></a>QImage::copy () const
</h3>
Returns a
<a href="shclass.html">deep copy</a> of the image.
<p> <p>See also <a href="#detach">detach</a>().
<h3 class=fn><a href="qimage.html">QImage</a> <a name="copy-2"></a>QImage::copy ( int x, int y, int w, int h, int conversion_flags = 0 ) const
</h3> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p> Returns a
<a href="shclass.html">deep copy</a> of a sub-area of the image.
<p> The returned image is always <em>w</em> by <em>h</em> pixels in size, and is
copied from position <em>x</em>, <em>y</em> in this image.
In areas beyond this image pixels are filled with pixel 0.
<p> If the image needs to be modified to fit in a lower-resolution
result (eg. converting from 32-bit to 8-bit), use the <em>conversion_flags</em> to specify how you'd prefer this to happen.
<p> <p>See also <a href="qpaintdevice.html#bitBlt-2">bitBlt</a>() and <a href="qt.html#ImageConversionFlags-enum">Qt::ImageConversionFlags</a>.
<h3 class=fn><a href="qimage.html">QImage</a> <a name="copy-3"></a>QImage::copy ( const <a href="qrect.html">QRect</a> & r ) const
</h3>
<p> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p> Returns a
<a href="shclass.html">deep copy</a> of a sub-area of the image.
<p> The returned image has always the size of the rectangle <em>r</em>.
In areas beyond this image pixels are filled with pixel 0.
<h3 class=fn>bool <a name="create"></a>QImage::create ( int width, int height, int depth, int numColors = 0, <a href="qimage.html#Endian-enum">Endian</a> bitOrder = IgnoreEndian )
</h3>
Sets the image <em>width</em>, <em>height</em>, <em>depth</em>, its number of colors
(in <em>numColors</em>), and bit order.
Returns TRUE if successful, or FALSE if the parameters are incorrect or
if memory cannot be allocated.
<p> The <em>width</em> and <em>height</em> is limited to 32767. <em>depth</em> must be 1, 8, or
32. If <em>depth</em> is 1, <em>bitOrder</em> must be set to either
QImage::LittleEndian or QImage::BigEndian. For other depths <em>bitOrder</em> must be QImage::IgnoreEndian.
<p> This function allocates a color table and a buffer for the image data.
The image data is not initialized.
<p> The image buffer is allocated as a single block that consists of a table
of <a href="#scanLine">scanline</a> pointers (<a href="#jumpTable">jumpTable</a>()) and the
image data (<a href="#bits">bits</a>()).
<p> <p>See also <a href="#fill">fill</a>(), <a href="#width">width</a>(), <a href="#height">height</a>(), <a href="#depth">depth</a>(), <a href="#numColors">numColors</a>(), <a href="#bitOrder">bitOrder</a>(), <a href="#jumpTable">jumpTable</a>(), <a href="#scanLine">scanLine</a>(), <a href="#bits">bits</a>(), <a href="#bytesPerLine">bytesPerLine</a>() and <a href="#numBytes">numBytes</a>().
<h3 class=fn>bool <a name="create-2"></a>QImage::create ( const <a href="qsize.html">QSize</a> &, int depth, int numColors = 0, <a href="qimage.html#Endian-enum">Endian</a> bitOrder = IgnoreEndian )
</h3>
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p>
<h3 class=fn><a href="qimage.html">QImage</a> <a name="createAlphaMask"></a>QImage::createAlphaMask ( int conversion_flags = 0 ) const
</h3>
Builds and returns a 1-bpp mask from the alpha buffer in this image.
Returns a null image if <a href="#setAlphaBuffer">alpha buffer mode</a>
is disabled.
<p> See <a href="qpixmap.html#convertFromImage">QPixmap::convertFromImage</a>() for a description of the <em>conversion_flags</em> argument.
<p> The returned image has little-endian bit order, which you can
convert to big-endianness using <a href="#convertBitOrder">convertBitOrder</a>().
<p> <p>See also <a href="#createHeuristicMask">createHeuristicMask</a>(), <a href="#hasAlphaBuffer">hasAlphaBuffer</a>() and <a href="#setAlphaBuffer">setAlphaBuffer</a>().
<h3 class=fn><a href="qimage.html">QImage</a> <a name="createHeuristicMask"></a>QImage::createHeuristicMask ( bool clipTight = TRUE ) const
</h3>
Creates and returns a 1-bpp heuristic mask for this image. It works by
selecting a color from one of the corners, then chipping away pixels of
that color starting at all the edges.
<p> The four corners vote for which color is to be masked away. In
case of a draw (this generally means that this function is not
applicable to the image), the result is arbitrary.
<p> The returned image has little-endian bit order, which you can
convert to big-endianness using <a href="#convertBitOrder">convertBitOrder</a>().
<p> If <em>clipTight</em> is TRUE the mask is just large enough to cover the
pixels; otherwise, the mask is larger than the data pixels.
<p> This function disregards the <a href="#hasAlphaBuffer">alpha buffer.</a>
<p> <p>See also <a href="#createAlphaMask">createAlphaMask</a>().
<h3 class=fn>int <a name="depth"></a>QImage::depth () const
</h3>
Returns the depth of the image.
<p> The image depth is the number of bits used to encode a single pixel, also
called bits per pixel (bpp) or bit planes of an image.
<p> The supported depths are 1, 8, 16 and 32.
<p> <p>See also <a href="#convertDepth">convertDepth</a>().
<h3 class=fn>void <a name="detach"></a>QImage::detach ()
</h3>
Detaches from shared image data and makes sure that this image is the
only one referring the data.
<p> If multiple images share common data, this image makes a copy of the
data and detaches itself from the sharing mechanism. Nothing is
done if there is just a single reference.
<p> <p>See also <a href="#copy">copy</a>().
<p>Example: <a href="themes-example.html#x223">themes/wood.cpp</a>.
<h3 class=fn>int <a name="dotsPerMeterX"></a>QImage::dotsPerMeterX () const
</h3>
<p> Returns the number of pixels that fit horizontally in a physical meter.
This and <a href="#dotsPerMeterY">dotsPerMeterY</a>() define the intended scale and aspect ratio
of the image.
<p> <p>See also <a href="#setDotsPerMeterX">setDotsPerMeterX</a>().
<h3 class=fn>int <a name="dotsPerMeterY"></a>QImage::dotsPerMeterY () const
</h3>
<p> Returns the number of pixels that fit vertically in a physical meter.
This and <a href="#dotsPerMeterX">dotsPerMeterX</a>() define the intended scale and aspect ratio
of the image.
<p> <p>See also <a href="#setDotsPerMeterY">setDotsPerMeterY</a>().
<h3 class=fn>void <a name="fill"></a>QImage::fill ( uint pixel )
</h3>
Fills the entire image with the pixel value <em>pixel</em>.
<p> If the <a href="#depth">depth</a> of this image is 1, only
the lowest bit is used. If you say <a href="#fill">fill</a>(0), fill(2), etc., the image
is filled with 0s. If you say fill(1), fill(3), etc., the image
is filled with 1s. If the depth is 8, the lowest 8 bits are used.
<p> If the depth is 32 and the image has no alpha buffer, the <em>pixel</em>
value is written to each pixel in the image. If the image has an
alpha buffer, only the 24 RGB bits are set and the upper 8 bits (alpha
value) are left unchanged.
<p> <p>See also <a href="#invertPixels">invertPixels</a>(), <a href="#depth">depth</a>(), <a href="#hasAlphaBuffer">hasAlphaBuffer</a>() and <a href="#create">create</a>().
<h3 class=fn>bool <a name="hasAlphaBuffer"></a>QImage::hasAlphaBuffer () const
</h3>
<p> Returns TRUE if alpha buffer mode is enabled, otherwise FALSE.
<p> <p>See also <a href="#setAlphaBuffer">setAlphaBuffer</a>().
<h3 class=fn>int <a name="height"></a>QImage::height () const
</h3>
Returns the height of the image.
<p>See also <a href="#width">width</a>(), <a href="#size">size</a>() and <a href="#rect">rect</a>().
<p>Examples: <a href="canvas-example.html#x2532">canvas/canvas.cpp</a> and <a href="qglwidget.html#x23">opengl/texture/gltexobj.cpp</a>.
<h3 class=fn>const char * <a name="imageFormat"></a>QImage::imageFormat ( const <a href="qstring.html">QString</a> & fileName )<tt> [static]</tt>
</h3>
Returns a string that specifies the image format of the file <em>fileName</em>,
or null if the file cannot be read or if the format is not recognized.
<p> The <a href="qimageio.html">QImageIO</a> documentation lists the guaranteed supported image
formats, or use <a href="#inputFormats">QImage::inputFormats</a>() and <a href="#outputFormats">QImage::outputFormats</a>()
to get lists that include the installed formats.
<p> <p>See also <a href="#load">load</a>() and <a href="#save">save</a>().
<h3 class=fn><a href="qstringlist.html">QStringList</a> <a name="inputFormatList"></a>QImage::inputFormatList ()<tt> [static]</tt>
</h3>
Returns a list of image formats that are supported for image input.
<p> Note that if you want to iterate over the list, you should
iterate over a copy, e.g.
<pre>
<a href="qstringlist.html">QStringList</a> list = myImage.inputFormatList();
QStringList::Iterator it = list.<a href="qvaluelist.html#begin">begin</a>();
while( it != list.<a href="qvaluelist.html#end">end</a>() ) {
myProcessing( *it );
++it;
}
</pre>
<p> <p>See also <a href="#outputFormatList">outputFormatList</a>(), <a href="#inputFormats">inputFormats</a>() and <a href="qimageio.html">QImageIO</a>.
<p>Example: <a href="showimg-example.html#x421">showimg/showimg.cpp</a>.
<h3 class=fn><a href="qstrlist.html">QStrList</a> <a name="inputFormats"></a>QImage::inputFormats ()<tt> [static]</tt>
</h3>
Returns a list of image formats that are supported for image input.
<p> <p>See also <a href="#outputFormats">outputFormats</a>(), <a href="#inputFormatList">inputFormatList</a>() and <a href="qimageio.html">QImageIO</a>.
<h3 class=fn>void <a name="invertPixels"></a>QImage::invertPixels ( bool invertAlpha = TRUE )
</h3>
Inverts all pixel values in the image.
<p> If the depth is 32: if <em>invertAlpha</em> is TRUE, the alpha bits are also
inverted, otherwise they are left unchanged.
<p> If the depth is not 32, the argument <em>invertAlpha</em> has no meaning.
<p> Note that inverting an 8-bit image means to replace all pixels using
color index <em>i</em> with a pixel using color index 255 minus <em>i</em>. Similarly
for a 1-bit image. The color table is not changed.
<p> <p>See also <a href="#fill">fill</a>(), <a href="#depth">depth</a>() and <a href="#hasAlphaBuffer">hasAlphaBuffer</a>().
<h3 class=fn>bool <a name="isGrayscale"></a>QImage::isGrayscale () const
</h3>
For 16-bit and 32-bit images, this function is equivalent to <a href="#allGray">allGray</a>().
<p> For 8-bpp images, this function returns TRUE if <a href="#color">color</a>(i) is QRgb(i,i,i) for
all indices of the color table.
<p> <p>See also <a href="#allGray">allGray</a>() and <a href="#depth">depth</a>().
<h3 class=fn>bool <a name="isNull"></a>QImage::isNull () const
</h3>
Returns TRUE if it is a null image, otherwise FALSE.
<p> A null image has all parameters set to zero and no allocated data.
<p>Examples: <a href="qtimage-nsplugin-example.html#x2438">qtimage/qtimage.cpp</a> and <a href="showimg-example.html#x422">showimg/showimg.cpp</a>.
<h3 class=fn>uchar ** <a name="jumpTable"></a>QImage::jumpTable () const
</h3>
Returns a pointer to the scanline pointer table.
<p> This is the beginning of the data block for the image.
<p> <p>See also <a href="#bits">bits</a>() and <a href="#scanLine">scanLine</a>().
<h3 class=fn>bool <a name="load"></a>QImage::load ( const <a href="qstring.html">QString</a> & fileName, const char * format = 0 )
</h3>
Loads an image from the file <em>fileName</em>.
Returns TRUE if the image was successfully loaded; otherwise returns FALSE.
<p> If <em>format</em> is specified, the loader attempts to read the image using the
specified format. If <em>format</em> is not specified (which is the default),
the loader reads a few bytes from the header to guess the file format.
<p> The <a href="qimageio.html">QImageIO</a> documentation lists the supported image formats and
explains how to add extra formats.
<p> <p>See also <a href="#loadFromData">loadFromData</a>(), <a href="#save">save</a>(), <a href="#imageFormat">imageFormat</a>(), <a href="qpixmap.html#load">QPixmap::load</a>() and <a href="qimageio.html">QImageIO</a>.
<h3 class=fn>bool <a name="loadFromData"></a>QImage::loadFromData ( const uchar * buf, uint len, const char * format = 0 )
</h3>
Loads an image from the first <em>len</em> bytes of binary data in <em>buf</em>.
Returns TRUE if the image was successfully loaded; otherwise returns FALSE.
<p> If <em>format</em> is specified, the loader attempts to read the image using the
specified format. If <em>format</em> is not specified (which is the default),
the loader reads a few bytes from the header to guess the file format.
<p> The <a href="qimageio.html">QImageIO</a> documentation lists the supported image formats and
explains how to add extra formats.
<p> <p>See also <a href="#load">load</a>(), <a href="#save">save</a>(), <a href="#imageFormat">imageFormat</a>(), <a href="qpixmap.html#loadFromData">QPixmap::loadFromData</a>() and <a href="qimageio.html">QImageIO</a>.
<h3 class=fn>bool <a name="loadFromData-2"></a>QImage::loadFromData ( <a href="qbytearray.html">QByteArray</a> buf, const char * format = 0 )
</h3>
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p> Loads an image from the <a href="qbytearray.html">QByteArray</a> <em>buf</em>.
<h3 class=fn><a href="qimage.html">QImage</a> <a name="mirror"></a>QImage::mirror () const
</h3>
Returns a QImage which is a vertically mirrored copy of this
image. The original QImage is not changed.
<h3 class=fn><a href="qimage.html">QImage</a> <a name="mirror-2"></a>QImage::mirror ( bool horizontal, bool vertical ) const
</h3> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p> Returns the image mirrored in the horizontal and/or the vertical
direction depending on whether <em>horizontal</em> and <em>vertical</em> are set
to TRUE or FALSE. The original image is not changed.
<p> <p>See also <a href="#smoothScale">smoothScale</a>().
<h3 class=fn>int <a name="numBytes"></a>QImage::numBytes () const
</h3>
Returns the number of bytes occupied by the image data.
<p> <p>See also <a href="#bytesPerLine">bytesPerLine</a>() and <a href="#bits">bits</a>().
<h3 class=fn>int <a name="numColors"></a>QImage::numColors () const
</h3>
Returns the size of the color table for the image.
<p> Notice that <a href="#numColors">numColors</a>() returns 0 for 16-bpp and 32-bpp images
because these images do not use color tables, but instead encode pixel
values as RGB triplets.
<p> <p>See also <a href="#setNumColors">setNumColors</a>() and <a href="#colorTable">colorTable</a>().
<p>Example: <a href="themes-example.html#x224">themes/wood.cpp</a>.
<h3 class=fn><a href="qpoint.html">QPoint</a> <a name="offset"></a>QImage::offset () const
</h3>
<p> Returns the number of pixels by which the image is intended to be
offset by when positioning relative to other images.
<h3 class=fn>bool <a name="operator!-eq"></a>QImage::operator!= ( const <a href="qimage.html">QImage</a> & i ) const
</h3> Returns TRUE if this image and image <em>i</em> have different contents;
otherwise returns FALSE. The comparison can be slow, unless there
is some obvious difference, such as different widths, in which
case the function will return quickly.
<p> <p>See also <a href="#operator-eq">operator=</a>().
<h3 class=fn><a href="qimage.html">QImage</a> & <a name="operator-eq"></a>QImage::operator= ( const <a href="qimage.html">QImage</a> & image )
</h3>
Assigns a
<a href="shclass.html">shallow copy</a>
of <em>image</em> to this image and returns a reference to this image.
<p> <p>See also <a href="#copy">copy</a>().
<h3 class=fn><a href="qimage.html">QImage</a> & <a name="operator-eq-2"></a>QImage::operator= ( const <a href="qpixmap.html">QPixmap</a> & pixmap )
</h3> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p> Sets the image bits to the <em>pixmap</em> contents and returns a reference to
the image.
<p> If the image shares data with other images, it will first dereference
the shared data.
<p> Makes a call to <a href="qpixmap.html#convertToImage">QPixmap::convertToImage</a>().
<h3 class=fn>bool <a name="operator-eq-eq"></a>QImage::operator== ( const <a href="qimage.html">QImage</a> & i ) const
</h3> Returns TRUE if this image and image <em>i</em> have the same contents;
otherwise returns FALSE. The comparison can be slow, unless there
is some obvious difference, such as different widths, in which
case the function will return quickly.
<p> <p>See also <a href="#operator-eq">operator=</a>().
<h3 class=fn><a href="qstringlist.html">QStringList</a> <a name="outputFormatList"></a>QImage::outputFormatList ()<tt> [static]</tt>
</h3>
Returns a list of image formats that are supported for image output.
<p> Note that if you want to iterate over the list, you should
iterate over a copy, e.g.
<pre>
<a href="qstringlist.html">QStringList</a> list = myImage.outputFormatList();
QStringList::Iterator it = list.<a href="qvaluelist.html#begin">begin</a>();
while( it != list.<a href="qvaluelist.html#end">end</a>() ) {
myProcessing( *it );
++it;
}
</pre>
<p> <p>See also <a href="#inputFormatList">inputFormatList</a>(), <a href="#outputFormats">outputFormats</a>() and <a href="qimageio.html">QImageIO</a>.
<h3 class=fn><a href="qstrlist.html">QStrList</a> <a name="outputFormats"></a>QImage::outputFormats ()<tt> [static]</tt>
</h3>
Returns a list of image formats that are supported for image output.
<p> <p>See also <a href="#inputFormats">inputFormats</a>(), <a href="#outputFormatList">outputFormatList</a>() and <a href="qimageio.html">QImageIO</a>.
<p>Example: <a href="showimg-example.html#x423">showimg/showimg.cpp</a>.
<h3 class=fn>QRgb <a name="pixel"></a>QImage::pixel ( int x, int y ) const
</h3>
Returns the color of the pixel at the coordinates (<em>x</em>, <em>y</em>).
<p> If (<em>x</em>, <em>y</em>) is not <a href="#valid">on the image</a>, the results
are undefined.
<p> <p>See also <a href="#setPixel">setPixel</a>(), <a href="qcolor.html#qRed">qRed</a>(), <a href="qcolor.html#qGreen">qGreen</a>(), <a href="qcolor.html#qBlue">qBlue</a>() and <a href="#valid">valid</a>().
<p>Examples: <a href="canvas-example.html#x2533">canvas/canvas.cpp</a> and <a href="qmag-example.html#x696">qmag/qmag.cpp</a>.
<h3 class=fn>int <a name="pixelIndex"></a>QImage::pixelIndex ( int x, int y ) const
</h3>
Returns the pixel index at the given coordinates.
<p> If (<em>x</em>, <em>y</em>) is not <a href="#valid">valid</a>, or if
the image is not a paletted image (<a href="#depth">depth</a>() > 8), the results
are undefined.
<p> <p>See also <a href="#valid">valid</a>() and <a href="#depth">depth</a>().
<h3 class=fn><a href="qrect.html">QRect</a> <a name="rect"></a>QImage::rect () const
</h3>
Returns the enclosing rectangle (0,0,width(),height()) of the image.
<p>See also <a href="#width">width</a>(), <a href="#height">height</a>() and <a href="#size">size</a>().
<h3 class=fn>void <a name="reset"></a>QImage::reset ()
</h3>
Resets all image parameters and deallocates the image data.
<p>Example: <a href="qtimage-nsplugin-example.html#x2439">qtimage/qtimage.cpp</a>.
<h3 class=fn>bool <a name="save"></a>QImage::save ( const <a href="qstring.html">QString</a> & fileName, const char * format, int quality = -1 ) const
</h3>
Saves the image to the file <em>fileName</em>, using the image file format <em>format</em> and a quality factor of <em>quality</em>. <em>quality</em> must be in the range
0..100 or -1. Specify 0 to obtain small compressed files, 100 for
large uncompressed files, and -1 (the default) to use the default
settings.
<p> Returns TRUE if the image was successfully saved; otherwise returns FALSE.
<p> <p>See also <a href="#load">load</a>(), <a href="#loadFromData">loadFromData</a>(), <a href="#imageFormat">imageFormat</a>(), <a href="qpixmap.html#save">QPixmap::save</a>() and <a href="qimageio.html">QImageIO</a>.
<h3 class=fn><a href="qimage.html">QImage</a> <a name="scale"></a>QImage::scale ( int w, int h, <a href="qimage.html#ScaleMode-enum">ScaleMode</a> mode = ScaleFree ) const
</h3>
Returns a scaled copy of the image. The returned image has a size of
width <em>w</em> by height <em>h</em> pixels if <em>mode</em> is <a href="#ScaleMode-enum">ScaleFree</a>. The
modes <a href="#ScaleMode-enum">ScaleMin</a> and <a href="#ScaleMode-enum">ScaleMax</a> may be used to preserve the ratio
of the image: if <em>mode</em> is <a href="#ScaleMode-enum">ScaleMin</a>, the returned image is
guaranteed to fit into the rectangle specified by <em>w</em> and <em>h</em> (it
is as large as possible within the constraints); if <em>mode</em> is <a href="#ScaleMode-enum">ScaleMax</a>, the returned image fits at least into the specified
rectangle (it is a small as possible within the constraints).
<p> If either the width <em>w</em> or the height <em>h</em> is 0 or negative, this function
returns a null image.
<p> This function uses a rather simple algorithm; if you need a better
quality, use <a href="#smoothScale">smoothScale</a>() instead.
<p> <p>See also <a href="#scaleWidth">scaleWidth</a>(), <a href="#scaleHeight">scaleHeight</a>(), <a href="#smoothScale">smoothScale</a>() and <a href="#xForm">xForm</a>().
<h3 class=fn><a href="qimage.html">QImage</a> <a name="scale-2"></a>QImage::scale ( const <a href="qsize.html">QSize</a> & s, <a href="qimage.html#ScaleMode-enum">ScaleMode</a> mode = ScaleFree ) const
</h3> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p> The requested size of the image is <em>s</em>.
<h3 class=fn><a href="qimage.html">QImage</a> <a name="scaleHeight"></a>QImage::scaleHeight ( int h ) const
</h3> Returns a scaled copy of the image. The returned image has a height
of <em>h</em> pixels. This function automatically calculates the width of the
image so that the ratio of the image is preserved.
<p> If <em>h</em> is 0 or negative a null image is returned.
<p> <p>See also <a href="#scale">scale</a>(), <a href="#scaleWidth">scaleWidth</a>(), <a href="#smoothScale">smoothScale</a>() and <a href="#xForm">xForm</a>().
<p>Example: <a href="small-table-example-example.html#x2471">table/small-table-demo/main.cpp</a>.
<h3 class=fn><a href="qimage.html">QImage</a> <a name="scaleWidth"></a>QImage::scaleWidth ( int w ) const
</h3>
Returns a scaled copy of the image. The returned image has a width
of <em>w</em> pixels. This function automatically calculates the height of the
image so that the ratio of the image is preserved.
<p> If <em>w</em> is 0 or negative a null image is returned.
<p> <p>See also <a href="#scale">scale</a>(), <a href="#scaleHeight">scaleHeight</a>(), <a href="#smoothScale">smoothScale</a>() and <a href="#xForm">xForm</a>().
<h3 class=fn>uchar * <a name="scanLine"></a>QImage::scanLine ( int i ) const
</h3>
<p> Returns a pointer to the pixel data at the scanline with index <em>i</em>. The
first scanline is at index 0.
<p> The scanline data is aligned on a 32-bit boundary.
<p> <b>Warning:</b> If you are accessing 32-bpp image data, cast the returned
pointer to <tt>QRgb*</tt> (QRgb has a 32-bit size) and use it to read/write
the pixel value. You cannot use the <tt>uchar*</tt> pointer directly, because
the pixel format depends on the byte order on the underlying
platform. Hint: use <a href="qcolor.html#qRed">qRed()</a> and friends (qcolor.h)
to access the pixels.
<p> <b>Warning:</b> If you are accessing 16-bpp image data, you have to handle
endianness yourself for now.
<p> <p>See also <a href="#bytesPerLine">bytesPerLine</a>(), <a href="#bits">bits</a>() and <a href="#jumpTable">jumpTable</a>().
<p>Example: <a href="desktop-example.html#x1724">desktop/desktop.cpp</a>.
<h3 class=fn>void <a name="setAlphaBuffer"></a>QImage::setAlphaBuffer ( bool enable )
</h3>
Enables alpha buffer mode if <em>enable</em> is TRUE, otherwise disables it.
The default setting is disabled.
<p> An 8-bpp image has 8-bit pixels. A pixel is an index into the <a href="#color">color table</a>, which contains 32-bit color values.
In a 32-bpp image, the 32-bit pixels are the color values.
<p> This 32-bit value is encoded as follows: The lower 24 bits are used for
the red, green, and blue components. The upper 8 bits contain the alpha
component.
<p> The alpha component specifies the transparency of a pixel. 0 means
completely transparent and 255 means opaque. The alpha component is
ignored if you do not enable alpha buffer mode.
<p> The alpha buffer is used to set a mask when a QImage is translated to a
<a href="qpixmap.html">QPixmap</a>.
<p> <p>See also <a href="#hasAlphaBuffer">hasAlphaBuffer</a>() and <a href="#createAlphaMask">createAlphaMask</a>().
<h3 class=fn>void <a name="setColor"></a>QImage::setColor ( int i, QRgb c )
</h3>
<p> Sets a color in the color table at index <em>i</em> to <em>c</em>.
<p> A color value is an RGB triplet. Use the qRgb function (defined in qcolor.h)
to make RGB triplets.
<p> <p>See also <a href="#color">color</a>(), <a href="#setNumColors">setNumColors</a>() and <a href="#numColors">numColors</a>().
<p>Examples: <a href="desktop-example.html#x1725">desktop/desktop.cpp</a> and <a href="themes-example.html#x225">themes/wood.cpp</a>.
<h3 class=fn>void <a name="setDotsPerMeterX"></a>QImage::setDotsPerMeterX ( int x )
</h3>
Sets the value returned by <a href="#dotsPerMeterX">dotsPerMeterX</a>() to <em>x</em>.
<h3 class=fn>void <a name="setDotsPerMeterY"></a>QImage::setDotsPerMeterY ( int y )
</h3>
Sets the value returned by <a href="#dotsPerMeterY">dotsPerMeterY</a>() to <em>y</em>.
<h3 class=fn>void <a name="setNumColors"></a>QImage::setNumColors ( int numColors )
</h3>
Resizes the color table to <em>numColors</em> colors.
<p> If the color table is expanded, then all new colors will be set to black
(RGB 0,0,0).
<p> <p>See also <a href="#numColors">numColors</a>(), <a href="#color">color</a>(), <a href="#setColor">setColor</a>() and <a href="#colorTable">colorTable</a>().
<h3 class=fn>void <a name="setOffset"></a>QImage::setOffset ( const <a href="qpoint.html">QPoint</a> & p )
</h3>
Sets the value returned by <a href="#offset">offset</a>() to <em>p</em>.
<h3 class=fn>void <a name="setPixel"></a>QImage::setPixel ( int x, int y, uint index_or_rgb )
</h3>
Sets the pixel index or color at the coordinates (<em>x</em>, <em>y</em>) to <em>index_or_rgb</em>.
<p> If (<em>x</em>, <em>y</em>) is not <a href="#valid">valid</a>, the result is undefined.
<p> If the image is a paletted image (<a href="#depth">depth</a>() <= 8) and <em>index_or_rgb</em>
>= <a href="#numColors">numColors</a>(), the result is undefined.
<p> <p>See also <a href="#pixelIndex">pixelIndex</a>(), <a href="#pixel">pixel</a>(), <a href="qcolor.html#qRgb">qRgb</a>(), <a href="qcolor.html#qRgba">qRgba</a>() and <a href="#valid">valid</a>().
<h3 class=fn>void <a name="setText"></a>QImage::setText ( const char * key, const char * lang, const <a href="qstring.html">QString</a> & s )
</h3>
Records string <em>s</em> for the keyword <em>key</em>. The <em>key</em> should be
a portable keyword recognizable by other software - some suggested
values can be found in
<a href="http://www.libpng.org/pub/png/spec/PNG-Chunks.html#C.Anc-text">the PNG specification</a>. <em>s</em> can be any text. <em>lang</em> should
specify the language code (see
<a href="ftp://ftp.isi.edu/in-notes/1766">RFC 1766</a>) or 0.
<h3 class=fn><a href="qsize.html">QSize</a> <a name="size"></a>QImage::size () const
</h3>
Returns the size of the image, i.e. its width and height.
<p>See also <a href="#width">width</a>(), <a href="#height">height</a>() and <a href="#rect">rect</a>().
<h3 class=fn><a href="qimage.html">QImage</a> <a name="smoothScale"></a>QImage::smoothScale ( int w, int h, <a href="qimage.html#ScaleMode-enum">ScaleMode</a> mode = ScaleFree ) const
</h3>
Returns a smoothly scaled copy of the image. The returned image
has a size of width <em>w</em> by height <em>h</em> pixels if <em>mode</em> is <a href="#ScaleMode-enum">ScaleFree</a>. The modes <a href="#ScaleMode-enum">ScaleMin</a> and <a href="#ScaleMode-enum">ScaleMax</a> may be used to
preserve the ratio of the image: if <em>mode</em> is <a href="#ScaleMode-enum">ScaleMin</a>, the
returned image is guaranteed to fit into the rectangle specified by
<em>w</em> and <em>h</em> (it is as large as possible within the constraints);
if <em>mode</em> is <a href="#ScaleMode-enum">ScaleMax</a>, the returned image fits at least into the
specified rectangle (it is a small as possible within the
constraints).
<p> For 32-bpp images and 1-bpp/8-bpp color images the result will be 32-bpp,
whereas <a href="#allGray">all-gray</a> images (including black-and-white
1-bpp) will produce 8-bit <a href="#isGrayscale">grayscale</a> images with
the palette spanning 256 grays from black to white.
<p> This function uses code based on pnmscale.c by Jef Poskanzer.
<p> pnmscale.c - read a portable anymap and scale it
<p>
<p> Copyright (C) 1989, 1991 by Jef Poskanzer.
<p> Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted, provided
that the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation. This software is provided "as is" without express or
implied warranty.
<p> <p>See also <a href="#scale">scale</a>() and <a href="#mirror">mirror</a>().
<h3 class=fn><a href="qimage.html">QImage</a> <a name="smoothScale-2"></a>QImage::smoothScale ( const <a href="qsize.html">QSize</a> & s, <a href="qimage.html#ScaleMode-enum">ScaleMode</a> mode = ScaleFree ) const
</h3> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p> The requested size of the image is <em>s</em>.
<h3 class=fn><a href="qimage.html">QImage</a> <a name="swapRGB"></a>QImage::swapRGB () const
</h3>
Returns a QImage in which the values of the red and blue components of
all pixels have been swapped, effectively converting an RGB image to
a BGR image. The original QImage is not changed.
<h3 class=fn><a href="qimage.html#Endian-enum">Endian</a> <a name="systemBitOrder"></a>QImage::systemBitOrder ()<tt> [static]</tt>
</h3>
Determines the bit order of the display hardware.
Returns QImage::LittleEndian (LSB first) or QImage::BigEndian (MSB first).
<p> <p>See also <a href="#systemByteOrder">systemByteOrder</a>().
<h3 class=fn><a href="qimage.html#Endian-enum">Endian</a> <a name="systemByteOrder"></a>QImage::systemByteOrder ()<tt> [static]</tt>
</h3>
Determines the host computer byte order.
Returns QImage::LittleEndian (LSB first) or QImage::BigEndian (MSB first).
<p> <p>See also <a href="#systemBitOrder">systemBitOrder</a>().
<h3 class=fn><a href="qstring.html">QString</a> <a name="text"></a>QImage::text ( const char * key, const char * lang = 0 ) const
</h3>
Returns the string recorded for the keyword <em>key</em> in language <em>lang</em>,
or in a default language if <em>lang</em> is 0.
<h3 class=fn><a href="qstring.html">QString</a> <a name="text-2"></a>QImage::text ( const QImageTextKeyLang & kl ) const
</h3> This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p> Returns the string recorded for the keyword and language <em>kl</em>.
<h3 class=fn><a href="qstringlist.html">QStringList</a> <a name="textKeys"></a>QImage::textKeys () const
</h3>
Returns the keywords for which some texts are recorded.
<p> Note that if you want to iterate over the list, you should
iterate over a copy, e.g.
<pre>
<a href="qstringlist.html">QStringList</a> list = myImage.textKeys();
QStringList::Iterator it = list.<a href="qvaluelist.html#begin">begin</a>();
while( it != list.<a href="qvaluelist.html#end">end</a>() ) {
myProcessing( *it );
++it;
}
</pre>
<p> <p>See also <a href="#textList">textList</a>(), <a href="#text">text</a>(), <a href="#setText">setText</a>() and <a href="#textLanguages">textLanguages</a>().
<h3 class=fn><a href="qstringlist.html">QStringList</a> <a name="textLanguages"></a>QImage::textLanguages () const
</h3>
Returns the language identifiers for which some texts are recorded.
<p> Note that if you want to iterate over the list, you should
iterate over a copy, e.g.
<pre>
<a href="qstringlist.html">QStringList</a> list = myImage.textLanguages();
QStringList::Iterator it = list.<a href="qvaluelist.html#begin">begin</a>();
while( it != list.<a href="qvaluelist.html#end">end</a>() ) {
myProcessing( *it );
++it;
}
</pre>
<p> <p>See also <a href="#textList">textList</a>(), <a href="#text">text</a>(), <a href="#setText">setText</a>() and <a href="#textKeys">textKeys</a>().
<h3 class=fn><a href="qvaluelist.html">QValueList</a><QImageTextKeyLang> <a name="textList"></a>QImage::textList () const
</h3>
Returns a list of QImageTextKeyLang objects that enumerate
all the texts key/language pairs set by <a href="#setText">setText</a>() for this image.
<p> Note that if you want to iterate over the list, you should
iterate over a copy, e.g.
<pre>
<a href="qvaluelist.html">QValueList</a><QImageTextKeyLang> list = myImage.textList();
QValueList<QImageTextKeyLang>::Iterator it = list.<a href="qvaluelist.html#begin">begin</a>();
while( it != list.<a href="qvaluelist.html#end">end</a>() ) {
myProcessing( *it );
++it;
}
</pre>
<h3 class=fn>bool <a name="valid"></a>QImage::valid ( int x, int y ) const
</h3>
Returns TRUE if ( <em>x</em>, <em>y</em> ) is a valid coordinate in the image, otherwise
it returns FALSE.
<p> <p>See also <a href="#width">width</a>(), <a href="#height">height</a>() and <a href="#pixelIndex">pixelIndex</a>().
<p>Examples: <a href="canvas-example.html#x2534">canvas/canvas.cpp</a> and <a href="qmag-example.html#x697">qmag/qmag.cpp</a>.
<h3 class=fn>int <a name="width"></a>QImage::width () const
</h3>
Returns the width of the image.
<p>See also <a href="#height">height</a>(), <a href="#size">size</a>() and <a href="#rect">rect</a>().
<p>Examples: <a href="canvas-example.html#x2535">canvas/canvas.cpp</a> and <a href="qglwidget.html#x24">opengl/texture/gltexobj.cpp</a>.
<h3 class=fn><a href="qimage.html">QImage</a> <a name="xForm"></a>QImage::xForm ( const <a href="qwmatrix.html">QWMatrix</a> & matrix ) const
</h3>
Returns a copy of the image that is transformed using the
transformation matrix, <em>matrix</em>.
<p> The transformation <em>matrix</em> is internally adjusted to compensate
for unwanted translation, i.e. <a href="#xForm">xForm</a>() returns the smallest image
that contains all the transformed points of the original image.
<p> <p>See also <a href="#scale">scale</a>(), <a href="qpixmap.html#xForm">QPixmap::xForm</a>(), <a href="qpixmap.html#trueMatrix">QPixmap::trueMatrix</a>() and <a href="qwmatrix.html">QWMatrix</a>.
<hr><h2>Related Functions</h2>
<h3 class=fn><a href="qdatastream.html">QDataStream</a> & <a name="operator-lt-lt"></a>operator<< ( <a href="qdatastream.html">QDataStream</a> & s, const <a href="qimage.html">QImage</a> & image )
</h3>
Writes the image <em>image</em> to the stream <em>s</em> as a PNG image.
<p>See also <a href="#save">QImage::save</a>() and <a href="datastreamformat.html">Format of the QDataStream operators</a>.
<h3 class=fn><a href="qdatastream.html">QDataStream</a> & <a name="operator-gt-gt"></a>operator>> ( <a href="qdatastream.html">QDataStream</a> & s, <a href="qimage.html">QImage</a> & image )
</h3>
Reads an image from the stream <em>s</em> and stores it in <em>image</em>.
<p>See also <a href="#load">QImage::load</a>() and <a href="datastreamformat.html">Format of the QDataStream operators</a>.
<!-- eof -->
<hr><p>
This file is part of the <a href="index.html">Qt toolkit</a>.
Copyright © 1995-2001
<a href="http://www.trolltech.com/">Trolltech</a>. All Rights Reserved.<p><address><hr><div align=center>
<table width=100% cellspacing=0 border=0><tr>
<td>Copyright © 2001
<a href="http://www.trolltech.com">Trolltech</a><td><a href="http://www.trolltech.com/trademarks.html">Trademarks</a>
<td align=right><div align=right>Qt version 3.0.2</div>
</table></div></address></body>
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