QImageDecoder Class Reference

Detailed Description

New formats are installed by creating objects of class QImageFormatType; the QMovie class can be used for all installed incremental image formats. QImageDecoder is only useful for creating new ways of feeding data to an QImageConsumer.

A QImageDecoder is a machine that decodes images. It takes encoded image data via its decode() method and expresses its decoding by supplying information to a QImageConsumer. It implements its decoding by using a QImageFormat created by one of the currently-existing QImageFormatType factory objects.

QImageFormatType and QImageFormat are the classes that you might need to implement support for additional image formats.

Qt supports GIF reading if it is configured that way during installation (see qgif.h). If it is, we are required to state that "The Graphics Interchange Format(c) is the Copyright property of CompuServe Incorporated. GIF(sm) is a Service Mark property of CompuServe Incorporated."

Warning: If you are in a country that recognizes software patents and in which Unisys holds a patent on LZW compression and/or decompression and you want to use GIF, Unisys may require you to license that technology. Such countries include Canada, Japan, the USA, France, Germany, Italy and the UK.

GIF support may be removed completely in a future version of Qt. We recommend using the MNG or PNG format.

See also Graphics Classes, Image Processing Classes, and Multimedia Classes.

Member Function Documentation

QImageDecoder::QImageDecoder ( QImageConsumer * c )

QImageDecoder::~QImageDecoder ()

int QImageDecoder::decode ( const uchar * buffer, int length )

Returns the number of bytes consumed: 0 if consumption is complete, and -1 if decoding fails due to invalid data.

QImageFormatType * QImageDecoder::format ( const char * name ) [static]

const char * QImageDecoder::formatName ( const uchar * buffer, int length ) [static]

Returns 0 if the format is not recognized.

const QImage & QImageDecoder::image ()

Returns the image currently being decoded.

QStrList QImageDecoder::inputFormats () [static]

void QImageDecoder::registerDecoderFactory ( QImageFormatType * f ) [static]

void QImageDecoder::unregisterDecoderFactory ( QImageFormatType * f ) [static]

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