QImageWriter Class Reference
[QtGui module]

Detailed Description

The QImageWriter class provides a format independent interface for writing images to files or other devices.

QImageWriter supports setting format specific options, such as the gamma level, compression level and quality, prior to storing the image. If you do not need such options, you can use QImage::save() or QPixmap::save() instead.

To store an image, you start by constructing a QImageWriter object. Pass either a file name or a device pointer, and the image format to QImageWriter's constructor. You can then set several options, such as the gamma level (by calling setGamma()) and quality (by calling setQuality()). canWrite() returns true if QImageWriter can write the image (i.e., the image format is supported and the device is open for writing). Call write() to write the image to the device.

If any error occurs when writing the image, write() will return false. You can then call error() to find the type of error that occurred, or errorString() to get a human readable description of what went wrong.

Call supportedImageFormats() for a list of formats that QImageWriter can write. QImageWriter supports all built-in image formats, in addition to any image format plugins that support writing.

See also QImageReader, QImageIOHandler, and QImageIOPlugin.

Member Type Documentation

 QImageWriter writer;
 writer.setFormat("png"); // same as writer.setFormat("PNG");

 QImage image("some/image.jpeg");
 QImageWriter writer("images/outimage.png", "png");
 writer.setText("Author", "John Smith");
 writer.write(image);

 QImageWriter writer(fileName);
 if (writer.supportsOption(QImageIOHandler::Description))
     writer.setText("Author", "John Smith");