---
name: "qpngimagepacker"
section: "3qt"
platform: "linux"
package: "qt3-doc"
version: "3:3.3.8b-7"
release: "Debian 6.0 (Squeeze)"
platforms: ["linux"]
url: "https://new.carta.tech/qpngimagepacker"
---

# qpngimagepacker(3qt)

Creates well-compressed PNG animations

## NAME

QPNGImagePacker - Creates well-compressed PNG animations

## SYNOPSIS

`#include <qpngio.h>`

### Public Members

**QPNGImagePacker ( QIODevice \* iod, int storage\_depth, int conversionflags )**\
 **void setPixelAlignment ( int x )**\
 **bool packImage ( const QImage & img )**\

## DESCRIPTION

The QPNGImagePacker class creates well-compressed PNG animations.

By using transparency, QPNGImagePacker allows you to build a PNG image from a sequence of QImages.

Images are added using packImage().

See also Graphics Classes and Image Processing Classes.

## MEMBER FUNCTION DOCUMENTATION

## QPNGImagePacker::QPNGImagePacker ( QIODevice \* iod, int storage\_depth, int conversionflags )

Creates an image packer that writes PNG data to IO device *iod* using a *storage\_depth* bit encoding (use 8 or 32, depending on the desired quality and compression requirements).

If the image needs to be modified to fit in a lower-resolution result (e.g. converting from 32-bit to 8-bit), use the *conversionflags* to specify how you'd prefer this to happen.

See also Qt::ImageConversionFlags.

## bool QPNGImagePacker::packImage ( const QImage & img )

Adds the image *img* to the PNG animation, analyzing the differences between this and the previous image to improve compression.

## void QPNGImagePacker::setPixelAlignment ( int x )

Aligns pixel differences to *x* pixels. For example, using 8 can improve playback on certain hardware. Normally the default of 1-pixel alignment (i.e. no alignment) gives better compression and performance.

## SEE ALSO

**http://doc.trolltech.com/qpngimagepacker.html** **http://www.trolltech.com/faq/tech.html**

## COPYRIGHT

Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com.  See the license file included in the distribution for a complete license statement.

## AUTHOR

Generated automatically from the source code.

## BUGS

If you find a bug in Qt, please report it as described in **http://doc.trolltech.com/bughowto.html**. Good bug reports help us to help you. Thank you.

The definitive Qt documentation is provided in HTML format; it is located at $QTDIR/doc/html and can be read using Qt Assistant or with a web browser. This man page is provided as a convenience for those users who prefer man pages, although this format is not officially supported by Trolltech.

If you find errors in this manual page, please report them to **qt-bugs@trolltech.com**. Please include the name of the manual page (qpngimagepacker.3qt) and the Qt version (3.3.8).