IlvPNGStreamer Class Reference

Bitmap streamer class. More...

#include <ilviews/bitmaps/png.h>

Inheritance diagram for IlvPNGStreamer:

Public Member Functions
	IlvPNGStreamer ()
	Initializes a new IlvPNGStreamer instance.
IlBoolean	canRead () const
	Indicates that the instance can read from a stream. More...
IlBoolean	canWrite () const
	Indicates that the instance can write to a stream. More...
IlBoolean	checkSignature (const IlUChar *data, IlUInt size)
	Checks the signature of the input stream. More...
IlUInt	getAlphaLevel () const
	Gets the alpha level of the PNG streamer. More...
IlUInt	getCompressionLevel () const
	Gets the compression level of the generated PNG stream. More...
IlUShort	getIndexedColors () const
	Returns the number of colors to quantize to. More...
IlBoolean	hasInterlace () const
	Gets whether the generated PNG stream is interlaced. More...
IlBoolean	isIndexed () const
IlvBitmapData *	read (std::istream &stream)
	Reads a PNG image from a stream. More...
void	setAlphaLevel (IlUInt level)
	Sets the alpha level for the PNG stream. More...
void	setCompressionLevel (IlUInt level)
	Sets the compression level of the generated PNG stream. More...
void	setIndexed (IlBoolean indexed, IlUShort numcols=256)
	Sets whether the generated PNG stream is indexed. More...
void	setInterlace (IlBoolean interlace)
	Sets whether the generated PNG stream is interlaced. More...
IlBoolean	write (IlvBitmapData *data, std::ostream &stream)
	Writes an IlvBitmapData to a PNG stream. More...
Public Member Functions inherited from IlvBitmapStreamer
virtual void	callReadProgressCallback (IlUInt current, IlUInt max)
	Calls the callback for read progression. More...
virtual void	callWriteProgressCallback (IlUInt current, IlUInt max)
	Calls the callback for write progression. More...
virtual const char *	getName () const
	Returns the internal name of the streamer. More...
IlvQuantizer *	getQuantizer () const
	Returns the quantizer used by this streamer. More...
virtual IlvBitmapInformation *	readInfo (std::istream &stream)
	Reads information from a stream. More...
void	setQuantizer (IlvQuantizer *quantizer)
	Sets the quantizer used (if needed) by this streamer. More...
virtual void	setReadProgressCallback (IlvProgressCallback rpCallback, IlAny arg=0)
	Sets the callback for read progression. More...
virtual void	setWriteProgressCallback (IlvProgressCallback wpCallback, IlAny arg=0)
	Sets the callback for write progression. More...
Public Member Functions inherited from IlvValueInterface
virtual IlBoolean	applyValue (const IlvValue &value)
	Apply an accessor. More...
virtual IlBoolean	changeValue (const IlvValue &val)
	Changes the value of an accessor. More...
virtual IlBoolean	changeValues (const IlvValue *values, IlUShort count=0)
	Changes several accessor values simultaneously. More...
virtual void	getAccessors (const IlSymbol *const **names, const IlvValueTypeClass *const **types, IlUInt &count) const
	Retrieves the list of available accessors of an object. More...
virtual IlvValue &	queryValue (IlvValue &val) const
	Retrieves an accessor value. More...
virtual void	queryValues (IlvValue *values, IlUShort count) const
	Retrieves multiple accessor values simultaneously. More...

Additional Inherited Members
Static Public Member Functions inherited from IlvBitmapStreamer
static IlvBitmapStreamer *	Get (const char *name)
	Returns a streamer from its name. More...
static IlvBitmapStreamer **	GetRegisteredStreamers (IlUInt &count)
	Returns the registered streamers. More...
static IlvBitmap *	Read (IlvDisplay *display, std::istream &stream, const IlUChar *signature, IlUInt signatureLen)
	Reads a bitmap using the registered streamers. More...
static IlvBitmapData *	ReadBitmapData (std::istream &stream, const IlUChar *signature, IlUInt signatureLen)
	Reads bitmap data using the registered streamers. More...
static IlvBitmapInformation *	ReadInfo (std::istream &stream, const IlUChar *signature, IlUInt signatureLen)
	Reads bitmap information using the registered streamers. More...
static void	Register (IlvBitmapStreamer *streamer)
	Registers the given streamer. More...
static IlBoolean	UnRegister (IlvBitmapStreamer *streamer)
	Unregisters the given streamer. More...

Detailed Description

Bitmap streamer class.

Library: xviews or winviews or mviews (mutually exclusive)
This streamer provides methods to deal with a stream containing a PNG image. It supports reading from all PNG streams. It handles transparent images by mapping alpha values greater than 50 to opaque and others to transparent.
This streamer can read and write.
When writing, it is possible to force indexed output using a specified number of colors. When reading or writing interlaced images, callbacks will be called at each pass. When reading or writing non-interlaced images, callbacks will be called at each scanline.

Member Function Documentation

canRead()

IlBoolean IlvPNGStreamer::canRead ( ) const

virtual

Indicates that the instance can read from a stream.

Returns

IlTrue.

Reimplemented from IlvBitmapStreamer.

canWrite()

IlBoolean IlvPNGStreamer::canWrite ( ) const

virtual

Indicates that the instance can write to a stream.

Returns

IlTrue.

Reimplemented from IlvBitmapStreamer.

checkSignature()

IlBoolean IlvPNGStreamer::checkSignature ( const IlUChar *  data, IlUInt  size  )

virtual

Checks the signature of the input stream.

Parameters

data	The data containing the signature of the stream.
size	The size of the data containing the signature.

Returns

IlTrue if the data contains a PNG signature.

Implements IlvBitmapStreamer.

getAlphaLevel()

IlUInt IlvPNGStreamer::getAlphaLevel

(

)

const

Gets the alpha level of the PNG streamer.

Returns

The alpha level.

getCompressionLevel()

IlUInt IlvPNGStreamer::getCompressionLevel

(

)

const

Gets the compression level of the generated PNG stream.

Returns

The compression level.

getIndexedColors()

IlUShort IlvPNGStreamer::getIndexedColors

(

)

const

Returns the number of colors to quantize to.

Returns

The number of colors.

hasInterlace()

IlBoolean IlvPNGStreamer::hasInterlace

(

)

const

Gets whether the generated PNG stream is interlaced.

Returns

IlTrue if the generated PNG stream is interlaced.

isIndexed()

IlBoolean IlvPNGStreamer::isIndexed

(

)

const

Gshort Gets whether the generated PNG stream is indexed .

Returns

IlTrue if the generated PNG stream is indexed.

read()

IlvBitmapData* IlvPNGStreamer::read ( std::istream &  stream )

virtual

Reads a PNG image from a stream.

Parameters

stream

The stream to read from.

Returns

An instance of IlvBitmapData.

Reimplemented from IlvBitmapStreamer.

setAlphaLevel()

void IlvPNGStreamer::setAlphaLevel

(

IlUInt

level

)

Sets the alpha level for the PNG stream.

Alpha levels greater than the given argument are converted to a fully opaque value while alpha levels smaller than the given argument are converted to a fully transparent value.

Parameters

level

The alpha level.

setCompressionLevel()

void IlvPNGStreamer::setCompressionLevel

(

IlUInt

level

)

Sets the compression level of the generated PNG stream.

Parameters

level

The compression level: 0: No compression. 1: Best speed compression 2: Best compression.

setIndexed()

void IlvPNGStreamer::setIndexed	(	IlBoolean	indexed,
		IlUShort	numcols = 256
	)

Sets whether the generated PNG stream is indexed.

Parameters

indexed	IlTrue if the stream is generated in indexed mode.
numcols	The number of desired colors if quantization is performed.

setInterlace()

void IlvPNGStreamer::setInterlace

(

IlBoolean

interlace

)

Sets whether the generated PNG stream is interlaced.

Parameters

interlace

IlTrue if the stream is interlaced.

write()

IlBoolean IlvPNGStreamer::write ( IlvBitmapData *  data, std::ostream &  stream  )

virtual

Writes an IlvBitmapData to a PNG stream.

Parameters

data	The bitmap data to write.
stream	The stream to write to.

Returns

IlTrue if the bitmap data has been written.

Reimplemented from IlvBitmapStreamer.