Exiv2::Internal::PngChunk Class Reference

Stateless parser class for data in PNG chunk format. Images use this class to decode and encode PNG-based data. More...

#include <pngchunk_int.hpp>

Public Types
enum	TxtChunkType { tEXt_Chunk = 0, zTXt_Chunk = 1, iTXt_Chunk = 2 }
	Text Chunk types.

Static Public Member Functions
static void	decodeIHDRChunk (const DataBuf &data, int *outWidth, int *outHeight)
	Decode PNG IHDR chunk data from a data buffer data and return image size to outWidth and outHeight. More...
static void	decodeTXTChunk (Image *pImage, const DataBuf &data, TxtChunkType type)
	Decode PNG tEXt, zTXt, or iTXt chunk data from pImage passed by data buffer data and extract Comment, Exif, Iptc, Xmp metadata accordingly. More...
static DataBuf	decodeTXTChunk (const DataBuf &data, TxtChunkType type)
	Decode PNG tEXt, zTXt, or iTXt chunk data from pImage passed by data buffer data and extract Comment, Exif, Iptc, Xmp to DataBuf. More...
static DataBuf	keyTXTChunk (const DataBuf &data, bool stripHeader=false)
	Return PNG TXT chunk key as data buffer. More...
static std::string	makeMetadataChunk (const std::string &metadata, MetadataId type)
	Return a complete PNG chunk data compressed or not as buffer. Data returned is formated accordingly with metadata type to host passed by metadata. More...

Friends
class	Exiv2::PngImage

Detailed Description

Stateless parser class for data in PNG chunk format. Images use this class to decode and encode PNG-based data.

Member Function Documentation

decodeIHDRChunk()

static void Exiv2::Internal::PngChunk::decodeIHDRChunk ( const DataBuf &  data, int *  outWidth, int *  outHeight  )

static

Decode PNG IHDR chunk data from a data buffer data and return image size to outWidth and outHeight.

Parameters

data	PNG Chunk data buffer.
outWidth	Integer pointer to be set to the width of the image.
outHeight	Integer pointer to be set to the height of the image.

decodeTXTChunk() [1/2]

static void Exiv2::Internal::PngChunk::decodeTXTChunk ( Image *  pImage, const DataBuf &  data, TxtChunkType  type  )

static

Decode PNG tEXt, zTXt, or iTXt chunk data from pImage passed by data buffer data and extract Comment, Exif, Iptc, Xmp metadata accordingly.

Parameters

pImage	Pointer to the image to hold the metadata
data	PNG Chunk data buffer.
type	PNG Chunk TXT type.

decodeTXTChunk() [2/2]

static DataBuf Exiv2::Internal::PngChunk::decodeTXTChunk ( const DataBuf &  data, TxtChunkType  type  )

static

Decode PNG tEXt, zTXt, or iTXt chunk data from pImage passed by data buffer data and extract Comment, Exif, Iptc, Xmp to DataBuf.

Parameters

data	PNG Chunk data buffer.
type	PNG Chunk TXT type.

keyTXTChunk()

static DataBuf Exiv2::Internal::PngChunk::keyTXTChunk ( const DataBuf &  data, bool  stripHeader = false  )

static

Return PNG TXT chunk key as data buffer.

Parameters

data	PNG Chunk data buffer.
stripHeader	Set true if chunk data start with header bytes, else false (default).

makeMetadataChunk()

static std::string Exiv2::Internal::PngChunk::makeMetadataChunk ( const std::string &  metadata, MetadataId  type  )

static

Return a complete PNG chunk data compressed or not as buffer. Data returned is formated accordingly with metadata type to host passed by metadata.

Parameters

metadata	metadata buffer.
type	metadata type.

---

The documentation for this class was generated from the following file:

• pngchunk_int.hpp