Exiv2::PngImage Class Reference

Class to access PNG images. Exif and IPTC metadata are supported directly. More...

#include <pngimage.hpp>

Inheritance diagram for Exiv2::PngImage:

Public Member Functions

Creators
 PngImage (BasicIo::AutoPtr io, bool create)
 Constructor that can either open an existing PNG image or create a new image from scratch. If a new image is to be created, any existing data is overwritten. Since the constructor can not return a result, callers should check the good() method after object construction to determine success or failure. More...
 
Manipulators
void readMetadata ()
 Read all metadata supported by a specific image format from the image. Before this method is called, the image metadata will be cleared. More...
 
void writeMetadata ()
 Write metadata back to the image. More...
 
void printStructure (std::ostream &out, PrintStructureOption option, int depth)
 Print out the structure of image file. More...
 
Accessors
std::string mimeType () const
 Return the MIME type of the image. More...
 
- Public Member Functions inherited from Exiv2::Image
 Image (int imageType, uint16_t supportedMetadata, BasicIo::AutoPtr io)
 Constructor taking the image type, a bitmap of the supported metadata types and an auto-pointer that owns an IO instance. See subclass constructor doc.
 
virtual ~Image ()
 Virtual Destructor.
 
virtual void setExifData (const ExifData &exifData)
 Assign new Exif data. The new Exif data is not written to the image until the writeMetadata() method is called. More...
 
virtual void clearExifData ()
 Erase any buffered Exif data. Exif data is not removed from the actual image until the writeMetadata() method is called.
 
virtual void setIptcData (const IptcData &iptcData)
 Assign new IPTC data. The new IPTC data is not written to the image until the writeMetadata() method is called. More...
 
virtual void clearIptcData ()
 Erase any buffered IPTC data. IPTC data is not removed from the actual image until the writeMetadata() method is called.
 
virtual void setXmpPacket (const std::string &xmpPacket)
 Assign a raw XMP packet. The new XMP packet is not written to the image until the writeMetadata() method is called. More...
 
virtual void clearXmpPacket ()
 Erase the buffered XMP packet. XMP data is not removed from the actual image until the writeMetadata() method is called. More...
 
virtual void setXmpData (const XmpData &xmpData)
 Assign new XMP data. The new XMP data is not written to the image until the writeMetadata() method is called. More...
 
virtual void clearXmpData ()
 Erase any buffered XMP data. XMP data is not removed from the actual image until the writeMetadata() method is called. More...
 
virtual void setComment (const std::string &comment)
 Set the image comment. The new comment is not written to the image until the writeMetadata() method is called. More...
 
virtual void clearComment ()
 Erase any buffered comment. Comment is not removed from the actual image until the writeMetadata() method is called.
 
virtual void setIccProfile (DataBuf &iccProfile, bool bTestValid=true)
 Set the image iccProfile. The new profile is not written to the image until the writeMetadata() method is called. More...
 
virtual void clearIccProfile ()
 Erase iccProfile. the profile is not removed from the actual image until the writeMetadata() method is called.
 
virtual bool iccProfileDefined ()
 Erase iccProfile. the profile is not removed from the actual image until the writeMetadata() method is called.
 
virtual DataBuficcProfile ()
 return iccProfile
 
virtual void setMetadata (const Image &image)
 Copy all existing metadata from source Image. The data is copied into internal buffers and is not written to the image until the writeMetadata() method is called. More...
 
virtual void clearMetadata ()
 Erase all buffered metadata. Metadata is not removed from the actual image until the writeMetadata() method is called.
 
virtual ExifDataexifData ()
 Returns an ExifData instance containing currently buffered Exif data. More...
 
virtual IptcDataiptcData ()
 Returns an IptcData instance containing currently buffered IPTC data. More...
 
virtual XmpDataxmpData ()
 Returns an XmpData instance containing currently buffered XMP data. More...
 
virtual std::string & xmpPacket ()
 Return a modifiable reference to the raw XMP packet.
 
void writeXmpFromPacket (bool flag)
 Determine the source when writing XMP. More...
 
void setByteOrder (ByteOrder byteOrder)
 Set the byte order to encode the Exif metadata in. More...
 
void printTiffStructure (BasicIo &io, std::ostream &out, PrintStructureOption option, int depth, size_t offset=0)
 Print out the structure of image file. More...
 
void printIFDStructure (BasicIo &io, std::ostream &out, Exiv2::PrintStructureOption option, uint32_t start, bool bSwap, char c, int depth)
 Print out the structure of a TIFF IFD.
 
bool isBigEndianPlatform ()
 is the host platform bigEndian
 
bool isLittleEndianPlatform ()
 is the host platform littleEndian
 
bool isStringType (uint16_t type)
 
bool isShortType (uint16_t type)
 
bool isLongType (uint16_t type)
 
bool isLongLongType (uint16_t type)
 
bool isRationalType (uint16_t type)
 
bool is2ByteType (uint16_t type)
 
bool is4ByteType (uint16_t type)
 
bool is8ByteType (uint16_t type)
 
bool isPrintXMP (uint16_t type, Exiv2::PrintStructureOption option)
 
bool isPrintICC (uint16_t type, Exiv2::PrintStructureOption option)
 
uint64_t byteSwap (uint64_t value, bool bSwap) const
 
uint32_t byteSwap (uint32_t value, bool bSwap) const
 
uint16_t byteSwap (uint16_t value, bool bSwap) const
 
uint16_t byteSwap2 (const DataBuf &buf, size_t offset, bool bSwap) const
 
uint32_t byteSwap4 (const DataBuf &buf, size_t offset, bool bSwap) const
 
uint64_t byteSwap8 (const DataBuf &buf, size_t offset, bool bSwap) const
 
ByteOrder byteOrder () const
 Return the byte order in which the Exif metadata of the image is encoded. Initially, it is not set (invalidByteOrder).
 
bool good () const
 Check if the Image instance is valid. Use after object construction. More...
 
virtual int pixelWidth () const
 Return the pixel width of the image.
 
virtual int pixelHeight () const
 Return the pixel height of the image.
 
virtual const ExifDataexifData () const
 Returns an ExifData instance containing currently buffered Exif data. More...
 
virtual const IptcDataiptcData () const
 Returns an IptcData instance containing currently buffered IPTC data. More...
 
virtual const XmpDataxmpData () const
 Returns an XmpData instance containing currently buffered XMP data. More...
 
virtual std::string comment () const
 Return a copy of the image comment. May be an empty string.
 
virtual const std::string & xmpPacket () const
 Return the raw XMP packet as a string.
 
virtual BasicIoio () const
 Return a reference to the BasicIo instance being used for Io. More...
 
AccessMode checkMode (MetadataId metadataId) const
 Returns the access mode, i.e., the metadata functions, which this image supports for the metadata type metadataId. More...
 
bool supportsMetadata (MetadataId metadataId) const
 Check if image supports a particular type of metadata. This method is deprecated. Use checkMode() instead.
 
bool writeXmpFromPacket () const
 Return the flag indicating the source when writing XMP metadata.
 
const NativePreviewListnativePreviews () const
 Return list of native previews. This is meant to be used only by the PreviewManager.
 
void setTypeSupported (int imageType, uint16_t supportedMetadata)
 set type support for this image format
 
int imageType () const
 set type support for this image format
 

Additional Inherited Members

- Public Types inherited from Exiv2::Image
typedef std::auto_ptr< ImageAutoPtr
 Image auto_ptr type.
 
- Protected Member Functions inherited from Exiv2::Image
const std::string & tagName (uint16_t tag)
 Return tag name for given tag id.
 
const char * typeName (uint16_t tag) const
 Return tag type for given tag id.
 
- Protected Attributes inherited from Exiv2::Image
BasicIo::AutoPtr io_
 Image data IO pointer.
 
ExifData exifData_
 Exif data container.
 
IptcData iptcData_
 IPTC data container.
 
XmpData xmpData_
 XMP data container.
 
DataBuf iccProfile_
 ICC buffer (binary data)
 
std::string comment_
 User comment.
 
std::string xmpPacket_
 XMP packet.
 
int pixelWidth_
 image pixel width
 
int pixelHeight_
 image pixel height
 
NativePreviewList nativePreviews_
 list of native previews
 

Detailed Description

Class to access PNG images. Exif and IPTC metadata are supported directly.

Constructor & Destructor Documentation

◆ PngImage()

Exiv2::PngImage::PngImage ( BasicIo::AutoPtr  io,
bool  create 
)

Constructor that can either open an existing PNG image or create a new image from scratch. If a new image is to be created, any existing data is overwritten. Since the constructor can not return a result, callers should check the good() method after object construction to determine success or failure.

Parameters
ioAn auto-pointer that owns a BasicIo instance used for reading and writing image metadata. Important: The constructor takes ownership of the passed in BasicIo instance through the auto-pointer. Callers should not continue to use the BasicIo instance after it is passed to this method. Use the Image::io() method to get a temporary reference.
createSpecifies if an existing image should be read (false) or if a new file should be created (true).

Member Function Documentation

◆ mimeType()

std::string Exiv2::PngImage::mimeType ( ) const
virtual

Return the MIME type of the image.

Note
For each supported image format, the library knows only one MIME type. This may not be the most specific MIME type for that format. In particular, several RAW formats are variants of the TIFF format with the same magic as TIFF itself. Class TiffImage handles most of them and thus they all have MIME type "image/tiff", although a more specific MIME type may exist (e.g., "image/x-nikon-nef").

Implements Exiv2::Image.

◆ printStructure()

void Exiv2::PngImage::printStructure ( std::ostream &  out,
PrintStructureOption  option,
int  depth 
)
virtual

Print out the structure of image file.

Exceptions
Errorif reading of the file fails or the image data is not valid (does not look like data of the specific image type).
Warning
This function is not thread safe and intended for exiv2 -pS for debugging.

Reimplemented from Exiv2::Image.

◆ readMetadata()

void Exiv2::PngImage::readMetadata ( )
virtual

Read all metadata supported by a specific image format from the image. Before this method is called, the image metadata will be cleared.

This method returns success even if no metadata is found in the image. Callers must therefore check the size of individual metadata types before accessing the data.

Exceptions
Errorif opening or reading of the file fails or the image data is not valid (does not look like data of the specific image type).

Implements Exiv2::Image.

◆ writeMetadata()

void Exiv2::PngImage::writeMetadata ( )
virtual

Write metadata back to the image.

All existing metadata sections in the image are either created, replaced, or erased. If values for a given metadata type have been assigned, a section for that metadata type will either be created or replaced. If no values have been assigned to a given metadata type, any exists section for that metadata type will be removed from the image.

Exceptions
Errorif the operation fails

Implements Exiv2::Image.


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