PngMetadataReader

java.lang.Object

com.drew.imaging.png.PngMetadataReader

public class PngMetadataReader extends Object

Field Summary

Fields

Modifier and Type

Field

Description

private static Set<PngChunkType>

_desiredChunkTypes

private static Charset

_latin1Encoding

The PNG spec states that ISO_8859_1 (Latin-1) encoding should be used for: "tEXt" and "zTXt" chunks, both for keys and values (https://www.w3.org/TR/PNG/#11tEXt) "iCCP" chunks, for the profile name (https://www.w3.org/TR/PNG/#11iCCP) "sPLT" chunks, for the palette name (https://www.w3.org/TR/PNG/#11sPLT) Note that "iTXt" chunks use UTF-8 encoding (https://www.w3.org/TR/PNG/#11iTXt).
Constructor Summary

Constructors

Constructor

Description

PngMetadataReader()
Method Summary

Modifier and Type

Method

Description

private static void

processChunk(Metadata metadata, PngChunk chunk)

static Metadata

readMetadata(File file)

static Metadata

readMetadata(InputStream inputStream)

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details
- _desiredChunkTypes
  
  private static Set<PngChunkType> _desiredChunkTypes
- _latin1Encoding
  
  private static Charset _latin1Encoding
  The PNG spec states that ISO_8859_1 (Latin-1) encoding should be used for:
  
  "tEXt" and "zTXt" chunks, both for keys and values (https://www.w3.org/TR/PNG/#11tEXt)
  
  "iCCP" chunks, for the profile name (https://www.w3.org/TR/PNG/#11iCCP)
  
  "sPLT" chunks, for the palette name (https://www.w3.org/TR/PNG/#11sPLT)
  
  Note that "iTXt" chunks use UTF-8 encoding (https://www.w3.org/TR/PNG/#11iTXt).
  For more guidance: http://www.w3.org/TR/PNG-Decoders.html#D.Text-chunk-processing
Constructor Details
- PngMetadataReader
  
  public PngMetadataReader()
Method Details
- readMetadata
  
  public static Metadata readMetadata(File file) throws PngProcessingException, IOException
  
  Throws:
  
  PngProcessingException
  
  IOException
- readMetadata
  
  public static Metadata readMetadata(InputStream inputStream) throws PngProcessingException, IOException
  
  Throws:
  
  PngProcessingException
  
  IOException
- processChunk
  
  private static void processChunk(Metadata metadata, PngChunk chunk) throws PngProcessingException, IOException
  
  Throws:
  
  PngProcessingException
  
  IOException