Class PNGDecoder

java.lang.Object

is.galia.codec.AbstractDecoder

is.galia.codec.AbstractImageIODecoder

is.galia.codec.png.PNGDecoder

All Implemented Interfaces:

Decoder, AutoCloseable

public final class PNGDecoder
extends AbstractImageIODecoder
implements Decoder

Implementation wrapping the default JDK Image I/O PNG ImageReader.

Field Summary

Fields inherited from class is.galia.codec.AbstractImageIODecoder

iioReader

Fields inherited from class is.galia.codec.AbstractDecoder

arena, imageFile, inputStream

Constructor Summary

Constructors

Constructor	Description
PNGDecoder()

Method Summary

Modifier and Type	Method	Description
boolean	canSeek()
Format	detectFormat()	Called after a source has been set.
protected org.slf4j.Logger	getLogger()
protected String[]	getPreferredIIOImplementations()	N.B.: This method returns a list of strings rather than classes because some readers reside under the com.sun package, which is encapsulated.
Set<Format>	getSupportedFormats()
Metadata	readMetadata(int imageIndex)	Reads metadata pertaining to the image at the given index.

Methods inherited from class is.galia.codec.AbstractImageIODecoder

close, decode, decode, decodeSequence, dispose, getNumImages, getNumResolutions, getNumThumbnails, getSize, getThumbnailSize, getTileSize, handle, initializeInputStream, readMonoResolution, readSmallestUsableSubimage, readThumbnail

Methods inherited from class is.galia.codec.AbstractDecoder

setArena, setSource, setSource

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface is.galia.codec.Decoder

close, decode, decode, decodeSequence, getNumImages, getNumResolutions, getNumThumbnails, getSize, getThumbnailSize, getTileSize, readThumbnail, setArena, setSource, setSource

Constructor Details

PNGDecoder

public PNGDecoder()

Method Details

canSeek

public boolean canSeek()

Specified by:

canSeek in class AbstractImageIODecoder

detectFormat

public Format detectFormat()
                    throws IOException

Description copied from interface: Decoder

Called after a source has been set.

If reading from a Decoder.setSource(ImageInputStream) stream}, the stream position is reset to 0 before returning.

Unlike many of the other interface methods, implementations should not throw a SourceFormatException, and instead just return Format.UNKNOWN.

Specified by:

detectFormat in interface Decoder

Returns:

Format of the image to decode, if supported by the instance; otherwise Format.UNKNOWN. The implementation must create the instance from scratch and not obtain it from the format registry, which may be empty at the time this method is invoked.

Throws:

IOException - if there is some other error reading the image.

getLogger

protected org.slf4j.Logger getLogger()

Specified by:

getLogger in class AbstractImageIODecoder

getPreferredIIOImplementations

protected String[] getPreferredIIOImplementations()

Description copied from class: AbstractImageIODecoder

N.B.: This method returns a list of strings rather than classes because some readers reside under the com.sun package, which is encapsulated.

Specified by:

getPreferredIIOImplementations in class AbstractImageIODecoder

Returns:

Preferred reader implementation classes, in order of highest to lowest priority, or an empty array if there is no preference.

getSupportedFormats

public Set<Format> getSupportedFormats()

Specified by:

getSupportedFormats in interface Decoder

Specified by:

getSupportedFormats in class AbstractImageIODecoder

Returns:

All formats supported by the implementation. The instances must be created from scratch and not obtained from the format registry, which may be empty at the time this method is invoked.

readMetadata

public Metadata readMetadata(int imageIndex)
                      throws IOException

Description copied from interface: Decoder

Reads metadata pertaining to the image at the given index.

Specified by:

readMetadata in interface Decoder

Specified by:

readMetadata in class AbstractImageIODecoder

Returns:

Metadata for the image at the given index. If there is none, an EmptyMetadata can be returned.

Throws:

IOException - if there is some other error reading the metadata.