org.jboss.dna.sequencer.images
Class ImageMetadataSequencer

java.lang.Object
  org.jboss.dna.sequencer.images.ImageMetadataSequencer

All Implemented Interfaces:

StreamSequencer

public class ImageMetadataSequencer
extends java.lang.Object
implements StreamSequencer

A sequencer that processes the binary content of an image file, extracts the metadata for the image, and then writes that image metadata to the repository.

This sequencer produces data that corresponds to the following structure:

• image:metadata node of type image:metadata
  • jcr:mimeType - optional string property for the mime type of the image
  • jcr:encoding - optional string property for the encoding of the image
  • image:formatName - string property for the name of the format
  • image:width - optional integer property for the image's width in pixels
  • image:height - optional integer property for the image's height in pixles
  • image:bitsPerPixel - optional integer property for the number of bits per pixel
  • image:progressive - optional boolean property specifying whether the image is stored in a progressive (i.e., interlaced) form
  • image:numberOfImages - optional integer property for the number of images stored in the file; defaults to 1
  • image:physicalWidthDpi - optional integer property for the physical width of the image in dots per inch
  • image:physicalHeightDpi - optional integer property for the physical height of the image in dots per inch
  • image:physicalWidthInches - optional double property for the physical width of the image in inches
  • image:physicalHeightInches - optional double property for the physical height of the image in inches

This structure could be extended in the future to add EXIF and IPTC metadata as child nodes. For example, EXIF metadata is structured as tags in directories, where the directories form something like namespaces, and which are used by different camera vendors to store custom metadata. This structure could be mapped with each directory (e.g. "EXIF" or "Nikon Makernote" or "IPTC") as the name of a child node, with the EXIF tags values stored as either properties or child nodes.

Author:

Randall Hauch

Field Summary

static java.lang.String	IMAGE_BITS_PER_PIXEL
static java.lang.String	IMAGE_ENCODING
static java.lang.String	IMAGE_FORMAT_NAME
static java.lang.String	IMAGE_HEIGHT
static java.lang.String	IMAGE_MIME_TYPE
static java.lang.String	IMAGE_MIXINS
static java.lang.String	IMAGE_NUMBER_OF_IMAGES
static java.lang.String	IMAGE_PHYSICAL_HEIGHT_DPI
static java.lang.String	IMAGE_PHYSICAL_HEIGHT_INCHES
static java.lang.String	IMAGE_PHYSICAL_WIDTH_DPI
static java.lang.String	IMAGE_PHYSICAL_WIDTH_INCHES
static java.lang.String	IMAGE_PRIMARY_TYPE
static java.lang.String	IMAGE_PROGRESSIVE
static java.lang.String	IMAGE_WIDTH
static java.lang.String	METADATA_NODE

Constructor Summary

ImageMetadataSequencer()

Method Summary

void	sequence(java.io.InputStream stream, SequencerOutput output, ProgressMonitor progressMonitor) Sequence the data found in the supplied stream, placing the output information into the supplied map.

Methods inherited from class java.lang.Object

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

Field Detail

METADATA_NODE

public static final java.lang.String METADATA_NODE

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Constant Field Values

IMAGE_PRIMARY_TYPE

public static final java.lang.String IMAGE_PRIMARY_TYPE

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Constant Field Values

IMAGE_MIXINS

public static final java.lang.String IMAGE_MIXINS

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Constant Field Values

IMAGE_MIME_TYPE

public static final java.lang.String IMAGE_MIME_TYPE

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Constant Field Values

IMAGE_ENCODING

public static final java.lang.String IMAGE_ENCODING

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Constant Field Values

IMAGE_FORMAT_NAME

public static final java.lang.String IMAGE_FORMAT_NAME

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Constant Field Values

IMAGE_WIDTH

public static final java.lang.String IMAGE_WIDTH

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Constant Field Values

IMAGE_HEIGHT

public static final java.lang.String IMAGE_HEIGHT

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Constant Field Values

IMAGE_BITS_PER_PIXEL

public static final java.lang.String IMAGE_BITS_PER_PIXEL

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Constant Field Values

IMAGE_PROGRESSIVE

public static final java.lang.String IMAGE_PROGRESSIVE

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Constant Field Values

IMAGE_NUMBER_OF_IMAGES

public static final java.lang.String IMAGE_NUMBER_OF_IMAGES

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Constant Field Values

IMAGE_PHYSICAL_WIDTH_DPI

public static final java.lang.String IMAGE_PHYSICAL_WIDTH_DPI

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Constant Field Values

IMAGE_PHYSICAL_HEIGHT_DPI

public static final java.lang.String IMAGE_PHYSICAL_HEIGHT_DPI

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Constant Field Values

IMAGE_PHYSICAL_WIDTH_INCHES

public static final java.lang.String IMAGE_PHYSICAL_WIDTH_INCHES

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Constant Field Values

IMAGE_PHYSICAL_HEIGHT_INCHES

public static final java.lang.String IMAGE_PHYSICAL_HEIGHT_INCHES

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Constant Field Values

Constructor Detail

ImageMetadataSequencer

public ImageMetadataSequencer()

Method Detail

sequence

public void sequence(java.io.InputStream stream,
                     SequencerOutput output,
                     ProgressMonitor progressMonitor)

Sequence the data found in the supplied stream, placing the output information into the supplied map.

JBoss DNA's SequencingService determines the sequencers that should be executed by monitoring the changes to one or more workspaces that it is monitoring. Changes in those workspaces are aggregated and used to determine which sequencers should be called. If the sequencer implements this interface, then this method is called with the property that is to be sequenced along with the interface used to register the output. The framework takes care of all the rest.

This operation should report progress to the supplied ProgressMonitor. At the beginning of the operation, call ProgressMonitor.beginTask(double, org.jboss.dna.common.i18n.I18n, Object...) with a meaningful message describing the operation and a total for the amount of work that will be done by this sequencer. Then perform the sequencing work, periodically reporting work by specifying the amount of work that has was just completed or by creating a subtask and reporting work against that subtask monitor.

The implementation should also periodically check whether the operation has been cancelled. If this method returns true, the implementation should abort all work as soon as possible and close any resources that were acquired or opened.

Finally, the implementation should call ProgressMonitor.done() when the operation has finished.

Specified by:

sequence in interface StreamSequencer

Parameters:

stream - the stream with the data to be sequenced; never null

output - the output from the sequencing operation; never null

progressMonitor - the progress monitor that should be kept updated with the sequencer's progress and that should be frequently consulted as to whether this operation has been cancelled.