org.dspace.app.mediafilter

Class XPDF2Thumbnail

java.lang.Object

org.dspace.app.mediafilter.MediaFilter

org.dspace.app.mediafilter.XPDF2Thumbnail

All Implemented Interfaces:

FormatFilter

public class XPDF2Thumbnail
extends MediaFilter

Thumbnail MediaFilter for PDF sources This filter generates thumbnail images for PDF documents, _including_ 3D PDF documents with 2D "poster" images. Since the PDFBox library does not understand these, and fails to render a lot of other PDFs, this filter forks a process running the "pdftoppm" program from the XPdf suite -- see http://www.foolabs.com/xpdf/ This is a suite of open-source PDF tools that has been widely ported to Unix platforms and the ones we use (pdftoppm, pdfinfo) even run on Win32. This was written for the FACADE project but it is not directly connected to any of the other FACADE-specific software. The FACADE UI expects to find thumbnail images for 3D PDFs generated by this filter. Requires DSpace config properties keys: xpdf.path.pdftoppm -- absolute path to "pdftoppm" executable (required!) xpdf.path.pdfinfo -- absolute path to "pdfinfo" executable (required!) thumbnail.maxwidth -- borrowed from thumbnails, max dim of generated image

Author:

Larry Stone

See Also:

MediaFilter

Constructor Summary

Constructors

Constructor and Description
XPDF2Thumbnail()

Method Summary

Methods

Modifier and Type	Method and Description
BufferedImage	getBlurredInstance(BufferedImage buf)
String	getBundleName()
String	getDescription()
InputStream	getDestinationStream(InputStream sourceStream)
String	getFilteredName(String oldFilename) Get a filename for a newly created filtered bitstream
String	getFormatString()
String[]	getInputDescriptions()
String[]	getInputExtensions()
String[]	getInputMIMETypes()
BufferedImage	getNormalizedInstance(BufferedImage buf)
BufferedImage	getScaledInstance(BufferedImage buf, int targetWidth, int targetHeight, Object hint, boolean higherQuality) Convenience method that returns a scaled instance of the provided BufferedImage.

Methods inherited from class org.dspace.app.mediafilter.MediaFilter

postProcessBitstream, preProcessBitstream

Methods inherited from class java.lang.Object

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

Constructor Detail

XPDF2Thumbnail

public XPDF2Thumbnail()

Method Detail

getFilteredName

public String getFilteredName(String oldFilename)

Description copied from interface: FormatFilter

Get a filename for a newly created filtered bitstream

Parameters:

oldFilename - name of source bitstream

Returns:

filename generated by the filter - for example, document.pdf becomes document.pdf.txt

getBundleName

public String getBundleName()

Returns:

name of the bundle this filter will stick its generated Bitstreams

getFormatString

public String getFormatString()

Returns:

name of the bitstream format (say "HTML" or "Microsoft Word") returned by this filter look in the bitstream format registry or mediafilter.cfg for valid format strings.

getDescription

public String getDescription()

Returns:

string to describe the newly-generated Bitstream's - how it was produced is a good idea

getDestinationStream

public InputStream getDestinationStream(InputStream sourceStream)
                                 throws Exception

Parameters:

sourceStream - input stream

Returns:

result of filter's transformation, written out to a bitstream

Throws:

Exception

getInputMIMETypes

public String[] getInputMIMETypes()

getInputDescriptions

public String[] getInputDescriptions()

getInputExtensions

public String[] getInputExtensions()

getNormalizedInstance

public BufferedImage getNormalizedInstance(BufferedImage buf)

getBlurredInstance

public BufferedImage getBlurredInstance(BufferedImage buf)

getScaledInstance

public BufferedImage getScaledInstance(BufferedImage buf,
                              int targetWidth,
                              int targetHeight,
                              Object hint,
                              boolean higherQuality)

Convenience method that returns a scaled instance of the provided BufferedImage.

Parameters:

buf - the original image to be scaled

targetWidth - the desired width of the scaled instance, in pixels

targetHeight - the desired height of the scaled instance, in pixels

hint - one of the rendering hints that corresponds to RenderingHints.KEY_INTERPOLATION (e.g. RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR, RenderingHints.VALUE_INTERPOLATION_BILINEAR, RenderingHints.VALUE_INTERPOLATION_BICUBIC)

higherQuality - if true, this method will use a multi-step scaling technique that provides higher quality than the usual one-step technique (only useful in downscaling cases, where targetWidth or targetHeight is smaller than the original dimensions, and generally only when the BILINEAR hint is specified)

Returns:

a scaled version of the original BufferedImage