Package org.apache.pdfbox.filter

Class DCTFilter

java.lang.Object

org.apache.pdfbox.filter.Filter

org.apache.pdfbox.filter.DCTFilter

final class DCTFilter
extends Filter

Decompresses data encoded using a DCT (discrete cosine transform) technique based on the JPEG standard.

Field Summary

Fields

Modifier and Type	Field	Description
private static java.lang.String	ADOBE
private static org.apache.commons.logging.Log	LOG
private static int	POS_TRANSFORM

Fields inherited from class org.apache.pdfbox.filter.Filter

SYSPROP_DEFLATELEVEL

Constructor Summary

Constructors

Constructor	Description
DCTFilter()

Method Summary

Modifier and Type	Method	Description
private int	clamp(float value)
DecodeResult	decode(java.io.InputStream encoded, java.io.OutputStream decoded, COSDictionary parameters, int index)	Decodes data, producing the original non-encoded data.
DecodeResult	decode(java.io.InputStream encoded, java.io.OutputStream decoded, COSDictionary parameters, int index, DecodeOptions options)	Decodes data, with optional DecodeOptions.
protected void	encode(java.io.InputStream input, java.io.OutputStream encoded, COSDictionary parameters)
private java.awt.image.WritableRaster	fromBGRtoRGB(java.awt.image.Raster raster)
private java.awt.image.WritableRaster	fromYCCKtoCMYK(java.awt.image.Raster raster)
private java.lang.Integer	getAdobeTransform(javax.imageio.metadata.IIOMetadata metadata)
private int	getAdobeTransformByBruteForce(javax.imageio.stream.ImageInputStream iis)
private java.lang.String	getNumChannels(javax.imageio.ImageReader reader)
private java.awt.image.Raster	readImageRaster(javax.imageio.ImageReader reader, javax.imageio.ImageReadParam irp)

Methods inherited from class org.apache.pdfbox.filter.Filter

decode, encode, findImageReader, findRasterReader, getCompressionLevel, getDecodeParams

Methods inherited from class java.lang.Object

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

Field Detail

LOG

private static final org.apache.commons.logging.Log LOG

POS_TRANSFORM

private static final int POS_TRANSFORM

See Also:

Constant Field Values

ADOBE

private static final java.lang.String ADOBE

See Also:

Constant Field Values

Constructor Detail

DCTFilter

DCTFilter()

Method Detail

decode

public DecodeResult decode(java.io.InputStream encoded,
                           java.io.OutputStream decoded,
                           COSDictionary parameters,
                           int index,
                           DecodeOptions options)
                    throws java.io.IOException

Description copied from class: Filter

Decodes data, with optional DecodeOptions. Not all filters support all options, and so callers should check the options' honored flag to test if they were applied.

Overrides:

decode in class Filter

Parameters:

encoded - the encoded byte stream

decoded - the stream where decoded data will be written

parameters - the parameters used for decoding

index - the index to the filter being decoded

options - additional options for decoding

Returns:

repaired parameters dictionary, or the original parameters dictionary

Throws:

java.io.IOException - if the stream cannot be decoded

readImageRaster

private java.awt.image.Raster readImageRaster(javax.imageio.ImageReader reader,
                                              javax.imageio.ImageReadParam irp)
                                       throws java.io.IOException

Throws:

java.io.IOException

decode

public DecodeResult decode(java.io.InputStream encoded,
                           java.io.OutputStream decoded,
                           COSDictionary parameters,
                           int index)
                    throws java.io.IOException

Description copied from class: Filter

Decodes data, producing the original non-encoded data.

Specified by:

decode in class Filter

Parameters:

encoded - the encoded byte stream

decoded - the stream where decoded data will be written

parameters - the parameters used for decoding

index - the index to the filter being decoded

Returns:

repaired parameters dictionary, or the original parameters dictionary

Throws:

java.io.IOException - if the stream cannot be decoded

getAdobeTransform

private java.lang.Integer getAdobeTransform(javax.imageio.metadata.IIOMetadata metadata)

getAdobeTransformByBruteForce

private int getAdobeTransformByBruteForce(javax.imageio.stream.ImageInputStream iis)
                                   throws java.io.IOException

Throws:

java.io.IOException

fromYCCKtoCMYK

private java.awt.image.WritableRaster fromYCCKtoCMYK(java.awt.image.Raster raster)

fromBGRtoRGB

private java.awt.image.WritableRaster fromBGRtoRGB(java.awt.image.Raster raster)

getNumChannels

private java.lang.String getNumChannels(javax.imageio.ImageReader reader)

clamp

private int clamp(float value)

encode

protected void encode(java.io.InputStream input,
                      java.io.OutputStream encoded,
                      COSDictionary parameters)
               throws java.io.IOException

Specified by:

encode in class Filter

Throws:

java.io.IOException