Package steganography.util

Class ImageStegIOJava

java.lang.Object

steganography.util.ImageStegIOJava

All Implemented Interfaces:

ImageStegIO

public class ImageStegIOJava
extends java.lang.Object
implements ImageStegIO

This Class exists to handle reading and writing of BufferedImages to and from byte arrays as well as choosing the appropriate encoders (and their overlays) for the given image. It holds on to the image during its en- or decoding.

Constructor Summary

Constructors

Constructor	Description
ImageStegIOJava(byte[] image, boolean useTransparent)	Creates an object that exists to handle reading and writing of BufferedImages to and from byte arrays as well as choosing the appropriate encoders (and their overlays) for the given image.

Method Summary

Modifier and Type	Method	Description
BuffImgEncoder	getEncoder(long seed)	Determines and returns the suitable encoder (and overlay) for the image according to its type.
java.lang.String	getFormat()	Returns the images format.
byte[]	getImageAsByteArray()	Returns the image in its current state (Output-Image) as a byte Array.
protected PixelCoordinateOverlay	getOverlay(java.awt.image.BufferedImage bufferedImage, long seed)	Returns an overlay according to the global variable useTransparent

Methods inherited from class java.lang.Object

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

Constructor Detail

ImageStegIOJava

public ImageStegIOJava(byte[] image,
                       boolean useTransparent)

Creates an object that exists to handle reading and writing of BufferedImages to and from byte arrays as well as choosing the appropriate encoders (and their overlays) for the given image. It holds on to the image during its en- or decoding.

The image will only be processed if the methods getFormat() or getEncoder() are called.

Parameters:

image - the image to handle In- and Output of

useTransparent - if true, returned encoders will use fully transparent pixels

Method Detail

getImageAsByteArray

public byte[] getImageAsByteArray()
                           throws java.io.IOException,
                                  ImageWritingException

Returns the image in its current state (Output-Image) as a byte Array.

If the image was not yet processed, return == input

Specified by:

getImageAsByteArray in interface ImageStegIO

Returns:

the image in its current state as a byte array

Throws:

java.io.IOException - if there was an error during writing of BufferedImage to a byte array

ImageWritingException - if the image was not written to a byte array for unknown reasons

getFormat

public java.lang.String getFormat()
                           throws UnsupportedImageTypeException,
                                  java.io.IOException,
                                  NoImageException

Returns the images format.

Processes the image if necessary.

Specified by:

getFormat in interface ImageStegIO

Returns:

the images format (png, bmp, ...) as a String

Throws:

UnsupportedImageTypeException - if the image type read from input is not supported

java.io.IOException - if there was an error during reading of input

NoImageException - if no image could be read from input

getEncoder

public BuffImgEncoder getEncoder(long seed)
                          throws UnsupportedImageTypeException,
                                 java.io.IOException,
                                 NoImageException

Determines and returns the suitable encoder (and overlay) for the image according to its type.

Processes the image if it was not processed already.

Specified by:

getEncoder in interface ImageStegIO

Parameters:

seed - to hand to the overlay

Returns:

BuffImgEncoder with set PixelCoordinateOverlay, chosen accordingly to the images type

Throws:

UnsupportedImageTypeException - if the images type is not supported by any known encoder / overlay

java.io.IOException - if there was an error during reading of input

NoImageException - if no image could be read from input

getOverlay

protected PixelCoordinateOverlay getOverlay(java.awt.image.BufferedImage bufferedImage,
                                            long seed)
                                     throws UnsupportedImageTypeException

Returns an overlay according to the global variable useTransparent

Parameters:

bufferedImage - BufferedImage to hand to overlay

seed - Seed to hand to overlay

Returns:

ShuffleOverlay or RemoveTransparentShuffleOverlay

Throws:

UnsupportedImageTypeException - if the image type is not supported by the overlay