Package steganography.image

Class AnimatedGif

java.lang.Object

steganography.image.AnimatedGif

All Implemented Interfaces:

Steganography

public class AnimatedGif
extends java.lang.Object
implements Steganography

Author:

Selina Wernike The class splits an animated gif into several single frame gifs or vice versa

Constructor Summary

Constructors

Constructor	Description
AnimatedGif()

Method Summary

Modifier and Type	Method	Description
byte[]	decode(byte[] steganographicData)	Decodes a hidden message in the given steganographicData and returns it as a byte array.
byte[]	decode(byte[] stegGif, long seed)	Decodes a payload from an animated GIF
byte[]	encode(byte[] carrier, byte[] payload)	Encodes the given payload in the given carrier (image, mp3, ...) and returns the result.
byte[]	encode(byte[] payload, byte[] animatedGif, long seed)	Encodes a payload into the frames of an animated Gif and returns a gif
boolean	isSteganographicData(byte[] data)	Tests whether the given data has a hidden message encoded in it.
boolean	isSteganographicData(byte[] data, long seed)	Tests whether the given data has a hidden message encoded in it.

Methods inherited from class java.lang.Object

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

Constructor Detail

AnimatedGif

public AnimatedGif()

Method Detail

encode

public byte[] encode(byte[] carrier,
                     byte[] payload)
              throws java.io.IOException,
                     MediaNotFoundException,
                     UnsupportedMediaTypeException,
                     MediaReassemblingException,
                     MediaCapacityException

Description copied from interface: Steganography

Encodes the given payload in the given carrier (image, mp3, ...) and returns the result. The format of the returned media will be the same as carrier. Carrier needs to be an exact media representation as it would be read from a file by an InputStream.

Specified by:

encode in interface Steganography

Parameters:

carrier - media used to hide the payload

payload - data to hide

Returns:

steganographic data - exact media representation. Can be stored as it is to a file to open externally

Throws:

java.io.IOException - if a problem occurs during reading of carrier or payload

MediaNotFoundException - if the intended media (e.g. Image, Video, ...) could not be read from carrier

UnsupportedMediaTypeException - if the Media Type (e.g. JPG) is not supported

MediaReassemblingException - if a problem occurred during writing of the result media

MediaCapacityException - if the payload doesn't fit in the carrier

encode

public byte[] encode(byte[] payload,
                     byte[] animatedGif,
                     long seed)
              throws java.io.IOException,
                     MediaNotFoundException,
                     UnsupportedMediaTypeException,
                     MediaReassemblingException,
                     MediaCapacityException

Encodes a payload into the frames of an animated Gif and returns a gif

Specified by:

encode in interface Steganography

Parameters:

payload - media used to hide the payload

animatedGif - data to hide

seed - affects the resulting steganographic data (similar to a password)

Returns:

steganographic data - exact media representation. Can be stored as it is to a file to open externally

Throws:

java.io.IOException - if a problem occurs during reading of carrier or payload

MediaNotFoundException - if the intended media (e.g. Image, Video, ...) could not be read from carrier

UnsupportedMediaTypeException - if the Media Type (e.g. JPG) is not supported

MediaReassemblingException - if a problem occurred during writing of the result media

MediaCapacityException - if the payload doesn't fit in the carrier

See Also:

GIFMakerImageIO.splitGIF(byte[]), GIFMakerImageIO.sequenzGIF(byte[][])

decode

public byte[] decode(byte[] steganographicData)
              throws java.io.IOException,
                     MediaNotFoundException,
                     UnsupportedMediaTypeException,
                     UnknownStegFormatException

Description copied from interface: Steganography

Decodes a hidden message in the given steganographicData and returns it as a byte array.

steganographicData needs to be an exact media representation as it would be read from a file by an InputStream.

This method only works if the message was encoded using no Seed or the respective default Seed. Otherwise it will throw an UnknownStegFormat as if no message was found.

Specified by:

decode in interface Steganography

Parameters:

steganographicData - Media containing the hidden message to decode

Returns:

the hidden message as a byte array

Throws:

java.io.IOException - if a problem occurs during reading of steganographicData

MediaNotFoundException - if the intended media (e.g. Image, Video, ...) could not be read from steganographicData

UnsupportedMediaTypeException - if the Media Type (e.g. JPG) is not supported

UnknownStegFormatException - if no hidden message was found

decode

public byte[] decode(byte[] stegGif,
                     long seed)
              throws UnsupportedImageTypeException,
                     NoImageException,
                     java.io.IOException

Decodes a payload from an animated GIF

Specified by:

decode in interface Steganography

Parameters:

stegGif - Media containing the hidden message to decode

seed - seed that was used to encode the given stenographicData

Returns:

the hidden message as a byte array

Throws:

java.io.IOException - if a problem occurs during reading of steganographicData

UnsupportedImageTypeException

NoImageException

See Also:

GIFMakerImageIO.splitGIF(byte[]), GIFMakerImageIO.sequenzGIF(byte[][])

isSteganographicData

public boolean isSteganographicData(byte[] data)
                             throws java.io.IOException,
                                    MediaNotFoundException,
                                    UnsupportedMediaTypeException

Description copied from interface: Steganography

Tests whether the given data has a hidden message encoded in it. This method only works if the message was encoded using the given Seed or the respective default Seed. Otherwise it will always return false.

The use of this method is discouraged. It saves very little resources compared to decode(...). So unless you need to test a lot of possible steganographicData, just use decode(...) and catch the UnknownStegFormatException

Specified by:

isSteganographicData in interface Steganography

Parameters:

data - data to test

Returns:

true if the given data has a hidden message encoded in it

Throws:

java.io.IOException - if a problem occurs during reading of data

MediaNotFoundException - if the intended media (e.g. Image, Video, ...) could not be read from data

UnsupportedMediaTypeException - if the Media Type (e.g. JPG) is not supported

isSteganographicData

public boolean isSteganographicData(byte[] data,
                                    long seed)
                             throws java.io.IOException,
                                    MediaNotFoundException,
                                    UnsupportedMediaTypeException

Description copied from interface: Steganography

Tests whether the given data has a hidden message encoded in it. This method only works if the message was encoded using the given Seed. Otherwise it will always return false.

The use of this method is discouraged. It saves very little resources compared to decode(...). So unless you need to test a lot of possible steganographicData, just use decode(...) and catch the UnknownStegFormatException

Specified by:

isSteganographicData in interface Steganography

Parameters:

data - data to test

seed - seed the hidden message was encoded with

Returns:

true if the given data has a hidden message encoded in it

Throws:

java.io.IOException - if a problem occurs during reading of data

MediaNotFoundException - if the intended media (e.g. Image, Video, ...) could not be read from data

UnsupportedMediaTypeException - if the Media Type (e.g. JPG) is not supported