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Problems with regenerating a steganography-file

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Fabian Pursche

Problems with regenerating a steganography-file

Hello,

I'm trying to write two Plugins for ImageJ to hide a file in picture (8-bit
greyshade) and two read it out again. It works quite well, but I don't know
how to fit the new file right. I've implemented a header of two bytes in
front of my fileInputStream, but after regaining the header, the filesize
doesn't match.

Here are both codes:

//written by F.Pursche 2008

import ij.ImagePlus;
import ij.plugin.filter.PlugInFilter;
import ij.process.ImageProcessor;
import java.io.*;

public class Steganography_ implements PlugInFilter{

public int setup (String arg, ImagePlus imp) {
return DOES_8G;
}

public void run (ImageProcessor ip) {

int w = ip.getWidth();
int h = ip.getHeight();
int maxsize = w*h;
int counter;
long header;
counter = 0;
header = 0;
Exception E = null;

File file = new File("C:\\source.txt");
try{
if(file.exists()){
FileInputStream stream = new FileInputStream(file);
if (((stream.available()*8)-16) > maxsize){throw E;}
else{
int buffer;
int fileSize = stream.available();
int fileSizeH = ((fileSize & 65280)/ 256);
int fileSizeL = fileSize & 255;
int firstByte = 0;

for (int x=0; x<w; x++) {
for (int y=0; y<h; y++) {

if(header == 0){
buffer = fileSizeH;
}
if(header == 1){
buffer = fileSizeL;
}
else{
buffer = firstByte;
}
int bit = 0;
int lsb = 0;
int p = 0;
int pixel = ip.getPixel(x, y);

if(counter == 0){
lsb = buffer & 1;
if(lsb == 1){
bit = 1;
}
}
if(counter == 1){
lsb = buffer & 2;
if(lsb == 2){
bit = 1;
}
}
if(counter == 2){
lsb = buffer & 4;
if(lsb == 4){
bit = 1;
}
}
if(counter == 3){
lsb = buffer & 8;
if(lsb == 8){
bit = 1;
}
}
if(counter == 4){
lsb = buffer & 16;
if(lsb == 16){
bit = 1;
}
}
if(counter == 5){
lsb = buffer & 32;
if(lsb == 32){
bit = 1;
}
}
if(counter == 6){
lsb = buffer & 64;
if(lsb == 64){
bit = 1;
}
}
if(counter == 7){
lsb = buffer & 128;
if(lsb == 128){
bit = 1;
}
counter = -1;
header++;
if(header > 1){
buffer=stream.read();
}

}

p = (pixel & 254) + bit;

ip.putPixel(x,y,p);
counter++;

}
}
}

}
}
catch (Exception e) {
System.out.println(e.toString());
}

}
}

2nd code:

//written by F.Pursche 2008

import ij.ImagePlus;
import ij.plugin.filter.PlugInFilter;
import ij.process.ImageProcessor;
import java.io.*;

public class ReSteganography_ implements PlugInFilter{

public int setup (String arg, ImagePlus imp) {
return DOES_8G;
}

public void run (ImageProcessor ip) {

int w = ip.getWidth();
int h = ip.getHeight();

int counter, sizeCounter;
counter = 0;
sizeCounter = 0;
long header = 0;
int buffer=0;
int fileSize, fileSizeH, fileSizeL;
fileSizeH = 0;
fileSizeL = 0;
fileSize = -1;

File file = new File("C:\\newfile.txt");
try{

FileOutputStream stream = new FileOutputStream(file);

for (int x=0; x<w; x++) {
for (int y=0; y<h; y++) {
int bit = 0;
int lsb;

int pixel = ip.getPixel(x, y);

lsb = pixel & 1;

if(counter == 0){
if(lsb == 1){
bit = 1;
buffer = buffer | bit;
}
}
if(counter == 1){
if(lsb == 1){
bit = 2;
buffer = buffer | bit;
}
}
if(counter == 2){
if(lsb == 1){
bit = 4;
buffer = buffer | bit;
}
}
if(counter == 3){
if(lsb == 1){
bit = 8;
buffer = buffer | bit;
}
}
if(counter == 4){
if(lsb == 1){
bit = 16;
buffer = buffer | bit;
}
}
if(counter == 5){
if(lsb == 1){
bit = 32;
buffer = buffer | bit;
}
}
if(counter == 6){
if(lsb == 1){
bit = 64;
buffer = buffer | bit;
}
}
if(counter == 7){
if(lsb == 1){
bit = 128;
buffer = buffer | bit;
}

if(header == 0){
fileSizeH = buffer;
}
if(header == 1){
fileSizeL = buffer;
fileSize = (fileSizeH * 256) | fileSizeL;

}
if(header > 1){
if(sizeCounter <= fileSize){
stream.write(buffer);
sizeCounter++;

}

}
header++;
buffer = 0;
counter = -1;
}
counter++;
}
}
stream.close();
}

catch (Exception e) {
System.out.println(e.toString());
}
}
}

Just change the file in the first filter, maybe a txt-file.

Thanks
Fabian

Joachim Wesner

Problem with Version 1.40b!!

Hi list,

I just noted that upgrading to ImageJ 1.40b messes with my "locale",
suddenly the decimal "point" becomes a comma in input boxes etc. (German
setup), breaking a lot of my Plugins!
After downgrading to 1.39x everything is OK again! I´m not sure if this
already existed with 1.40a, due to the new nice updater mechanism I dont
have a copy anymore.

Any ideas?

(Windows 2000, Imagej bundled Java 1.6.0_02)

Joachim

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dscho

Re: Problem with Version 1.40b!!

Hi Joachim,

On Wed, 2 Apr 2008, Joachim Wesner wrote:

> I just noted that upgrading to ImageJ 1.40b messes with my "locale",
> suddenly the decimal "point" becomes a comma in input boxes etc. (German
> setup), breaking a lot of my Plugins!
>
> After downgrading to 1.39x everything is OK again! I´m not sure if this
> already existed with 1.40a, due to the new nice updater mechanism I dont
> have a copy anymore.

Do you mean 1.38x, or 1.39u? I never had 1.39x.

In case you meant 1.39u, I cannot find anything in the changes that
relates to the locale, except the use of toLowerCase(Locale.US), which is
used throughout the code, though.

Ciao,
Dscho

Joachim Wesner

Antwort: Re: Problem with Version 1.40b!!

Sorry, typo, I meant 1.39u

Yep, strange, I will need to check this with my other system at home.

I´m not totally sure if I did something strange recently that caused this,
nevertheless I can now switch on and off this effect by simply changing
versions
via the Updater (still the extra plugin)

Is there anything in IJ_prefs.txt handling that might be related to version
numbering?
So that 1.40 reads IJ_prefs differntly from 1.39u?

Joachim

Johannes
Schindelin
<Johannes.Schinde An
[hidden email]> Joachim Wesner
<joachim.wesner@LEICA-MICROSYSTEMS
02.04.2008 18:10 .COM>
Kopie
[hidden email]
Thema
Re: Problem with Version 1.40b!!

Hi Joachim,

On Wed, 2 Apr 2008, Joachim Wesner wrote:

> I just noted that upgrading to ImageJ 1.40b messes with my "locale",
> suddenly the decimal "point" becomes a comma in input boxes etc. (German
> setup), breaking a lot of my Plugins!
>
> After downgrading to 1.39x everything is OK again! I´m not sure if this
> already existed with 1.40a, due to the new nice updater mechanism I dont
> have a copy anymore.

Do you mean 1.38x, or 1.39u? I never had 1.39x.

In case you meant 1.39u, I cannot find anything in the changes that
relates to the locale, except the use of toLowerCase(Locale.US), which is
used throughout the code, though.

Ciao,
Dscho

______________________________________________________________________
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Wayne Rasband

Re: Problem with Version 1.40b!!

In reply to this post by Joachim Wesner

> I just noted that upgrading to ImageJ 1.40b messes with my "locale",
> suddenly the decimal "point" becomes a comma in input boxes etc.
> (German setup), breaking a lot of my Plugins!
> After downgrading to 1.39x everything is OK again! I´m not sure if
> this already existed with 1.40a, due to the new nice updater
> mechanism I don't have a copy anymore.

This bug is fixed in v1.40c, now available via the
Plugins>Utilities>Update ImageJ command.

-wayne

Richard Cole

Re: Problem with Version 1.40b!!

Dear Group,

OK, maybe I am a little slow on the uptake here, but I do not see the
Plugins>Utilities>Update ImageJ command. I use to download the jar from the
ImageJ website and drop it in the correct folder.

Cheers

RWC

Richard Cole
Research Scientist IV
Director: Advanced Light Microscopy Core Unit
Wadsworth Center
P.O. Box 509 Albany N.Y. 12201-0509
518-474-7048 Phone
518-474-4430 Fax

Email [hidden email]
Website www.wadsworth.org/cores/alm/index.htm

-----Original Message-----
From: ImageJ Interest Group [mailto:[hidden email]] On Behalf Of Wayne
Rasband
Sent: Wednesday, April 02, 2008 1:58 PM
To: [hidden email]
Subject: Re: Problem with Version 1.40b!!

> I just noted that upgrading to ImageJ 1.40b messes with my "locale",
> suddenly the decimal "point" becomes a comma in input boxes etc.
> (German setup), breaking a lot of my Plugins!
> After downgrading to 1.39x everything is OK again! I´m not sure if
> this already existed with 1.40a, due to the new nice updater
> mechanism I don't have a copy anymore.

This bug is fixed in v1.40c, now available via the
Plugins>Utilities>Update ImageJ command.

-wayne

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system. Thank you for your cooperation.

Joachim Wesner

Antwort: Re: Problem with Version 1.40b!!

Hi RWC.

Haha, you are a victim of a "Catch22" situation, if your version is too
old, you also do not yet have the Updater to upgrade! ;-((

Sincerely, at best you get the external updater plugin from

http://rsb.info.nih.gov/ij/plugins/imagej-updater.html

first, only the newest versions have this updater built in as indicated!

Sincerely

Joachim

ImageJ Interest Group <[hidden email]> schrieb am 02.04.2008 22:11:41:

> Dear Group,
>
> OK, maybe I am a little slow on the uptake here, but I do not see the
> Plugins>Utilities>Update ImageJ command. I use to download the jar from
the

> ImageJ website and drop it in the correct folder.
>
> Cheers
>
> RWC
>
>
>
>
>

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