Steganography (Hidden Images-secret agenty stuff) v3.0 Updated July 12, 2014

[pyrochild]

BoltBait! Mind sharing the source?

[Paint_boy]

This is amazing... How in the world do I do the tree to a cat thing on the wikipedia page though?

( Gone to change sig )

[BoltBait]

BoltBait! Mind sharing the source?

Well, I started with pleska's Photo Flood Fill plugin (source is available in this forum). And, it's not really very clean. I'll post the algorithm that I'm using if that would do.

[Paint_boy]

Yay new sig! It looks at a little blurry because it used to be like 92px high and 650 wide.... This is really cool! I have no idea how it works but it's cool. Also I fugred out how to get that cat from a tree

[pyrochild]

BoltBait! Mind sharing the source?

Well, I started with pleska's Photo Flood Fill plugin (source is available in this forum). And, it's not really very clean. I'll post the algorithm that I'm using if that would do.

sounds good.

[Paint_boy]

I noticed that transparent stuff kinda messes it up a bit. :?

[blooper101]

I like the plug-in, Kinda funny... But, I can't figure out what it can be used for... Not trying to flame or anything

[BoltBait]

No offense taken. This plugin is useless*--which I pointed out on page 2 of this thread:

http://paintdotnet.12.forumer.com/viewt ... 8441#58441

*as are most of my plugins

[Myrddin]

*as are most of my plugins

^^Says the creator of two plugins which are being bundled in the next release of PDN.

[BoltBait]

Myrddin, click the 'more' link in my sig and tell me how many of the plugins I've developed are actually useful.

X/21 = ?

[PineappleQc]

19.5/21

All useful exept this stenographie, and the pastel which really needs revising. That could be a good idea btw, revise pastel effect <_,<

[Akkarins_Spirit]

Ink Sketch, Portrait, Delete Primary Colour (hand for getting rid of white), Flip Selection, Transparency, Reflection, Grid-Maker and Gradient (when it was needed.)

[Myrddin]

Okay then:-

Standard Shapes Effect

Feather Effect

Flip Selection Effect (hilariously useful)

Ink Sketch Effect - clearly useful for it to included next release

Portrait Effect - " "

CodeLab

RGB to CMYK Color Space

I would have included Arrow Effect but that's been superseded by the actual feature, but at the time very useful. Same with Gradient. A few others like the Reflection, although could be done without said effect it does make the job much, much easier and more professional.

[BoltBait]

Heh. I only count 10/21. And, I'm being generous.

Arrows, Gradient, Grid, scanlins, halo, seamless, DPC, and Flip all have better versions out now which makes them useless.

Now, compare that to someone like Ed Harvey who has 20+ GOOD plugins. *sigh*

I need to work harder...

(OK, maybe I'm just tired and cranky as I'm in the middle of a 24 hour shift due to a massive deadline later today. So, what am I doing? Surfing, of course!)

[PineappleQc]

I can lend you a rope if you want. Or, CODE MORE PLUGINS! MOOOOORE!!!

[The_Lionhearted]

"Catch a wave and you're sittin' on top of the world..."

[guspaz]

I realize that this thread is almost a month old, but it's still on the first page, so hopefully that's considered recent enough

I've got two solutions that would both help towards making the encoded image perceptually invisible

For example, say you want to encode a 1-bit image into a 24-bit image. You're commandeering, I imagine, the least significant 3 bits (one per channel) in each pixel.

First, for a 1-bit source image, you should get three hidden pixels per one real pixel. If we're only encoding a 1-bit image, might as well take advantage of all the available bits. This also means that the hidden image can be up to three times larger (in number of pixels) than the final image.

The second suggestion, and this is the most effective part, is to apply a compression algorithm to the image you're hiding (.NET directly supports several compression systems already). Compressed files look a lot like random bits. This is because a good compression algorithm produces data that has few patterns. Because patterns are compressible, that'd mean that the compression algorithm wasn't doing a good job.

Just to sum that up, when you compress data, the output looks random. So if you take a 1-bit image, compress it using something fairly simple (deflate, for example), and THEN overlay the compressed data (one bit at a time) over the final image, the overlay will look random. There won't be any pattern, and slight random variations in pixels are pretty much invisible to the human eye!

The other benefit, of course, is that since we're taking a 1-bit image, encoding 3 bits per pixel, and compressing it, you can either fit significantly larger images in, or work in redundancy to survive lossy compression. Or you could just repeat the data to get a uniform random jitter on all pixels.

EDIT: Here's an image with a 1-bit random image (OK, semi-random, it was the PDN Cloud plugin with minimum size, and then a threshold applied, it looks random enough). it gets added as just slight noise being added to the photo, no chance to see it on top of a photograph:

Except that slight random noise could be holding an actual image once you extract and decompress it.

[david.atwell]

"Stegged," eh? Sounds like a good way to abbreviate our favorite secret agenty stuff...

[RECON04]

lol cool plug-in you ppl got me stegging everything lol

great messege in your sig david lol

[Project Spartan]

Here is mine. Anyone care to try it out? It is hilarious!!!

Awesome tut for your awesome Plug-in.

EDIT: I couldn't read the message in Davids sig, i tried but some words were just apsolutey positively impossible to read.

[BoltBait]

Project Spartan, the problem with your image is that you've save in jpg format. It is critical for the integrity of the hidden image that a lossless format be used to store the image. Try PNG next time.

[Boo]

i LOVE this ^^

but

is there a way that the quality of the picture doesn't go lower?

prolly not

i found some ways you can reveal hidden pics on a white background

autolevel

bucket (at low tolerance)

...

[Paint_boy]

Here is mine. Anyone care to try it out? It is hilarious!!!

Awesome tut for your awesome Plug-in.

EDIT: I couldn't read the message in Davids sig, i tried but some words were just apsolutey positively impossible to read.

I pre-ordered halo 3

Also this is an awesome plugin that you guys should try. for all you know you might find some hidden images in signatures avatars etc...

[BoltBait]

i LOVE this ^^

but

is there a way that the quality of the picture doesn't go lower?

prolly not

Quality of both images will always suffer.

To hide a color image, the main image is losing 9 out of 24 bits of information. Plus, the hidden image is being converted from whatever you are using (24 bit?) down to 9 bits. There is no way around this with the algorithm I'm using.

There are an unlimited number of algorithms that could be implemented--many that could be encrypted or lossless. So, if you want to code your own, go for it!

[Scyphrex]

Very Good effect