Avoiding Camera Noise Signatures

It may not happen where you live, but there are places in the world where
the government gets very uptight about images of some of their activities
becoming public.

Not everyone seeking anonymity is paranoid.

darus67 is dead spot on. The argument of "If you aren't doing anything wrong, you'd have nothing to hide" is insidious and shameful. We all, as human beings, have a right to privacy and free speech - but, in a world where one's every move is recorded, tracked, collated, quantified, and reported (and we've seen proof positive that it is, at least in places like London - I' m sure many other parts of the world are the same), then the only way to exercise these rights is through so-called paranoia.

As they quote so often on the Internet these days, "If you give me six lines written by the most honest man, I will find something in them to hang him."

Thanks, darus67!

Regarding the paper-thin 'I've Got Nothing to Hide' argument against privacy, here's an excellent article from the San Diego Law Review .

What's "Shameful and insidious" is that some people insist on ABUSING the right to privacy. Your so called right to privacy is GONE, it was stolen in little pieces by every criminal or terrorist you've ever heard of, and a lot you haven't. It's sad, but it's a fact. Accept it, live with it, or take it up with the people who use YOUR "rights" to conceal their own shameful and insidious agendas.

For my two penny worth, anything that identifies an image as MY property is a good thing. Anything that helps identify a criminal or prove the innocence of a law abiding citizen should be encouraged, and anyone who is researching additional ways to fight that particular battle is a hero.

I did find this Instructable very interesting however and I'm grateful to the original poster for bringing it to my attention.

and anyone who is researching additional ways to fight that particular battle is a hero.

I really think that's the point of this instructable--that the "battle" has far overshot it's legitimate anti-terrorism origins.

Accept it, live with it, or take it up with the people who use YOUR "rights" to conceal their own shameful and insidious agendas.

Hey, I don't have to accept anything of the sort. FAR more people have died in previous wars specifically to protect my rights, and I'm not about to concede them without a ruckus. And that is what's happening here--people fighting shameful and insidious agendas .

I could not agree more we should never give up our rights with out a fight.

Right on. Although Dream Dragon is well intentioned, I simply cannot accept the loss of my liberties because of criminal or terrorist actions. Isn't that one of their goals? Like the good man Ben Franklin said, those who give up liberty for security deserve neither (and will probably get neither).

Some cameras even save Body Number of the camera.

Recently I was a victim of a crime, and was talking with the Police Detective about his investigation into the main suspect. He told me that person was ruled out, because he had checked into the location of his cellphone at the time of the crime, and he was not there (or at least his phone wasn't there).

Most people will think you are paranoid if you tell them that "they" are LOGGING the physical location of your phone at all times, Just In Case they need to look at the data later. The three-judge panel whose job it is to authorize warrants for that data elevated their standard of evidence awhile by one level awhile ago, but not much has changed.

And on an even more relevant note, people doubting the government's determination to track people's activities using cameras and printers should look at this:

http://www.seeingyellow.com/

they really are after you.

I knew about the yellow dots but it would be nice to find a site with software patches for the printers. But I'm glad I don't live in a place like China.

how about simply just using your camera and not worrying and being paranoid, and doing the:"THE GOVERNMENT IS ABOUT TO GET ME FOR TAKING LANDSCAPE PHOTOGRAPHS" person...
or,simply use TWO or THREE different cameras,ebay them MONTHLY,or do a random sell pattern so then every so often,or maybe mayyyybe,oh yeah reality check...sheesh,talk about conspiracy theory's run amuck....dude,do you realize just HOW many pictures are on hosting sites?
and why would a generic outside picture make them "home in on you"?
just don't take pictures at OBVIOUS Government facilities Ie; SECRET SERVICE/CIA/NSA/USDA/BATF that will also "take pictures of you,because you took pictures of US..first" a little common sense makes alot more sense..good info though,thanks

Ever lived somewhere where simply voicing any negative thoughts about the current regime will get you killed? Obviously not.

Just because you live somewhere where you don't have the secret police making people disappear nightly doesn't mean the rest of the world is that friendly.

i'd suggest you'd move then

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well if you WANTED a detailed answer concerning the fate of people living in place with socialists/facists ....no....not even,I wont go there,it's too easy to blow your arguments off as childish.
sorry,I deem you not worthy of a long thoughtful response concerning my previous answer,your rude,and overly simplistic,when I was merely stating a obvious conclusion to a not even concise stating of WHAT nations they meant..as the protagonists in question.
and any country that has a democracy ,HAS NO REGIME,it's a duly elected representation of the population.
dont like Bush/Cheney?
work to get your guys elected,or at least HAVE a worthy candidate...Obama is a racist afro centrist xeno/anglophobe, and Hillery is a corrupt government hack..MacCain aint exactly who I'd vote for anyways,he's a suck up to anyone who'll listen

McCain's not a corrupt government hack? I'd love to see someone prove that, and by the way prove Obama's an anglophobe, racist or xenophobic, or afro-centrist while you're at it

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I think we need to keep opinions relevant to the topic at hand. I expect we'll all get bounced if we keep up the ranting about the US presidential race.

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That's very noble of you and you're right to stand up for your beliefs... but I have no idea what you're talking about. (Who is this "mods" and why would anyone be afraid of him?)

I'm not an American nor am I in America and none of this has anything to do with instructables or photography. Perhaps you could make an instructable about how to make a blog where we could all enjoy your opinions for pages and pages?

Umm... okay.
That's a very insightful look into this instructable. Thank you for sharing.

opinions vary

Lawl. Half of these responses are simply precious: it's like no one has a friggin' clue OR sense of humor. Great Instructable and great book, w1n5t0n.

Yeah... and I was the one who got censured. (I thought I was funny - I was trying anyway.)

Seems to me like most people wouldn't have to worry about the federal government targeting them, but there are many good reasons why the average citizen might be picked on by local "law enforcement." So yes, it is a little paranoid (but not necessarily a bad idea) to worry about some CIA contract on your head for taking landscape photographs, but taking a urban landscape photograph and then posting it could easily lead to some pencil-pusher deciding that you've taken one too many photos of the U.S. mint. Further, photographing, accidentally or on purose, police activity is legal. That doesn't mean the cops won't hassle you, railroad you, or try to find an excuse to book you or charge you with something.

For example, the people that film protests with Denver CopWatch regularly get harassed, their cameras sometimes confiscated, and ALWAYS asked, told, then ordered (with no actual authority) to shut off their cameras. Therefore, it is reasonable that the Denver police may look up internet postings of photos of their conduct, compare signatures, and then look for a photograph that they can get a charge or citation to stick to, based on that signature. That provides just one more probable cause to arrest a member of Denver CopWatch, a retribution for filming them.

I think that masking the image with noise on all 3 channels might be a very effective way to remove the signature. It shouldn't be photoshop's noise though, because I don't think that's truely random. A quick google gave me this:
http://www.random.org/bitmaps/
Using that to generate a new pattern every time would make it impossible to find out what the signature pattern looks like, because you would never know how much lighter/darker each pixel is, without any reference.
Unfortunately, it only gives 1/0 results, so either total black or total white pixels, which is propably not enough...

Very nice idea, but the only real use I'd see for this would be child porn or photos from area 51.

also, never print your pictures
http://en.wikipedia.org/wiki/Laser_printer
and go to the
"Steganographic anti-counterfeiting" part

That only applies to certain Laser printers. :)
If you want to be 100% sure, get a Oki, Samsung, or Certain Xerox Models, because they do not print tracking dots.
Here is a list of printers that do and do not print them:
http://www.eff.org/pages/list-printers-which-do-or-do-not-display-tracking-dots

Also, Inkjet printers do not print tracking dots.

we know what SOMEBODY has been doing with their camera.....

very nice. good job. what other cool instructables are you planning?

ahhhhhhhh the government!!!!!

Tor isn't inherently a better or safer idea, unless you use full end to end encryption independent of Tor. It encrypts within the network, but the exit nodes are not encrypted. Thus the exits are good choke points to sniff at.

http://czarism.com/tor-vs-security-sniffing-exit-nodes

Tor is an inherently better idea in a case like this (posting images).

The link you posted discusses the ability for an exit node to sniff the traffic coming out, but I'm pretty certain the author of this instructable is more concerned about anonymity (which would still be preserved) than someone getting a hold of some of his traffic (only some, as tor will change exit nodes each request). He's talking about posting the images online anyways, so someone sniffing them and getting a copy is really not a concern at all.

@ mightysinetheta -
End to End encryption (e.g. PGP encrypted files or emails, or SSL secure web sessions) on its own might protect the Confidentiality of your uploaded images in transit or storage, but does nothing to preserve your Anonymity from powerful snoopers who have access to either your computer's Communications Traffic Data, or that of the target upload computer i.e. host IP address, time, date, amount of data uploaded, and possibly other web browser environment variables etc.

If, for example, you are uploading pictures of riots being brutally suppressed by the authorities, and yours is one of the few, or perhaps the only, upload session to a particular website, from say, Burma, Tibet or Zimbabwe, then the fact that you have used End to End Encryption will make little difference, as you, your family, friends and associates, are hunted down by the local secret police.

One approach may be to use an encrypted Secure Sockets Layer web server upload session (https:// as used for online credit card and internet banking transactions) in combination with a Tor Hidden Service running on the same machine.
e.g. one of the methods of secure anonymous uploading offered by the wikileaks.org whistleblower website:

http://wikileaks.org/wiki/Tor

This is not that easy or swift to use, and is not infallible either - you have to trust that wikileaks.org or their former Pirate Bay web hosting company in Stockholm, Sweden, has not been infiltrated. Anybody posting banned or controversial images, has to make their own risk calculation, balancing risk of discovery with speed and convenience.

Wikileaks archives of censored images of riots in Tibet

@ WikiLeak and NuclearDog

You guys are correct, I didn't mean to say that you shouldn't use Tor or that SSL was better alone for this application. (Should have worded my post better) What I wanted to point out was that Tor has its own issues as well, some of which are remedied by using SSL in conjunction with Tor. I think WikiLeak covered it very well in his post.

While this is nicely done... honestly, if you're that concerned about autonomy on the internet, and can't figure these sorts of things out on your own... then you most likely aren't smart enough to stay anonymous on the internet.

Oh yeah, try doing a light median filter on each colour channel, then reduce the size. This keeps your quality up while mostly removing your noise signature. If you're really concerned - add light noise above that and redo the median filter.

Hmmmm....

What's about simply, 'show' the screencap the picture and paste and save it again to medium/low jpg?

Wouldn't the 'presentation' by the OS simply kill the original noise/ add own ?!

nope, because the "noise" that he's talking about isn't actually some psuedo-spooky gov't hooba-jooba, but static introduced to the image as a side effect of the circitry of the camera. the thing to remember is that every wire in any peice of circitry acts as a mini-anttena, and that when the EM of the surrounding curcitry is introducied, it will have a reproducible effect, creating, in essance, a "signature" that will show up on any image that the camera takes. the way to get around this is to either 1) introduce new static that will mask the original signiature by adding superflois curcitry to the camera (make sure it's drawing off the camera battery) 2) artificially do the same w/ image editing software. it's easier to do the later simply due to the nature of computers. the best way of doing this, of corse, is to reduce the image to the point that any fine detail information is lost in the resizing process.
my $.02

I understood that pefectly,
But my guess was that the limited coulourdepth of the monitor would 'kill' the variances in the pixels, hence 'noise'. And in a secound step, screencaptureing it and saving this caputere as a medium quality JPG copy would basicly evade all additional information.
It would just be a dump from the screencontent! Your basicly going from digital file over presentation, back to digital copy.

I dont think you understand how "screen capturing" works. If you just hit the "Print Screen" button on your keyboard or use a screen capture program, there is no 'presentation' as you say. You are literally copying the bits from the frame buffer, so its still a digitally perfect copy.

You could always use a friend's camera and take a picture of your own monitor. ;)

I found this article highly interesting. Let me share with you a tip I use that might help:

When I'm scanning in images from a print source, I invariably see all the dots used to make up the image. The trick with those is to scan them at the highest optical resolution you can (1200 dpi or so). Zoom in to 100%, then apply gaussian blur. Push the radius just far enough that the dots start to run together. Then under resize image, chop the DPI in half, choose "bicubic sharper" and let it go.

The result is a smooth image, and usually I apply a gentle unsharp mask afterwards to restore some edge contrast.

In this case, you'd probably do well to just leave it a tad blurry. Any radius over 1.5 pixels should be enough to knock out the noise signature after it's resized.

Additionally, there's a very nice Perl script called exiftool that's part of the perl-Image-ExifTool module. It allows all kinds of scriptable exif manipulation, but the most important, is the ability to destroy the exif data completely.

Example: exiftool -all= <filename> (note the space after equals)

The article also mentions digital noise reduction. My Canon DSLR has such an option. (All Canon DSLR's offer this, from the original digital rebel up to the EOS Mark 1 DS) What it does is takes the shot, then takes the same shot with the mirror down and aperture closed to get a "noise print". It then subtracts the second data from the first. That should help slightly, although it may be possible that this creates a "hole" that can be identified also.

As the article says, any set of manipulations repeated will eventually hand someone a pattern should they choose to undertake such an option. (No doubt they will.)

To wit, you should take as much precaution in how you post your image as you do in scrubbing them to prevent them from being used against you.

Tor is a good start, but not a complete solution in and of itself. Consider stealing wireless from somewhere and then using Tor. Additionally, using services hosted outside your country (preferably ones that aren't cooperative with your government) can be a good road block also.

Lastly, remember that the truth will set you free!

I've worked as a professional astronomer, and I know a lot about methods of noise reduction in images.

The "evenly illuminated screen" method (called a flat-field) described is useful for taking out some portion of unchanging image noise, but there are other methods that we use as well. The one that's practical for use with regular digital cameras is the "image flat" -- we would take all of the images taken over the course of the night and average them together. The signal averages out given enough image, leaving only the unchanged noise -- you can then subtract it out from your actual images. The software we used doesn't work with JPGs, and it's a lot easier for monochrome images (you'd probably want to work separately with the blue, red, and green channels) but the principle should work just as well. Take a bunch of pictures of something fairly boring -- the sky on a cloudless day, a white piece of paper, whatever -- and average them together to get your flatfield.

I seem to recall a program called Vega that could do dark frames, and that sort of thing.

That could be quite useful, as presumably, subtracting the dark frame should do that. I think it works with jpgs.
I'm not sure where to find a copy, but whilst looking, I found a program called Astromix that looks promising.
Its at http://www.astromix.com/download.htm

While I doubt that I'll ever be in a situation where this will be necessary information, and although it is a bit paranoid, this was a well done instructable and should I ever be in a position to make use of this info i'll send my thanks accordingly :).

Good to realize that this exists and can/should be countered at least in some cases. As for the argument that adding noise will not remove noise that is there: that is true. A 6 megapixel image has 6 million independent pixels. I suppose JPEG removes a lot of dependency between pixels, but let's say that in dark environments there remain half a million 'noise' pixels. If every noise pixes has + or - 4 brightness values, how much noise would you have to add to block identifying a single picture? Probably adding the same nose again (including the filtering that the camera applies to the noise). What is you needed to identify two hundred? Better add the same noise to every picture, or the pictured can be averaged again to reveal the constant noise of the camera. By using the same noise for every picture, it just makes them look to be 'from the same camera', and averaging them will not reveal the underlying noise pattern.

I'm surprised nobody has posted up here yet about what I'm about to talk about!

I'm an amateur astronomer, I do a lot of astrophotography using regular off-the-shelf digital SLR cameras such as the Canon Digital Rebel XT / 350D. There are three main ways we remove noise and other imperfections from our images.

1) Dark frame subtraction - Take two pictures using the same ISO sensitivity, the same exposure time, etc. One of which has something (lens cap!) in the way so that no light can enter the lens & hit the sensor. The other has the lens cap removed and looks like a regular image. The Dark Frame will look almost entirely black, but will be speckled slightly, which represents the "digital signature" of your camera. Remove (literally subtract the pixel values) of the dark frame from the regular frame, and there you go. We typically take 5 or 10 dark frame images and average them together first (to even out random noise).

2) Flat-Field subtraction: Take a picture of something evenly illuminated to about 50%. Try a white piece of paper or something similar. Dark-frame subtract this image to remove 'constant' noise. (Also, take 5-10 images, and averaging them helps) Then you can use the pixel values in the image to make individual pixels slightly brighter or darker as compared to the average pixel brightness. This will remove dust and lens defects from your camera (particularly vignetting).

3) Image averaging: This isnt particularly applicable because it only removes the truely random noise and, thusly, isnt a 'signature' of your camera. But basically, take a bunch of images, do dark frame subtraction and flat field correction on them, and then average all of those images together. It will remove the random noise in the image.

Using #1 and #2, combined with removing the EXIF information from the jpg will make your images untraceable as well as keeping them BEAUTIFUL, without having to introduce more noise into the image. As a note, adding extra noise to the image will most certainly not make it any more difficult to trace an image back to your camera because the original noise is still there, its just behind other noise.

Good luck keeping the spies off of your back. :)

Do I smell a photoshop tutorial on how you do it? That would be awesome, even if it is something very easy to do. I dont know how to do it, but I would be interested in knowing how its done.

Finally, now I can post CP and not have to worry about the Feds :P