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Identifying Manipulated Images

CmdrTaco posted more than 6 years ago | from the check-that-out dept.

Graphics 162

Jamie found a cool story at MIT Tech Review. (As an aside, it sits behind an interstitial ad AND on 2 pages: normally I reject websites that do that, but it's a slow news day, so I'm letting it through.) Essentially, software is used to analyze light patterns in still photographs. Once you can figure out where the light sources are, it becomes a lot easier to determine if an image has been photoshopped.

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Steganography (4, Insightful)

unbug (1188963) | more than 6 years ago | (#22772960)

Does it also apply to steganography? Would sort of suck if it did.

Re:Steganography (5, Funny)

L4t3r4lu5 (1216702) | more than 6 years ago | (#22773078)

*Somewhere in the middle of the NSA / MI6 buildings, a check mark is put next to an IP address.*

Re:Steganography (1)

JeanBaptiste (537955) | more than 6 years ago | (#22773086)

Steganography is a good way to hide things from your Grandmother. I wouldn't trust it much past that.

Re:Steganography (2, Informative)

blueg3 (192743) | more than 6 years ago | (#22774140)

There's not much wrong with steganography of encrypted data, particularly if the data in the covert channel would have been statistically similar to random data anyway.

Most image steganography isn't that great, though, and steganography by a well-known means of cleartext data is fairly pointless.

Detector == Quality Control (5, Interesting)

Anonymous Coward | more than 6 years ago | (#22772988)

People who manipulate images will use these tools for quality control: When the fabrication passes all tests, it is ready to be released.

Re:Detector == Quality Control (1)

PrayerlessApostle (1192601) | more than 6 years ago | (#22775104)

Well very few will get released then. In that case the people who invented the detection technology have won then, haven't they? Fewer fakes released because the bar has been raised a lot now in terms of "quality control". Just because some photoshop nerd uses this for quality control doesn't mean it'll embue him with the power to photoshop pure gold fakes everytime he lays his hand on the mouse. If everyone implemented this as quality control before they released, there would be a lot less releases per week/month/year/whatever. Sure some people will still get through the net with fakes that fool this detection technology. But the point is very little will. So either a lot more fakes will get caught when this proliferates, or a lot more fakers will spend more time (a lot more) in photoshop trying to make an image that won't be found out to be a fake. A lot of them will probably never be able to release then, or will have to release with now-detectable faults in their image, because the bar is just too high now.

Everything is photo-shopped! (5, Funny)

jimboindeutchland (1125659) | more than 6 years ago | (#22773006)

Duh! [xkcd.com]

Re:Everything is photo-shopped! (0, Redundant)

ls -la (937805) | more than 6 years ago | (#22773438)

Damn, you beat me to it.

Re:Everything is photo-shopped! (2, Funny)

mlush (620447) | more than 6 years ago | (#22774148)

Damn, you beat me to it.

I'm sure there is an xkcd strip to cover this eventuality....

I'm sure its in here [xkcd.com] somewhere

Re:Everything is photo-shopped! (0, Troll)

Guy G (783837) | more than 6 years ago | (#22773608)

George Bush Jr is really just a simulation thanks to Sr. trying to get it right....If you don't believe just try to find a picture of him in front of a mirror!!!

Re:Everything is photo-shopped! (-1, Troll)

Anonymous Coward | more than 6 years ago | (#22773662)

No, more like junior is trying to emulate father but doing a terribly half-assed job of it.

Expert User Required (2, Insightful)

Anonymous Coward | more than 6 years ago | (#22773012)

TFA says an "expert user" is required. This expert user inputs coefficients that drive the equations that analyze the picture.

So basically, if you want an image to be doctored, you use one set of values. If you want an image to be genuine, you use another set of values. Maybe somebody else's requirements differ from mine, but this is not the kind of flexibility I want in a tool that is supposed to tell me if an image has been altered or not.

For an example of a better tool, see this article [slashdot.org] from Slashdot in August 2007.

Re:Expert User Required (4, Informative)

general_re (8883) | more than 6 years ago | (#22773360)

TFA says an "expert user" is required. This expert user inputs coefficients that drive the equations that analyze the picture.

So basically, if you want an image to be doctored, you use one set of values. If you want an image to be genuine, you use another set of values. Maybe somebody else's requirements differ from mine, but this is not the kind of flexibility I want in a tool that is supposed to tell me if an image has been altered or not.
Ummm, what? FTA:

Johnson's tool, which requires an expert user, works by modeling the lighting in the image based on clues garnered from various surfaces within the image. (It works best for images that contain surfaces of a fairly uniform color.) The user indicates the surface he wants to consider, and the program returns a set of coefficients to a complex equation that represents the surrounding lighting environment as a whole. That set of numbers can then be compared with results from other surfaces in the image. If the results fall outside a certain variance, the user can flag the image as possibly manipulated.
I mean, that's not even close to what you posted - "running the same analysis on different parts of the image and then comparing the results" is not the same as "you pick the results".

Re:Expert User Required (1)

fredklein (532096) | more than 6 years ago | (#22775778)

"running the same analysis on different parts of the image and then comparing the results" is not the same as "you pick the results".


It is if you get to pick the parts of the image.

I can tell... (2, Funny)

Anonymous Coward | more than 6 years ago | (#22773018)

I can tell just by looking at the pixels and cause ive seen a lot of 'shops.

Re:I can tell... (0)

Anonymous Coward | more than 6 years ago | (#22773692)

Damn. I wanted that one.

I for one welcome our new manipulated image sensing overlords.

Re:I can tell... (0)

Anonymous Coward | more than 6 years ago | (#22773816)

Shoop da woop! *lazer*

No ads, all on one page (5, Informative)

wile_e_wonka (934864) | more than 6 years ago | (#22773024)

The printer-friendly version:

http://www.technologyreview.com/printer_friendly_article.aspx?id=20423 [technologyreview.com]

Re:No ads, all on one page (1)

IBBoard (1128019) | more than 6 years ago | (#22773108)

Clever (yet annoying). I found that link as well, but it doesn't work.

First time I hit the article (from the link in the summary) it loaded fine. Clicked your link and I got an ad with the "skip this ad" link (although the ad wasn't there because of AdBlock) then it took me to the main article across two pages.

Looks like those damned evil news people don't want us to avoid their adverts.

Re:No ads, all on one page (3, Informative)

trolltalk.com (1108067) | more than 6 years ago | (#22773380)

The link works fine if, instead of clicking on it, you cut-n-paste it into a new browser tab. Here's what you get, if you can't be arsed to go to the trouble:

Monday, March 17, 2008
Identifying Manipulated Images
New tools that analyze the lighting in images help spot tampering.
By Erica Naone

Photo-editing software gets more sophisticated all the time, allowing users to alter pictures in ways both fun and fraudulent. Last month, for example, a photo of Tibetan antelope roaming alongside a high-speed train was revealed to be a fake, according to the Wall Street Journal, after having been published by China's state-run news agency. Researchers are working on a variety of digital forensics tools, including those that analyze the lighting in an image, in hopes of making it easier to catch such manipulations.

Tools that analyze lighting are particularly useful because "lighting is hard to fake" without leaving a trace, says Micah Kimo Johnson, a researcher in the brain- and cognitive-sciences department at MIT, whose work includes designing tools for digital forensics. As a result, even frauds that look good to the naked eye are likely to contain inconsistencies that can be picked up by software.

Many fraudulent images are created by combining parts of two or more photographs into a single image. When the parts are combined, the combination can sometimes be spotted by variations in the lighting conditions within the image. An observant person might notice such variations, Johnson says; however, "people are pretty insensitive to lighting." Software tools are useful, he says, because they can help quantify lighting irregularities--they can give solid information during evaluations of images submitted as evidence in court, for example--and because they can analyze more complicated lighting conditions than the human eye can. Johnson notes that in many indoor environments, there are dozens of light sources, including lightbulbs and windows. Each light source contributes to the complexity of the overall lighting in the image.

Johnson's tool, which requires an expert user, works by modeling the lighting in the image based on clues garnered from various surfaces within the image. (It works best for images that contain surfaces of a fairly uniform color.) The user indicates the surface he wants to consider, and the program returns a set of coefficients to a complex equation that represents the surrounding lighting environment as a whole. That set of numbers can then be compared with results from other surfaces in the image. If the results fall outside a certain variance, the user can flag the image as possibly manipulated.

Hany Farid, a professor of computer science at Dartmouth College, who collaborated with Johnson in designing the tool and is a leader in the field of digital forensics, says that "for tampering, there's no silver button." Different manipulations will be spotted by different tools, he points out. As a result, Farid says, there's a need for a variety of tools that can help experts detect manipulated images and can give a solid rationale for why those images have been flagged.

Neal Krawetz, who owns a computer consulting firm called Hacker Factor, presented his own image-analysis tools last month at the Black Hat 2008 conference in Washington, DC. Among his tools was one that looks for the light direction in an image. The tool focuses on an individual pixel and finds the lightest of the surrounding pixels. It assumes that light is coming from that direction, and it processes the image according to that assumption, color-coding it based on light sources. While the results are noisy, Krawetz says, they can be used to spot disparities in lighting. He says that his tool, which has not been peer-reviewed, is meant as an aid for average people who want to consider whether an image has been manipulated--for example, people curious about content that they find online.

Cynthia Baron, associate director of digital media programs at Northeastern University and author of a book on digital forensics, is familiar with both Krawetz's and Farid's work. She says that digital forensics is a new enough field of research that even the best tools are still some distance away from being helpful to a general user. In the meantime, she says, "it helps to be on the alert." Baron notes that, while sophisticated users could make fraudulent images that would evade detection by the available tools, many manipulations aren't very sophisticated. "It's amazing to me, some of the things that make their way onto the Web and that people believe are real," she says. "Many of the things that software can point out, you can see with the naked eye, but you don't notice it."

Johnson says that he sees a need for tools that a news agency, for example, could use to quickly perform a dozen basic checks on an image to look for fraud. While it might not catch all tampering, he says, such a tool would be an important step, and it could work "like an initial spam filter." As part of developing that type of tool, he says, work needs to be done on creating better interfaces for existing tools that would make them accessible to a general audience.

Re:No ads, all on one page (0)

Anonymous Coward | more than 6 years ago | (#22774084)

Johnson's tool, which requires an expert user
Yeah, my tool requires an expert user as well.

Re:No ads, all on one page (-1, Redundant)

Anonymous Coward | more than 6 years ago | (#22774238)

i c wut u did thar

Re:No ads, all on one page (1)

wile_e_wonka (934864) | more than 6 years ago | (#22773194)

Sorry people--it doesn't work.

Darn advertisers!

Re:No ads, all on one page (0)

Anonymous Coward | more than 6 years ago | (#22774420)

Then again, I'm using Netscape 4, which ignores a lot of today's ads by default. :)

Re:No ads, all on one page (0)

Anonymous Coward | more than 6 years ago | (#22774324)

Using Opera with Javascript turned off & using its ad blocker.

That should help (1)

WormholeFiend (674934) | more than 6 years ago | (#22773048)

with all those UFO hoax photos then... /I want to disbelieve

Re:That should help (2, Informative)

zotz (3951) | more than 6 years ago | (#22773388)

Funny thing, you don't always have to shop things to get odd results:

My vids on youtube:

http://www.youtube.com/user/zotzbro [youtube.com]

If you check the comments on the "UFO vs Paper plane test" you will see people talking of a real one.

Perhaps on some of the paper plane instruction vids too. If you watch those, as the camera pans in one of them, after the construction and before the flight test, you can see what the "UFO" really is.

all the best,

drew
http://zotzbro.blogspot.com/ [blogspot.com]

Re:That should help (5, Informative)

sm62704 (957197) | more than 6 years ago | (#22773552)

It's not needed and won't help. Most of the UFO photos are pre-Photoshop and were done with different methods:
  • Have a small model of the UFO and fling it into the air high enough that there's no context. Although those CAN be detected, they can't by this software.
  • The objects are secret military aircraft, not alien craft. The hoax of alien craft is started by the government (pick one) to mask the true meaning of the object photoed. This software won't help with that, either
  • It's something else flying around up there. Is it a bird? Is it a plane? Is it a weather balloon? Is it ball lightning? Who knows? If it's a flying thing and you don't know what it is, then it's an Unidentified Flying Object. This tool won't help here, either.
This tool can't do anything someone trained in art can't do. The first thing you learn in art school is how to see. You can't draw if you can't see, and that's usually the biggest reason most people can't draw.

As one of my instructors used to say, "I don't know what I like but I know what art is."

-mcgrew

Colombo did this on his 1970's TV show (5, Interesting)

jimwelch (309748) | more than 6 years ago | (#22773054)

Someone wore a photo mask and tripped a speed camera to give their partner proof that they were across town (LA) at the time of the murder. He noticed the shadow under the nose was wrong by comparing previous and following pictures from the same camera.
I am not sure which episode it was. Peter Falk as Det. Lt. Colombo

Re:Colombo did this on his 1970's TV show (1)

R2.0 (532027) | more than 6 years ago | (#22773240)

Speed cameras in the 70's? Sure about that?

Re:Colombo did this on his 1970's TV show (1, Informative)

Anonymous Coward | more than 6 years ago | (#22773326)

I believe the crook in that episode was Dabney Coleman.

Found the episode (4, Informative)

jimwelch (309748) | more than 6 years ago | (#22773418)

Columbo and the Murder of a Rock Star, 1991 and yes Dabney Coleman was the bad guy.

Re:Found the episode (1)

boredsenseless (1246818) | more than 6 years ago | (#22775328)

Wasn't Dabney Coleman always the bad guy?

Re:Colombo did this on his 1970's TV show (1)

jimwelch (309748) | more than 6 years ago | (#22773348)

The show ran from 1971 to 2003, like I said, I don't remember which episode, but I seen it several times.

Uh Oh (5, Funny)

Missing_dc (1074809) | more than 6 years ago | (#22773058)

This bodes ill for all those geeks out there with "out-of-state" girlfriends!!

Good (-1, Flamebait)

UWM (1162951) | more than 6 years ago | (#22773064)

Now we can analyze those fake moon landing pictures.

Goes both ways (4, Insightful)

Nerdposeur (910128) | more than 6 years ago | (#22773066)

...and then the photoshoppers will write evolutionary algorithms to modify their photographs until they pass evaluation by this tool.

Based on the same codebase, in fact (1)

phorm (591458) | more than 6 years ago | (#22773220)

You could even use the same codebase. If a particular method is using light-sources/shadow/etc to determine the authenticity of an image, then you could plot those same light-sources and have a plugin modify the image to be what the authentication plugin would expect.

Re:Based on the same codebase, in fact (2, Insightful)

Neotrantor (597070) | more than 6 years ago | (#22773394)

horse shit

changing the light source in a picture requires that you might have to desaturated some pixels and guess what their level/color might be, which is information you probably don't have available.

Horse shit ^ horse shit (1)

hummassa (157160) | more than 6 years ago | (#22773544)

Sorry for the subject line, but...
if you have enough information to test it, then you have enough information to fake it (at least well enough to pass the test).

Re:Goes both ways (0)

Anonymous Coward | more than 6 years ago | (#22773232)

They don't even need to write a line of code. If these tools are generally available, they can just run their doctored images trough it to catch any "problem areas" that need further work done.

Re:Goes both ways (3, Funny)

Linker3000 (626634) | more than 6 years ago | (#22773296)

Yeah, but do they blend?

weak (4, Interesting)

gnudutch (235983) | more than 6 years ago | (#22773070)

this method is way better

Forensic Analysis Reveals Al-Qaeda's Image Doctoring [slashdot.org]

way better? (2, Interesting)

CrazeeCracker (641868) | more than 6 years ago | (#22775702)

The interesting thing about that is... The code used in the article the OP linked to features the following lines:

Revision history: This code has been stripped out of imgana by Hacker Factor Solutions. (Imgana does much more than quality analysis, but that's all that is being released right now.)
Said program by Hacker Factor is also mentioned in TFA as a more basic approach to checking whether or not an image has been manipulated. I'll leave you to judge what this means.

As an unrelated sidenote, Hacker Factor features a very interesting javascript that guesses the gender [hackerfactor.com] of the author of a block of text (>300 words). Thus far, I've found it to be eerily accurate.

Limited utillity (2, Informative)

johnjaydk (584895) | more than 6 years ago | (#22773116)

In a studio or other arranged settings it's pretty standard to use multiple lighting sources. So this tool will mainly be usefull for outdoor settings. If it's up-close and personal then it's also very common to use lights or other tools outside. Sooo this tool should be used with moderation.

Re:Limited utillity (2, Insightful)

aadvancedGIR (959466) | more than 6 years ago | (#22773268)

Moreover, it is well known that photoshop is a standard and commonly used tool for professional studio photography anyway. I think the tool purpose is limited to check that a "genuine" photography used to prove a crime or the existence of UFO/Bigfoot is not a blatant fake.

This article was shopped (-1, Troll)

Anonymous Coward | more than 6 years ago | (#22773124)

I can tell, look at the pixels, they look a bit off plus I've seen many shops in my time.

Adds a step for the photoshoppers (4, Insightful)

crowemojo (841007) | more than 6 years ago | (#22773142)

One would think that it would be simple enough, after finishing whatever touch-ups that you want to perform, that you use this technique to calculate where the light sources should be, and then correct the minute details that would give it away as an altered image. Sounds like the kind of thing that would be a simple photoshop plugin actually, once you are all done you just run the "make undetectable from light source detection analysis" tool and call it a day.

Re:Adds a step for the photoshoppers (3, Interesting)

CambodiaSam (1153015) | more than 6 years ago | (#22773260)

Light sources have always been a pain for me when photoshopping. I'm not surprised that it's the key to this software, as it tends to be the most difficult aspect of manipulating an image (I'm a slightly more than casual user, but not a graphic designer). Light completely changes the color structure and I end up spending an inordinate amount of time trying to redo hues and fix shadows that don't line up.

If there's a plugin for helping me with that part of the struggle, I hereby scream to my fellow slashdotters to please fill me in!

Re:Adds a step for the photoshoppers (2, Insightful)

Anonymous Coward | more than 6 years ago | (#22773398)

This algorithm at least requires human intervention, to find contours (RTFA). Additionally, it's easier to find inconsistencies than to automatically resolve them in a way which doesn't cause potentially something else to look weird.

It's just another tool which requires (some) human ingenuity to use effectively and thus requires (just a little more) human ingenuity to use offensively. After all, you only need to miss one detail to be found out... and hiring a photodoctoring expert is something you don't want to do if you (e.g. news media) are trying to sneak this past the public. I'd say that it's not as symmetric as you suggest.

You can come up with a lot of confounding examples for this method anyway - imagine if one of the subjects in your photo has a flashlight, or is illuminated by a spotlight. "Make undetectable from light source analysis" (or "Detect Forgery by Light Source Analysis" for that matter) is something I'll expect to see in CSI, not reality.

This looks shopped (-1, Redundant)

Stormwatch (703920) | more than 6 years ago | (#22773144)

I can tell from some of the pixels and from seeing quite a few shops in my time.

Finding Photoshopped Pics for Fun (5, Interesting)

Dan East (318230) | more than 6 years ago | (#22773176)

Does anyone else have a habit at looking at pictures and trying to see how they've been manipulated? These types of pictures are rampant in advertising. Pick up any magazine and start looking, and the poorly edited pictures will jump out quickly. The more professionally edited pictures have much more subtle problems, and can take a bit of poring over to find. Many product images (on packaging and in catalogs) are the same way, and are usually the worst edited of the bunch. Some things I look for:
  • An object rubber-stamped in multiple places. Each copy is identical, which gives it away. They are often scaled, rotated or mirrored to make them look more unique.
  • Lighting and shadows, which is what the algorithm in this story deals with specifically.
  • Focus. Often multiple objects will be in focus at varying distances impossible with a single shot.
  • The same image of a person is used in multiple shots. This is most prevalent in product images in catalogs.
  • Poor masking, where edges of objects are over or under processed, either clipping part of the object (hair can be particularly tough to do), or showing some color edges from the original background.

Anyway, that's just the geek in me I guess, because I really do enjoy finding flaws in images. What I hate is an image that has a sort of surreal perfection to it that I know must be composited, but I can't find any smoking gun.

Re:Finding Photoshopped Pics for Fun (1)

jo42 (227475) | more than 6 years ago | (#22773538)

"If it looks too good to be true, it is."

Re:Finding Photoshopped Pics for Fun (2, Funny)

Dmala (752610) | more than 6 years ago | (#22774164)

Playboy is probably the worst offender at this. Most of the women these days are so heavily airbrushed/Photoshopped that they look more like paintings or cartoons than actual photos.

Er... I mean... I just read the articles, but that's what a friend told me about the pictures.

Re:Finding Photoshopped Pics for Fun (1)

hairykrishna (740240) | more than 6 years ago | (#22774580)

Essentially all catalog images are manipulated. Some are even computer renders rather than real photos. My housemate used to work for a company that imported a lot of the stuff sold in Argos (UK crappy catalog chain). They used to sometimes submit the product photos before the actual items existed, while they were still being manufactured in China.

Good (1, Offtopic)

Fri13 (963421) | more than 6 years ago | (#22773186)

Now when we have a tool what shows when image is manipulated by using Photoshop, we can start using GIMP or any other _image manipulation_ software because those tools cannot trace them because they dont "photoshop" images, they manipulate them.

Yah, bad sarcasm, im just tired that "photoshop this" "photoshop that" like there would not be any other image manipulation software. I bet that over 50% Photoshop owners just has a warez version of it and 80% of photoshop users could do their things with any other software.

Re:Good (-1, Offtopic)

DigitalSorceress (156609) | more than 6 years ago | (#22773408)

Actually an interesting point there.

I'm no graphic artist - I'm a web application developer. I leave the heavy lifting (graphics-wise) to the pros, but I often find that I'll use Paint Shop Pro (an older pre-Corel version) for resizes, rotates, and minor alterations. Heck, I even use Paint Shop Pro just fine for my occasional dalliances in the Fark Photoshop challenges.

My point is that I too find the "Verbing" of Photoshop to be a bit inaccurate. However, people have pretty much taken it and run with it. It's not too different from many of the other linguistic corruptions/evolution (depending on your viewpoint) that goes on every day.

On the bright side, at least it will keep future etymologists busy.

Re:Good (4, Funny)

Marvin01 (909379) | more than 6 years ago | (#22773414)

It just sounds wrong to say that an image has been "GIMPed".

Actually, now that I think about it, I kinda like it...

Re:Good (1)

qoncept (599709) | more than 6 years ago | (#22773440)

they dont "photoshop" images, they manipulate them.

I hope you don't have a runny nose or a paper cut, because you'd probably get upset if someone offered you a Kleenex or Bandaid. Unless those don't fit your agenda. All the pros are using MS Paint anyway.

Re:Good (2, Funny)

glwtta (532858) | more than 6 years ago | (#22773456)

im just tired that "photoshop this" "photoshop that" like there would not be any other image manipulation software

Do you also hang around the Epson at work explaining to people how they aren't really "xeroxing" anything?

Re:Good (3, Insightful)

dotancohen (1015143) | more than 6 years ago | (#22773636)

That's why I say "to gimp a photo" rather than say "to photoshop a photo". It spreads awareness, breaks the Adobe monopoly, and sounds more natural. Even Adobe discourages the use of "photoshop" as a verb.

Re:Good (4, Insightful)

m.ducharme (1082683) | more than 6 years ago | (#22773874)

Even Adobe discourages the use of "photoshop" as a verb.
You know why, right? If they let "photoshop" be corrupted in the language as a verb, they would eventually lose the trademark rights to the name. Eventually, companies would be able to get away with naming their software "MS Photoshopping Program" or "Gimp Photoshop Utility" or whatever, and Adobe wouldn't be able to do anything about it.

Are you sure now, that you want to discourage people from using "photoshop" as a verb?

Re:Good (0)

Anonymous Coward | more than 6 years ago | (#22775506)

no they wouldn't, everyone calls vacuum cleaners hoovers, doesn't mean that Electrolux can sell vacuum cleaners with hoover written on them.

Re:Good (1)

Herkum01 (592704) | more than 6 years ago | (#22775914)

You photoshopped my comment!

Re:Good (1)

Mister Whirly (964219) | more than 6 years ago | (#22773810)

"im just tired that "photoshop this" "photoshop that""

Just "Google" it. It is a legitimate verb now.

"I bet that over 50% Photoshop owners just has a warez version of it and 80% of photoshop users could do their things with any other software"

And I bet there is a 100% chance you pulled those numbers from right out of yer ass. Thinking something doesn't automagically make it a fact. And haven't you ever seen the GIMP vs. Photoshop discussions like a million times on Slashdot before? If not let me condense it for you - GIMP works great as a free software tool, but most professionals wouldn't use it to do their paid work, as it lacks some of the higher end features of Photoshop.

Re:Good (0)

Anonymous Coward | more than 6 years ago | (#22774638)

and 80% of photoshop users could do their things with any other software.
Assuming this number even vaguely reflects reality, you're right; they could. But they don't.

Content specific test (1)

grikdog (697841) | more than 6 years ago | (#22773234)

Does the "image" contain Lindsey Lohan, Paris Hilton, Hillary Clinton or Sarah Michelle Gellar? It's photochopped.

Re:Content specific test (1)

grikdog (697841) | more than 6 years ago | (#22773276)

Actually, I used to think the puffs of "white smoke" and "black smoke" in the Challenger disaster films were early photoshops. A puff of zeroes. A puff of ones. Recently, though, NASA seems to have released extraordinarily detailed movies (from the classified cameras and undocumented camera angles, evidently) that do show beautifully complex puffs of thick black roil. Maybe they can do that with fractals these days, but if so, is it still Photoshop? GIMP can't do that (yet).

Apollo (4, Funny)

sir_eccles (1235902) | more than 6 years ago | (#22773288)

I love how the first comment is asking if the apollo landing photos were photoshopped.

Re:Apollo (5, Funny)

lena_10326 (1100441) | more than 6 years ago | (#22773892)

I love how the first comment is asking if the apollo landing photos were photoshopped.
Photoshop was HUGE in 69. Huge.

That must be why (2, Funny)

sleeponthemic (1253494) | more than 6 years ago | (#22773290)

Elvis is always spotted in 7-11.

Easily masked light sources (hint: they're everywhere!).

Ad? What ad? (0, Offtopic)

brunes69 (86786) | more than 6 years ago | (#22773346)

Adblock - everyone should have this installed.

Re:Ad? What ad? (1)

francisstp (1137345) | more than 6 years ago | (#22773496)

Or use Opera which blocks these by itself...

This looks shopped... (0)

Anonymous Coward | more than 6 years ago | (#22773364)

I can tell from some of the pixels and from seeing quite a few shops in my day

Well, there goes the pr0n industry... (1)

amplt1337 (707922) | more than 6 years ago | (#22773508)

nt

The opposite (0)

kcdoodle (754976) | more than 6 years ago | (#22773532)

I have written code that does the opposite.

I have shape generating program (wire frame sphere distortions) I developed. I wanted to add shading to the shapes. So I pick a point for the light source at random and color the pixels closer to the light a little brighter than those pixels farther away from the light. Really works well.

Once I got that working, I wanted to add self-cast shadows. You know, when the generated shape twists back on itself and should cast a shadow onto itself. Never got there, still sits in my code archives as just a "cool dealie".

Shouldn't be too hard to work my code backward and calculate (or guess) where lighting is coming from. I mean heck, I am one guy and this isn't so hard.

I don't see how this is useful. (1)

Tokimasa (1011677) | more than 6 years ago | (#22773628)

If you analyzed the noise pattern of the image, any edits would be obvious - the noise pattern wouldn't exist over edited components.

Re:I don't see how this is useful. (1)

argent (18001) | more than 6 years ago | (#22774146)

That's another approach, how well does it do when the manipulator layered noise over the image.

Faked non-uniformly lit (2, Informative)

abqaussie (1250734) | more than 6 years ago | (#22773676)

The tool doesn't tell you if a photo is faked, it just analyzes whether there are light sources in the image that are not affecting different objects in the image the same way. From what I can tell it tries to tell if the way the light hits different objects in the picture "agree" with one another based on the position of the object, color, and probably other attributes not detailed in the article. If the photographer is controlling the light at all, using off-camera flash, focusing their light on some parts and blocking it from others, etc, then there would be components of the image that deliberately don't match when it comes to the lighting. People do that all the time, both deliberately and accidentally, when lighting a photo. Because the photographer has deliberately put a light on the subject that isn't hitting other elements, background, objects, the same way as it's hitting the subject. So it seems like the analysis would work great for cases where the light is ambient, and should affect all objects in the frame relatively the same. Otherwise it'd have a bad day.

Re:Faked vs. non-uniformly lit (1)

abqaussie (1250734) | more than 6 years ago | (#22773814)

Title on previous post should have read "Faked vs. non-uniformly lit"

NASA was here (1, Redundant)

brainwash (923821) | more than 6 years ago | (#22773998)

Time to run the test on the Apollo shots, for all the tinfoil hats.

strings (1)

TheDarkener (198348) | more than 6 years ago | (#22774000)

Or, with most dumb$*@&s who like to play off photoshopped images as real,

$ strings pic.jpg | grep -i photoshop

Re:strings (1)

blueg3 (192743) | more than 6 years ago | (#22774228)

It's a lot easier to edit those fields than to properly redo all the lighting so that a lighting-analysis program can't detect it.

anyione (1)

SnarfQuest (469614) | more than 6 years ago | (#22774060)

Anyione else notice the tyipo?

speaking of which (4, Interesting)

circletimessquare (444983) | more than 6 years ago | (#22774072)

did anyone else catch the blog in the new york times about the fenton photographs [wikipedia.org] ?

apparently this guy took some photos of some cannonballs in the crimean war that became famous as a poetic commentary on war. this documentary filmmaker, errol morris [wikipedia.org] , has gone completely unhinged obsessive compulsive over whether or not the photos are fake and/ or manipulated. it's utterly fascinating, and a little weird, to see so much time and effort devoted to these photos. specifically, cannons and shadows. utterly esoteric and thorough. he also expands into the larger topic of the history of manipulated politically sensitive photos. makes for a good read, especially if you are interested in pre-photoshop image manipulation

check it out, talk about thorough [nytimes.com]

Re:speaking of which (1)

argent (18001) | more than 6 years ago | (#22775212)

There appear to be a number of balls in the "OFF" picture that do not appear in the "ON" picture, further up the hill than the ditch. To make it easier to find the differences I aligned the images and applied a false color mask using red and green overlays for the two images:

http://scarydevil.com/~peter/images/Extra-balls-in-OFF.png [scarydevil.com]
http://scarydevil.com/~peter/images/OFF-plus-false-color.png [scarydevil.com]
http://scarydevil.com/~peter/images/ON-plus-false-color.png [scarydevil.com]

dude (1)

circletimessquare (444983) | more than 6 years ago | (#22775774)

send your work to errol morris. he is sure to use the data and give you a shout out

Re:dude (1)

Reziac (43301) | more than 6 years ago | (#22775926)

I didn't go that far. I looked at the length of the road visible beyond the foreground area, concluded that it had already been cleared of loose cannonballs (since there are none on the rest of its visible length), and that therefore the cannonballs lying on the road had to have been placed there FOR the 2nd photo.

Also, the area appears to have been slightly muddy, and the cannonballs on the road show no sinkage, while those elsewhere do. Ergo, those on the road have been there less time than those in the ditch.

Silver Button? (1)

Jaqenn (996058) | more than 6 years ago | (#22774168)

Hany Farid, a professor of computer science at Dartmouth College...says that "for tampering, there's no silver button."
Silver button? What the heck is a silver button?

I'm assuming he was trying to say silver bullet. Do we blame the professor, or the journalist?

What is "manipulated?" (1)

toddhisattva (127032) | more than 6 years ago | (#22774334)

How are we to define "manipulation?"

Gamma adjustment and color correction. Dodging and burning. Red-eye and dust removal. Cropping. JPEG or other data compression. Dynamic range compression.

The only non-manipulated image is the raw data from the sensors. This is actually an improvement over film, where developing techniques can have quite an impact on the negatives - in film photography, there are no un-manipulated images.

Any serious news bureau should provide their raw images to interested parties. Only this way can their customers (us!) tell how much manipulation an image has undergone.

Analyze, not "analyize" (1)

1u3hr (530656) | more than 6 years ago | (#22774396)

Taco, I will try not to make the obvious "anal" jokes, but FFS, is clicking spellcheck really so hard?

tag: moonlanding (0)

Anonymous Coward | more than 6 years ago | (#22774674)

Now a method to refute all those "moon landing never happened" conspiracy theorists.

So what you're telling me (1)

Provocateur (133110) | more than 6 years ago | (#22774766)

...is that Keith Richards actually looks like that? Without any enhancements at all?

Mars Photos (0)

Anonymous Coward | more than 6 years ago | (#22774776)

So, are the Mars photographs from NASA doctored or what?!

Some other stuff (1)

SCHecklerX (229973) | more than 6 years ago | (#22774896)

Light source analysis was one of several methods used at a talk at Blackhat DC this year. The much more visually impressive tool, for me, was the ability to show quite explicitly what has been modified in a lossy-compressed (like jpeg) image:

http://www.blackhat.com/presentations/bh-dc-08/Krawetz/Presentation/bh-dc-08-krawetz.pdf [blackhat.com]

Compresion analysis tool:
http://www.blackhat.com/presentations/bh-dc-08/Krawetz/Extra/jpegquality.c [blackhat.com]

We have a motto... (0)

Anonymous Coward | more than 6 years ago | (#22775240)

If you can tell it was photoshopped, then someone isn't doing their job correctly.

I work for a photography lab, and we retouch problematic images. However, we call photoshop a dark art, and/or voodoo, because when it is done correctly, then no one knows that reality was any different. In other words, the person that had the portrait done thinks that it was a true representation of what they saw.

If someone even thinks to ask if we used photoshop during the processing of the image, then we failed.

Oh, and by the way, we refer to ANY image manipulation tool as photoshop. We use several other products. The owner of the company has looked at lunix every year as a possible way of cutting costs on workstations, and every year it is still the same. Linux is not compatible with color calibration hardware such as the spyder3 or eye one. A workstation that does not show accurate color on the monitor is of no use to us no matter what the software does.

"photoshopped"? (2, Insightful)

Lxy (80823) | more than 6 years ago | (#22775512)

When did "photoshop" become a verb?

This post has been gimped by the gimper

Another good tool for detecting photoshopping (2, Informative)

Reziac (43301) | more than 6 years ago | (#22775658)

...and for diagnosing damaged JPGs (I used it extensively when reconstructing mangled JPGs from someone's disk crash):

JPEGsnoop, by Calvin Hass
In very active development; suggestions and bug reports welcome. Free download from http://www.impulseadventure.com/photo/jpeg-snoop.html [impulseadventure.com]

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