Secret editing of EXIF data for photographs using freeware
EXIF Info
so that it is hard for a recipient to immediately know that the EXIF data
was modified?
Here is the manual procedure I use today to replace/modify EXIF data:
0) Starting with known good EXIF data in a jpg file called "old.jpg".
1) Replace the exif data: c:\> jhead -te old.jpg new.jpg
So as not to trip up with the EXIF size information, I reset it:
2) Reset image size data: exifer: EXIF/IPTC->Update EXIF image size values
Likewise with the EXIF thumbnails (which trip up a lot of people):
3) Remove old exif thumbnail: exifer: EXIF/IPTC->Thumbnail->Remove
thumbnail
4) Create new exif thumbnail: exifer: EXIF/IPTC->Thumbnail->Create
thumbnail
But, what else am I missing that will be a tell tale sign that the EXIF
data was modified? Am I missing anything obvious that will trip me up?
For example, how/should do I modify those other telltale EXIF info fields?
* ShutterSpeedValue
* SubjectDistance
* ImageNumber
* OwnerName
* Software
etc.
EXIF Info
> * ShutterSpeedValue
> * SubjectDistance
> * ImageNumber
> * OwnerName
> * Software
I forgot to mention that exifer doesn't edit these fields so how my
question is two fold (how + what).
a) How do we edit EXIF fields such as "software" and "ownername"?
b) What other EXIF fields are dead giveaways that the EXIF was modified?
Dave
Try taking the pictures yourself.
Dave
--
Registered Linux user # 444770
Tact is the ability to tell a man he has an open mind when he has a
hole in his head.
Steve
> Can you give me advice on how best to modify EXIF info for digital photos
> so that it is hard for a recipient to immediately know that the EXIF data
> was modified?
You can not modify these exif tags because they are permanent in the system
and will always be visable. It can't be done.
VanguardLH
http://www.kiwiczech.net/index.php?menu=353&sub=4
Never used it. Just found it in a photo forum where someone asked about
editing the EXIF data. It just went freeware yesterday. If you try it,
post back here on what you thought of it.
I'm not familiar with EXIF metadata. You make it sound like there is a
history of changes to records within the EXIF metadata. Or are you just
guessing?
nospam
<steve_...@hotmail.com> wrote:
>
> > Can you give me advice on how best to modify EXIF info for digital photos
> > so that it is hard for a recipient to immediately know that the EXIF data
> > was modified?
>
> You can not modify these exif tags because they are permanent in the system
> and will always be visable. It can't be done.
nonsense. there are numerous tools that can edit exif data, exiftool
being one of the best.
Penis Kolada
Of course you can. I have had occasion to do it, usually when setting
someone up. You need more than photographic skills and software though,
you need to be at least a little bit hacker inclined.
PK
CoMa
>
> Can you give me advice on how best to modify EXIF info for digital photos
> so that it is hard for a recipient to immediately know that the EXIF data
> was modified?
You can try
ExifTool
http://www.sno.phy.queensu.ca/~phil/exiftool/
With this Windows GUI
http://freeweb.siol.net/hrastni3/foto/exif/exiftoolgui.htm
or try this Windows program
http://www.photome.de/
Matt Ion
You could just strip the EXIF data altogether...
Ofnuts
The best way is to strip these data out. Many image handling programs
don't even attempt to save them, and those which know how to usually
have the option to strip them.
Making fake data is harder, some points to consider:
- camera make/model:
- you have to find the actual string used by the target model (which
may be different depending on continent).
- for SLRs, some makes (Nikon, at least) include technical data on
the lens used: min/max focal length and associated apertures.
- other data should be compatible with that different model:
original image size and aspect ratio, ISO, aperture, speed, focal length
and focal length/equivalent 35mm focal length ratio (physical sensor
size), flash mode, various data (scene mode), exif version, and possibly
the format of some fields.
- date/time/position:
- should be reasonably consistent with picture (lighting and sun
position, weather...)(and this is in several places).
- With GPS one can check things out on GoogleEarth (it is even
possible to crosscheck these mountains in the background)
- technical shoot data:
- an expert eye will have a rough idea of the focal length used. You
can cheat a bit there, though (1.5x both sides), but if you have the
subject distance in the Exif, it will be harder. I don't know if DSLRs
- you have to remain within a reasonably consistent set of values
for focal length, aperture, sensor size, and depth of field (and of
course camera/lens)
Good luck :-)
[Image]
Make = Panasonic
Model = DMC-FZ8
Orientation = top/left
Software = Ver.1.0
Date Time = 2007-08-18 10:43:36
[Camera]
Exposure Time = 1/200"
F Number = F5
Exposure Program = Normal program
ISO Speed Ratings = 100
Exif Version = Version 2.21
Date Time Original = 2007-08-18 10:43:36
Date Time Digitized = 2007-08-18 10:43:36
Exposure Bias Value = ą0EV
Max Aperture Value = F2.83
Metering Mode = Pattern
Light Source = Fine weather
Flash = Flash did not fire, compulsory flash mode
Focal Length = 55.2mm
Maker Note = 6786 Byte
Flashpix Version = Version 1.0
Color Space = sRGB
Exif Image Width = 3072
Exif Image Height = 2304
Sensing Method = One-chip color area sensor
File Source = DSC
Scene Type = A directly photographed image
Custom Rendered = Normal process
Exposure Mode = Auto exposure
White Balance = Manual white balance
Digital Zoom Ratio =
Focal Length In 35mm Film = 331mm
Scene Capture Type = Normal
Gain Control = None
Contrast = Normal
Saturation = Normal
Sharpness = Normal
[Thumbnail Info]
Orientation = top/left
[Thumbnail]
Thumbnail = 160 x 120
--
Bertrand
hummingbird
On Wed, 25 Jun 2008 23:17:18 -0700 'Matt Ion'
wrote this on alt.comp.freeware:
>You could just strip the EXIF data altogether...
That's easy but methinks the OP wants to modify it for some reason
or other, which he hasn't stated.
--
"All truth passes through three stages.
First, it is ridiculed, second it is violently opposed,
and third, it is accepted as self-evident"
(Arthur Schopenhauer)
John Corliss
Thanks very much for posting that, CoMa. *VERY* nice little pair of
programs.
--
John Corliss BS206. I use nFilter to block all crossposts and all Google
Groups posts because of Googlespam. No ad, cd, commercial, cripple,
demo, dotnet, nag, share, spy, time-limited, trial or web wares OR warez
for me, please.
CoMa
wrote:
>CoMa wrote:
>
>> ExifTool
>> http://www.sno.phy.queensu.ca/~phil/exiftool/
>> With this Windows GUI
>> http://freeweb.siol.net/hrastni3/foto/exif/exiftoolgui.htm
>>
>> or try this Windows program
>> http://www.photome.de/
>
>Thanks very much for posting that, CoMa. *VERY* nice little pair of
>programs.
You are very Welcome J.C.
Ron May
wrote:
> Can you give me advice on how best to modify EXIF info for digital photos
> so that it is hard for a recipient to immediately know that the EXIF data
> was modified?
I guess the real question is why you would want to conceal the fact
that you've *forged* the EXIF data (deliberately input false
information) rather than just strip the data altogether or simply edit
the data which, ISTM, should be sufficient for casual purposes?
--
Ron M.
(I filter Googlespam)
alt.comp.freeware information pages:
http://www.pricelesswarehome.org/acf/Index.php
Mike Mills
news:K7-dnfyejLxu6v7V...@posted.ccountrynet:
> CoMa wrote:
>> On Wed, 25 Jun 2008 16:22:05 -0700, EXIF Info wrote:
>>> Can you give me advice on how best to modify EXIF info for
>>> digital photos so that it is hard for a recipient to immediately
>>> know that the EXIF data was modified?
The commandline program Jhead will do all this and more.
Sorry no link.. I'm sure that you can find it.
CoMa
>The commandline program Jhead will do all this and more.
EXIF Info
> Making fake data is harder, some points to consider:
Exactly the point! The false EXIF data needs to roughly match the
photograph! But how?
> - date/time/position:
> - lighting and sun position
Good point to check the shadows for outdoor shots to see if they match with
the time the picture was falsly taken. I'll add this to my checklist.
> - an expert eye will have a rough idea of the focal length used.
> - if you have the subject distance in the Exif, it will be harder.
Yes indeed! This is the type of observation I was looking for.
I try to change the EXIF subject distance to match the photograph but I
didn't think about the focal length having to match. Are you sure an expert
could guess the focal length from a photograph?
> - you have to remain within a reasonably consistent set of values
> for focal length, aperture, sensor size, and depth of field (and of
> course camera/lens)
Sensor size? Hmmmmmm.... From any given photograph, how would "sensor size"
be obvious to a trained observer? I don't know how to fake sensor size.
What would be rough estimation points for the falsified EXIF?
EXIF Info
> I guess the real question is why you would want to conceal the fact
> that you've *forged* the EXIF data (deliberately input false
> information) rather than just strip the data altogether or simply edit
> the data which, ISTM, should be sufficient for casual purposes?
PK said it well already as to why ... as for editing data ... that's the
whole point.
What program edits ALL (or almost all) EXIF data fields. Exifer does not.
But it seems that CoMa's suggestion (ExifTool + Windows GUI) does edit some
of the harder to modify fields and Ofnut's hints as to which fields to
focus on helps greatly.
The main approach I use to "believably" falsify EXIF data is:
1. Find reasonably believable EXIF template data (I save dozens)
2. Swap out EXIF data and thumbnails and reset thumbnails
3. Modify individual EXIF fields as needed (e.g., subject distance, focal
length, aperture, flash settings, etc.)
EXIF Info
>>You could just strip the EXIF data altogether...
>
> That's easy but methinks the OP wants to modify it for some reason
> or other, which he hasn't stated.
The reason is to create a believable yet false EXIF trail instead of no
EXIF whatsoever.
That is, the viewer, perhaps thousands of them for any one photograph,
needs to believe the photograph was taken at the time and place with the
camera, setting, and lighting conditions that are in the EXIF fields.
EXIF Info
> ExifTool
> http://www.sno.phy.queensu.ca/~phil/exiftool/
> With this Windows GUI
> http://freeweb.siol.net/hrastni3/foto/exif/exiftoolgui.htm
Thank you CoMa! ExifTool + the GUI was able to edit fields that exifer just
couldn't touch such as "Software" and "Owner Name".
Interestingly, ExifTool goofed somewhat (I think) in that it allowed
blanking of "Owner Name" but blanking "Software" actually REMOVED the field
altogether from the EXIF data viewable by the freeware Irfanview.
The question for me to figure out is whether removing the "Software" EXIF
field would be indicative in certain cameras of tampering. Otherwise, I'll
need to come up with a series of believable software values.
BTW, what I was hoping to find was a freeware tool to spit EXIF data to a
text (or comma separated value) file which could then be edited and read
back in so that ALL EXIF fields of situational pertinence could be modified
believably with a text editor without the tampering being readily apparent.
EXIF Info
>>The commandline program Jhead will do all this and more.
> http://www.sentex.net/~mwandel/jhead/
My bad for not explaining that jhead will only replace one EXIF data with
another. AFAIK, jhead won't "fix" the thumbnail, nor will jhead set the
EXIF data to match the photograph (e.g., pixel dimensions, subject
distance, ownership information, etc.).
As stated in the first post, I do use jhead to get a starting point for the
believably falsified EXIF data, deliberately choosing out of scores of EXIF
templates the closest match as a starting point.
It would be nice if there was a freeware program that read in EXIF data
from a TEXT file so that each field could be edited with a text editor and
then jheaded over to the scented digital photograph.
EXIF Info
> I'm not familiar with EXIF metadata. You make it sound like there is a
> history of changes to records within the EXIF metadata.
One new item for the exif-editing checklist this brings up is the potential
for unintentional "watermarking" in the EXIF data. That would be bad.
To prevent unintentional watermarking, I would have to be sure to make the
falsified EXIF data universal enough that a simple search engine didn't
flag my particular photos any more than others in a programatic EXIF search
such as that which Flickr and other public photo sharing sites routinely
perform.
Thanks for one more item for the checklist!
Tom Yost
wrote:
>On Thu, 26 Jun 2008 10:45:48 +0100, hummingbird wrote:
Sounds rather dodgy to me.
John Corliss
Good luck in court! 80)>
EXIF Info
>> or try this Windows program
>> http://www.photome.de/
Interesting that freeware PhotoMe EXIF metadata editing program.
PhotoMe runs a process called "Geonames.exe" which is apparently a
geolocate feature which may be useful if we can point to a spot on Google
Earth and have a program automatically insert EXIF metadata corresponding
to the corresponding GPS coordinates.
us...@domain.invalid
You can also edit the file with a binary editor, such as Hexedit. This
allows changing absolutely anything. But there is a catch, a big one:
you are stuck with the field lengths that already exist. Sure, you can
pad with spaces, but this is rather "obvious". What you can do, is
use Exiftool to make a very short field with some bogus value like XY
and use a hex editor to change that to two spaces.
Doug McDonald
EXIF Info
>>That is, the viewer, perhaps thousands of them for any one photograph,
>>needs to believe the photograph was taken at the time and place with the
>>camera, setting, and lighting conditions that are in the EXIF fields.
>
> Sounds rather dodgy to me.
Practical applications
- Privacy (hide situational information from industrial search engines)
- Personals (make yourself younger and wider traveled)
- Watermarking (create intentionally unique EXIF codes for search engines)
etc.
Oh, and the Loch Ness monster Area 54 style believable jokes too!
EXIF Info
>> BTW, what I was hoping to find was a freeware tool to spit EXIF data to a
>> text (or comma separated value) file which could then be edited and read
>> back in so that ALL EXIF fields of situational pertinence could be modified
>
> You can also edit the file with a binary editor, such as Hexedit.
Very interesting. Will try.
I wonder what happens when I accidentally insert bogus (i.e., invalid)
information into the EXIF field with the binary editor ..............
Should be interesting to test...... especially if a text-import tool
doesn't yet exist.
Ofnuts
> On Thu, 26 Jun 2008 10:46:26 +0200, Ofnuts wrote:
>
>> Making fake data is harder, some points to consider:
> Exactly the point! The false EXIF data needs to roughly match the
> photograph! But how?
>
>> - date/time/position:
>> - lighting and sun position
> Good point to check the shadows for outdoor shots to see if they match with
> the time the picture was falsly taken. I'll add this to my checklist.
>
>> - an expert eye will have a rough idea of the focal length used.
>> - if you have the subject distance in the Exif, it will be harder.
> Yes indeed! This is the type of observation I was looking for.
> I try to change the EXIF subject distance to match the photograph but I
> didn't think about the focal length having to match. Are you sure an expert
> could guess the focal length from a photograph?
I'm far from an expert and I can usually tell if the picture was taken
with a 35 or 50mm lens (35mm equiv. of course). How goof experts really
are is your guess.
>> - you have to remain within a reasonably consistent set of values
>> for focal length, aperture, sensor size, and depth of field (and of
>> course camera/lens)
>
> Sensor size? Hmmmmmm.... From any given photograph, how would "sensor size"
> be obvious to a trained observer? I don't know how to fake sensor size.
> What would be rough estimation points for the falsified EXIF?
Because the sensor size has a great influence on the DOF. A small sensor
at 2.8 (P&S, bridge) has the same DOF as an APS/C sensor several f-stops
higher (how much is "several" is a matter of actual sensor size, but
IIRC on the 4/3 sensor (which is not that much smaller than an APS/C)
you already have to open 2 f-stops more to achieve the same DOF).
--
Bertrand
hummingbird
On Thu, 26 Jun 2008 06:48:36 -0700 'EXIF Info'
wrote this on alt.comp.freeware:
Fine, I'm none the wiser but it's not my business. Good luck.
M.L.
> to a
> text (or comma separated value) file which could then be edited and
> read
> back in so that ALL EXIF fields of situational pertinence could be
> modified
> believably with a text editor without the tampering being readily
> apparent.
Doesn't PhotoMe import and export EXIF in XML text format?
http://www.photome.de/
VanguardLH
More likely is stenography which would embed a "watermark", code, or
other data within the image. You're just looking at the metadata tacked
onto the image content. The original author (since it seems like you
are trying to steal someone else's work) could embed their signature
into the image so it could still be identified as to whom was the
original author/owner along with a copy of that EXIF data that you are
trying to falsify. I've never gotten interested in hiding secret data
within an image so I don't know if editing an image, even to convert it
to a different format, would get rid of the encoded data.
Blinky the Shark
> "EXIF Info" wrote in <news:DjN8k.14647$Ri....@flpi146.ffdc.sbc.com>:
>
>> On Wed, 25 Jun 2008 23:31:38 -0500, VanguardLH wrote:
>>
>>> I'm not familiar with EXIF metadata. You make it sound like there is a
>>> history of changes to records within the EXIF metadata.
>>
>> One new item for the exif-editing checklist this brings up is the potential
>> for unintentional "watermarking" in the EXIF data. That would be bad.
>>
>> To prevent unintentional watermarking, I would have to be sure to make the
>> falsified EXIF data universal enough that a simple search engine didn't
>> flag my particular photos any more than others in a programatic EXIF search
>> such as that which Flickr and other public photo sharing sites routinely
>> perform.
>>
>> Thanks for one more item for the checklist!
>
> More likely is stenography which would embed a "watermark", code, or
Uh...steganography?
Follow-up not set to any stenographers' newsgroups. ;)
--
Blinky
Killing all posts from Google Groups
The Usenet Improvement Project --> http://improve-usenet.org
Found: a free GG-blocking news *feed* --> http://usenet4all.se
Ron May
wrote:
> On Thu, 26 Jun 2008 07:10:05 -0700, Tom Yost wrote:
>
> >>That is, the viewer, perhaps thousands of them for any one photograph,
> >>needs to believe the photograph was taken at the time and place with the
> >>camera, setting, and lighting conditions that are in the EXIF fields.
> >
> > Sounds rather dodgy to me.
>
> Practical applications
> - Privacy (hide situational information from industrial search engines)
Can be accomplished by simply deleting the info
> - Personals (make yourself younger and wider traveled)
Again, deletion works, but if deception is wanted in that case, isn't
exposure a given when there's a physical meeting.
> - Watermarking (create intentionally unique EXIF codes for search engines)
> etc.
That can be done by simple editing.
>
> Oh, and the Loch Ness monster Area 54 style believable jokes too!
Anyone who'd fall for Nessie or Area *51* style "jokes" doesn't have
the gray matter to even KNOW about EXIF data, much less spot a spoof.
I'm sorry, but the need for DECEPTION is what's bothering me, even
more so now that you're reluctant to disclose the real reason for
forgery.
John Fitzsimons
wrote:
< snip >
>That is, the viewer, perhaps thousands of them for any one photograph,
>needs to believe the photograph was taken at the time and place with the
>camera, setting, and lighting conditions that are in the EXIF fields.
Why ?
Alan Meyer
Imagine that person you never met before approaches you in the
street and tells you he needs to falsify a document and would
like some advice on how to do it.
"What kind of document is it?", you ask.
He says, "Just a document, any document."
"How do you want to falsify it?", you ask.
"Any way at all", he answers.
"Do you want to lie about who wrote the document?"
"Maybe - but that's my business" he answers.
"Who are you trying to fool?", you ask.
"None of your business", he answsers.
"What's your name?", you ask.
"Why my name is EXIF Info. I'm the son of Mr. Gimmeyour Info and
Mrs. Whosaysitsnotmy Info.
My advice to EXIF Info is that he's probably already left an
indelible trace of himself, including a unique and traceable IP
address leading to his front door, stored in his ISP's archives
(within reach of a subpoena), asking for advice on how to falsify
evidence.
So, if I were you Mr. Info, I would take up honest work. You'd
be surprised. It's actually very satisfying, less anxiety
producing, and more fun. It produces more long lasting rewards
than falsifying data. It may even keep you out of trouble.
Alan
VanguardLH
<news:pan.2008.06.26....@thurston.blinkynet.net>:
> VanguardLH wrote:
>
>> "EXIF Info" wrote in <news:DjN8k.14647$Ri....@flpi146.ffdc.sbc.com>:
>>
>>> On Wed, 25 Jun 2008 23:31:38 -0500, VanguardLH wrote:
>>>
>>>> I'm not familiar with EXIF metadata. You make it sound like there is a
>>>> history of changes to records within the EXIF metadata.
>>>
>>> One new item for the exif-editing checklist this brings up is the potential
>>> for unintentional "watermarking" in the EXIF data. That would be bad.
>>>
>>> To prevent unintentional watermarking, I would have to be sure to make the
>>> falsified EXIF data universal enough that a simple search engine didn't
>>> flag my particular photos any more than others in a programatic EXIF search
>>> such as that which Flickr and other public photo sharing sites routinely
>>> perform.
>>>
>>> Thanks for one more item for the checklist!
>>
>> More likely is stenography which would embed a "watermark", code, or
>
> Uh...steganography?
>
> Follow-up not set to any stenographers' newsgroups. ;)
I knew I wasn't using the correct term but couldn't remember it to go
look it up. I was a bit distracted after finding out someone hit my
door lock with a chunk of cement trying to break into my car along with
finding my alternator isn't working, so calling the insurance guy and
parts store were higher priority. Hey, I only missed the "ga" in the
word. I was hoping someone would come up with the right word. Rather
than "it's on the tip of my tongue", it was "it rolled off my tongue a
bit incomplete".
VanguardLH
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> From: be...@mail.invalid
> Newsgroups: alt.comp.freeware
> Subject: Re: Secret editing of EXIF data for photographs using freeware
> Date: Fri, 27 Jun 2008 00:39:48 +0100
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> VanguardLH wrote:
>
>> "EXIF Info" wrote:
>>
>>> VanguardLH wrote:
>>>
>>>> I'm not familiar with EXIF metadata. You make it sound like
>>>> there is a history of changes to records within the EXIF
>>>> metadata.
>>>
>>> One new item for the exif-editing checklist this brings up is the
>>> potential for unintentional "watermarking" in the EXIF data. That
>>> would be bad. ...
>>
>> More likely is stenography which would embed a "watermark", ...
>
> steganography.
> not short hand.
See my reply to Blinky who already provided the correction over 3 hours
earlier. You won't like my following rant so to perserve your calm you
might want to skip it.
<rant title="To Lambaste a User of the X-No-Archive Header">
To deliberately thwart the no-archive request, the original post is
shown above, including its headers. Alas, you really don't want an
answer because you don't even want your original post to stick around.
> X-No-Archive: yes
- It reduces the number of users that will see your post. This is
Usenet which doesn't command the immediacy of a prattling venue, like
some chat room where you won't see responses when you exit a session.
Potential respondents won't see your post after 6 days, or however long
is the no-archive expiration which could be shorter.
- It reduces the value of the thread to other users because the thread
get punched full of "holes" from posters that use this header.
Responses that are archived may only have a partial quoting of a prior
no-archived post plus all headers are lost from the original post. This
header corrupts the flow of the discussion. The discussion becomes
incomplete due to all the greedy bastards that don't want to share what
they've said.
- What boob self-censors their own posts by asking that they vaporize
before a week has elapsed?
- Spammers, trolls, flamers, cowards, liars, nymshifters, and
malcontents use this header to hide their history (which answers the
previous question as to who uses this header). They don't want anyone
to know just how long and how often they've been around. Is this the
group of users to whom you wish to affiliate yourself?
- Because of the user types that use this no-archive header (boobs,
newbies, greedy posters not willing to share the discussion, spammers,
trolls, cowards), some users will filter out your post. They may either
delete any no-archive posts (as YOU requested) or weight them as spam or
"bad" posts which can reduce the number of potential respondents to your
post. One of those respondents might have had the answer you were
looking for but you chose to hide your post before they visited the
group. They don't see your post so they don't respond. Maybe they
would have been the only one willing to respond. Maybe they would have
been the only one with the expertise to help you. You don't know. To
you, it looks like no one bothered to answer your post when, in fact,
you chose to hide it from them or affiliate yourself with a type of
poster that the respondent filters out.
- You inflame other users by trying to steal away the help that you
received. You want to get help but are unwilling to share it with
others that may later encounter the same or similar problem. They
cannot find your prior post. If respondents were similarly inclined and
also used the X-No-Archive header then the entire thread disappears. If
you don't want anyone to see your post or do not want to keep the thread
intact then don't post. Usenet is for SHARING.
- The use of this header is anti-social and outright rude. It is
employed by cowards.
- You don't consider your post important enough to have it archived.
Likewise, why would anyone participate or help you on a post that you
have deemed valueless?
- While you might consider your post to be valueless or you are just
being greedy in trying not to share with anyone else at a later time,
the archived threads are used to discover existing solutions or just to
see if the topic has been previously discussed. If you don't want your
posts to echo through eternity, speak into a well insulated empty soup
can so no one else can hear you. If you want to keep it to yourself, do
it upfront by not posting.
- Only boobs or newbies believe that this header will prevent their post
from getting archived. There are many forums that use a gateway to
Usenet so your post will get archived there (and may remain archived for
years). It isn't just Google Groups where your post will get archived.
Also, the retention interval of NNTP hosts (of which the vast majority
will not honor the X-No-Archive header) will far outstrip the 6-day
no-archive expiration at Google Groups. The use of this header makes
you look stupid.
- "regular newsgroup participants were concerned about privacy rights"
(http://en.wikipedia.org/wiki/X-No-Archive). Privacy is your
responsibility. Don't use your true e-mail address in your posts if you
don't want it abused. Munge it, require a passcode in the Subject to
bypass an auto-delete filter (as proof that a human used it) that you
mention in your signature (because spambots can't read instructions), or
use a bogus one (but one in which the domain is not registered, or use
.invalid as the top-level domain, as in y...@domain.invalid). Google
carried on a tradition that Deja News employed at the behest of some
frightened users in an environment that is not the same today; however,
not all traditions are sensible when established or remain applicable
over time, especially when based on a trust model.
- You requested your post be deleted from any archive that honors the
X-No-Archive header. Anyone that honors your request chooses their own
expiration interval. You don't get to specify WHEN the no-archive
request is honored. For the vast number of NNTP server, this header is
NOT honored (i.e., it is ignored). For Google Groups, deletion is after
6 days. For me, the deletion is immediate upon recognition or
immediately after responding, whichever is later. Hey, you are the one
that requested your post be automatically deleted, you are the one that
considers your post of no value beyond someone else's configured
expiration interval, and you are the one that doesn't want anyone to see
your prior posts or to fuck up the continuity of your past threads.
Your wish has been granted: your post is no longer archived by me and
it's just like it never existed. Poof, gone, you never here.
</rant>
ASAAR
>> More likely is stenography which would embed a "watermark", code, or
>
> Uh...steganography?
>
> Follow-up not set to any stenographers' newsgroups. ;)
That's the Pits, man . . .
> Last year, he and his wife had made a trip to the US, where both their son
> and daughter are working. "I have seen all the places to be seen in the US,"
> Ramu wrote. Knowing his nature, I believe him. In fact, I would not be
> surprised if he had managed to gatecrash into the White House and chatted
> with Bill and Hillary Clinton.
>
> If such a meeting had taken place, what would Ramu have discussed with the
> president of the United States? I am sure of at least one of the topics. Sir Issac
> Pitman. Yes, the man who invented shorthand. Ramu would have categorically
> told the president that the US would be able to solve most of its problems if only
> its citizens learnt shorthand. And, of course, prayed to Pitman.
EXIF Info
> Doesn't PhotoMe import and export EXIF in XML text format?
> http://www.photome.de/
1. Start PhotoMe freeware
2. PhotoMe: Open File -> original_exif_info.jpg
3. PhotoMe: Import/Export -> Text Only -> Sections -> All
This can only copy to the clipboard but can not paste to another file.
1. Start PhotoMe freeware
2. PhotoMe: Open File -> source_exif_info.jpg
3. PhotoMe: Import/Export -> Export EXIF data -> filename.exif
Drat. This is a binary file that can't be edited with a text editor.
There is no other file-type option other than "*.exif".
While PhotoMe doesn't seem to be able to write to a text-editable file that
can subsequently be read back in, PhotoMe can edit "some" (some but not
all) EXIF fields and then that result can be exported and imported (which
is no better than what we had before).
In summary, if PhotoMe can write to a text-editable file, nobody has yet
found out how. Too bad. It would be a very useful feature.
clandestin_écureuil
> On Thu, 26 Jun 2008 06:48:36 -0700 'EXIF Info'
> wrote this on alt.comp.freeware:
>
>> On Thu, 26 Jun 2008 10:45:48 +0100, hummingbird wrote:
>>
>>>> You could just strip the EXIF data altogether...
>
>
>>> That's easy but methinks the OP wants to modify it for some reason
>>> or other, which he hasn't stated.
>
>
>> The reason is to create a believable yet false EXIF trail instead of no
>> EXIF whatsoever.
>>
>> That is, the viewer, perhaps thousands of them for any one photograph,
>> needs to believe the photograph was taken at the time and place with the
>> camera, setting, and lighting conditions that are in the EXIF fields.
>
> Fine, I'm none the wiser but it's not my business. Good luck.
>
>
As the time is dependent on the camera owner setting it correctly and most
cameras don't have geo-data capability, the only real value in EXIF data is
to identify the camera and its settings. Are you trying win an argument
about camera or lens capability by substituting one camera for another?
EXIF is commonly used but isn't an accepted standard so it has no legal
value, and the number of ways of altering it, as you are trying to learn to
do, are so well known that no one other than a novice would believe it if
they had reason to suspect it to be false.
Secret Squirrel
--
Ingrid Rose
clandestin.ecureuil(insert missing symbol here)gmail.com
Blinky the Shark
> "Blinky the Shark" wrote in
> <news:pan.2008.06.26....@thurston.blinkynet.net>:
>
>> VanguardLH wrote:
>>
>>> "EXIF Info" wrote in <news:DjN8k.14647$Ri....@flpi146.ffdc.sbc.com>:
>>>
>>>> On Wed, 25 Jun 2008 23:31:38 -0500, VanguardLH wrote:
>>>>
>>>>> I'm not familiar with EXIF metadata. You make it sound like there is a
>>>>> history of changes to records within the EXIF metadata.
>>>>
>>>> One new item for the exif-editing checklist this brings up is the potential
>>>> for unintentional "watermarking" in the EXIF data. That would be bad.
>>>>
>>>> To prevent unintentional watermarking, I would have to be sure to make the
>>>> falsified EXIF data universal enough that a simple search engine didn't
>>>> flag my particular photos any more than others in a programatic EXIF search
>>>> such as that which Flickr and other public photo sharing sites routinely
>>>> perform.
>>>>
>>>> Thanks for one more item for the checklist!
>>>
>>> More likely is stenography which would embed a "watermark", code, or
>>
>> Uh...steganography?
>>
>> Follow-up not set to any stenographers' newsgroups. ;)
>
> I knew I wasn't using the correct term but couldn't remember it to go
> look it up. I was a bit distracted after finding out someone hit my
> door lock with a chunk of cement trying to break into my car along with
> finding my alternator isn't working, so calling the insurance guy and
Hell of a day. Sorry to hear it was like that for you.
> parts store were higher priority. Hey, I only missed the "ga" in the
> word. I was hoping someone would come up with the right word. Rather
> than "it's on the tip of my tongue", it was "it rolled off my tongue a
> bit incomplete".
Happy to fill in the blanks.
Whenever I see "steganography" I think of taking photos of a stegosaurus,
which even Matthew Brady, coming along quite a while after the Jurassic,
wasn't able to accomplish.
--
Blinky
Is your ISP dropping Usenet?
Need a new feed?
http://blinkynet.net/comp/newfeed.html
Blinky the Shark
> On Thu, 26 Jun 2008 13:07:34 -0700, Blinky the Shark wrote:
>
>>> More likely is stenography which would embed a "watermark", code, or
>>
>> Uh...steganography?
>>
>> Follow-up not set to any stenographers' newsgroups. ;)
>
> That's the Pits, man . . .
Is that you, Mr. Gregg? :)
(http://en.wikipedia.org/wiki/Gregg_Shorthand)
My mom could do that; she apparently learned it just for the challenge
(about when I was in junior high, around 1960), as she never used it
professionally.
M.L.
>> Doesn't PhotoMe import and export EXIF in XML text format?
>> http://www.photome.de/
>
> 1. Start PhotoMe freeware
> 2. PhotoMe: Open File -> original_exif_info.jpg
> 3. PhotoMe: Import/Export -> Text Only -> Sections -> All
> This can only copy to the clipboard but can not paste to another file.
Perhaps there's a bug somewhere, but the "How To" page indicates that
text output can be pasted elsewhere.
http://www.photome.de/howto_en.html
Steve
On Thu, 26 Jun 2008 07:08:17 -0700, John Corliss
<jcor...@fake.invalid> wrote:
>EXIF Info wrote:
>> On Thu, 26 Jun 2008 10:45:48 +0100, hummingbird wrote:
>>
>>>> You could just strip the EXIF data altogether...
>>> That's easy but methinks the OP wants to modify it for some reason
>>> or other, which he hasn't stated.
>>
>> The reason is to create a believable yet false EXIF trail instead of no
>> EXIF whatsoever.
>>
>> That is, the viewer, perhaps thousands of them for any one photograph,
>> needs to believe the photograph was taken at the time and place with the
>> camera, setting, and lighting conditions that are in the EXIF fields.
>
>Good luck in court! 80)>
Thus the reason for programs like Nikon's Image Authentication
Software.
Steve
Cyberiade.it Anonymous Remailer
> As the time is dependent on the camera owner setting it correctly and mos=
t=20
> cameras don't have geo-data capability, the only real value in EXIF data =
is=20
> to identify the camera and its settings.
Wow.
You obviously have no knowledge what so ever with respect to what
EXIF is, does, and/or means.
clandestin_écureuil
I have enough knowledge to use exiftool and a beta version of Photome on a
regular basis when examining submissions. I don't it would seem, have your
magical ability to discern what people you don't know or have ever met know
about an issue.
The OP mentioned both time and place as being of concern, I am merely
pointing out that these are not really issues.
What is your point - apart from being obnoxious?
hummingbird
On Fri, 27 Jun 2008 13:45:00 +1000 'clandestin_écureuil'
wrote this on alt.comp.freeware:
>hummingbird wrote:
>> On Thu, 26 Jun 2008 06:48:36 -0700 'EXIF Info'
>> wrote this on alt.comp.freeware:
>>
>>> On Thu, 26 Jun 2008 10:45:48 +0100, hummingbird wrote:
>>>
>>>>> You could just strip the EXIF data altogether...
>>
>>
>>>> That's easy but methinks the OP wants to modify it for some reason
>>>> or other, which he hasn't stated.
>>
>>
>>> The reason is to create a believable yet false EXIF trail instead of no
>>> EXIF whatsoever.
>>>
>>> That is, the viewer, perhaps thousands of them for any one photograph,
>>> needs to believe the photograph was taken at the time and place with the
>>> camera, setting, and lighting conditions that are in the EXIF fields.
>>
>> Fine, I'm none the wiser but it's not my business. Good luck.
>As the time is dependent on the camera owner setting it correctly and most
>cameras don't have geo-data capability, the only real value in EXIF data is
>to identify the camera and its settings. Are you trying win an argument
>about camera or lens capability by substituting one camera for another?
No, I'm not trying to do anything. Your post is wrongly
attributed. I suggest you read the thread again.
>EXIF is commonly used but isn't an accepted standard so it has no legal
>value, and the number of ways of altering it, as you are trying to learn to
>do, are so well known that no one other than a novice would believe it if
>they had reason to suspect it to be false.
>
>Secret Squirrel
--
Steve
Oh, and another reason, if someone does what the OP is asking to do
with a photo swiped from me and tries to claim it's his, I can prove
it's mine if it ever becomes necessary because only the original one
from my D200 will authenticate no matter what he does. And I have my
copyright notice in the EXIF from my camera.
Steve
Tzortzakakis Dimitrios
? "Blinky the Shark" <no....@box.invalid> ?????? ??? ??????
news:pan.2008.06.27....@thurston.blinkynet.net...
<narrow> and in this context short, and graphy <writing>. Steganography
would mean stegano <sealed compartment> like the ones found on a ship,
although this word doesn't exist....
--
Tzortzakakis Dimitrios
major in electrical engineering
mechanized infantry reservist
hordad AT otenet DOT gr
Dan Cline
> Perhaps there's a bug somewhere, but the "How To" page indicates that
> text output can be pasted elsewhere.
> http://www.photome.de/howto_en.html
PhotoMe exports text which it doesn't then import.
PhotoMe exports binary which you can't edit before reimporting it.
There is no text exif standard.
Because of that, and I said it before and I'll say it now, there is no
program that reads in text exif metadata!
It can't be done. If it could be done, someone would have done it by now.
Ari
> Can you give me advice on how best to modify EXIF info for digital photos
> so that it is hard for a recipient to immediately know that the EXIF data
> was modified?
Not and have you live, no.
--
http://www.youtube.com/watch?v=fJVydzNJrno
Nomen Nescio
> Cyberiade.it Anonymous Remailer wrote:
> > clandestin_=3DC3=3DA9cureuil wrote:
> >=20
> >> As the time is dependent on the camera owner setting it correctly and =
mos=3D
> > t=3D20
> >> cameras don't have geo-data capability, the only real value in EXIF da=
ta =3D
> > is=3D20
> >> to identify the camera and its settings.
> >=20
> > Wow.
> >=20
> > You obviously have no knowledge what so ever with respect to what
> > EXIF is, does, and/or means.
> >=20
>=20
>=20
> I have enough knowledge to use exiftool and a beta version of Photome on =
a=20
Yes, as I said the nonexistant nature of your "knowledge" is
self-evident.
> What is your point
That toys like Exiftool and Photome don't even begin to scratch the
surface of the information modern cameras store in images. That
even competent tools won't help one "forge" EXIF data because much
of that stored information is proprietary, binary, and probably
undecipherable by anyone who doesn't have an NDA from the camera's
manufacturer in their pocket.
And that you're completely oblivious to all of that, as your
laughable "camera and it's settings" bloviation so succinctly
demonstrates.
Now would there be anything else I can clear up for you today?
George Orwell
> On Wed, 25 Jun 2008 16:22:05 -0700, EXIF Info wrote:
>
> > Can you give me advice on how best to modify EXIF info for digital photos
> > so that it is hard for a recipient to immediately know that the EXIF data
> > was modified?
>
> Not and have you live, no.
More James Bond delusions. How fascinating.
Still waiting for a VALID post through AIOE by the way.
Or for your nuts to drop.
LOL!
Il mittente di questo messaggio|The sender address of this
non corrisponde ad un utente |message is not related to a real
reale ma all'indirizzo fittizio|person but to a fake address of an
di un sistema anonimizzatore |anonymous system
Per maggiori informazioni |For more info
https://www.mixmaster.it
Peter Seiler
> Can you give me advice on how best to modify EXIF info for digital photos
> so that it is hard for a recipient to immediately know that the EXIF data
[...]
--
by(e) PS
spam will be killfiled
clandestin_écureuil
> clandestin_=C3=A9cureuil wrote:
>
>> Cyberiade.it Anonymous Remailer wrote:
>>> clandestin_=3DC3=3DA9cureuil wrote:
>>> =20
>>>> As the time is dependent on the camera owner setting it correctly and =
> mos=3D
>>> t=3D20
>>>> cameras don't have geo-data capability, the only real value in EXIF da=
> ta =3D
>>> is=3D20
>>>> to identify the camera and its settings.
>>> =20
>>> Wow.
>>> =20
>>> You obviously have no knowledge what so ever with respect to what
>>> EXIF is, does, and/or means.
>>> =20
>> =20
>> =20
>> I have enough knowledge to use exiftool and a beta version of Photome on =
> a=20
>
> Yes, as I said the nonexistant nature of your "knowledge" is
> self-evident.
You said it, but it isn't so. I imagine that happens quite a lot with you.
I am not an expert, that is why I am here, hoping to learn more, but I
certainly have a good amount of general knowledge and experience.
>
>> What is your point
>
> That toys like Exiftool and Photome don't even begin to scratch the
> surface of the information modern cameras store in images.
Ok, if Exiftool and Photome are toys, enlighten me, what are the "real
deal" in such software?
> That even competent tools won't help one "forge" EXIF data because much
> of that stored information is proprietary, binary, and probably
> undecipherable by anyone who doesn't have an NDA from the camera's
> manufacturer in their pocket.
I have no interest in, nor have I suggested or implied that such a thing is
possible with any software program. I was asking someone else why they
wanted to change data other than time and place data. That data is usually
concerned with camera id and specific settings for each shot. You seem to
disagree. Is that simply because you are such a disagreeable person or do
have something valid to add?
Aside from camera id - model, make etc., and settings, what is it that you
find me to be so alarmingly ignorant of? What mystical data is there that
"toys" like Exiftool and Photome can't isolate? Is the Secret of Colonel
Sander's Eleven herbs and spices there? The whereabouts of Jimmy Hoffa? A
map leading to Elvis' whereabouts?
>
> And that you're completely oblivious to all of that, as your
> laughable "camera and it's settings" bloviation so succinctly
> demonstrates.
Bloviation? I was quite succinct. My use of succinct is valid, you on the
other hand seem to be implying that I was both verbose and concise. Make up
your mind.
>
> Now would there be anything else I can clear up for you today?
Yes. Are your parents going to invite you to their wedding?
Ari
> Ari <arisilv...@yahoo.com> wrote:
>
>> On Wed, 25 Jun 2008 16:22:05 -0700, EXIF Info wrote:
>>
>>> Can you give me advice on how best to modify EXIF info for digital photos
>>> so that it is hard for a recipient to immediately know that the EXIF data
>>> was modified?
>>
>> Not and have you live, no.
>
> More James Bond delusions. How fascinating.
Thanks!
You humourless AnonyTwat.
--
http://www.bushflash.com/idiot.html
Cyberiade.it Anonymous Remailer
> > Yes, as I said the nonexistant nature of your "knowledge" is
> > self-evident.
>=20
> You said it, but it isn't so.
It is so, and you self-demonstrated it so.
> Ok, if Exiftool and Photome are toys, enlighten me, what are the "real=20
> deal" in such software?
There's tools like exifprobe and exiv2, but even they won't ferret
out everything (although they do a much better job than the toys
you're using). To be thorough you'd need to use software specific
to the camera in question. Most of it costs big pesos, and you
still can't be sure you're seeing everything.
Bottom line is... EXIF is a wide open spec. It lets camera
manufacturers and software authors play fast an loose. Idiotic
statements like "camera and settings" are about as far from fact as
you can get and still be speaking about digital images generally.
> I have no interest in, nor have I suggested or implied that such a thing =
is=20
> possible with any software program. I was asking someone else why they=20
> wanted to change data other than time and place data. That data is usuall=
y=20
I couldn't care less what you think your "motives" are here kid,
I'm addressing a patently false statement you made. Period.
> Aside from camera id - model, make etc., and settings, what is it that yo=
u=20
Well, as an example all my Nikon DSLR's newer than about 2 years
read information from lenses and "encode" it in a 32-byte value. It
changes image to image even when the images are snapped in rapid
succession. What it consists of is "undefined". And there's several
fields where even the field name itself is a HEX value, so you can't
even know what that field pertains to let alone what the value
might mean.
Your toys probably don't even show much of this, let alone give you
a clue how to interpret or manage it.
Even my 10 year old P&S cameras have EXIF data that's undefinable
by name. And values in a dozen or so fields that's essentially
meaningless. So it's not just "upper end" hobbyist equipment and
better that do things this way. It's by design I'd imagine, and
specific to every camera make/model/revision.
> > And that you're completely oblivious to all of that, as your
> > laughable "camera and it's settings" bloviation so succinctly
> > demonstrates.
>=20
> Bloviation? I was quite succinct.
That's what I said. That simple statement defied the sum total of
your knowledge better than any protracted soliloquy ever could.
> Yes. Are your parents going to invite you to their wedding?
Lame ass "yo mama" retorts. Is that what passes for "wit" among
your peers?
How quaint...
us...@domain.invalid
HOWEVER, all this crap you are talking about should be
removeable by removing ALL non-picture data (e.g. by decoding
to a pure bitmap raw format (e.g. using Imagemagick) (not a
"camera raw" or a Windows .bmp) but a file containing ONLY the
bits themselves, creating a jpeg from that, and adding in
only what the user wants in a exif.
That method, of course, does not hide the fact that the exif
is "synthetic".
Of course, another method is to place the image data alone into
a file stolen off the net, complete with exif data. It won't be
bogus exif data ... just WRONG exif data. The human readable part
can then be changed at will.
Doug MCDonald
Floyd L. Davidson
>> Ok, if Exiftool and Photome are toys, enlighten me, what are the "real=20
>> deal" in such software?
>
>There's tools like exifprobe and exiv2, but even they won't ferret
>out everything (although they do a much better job than the toys
>you're using). To be thorough you'd need to use software specific
>to the camera in question. Most of it costs big pesos, and you
>still can't be sure you're seeing everything.
I'm not familiar with Photome. Claiming /exiftool/ to
be a toy compared to /exifprobe/ and /exiv2/ is an
interesting concept...
>Well, as an example all my Nikon DSLR's newer than about 2 years
>read information from lenses and "encode" it in a 32-byte value. It
>changes image to image even when the images are snapped in rapid
>succession. What it consists of is "undefined". And there's several
>fields where even the field name itself is a HEX value, so you can't
>even know what that field pertains to let alone what the value
>might mean.
You are confusing the information displayed by a program
with the Exif specification.
*All* records (called an Image File Description) are
keyed to a integer value in the ID Tag (index field).
There is no "field name" in the data kept with an image.
Rather there is, in the specification, a text title
assigned to each index tag value.
For example, there is a IFD with the tag name
"Orientation of Image" and with a "field name" of
"Orientation". The ID TAG value for this IFD is 112 in
hex (274 in decimal). Also included in the record is a
Type indicator which in this case will indicate the
value field will have a 16 bit integer, and a Count
indicator which will be 1. That single 16 bit value can
be decoded only as one of the following:
Value Row 0 Column 0
--------------------------
1 -- top left
2 -- top right
3 -- bottom right
4 -- bottom left
5 -- left top
6 -- right top
7 -- right bottom
8 -- left bottom
That IFD uses only 11 bytes of data in the image file
primarily because it does not include the ascii text for
the tag name or the field name.
One effect of that form of indexing is that a programmer
can write a display routine for "unknown data" (the
definition of which the programmer simply does not have
at the time). Typically such a display will provide the
(in hex) instead of a title in text. However, the value
for an unknown field often cannot be properly decoded,
and is usually displayed as one or more integer values
of unknown significance.
One of the reasons to use Exiftools is that the package
is well maintained and the current version is likely to
have appropriate titles and decoding schemes for what
will be labeled only with a hex value in other programs,
which is apparently what you are seeing and assuming the
displayed values mean it is unspecified. In fact those
values are specified, but your program is not up to date.
>Your toys probably don't even show much of this, let alone give you
>a clue how to interpret or manage it.
If you used Exiftool you probably would not have that
problem... (which is ironic because you addressed that
comment to someone who apparently does use Exiftool).
>Even my 10 year old P&S cameras have EXIF data that's undefinable
>by name. And values in a dozen or so fields that's essentially
>meaningless.
Well... make an image from an old P&S available for
download, and indicate which records in the Exif data
are "essentially meaningless", and lets find out if that
is true, or just ignorance... :-)
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) fl...@apaflo.com
Penis Kolada
> clandestin_=C3=A9cureuil wrote:
>
>>> Yes, as I said the nonexistant nature of your "knowledge" is
>>> self-evident.
>> =20
>> You said it, but it isn't so.
>
> It is so, and you self-demonstrated it so.
>
>> Ok, if Exiftool and Photome are toys, enlighten me, what are the "real=20
>> deal" in such software?
>
> There's tools like exifprobe and exiv2, but even they won't ferret
> out everything (although they do a much better job than the toys
> you're using). To be thorough you'd need to use software specific
> to the camera in question. Most of it costs big pesos, and you
> still can't be sure you're seeing everything.
So if it is almost impossible to ferret out this information then it
really isn't necessary to worry about it. Is it?
>
> Bottom line is... EXIF is a wide open spec. It lets camera
> manufacturers and software authors play fast an loose. Idiotic
> statements like "camera and settings" are about as far from fact as
> you can get and still be speaking about digital images generally.
Well I must be idiotic as well, as my only interest in Exif info is to
find out what camera, lens, place date, etc. plus those details that
show how the shot was composed. In fact almost everyone I know who uses
Exif data must also be idiotic, as that seems to be pretty much
universal as far as interest in Exif in my experience.
What does it feel like to be the only non-idiotic person among all us
idiots? Or otherwise as is more likely.
>
>> I have no interest in, nor have I suggested or implied that such a thing =
> is=20
>> possible with any software program. I was asking someone else why they=20
>> wanted to change data other than time and place data. That data is usuall=
> y=20
>
> I couldn't care less what you think your "motives" are here kid,
> I'm addressing a patently false statement you made. Period.
I must have missed that, and looking back I can't find it. Would you
like to point it out?
I see that she (or he, as in the case with Rita you never can be sure)
did say "the only real value in Exif data is to identify the camera and
its settings". Is that what you are taking exception to? I can't
understand why if that is the case. To her and many others, that is
probably quite true. To lawyers in a copyright law suit that may not be
true.
Are you taking issue with her mention of the techniques used to alter
it? Others have posted in the past few hours saying the same thing. You
can't do it with an off the shelf app, but you can sure alter any file
that uses fixed length fields, and with a little more effort, those that
have variable length fields and even checksums. I can do it, though I'd
be damned if I can see a reason to do so on more than one or two
occasions. If I don't want Exif data in my files I'll just strip them,
not bother fudging them.
I am also curious as to why the OP wants to spoof a file, but I doubt if
he'd give an honest answer.
PK
Matt Ion
Sure it can... it just needs to be done entirely within one program.
There doesn't need to be an import or export "standard" when both
functions are handled by the same program, because it can use whatever
internal "standard" suits the programmer.
PhotoMe DOESN'T do it, but that doesn't mean it CAN'T be done.
Non scrivetemi
> Cyberiade.it Anonymous Remailer wrote:
>
>
> HOWEVER, all this crap you are talking about should be
> removeable by removing ALL non-picture data (e.g. by decoding
Irrelevant.
And ripping EXIF data out that way will leave it's own "tells"
anyway. JPEG compression is lossy. The degradation caused by
converting it back and forth will be obvious to even a moderately
trained eye. Bye bye plausible deniability.
> to a pure bitmap raw format (e.g. using Imagemagick) (not a
> "camera raw" or a Windows .bmp) but a file containing ONLY the
> bits themselves, creating a jpeg from that, and adding in
> only what the user wants in a exif.
>
> That method, of course, does not hide the fact that the exif
> is "synthetic".
Exactly what the OP was trying to avoid. Thank you for your
agreement. :)
Anonymous Remailer (austria)
Floyd L. Davidson wrote:
> >Well, as an example all my Nikon DSLR's newer than about 2 years
> >read information from lenses and "encode" it in a 32-byte value. It
> >changes image to image even when the images are snapped in rapid
> >succession. What it consists of is "undefined". And there's several
> >fields where even the field name itself is a HEX value, so you can't
> >even know what that field pertains to let alone what the value
> >might mean.
>
> You are confusing the information displayed by a program
> with the Exif specification.
Wrong. I'm pointing out the fact that the EXIF spec is open ended
enough to allow camera manufacturers to include non-human-readable
and proprietary information.
>
> *All* records (called an Image File Description) are
> keyed to a integer value in the ID Tag (index field).
> There is no "field name" in the data kept with an image.
> Rather there is, in the specification, a text title
> assigned to each index tag value.
Quite a flowery way of saying "field name".
And the spec be damned, My Nikons use non-text values as field
names. Which really highlights the point I was making all along.
> If you used Exiftool
I do. And about a dozen other EXIF manipulation softwares. And
probably 20 different general image manipulation softwares. I've
even written a few special purpose tools from scratch, myself.
If you want to start trading "If you ever" barbs there kiddo, be
ready to pay the piper. <NFGAA>
> >Even my 10 year old P&S cameras have EXIF data that's undefinable
> >by name. And values in a dozen or so fields that's essentially
> >meaningless.
>
> Well... make an image from an old P&S available for
> download, and indicate which records in the Exif data
Not worth my time dragging one out of an archive. Sorry. Anyone who
has their own images and *decent* quality software tools can verify
it themselves. And they might learn something in the process.
> are "essentially meaningless", and lets find out if that
> is true, or just ignorance... :-)
If you can explain field names like 0x0029 and completely binary
data in the field itself, be my guest. Otherwise quit wasting my
time trying to blow smoke.
Floyd L. Davidson
>Floyd L. Davidson wrote:
>
>> >Well, as an example all my Nikon DSLR's newer than about 2 years
>> >read information from lenses and "encode" it in a 32-byte value. It
>> >changes image to image even when the images are snapped in rapid
>> >succession. What it consists of is "undefined". And there's several
>> >fields where even the field name itself is a HEX value, so you can't
>> >even know what that field pertains to let alone what the value
>> >might mean.
>>
>> You are confusing the information displayed by a program
>> with the Exif specification.
>
>Wrong. I'm pointing out the fact that the EXIF spec is open ended
>enough to allow camera manufacturers to include non-human-readable
>and proprietary information.
That is not Exif data, and of course an Exif
specification cannot prevent a manufacturer from writing
data other than that specified by Exif to the same file.
>> *All* records (called an Image File Description) are
>> keyed to a integer value in the ID Tag (index field).
>> There is no "field name" in the data kept with an image.
>> Rather there is, in the specification, a text title
>> assigned to each index tag value.
>
>Quite a flowery way of saying "field name".
There *is* a "field name", and it is *not* the ID Tag.
The point is that the text name is *not* in the file.
Never, ever. Only an ID Tag is, and that is the way
a specific record is identified.
In other words, it it has a text name it is necessarily
a specified record type, known to anyone who looks up
the current specification, but cannot be known just by
reading the data from the file.
>And the spec be damned, My Nikons use non-text values as field
>names. Which really highlights the point I was making all along.
Not only do Nikons use non-text values, *all*
identifiers in Exif data are non-text! Not a single one
of them has a field in the data for a text name of that
particular Exif data record.
Try using the "strings" utility to find various "field name"
entries in files that have Exif data. They aren't there.
>> If you used Exiftool
>
>I do. And about a dozen other EXIF manipulation softwares. And
>probably 20 different general image manipulation softwares. I've
>even written a few special purpose tools from scratch, myself.
>
>If you want to start trading "If you ever" barbs there kiddo, be
>ready to pay the piper. <NFGAA>
There is no point in "barbs", traded or otherwise.
There is also no point in you making claims about having
"written" tools, because it is very clear that you do
not have that kind of knowledge of Exif data structures,
or even a passing familiarity with the Exif
specification.
>> >Even my 10 year old P&S cameras have EXIF data that's undefinable
>> >by name. And values in a dozen or so fields that's essentially
>> >meaningless.
>>
>> Well... make an image from an old P&S available for
>> download, and indicate which records in the Exif data
>
>Not worth my time dragging one out of an archive. Sorry. Anyone who
>has their own images and *decent* quality software tools can verify
>it themselves. And they might learn something in the process.
>
>> are "essentially meaningless", and lets find out if that
>> is true, or just ignorance... :-)
>
>If you can explain field names like 0x0029 and completely binary
>data in the field itself, be my guest. Otherwise quit wasting my
>time trying to blow smoke.
There is NO extry with a "field name" of 0x0029. Field
names are *not* hex numbers. That would be a ID Tag
(and there is none with the number 0x0029).
Whatever, I have no interest in wasting more time
explaining this. You want to trade barbs, I don't
care...