Post on 22-Dec-2015
1
Information Management
DIG 3563
Spring 2012
Lecture 15:Metadata Removal
J. Michael Moshell
University of Central Florida
Original image* by Moshell et al .
-2 -Excerpt from DA Text
Metadata Management
(Including removal)
Introductory movie: Why we need to do this:
http://www.youtube.com/watch?v=-sVUMBuJ0YY&feature=player_embedded
-3 -nathansphere.com
Metadata Management
(Including removal)
So why not just
download a freebie
software removal tool?
FREEBIES ARE
DANGEROUS.
Many carry Trojans
into your computer.
-4 -
Metadata ManagementWhere to get trustworthy software?
I use www.cnet.com
They virus-check their stuff quite carefully
(But you STILL need your own anti-virus software)
I decide try out "File Buddy" on the Mac.
It has **** rating ...
-5 -
Metadata ManagementWhere to get trustworthy software?
I use www.cnet.com
They virus-check their stuff quite carefully
(But you STILL need your own anti-virus software)
I decide try out "File Buddy" on the Mac.
It has **** rating ...
I work with it for 20 minutes ... it's not doing much.
I go to the URL to look for documentation
-6 -
Metadata ManagementWhere to get trustworthy software?
I use www.cnet.com
They virus-check their stuff quite carefully
(But you STILL need your own anti-virus software)
I decide try out "File Buddy" on the Mac.
It has **** rating ..
www.skytag.com 404
They're GONE. Nobody to answer
questions ...> orphan software.
MORAL: Check for 'liveness' first, on free software.
-7 -
Metadata ManagementMicrosoft Products
Every version is different (@#$%!!)_
MS Word Mac 2011:
Word/Preferences/
Security:
-8 -
Metadata ManagementMicrosoft Word:File/Properties
-9 -
Metadata ManagementMicrosoft Word:File/Properties
Fill in existing tags; or create new tags
-10 -
Metadata ManagementMicrosoft Products
Every version is different (@#$%!!)_
MS Word Powerpoint 2011:
Powerpoint/Preferences/
Advanced:
-11 -
Metadata ManagementIIn File/Properties, I find:
-12 -
Metadata ManagementMicrosoft Operating Systems
Windows XP's meta-information access tools
could damage the metadata in JPG and other files.
Windows Vista and 7 are SUPPOSED to be safe ... but...
-13 -
Some Metadata FormatsEXIF is the digital camera metadata tag standard
- Based on TIFF metadata
- Typical data:
-14 -
Some Metadata FormatsIPTC is International Press Telecommunications Council
- Stores who/what/when/where type data
- Typical data:
-15 -
Some Metadata FormatsIPTC is International Press Telecommunications Council
- What's an IPTC code? http://www.iptc.org/cms/site/index.html?channel=CH0088
Examples:subj:01000000 – arts, culture and entertainment
subj:01005000 – cinema
subj:01005001 – film festival
-16 -
Some Metadata FormatsIPTC is International Press Telecommunications Council
- Stores who/what/when/where type data
- More data:
-17 -
Some Metadata FormatsIPTC is International Press Telecommunications Council
Some cool XML behind the scenes in the IPTC Codes:
<concept id="medtop01000000">
<conceptId created="2009-10-22T02:00:00+00:00" qcode="medtop:01000000"/>
<type qcode="cpnat:abstract"/>
<name xml:lang="en-GB">arts, culture and entertainment</name>
<definition xml:lang="en-GB">Matters pertaining to the advancement and
refinement of the human mind, of interests, skills, tastes and emotions
</definition>
<related rel="skos:exactMatch" qcode="subj:01000000"/>
</concept>
XML features in use: attribute-value pairs
-18 -
Some Metadata FormatsIPTC is International Press Telecommunications Council
Some cool XML behind the scenes:
<concept id="medtop01000000">
<conceptId created="2009-10-22T02:00:00+00:00" qcode="medtop:01000000"/>
<type qcode="cpnat:abstract"/>
<name xml:lang="en-GB">arts, culture and entertainment</name>
<definition xml:lang="en-GB">Matters pertaining to the advancement and
refinement of the human mind, of interests, skills, tastes and emotions
</definition>
<related rel="skos:exactMatch" qcode="subj:01000000"/>
</concept>
XML features in use: self-terminating element with two attributes
-19 -
Some Metadata FormatsIPTC is International Press Telecommunications Council
Some cool XML behind the scenes:
<concept id="medtop01000000">
<conceptId created="2009-10-22T02:00:00+00:00" qcode="medtop:01000000"/>
<type qcode="cpnat:abstract"/>
<name xml:lang="en-GB">arts, culture and entertainment</name>
<definition xml:lang="en-GB">Matters pertaining to the advancement and
refinement of the human mind, of interests, skills, tastes and emotions
</definition>
<related rel="skos:exactMatch" qcode="subj:01000000"/>
</concept>
XML features in use: namespace
-20 -
Metadata ManagementA handy Adobe CSx Tool: ADOBE BRIDGE
(I'd been wondering what it was for!)
File organizer
Metadata editor (kinda...)
(Demonstrate it – but unfortunately I can't, on this computer)
IPTC Restricted field: Date requires like 11/13/2011
-21 -
Bridge's Limitations
However: Bridge can only edit
the IPTC and some other metadata – and
there is much more out there
that needs editing!
-22 -
From Bridge, we observeA Medical metadata standard: DICOM
Digital Imaging and Communications in Medicine
-23 -
Metadata ManagementThe 800 pound idealistic volunteer:
Phil Harvey, who created:::: (drum roll) :::
"The Pan Galactic Gargle Blaster of EXIF tools" Open Photography Forums
EXIFtool:
http://owl.phy.queensu.ca/~phil/exiftool/
Phil's rant on metadata:
http://owl.phy.queensu.ca/~phil/exiftool/commentary.html
-24 -
EXIFtoolEXIF is a Command Line Tool
Windows Console: Inherited DOS commands
(A granddaughtrer of Unix' command set)
Mac Console ("Terminal"):
Uses UNIX/Linux Commands
So you need to know a minimal set of these commands!
-25 -
Unix CommandsPractice these on sulley via telnet
macishly: open Terminal, then
>ssh youraccount@sulley.dm.ucf.edu
"ssh" means "secure shell". Replace 'youraccount'
with your Sulley login, which is usually your NID.
You will be asked for your password.
NOTE: This only works (a) on campus, or (b) via VPN
-26 -
Unix CommandsI will demonstrate via Mac's Terminal.
Windows folk: Find out the same for your system
- but you must know the UNIX stuff, for exams
>ls : "list", shows the current directory
>ls –la : "list long form", shows details
>cd mywork : moves viewpoint into the 'mywork' dir.
If there is only one file that starts with 'my', you can
also type cd my*
(It's a very convenient short-cut.)
-27 -
Unix CommandsI will demonstrate via Mac's Terminal.
Windows folk: Find out the same for your system
- but you must know the UNIX stuff, for exams
>ls : "list", shows the current directory
>ls –la : "list long form", shows details
>cd mywork : moves viewpoint into the 'mywork' dir.
mywork>cd .. :moves "rootward" in hierarchy.
>cp filea fileb : copies filea into fileb
>mv filea fileb :renames filea into fileb
>mv filea mywork/. :moves filea into mywork dir.
-28 -
Unix Commands
>pwd
/Users/michaelmoshell/Documents/UCF/au11UCF/DIG3563
-- A good way to ask "where am I" in the file hierarchy.("pathway describe:")
How to delete a file:
>rm fileb :deletes fileb, usually without warning.
-29 -
Unix Commands
Changing the Protection of Files in Unix:
>ls –la map1.html
-rw-r--rw-@ 1 michaelmoshell admin 1314 Nov 6 11:00 map1.html
110100110 <privileges for "me, my group, strangers"
7 4 6 <octal notation (3 bits) for each privilege group.
>chmod 666 map1.html
>ls –la map1.html
-rw-rw-rw-@ 1 michaelmoshell admin 1314 Nov 6 11:00 map1.html
-30 -
Unix Commands
Important note: When someone accesses your
website (.html, .php, etc.) they are strangers
and your script's privileges are set to that value.
EXERCISE: With the privileges set as above,
would a PHP script be allowed to overwrite
(i. e. to replace) the file map1.html?
-rw-r—r--@ 1 michaelmoshell admin 1314 Nov 6 11:00 map1.html
-31 -
Unix Commands
Important note: When someone accesses your
website (.html, .php, etc.) they are strangers
and your script's privileges are set to that value.
NO because r– means read, not write, not execute.
-rw-r—r--@ 1 michaelmoshell admin 1314 Nov 6 11:00 map1.html
-32 -
Unix Commands
Important note: When someone accesses your
website (.html, .php, etc.) they are strangers
and your script's privileges are set to that value.
EXERCISE: What chmod command would change
the privileges of map1.html so that it could be
overwritten?
-rw-r—r--@ 1 michaelmoshell admin 1314 Nov 6 11:00 map1.html
-33 -
Unix Commands
Important note: When someone accesses your
website (.html, .php, etc.) they are strangers
and your script's privileges are set to that value.
Answer: chmod 666 map1.html
(or anything with 3 digits, last one being 6)
-rw-r—r--@ 1 michaelmoshell admin 1314 Nov 6 11:00 map1.html
-34 -
Unix Commands
Important note: When someone accesses your
website (.html, .php, etc.) they are strangers
and your script's privileges are set to that value.
Answer: chmod 666 map1.html
(or anything with 3 digits, last one being 6)
why? rw-rw-rw- corresponds to 110 110 110
-rw-r—r--@ 1 michaelmoshell admin 1314 Nov 6 11:00 map1.html
-35 -
EXIFtoolEXIF is the digital camera metadata tag standard
EXIFtool works with metadata in MANY file formats.
See Wikipedia article on EXIF http://en.wikipedia.org/wiki/Exchangeable_image_file_format
and then Wikipedia article on EXIFtool
http://en.wikipedia.org/wiki/ExifTool
and then read first article in
http://www.sno.phy.queensu.ca/~phil/exiftool/faq.html
-36 -
EXIFtool(why do I trust this download?)
- download directly from a reputable university site
- well regarded by several external reviews
- site is ** extremely ** alive/active
** but it could still be risky ... if you have a PC,
make SURE your anti-virus is up to date!
-37 -
Experimenting with EXIFtool
Key concepts:
tag name:
has no spaces, e. g. ImageWidth
tag ID:
a machine representation; e. g. 0x0100
description:
a brief English (French etc.) explanation of a tag
Very useful table:
http://www.sno.phy.queensu.ca/~phil/exiftool/TagNamesindex.html
-38 -
EXIFtoolFirst example of use:
>cd
>cd Documents/UCF/au12UCF/teaching/DIG3563/EXIFexper
>exifTool exampleWithGPS.jpg
and much
more....
-39 -
First example of use, continued:
>exifTool exampleWithGPS.jpg
These are descriptions
including
GPS
data
-40 -
To see tag names, use this command:
>exifTool –s exampleWithGPS.jpg
Descr Tag Value
including
GPS
data
-41 -
Now, how can find out how to REMOVE data?
Most Unix tools are self-explaining.
>exiftool
-42 -
Now, how can find out how to REMOVE data?
Most Unix tools are self-explaining.
>exiftool
... but it runs to MANY MANY PAGES!
How to get out? It's an arcane Unix command:
ZZ
sikh-history.com
-43 -
Now, how can find out how to REMOVE data?
Most Unix tools are self-explaining.
>exiftool
... but it runs to MANY MANY PAGES!
How to get out? It's an arcane Unix command:
ZZ
How did I know that?
Experience!
sikh-history.com
-44 -
arcane Unix command:
<<Any time you hear a word from me, if you don't
know what it means, LOOK IT UP.
<< All such words are fair game in the brutal sport
of examination-writing.
Arcane (adjective:) Understood by few;
mysterious or secret.
-45 -
arcane Unix command:
<<Any time you hear a word from me, if you don't
know what it means, LOOK IT UP.
<< All such words are fair game in the brutal sport
of examination-writing.
Here's a couple more arcane Unix commands:
ctrl-C and ctrl-D: These can (sometimes) STOP a
process that is taking too long (or seems stuck.)
-46 -
I put the entire exiftool document on the course
website as a .doc file. (EXIF Documentation)
Searching therein, I found this: The special "All" tag may be used in this syntax only if a VALUE
is NOT given. This causes all meta information to be deleted (or
all information in a group if "-GROUP:All=" is used). Note that
not all groups are deletable. Use the -listd option for a
complete list of deletable groups.
So, I try >exiftool -listd
-47 -
Try this:exiftool –GPS:ALL= gpsvictim.jpg
Now the directory contains
gpsvictim.jpg
gpsvictim.jpg_original
So I have a looksee:
>exiftool gpsvictim.jpg
AND all the GPS metadata is gone!
-48 -
We go back and have a look-see with Adobe Bridge.
-49 -
We go back and have a look-see with Adobe Bridge.
Whereas, the original file shows:
-50 -
ASSIGNMENT: (25 points 'prof points' credit, if you
have no "extra credit" for Website Review.
Install EXIFtool on your laptop*.
Read the documentation
Figure out how to modify ONE metadata tag
Get an image file
Modify one metadata tag
Be prepared to show me, next Tuesday,
what you did.
* (If you have NO laptop, speak to me for alternate)
-51 -
Bottom line: What's to know about metadata removal?
- there are simple tools available. BE CAREFUL
where you get them!
a) reliable, virus-free source
b) make sure it's a live source, for support.
- the powerful tool, exifTool, requires some learning
but can do many things quickly.
-52 -
Bottom line: What's to know about metadata?
- What is EXIF?
- How to use exifTool to examine and remove metadata
- What is IPTC?
- What is Adobe Bridge? What can/cannot it do?
- What is DICOM? Where might you find it?
- Unix command line, basic commands including
cd, ls, mv, cp, chmod, pwd, and ZZ, ctrl-C, ctrl-D
- Octal numbers for use with chmod