LISTSERV mailing list manager LISTSERV 16.5

Help for CODE4LIB Archives


CODE4LIB Archives

CODE4LIB Archives


CODE4LIB@LISTS.CLIR.ORG


View:

Message:

[

First

|

Previous

|

Next

|

Last

]

By Topic:

[

First

|

Previous

|

Next

|

Last

]

By Author:

[

First

|

Previous

|

Next

|

Last

]

Font:

Monospaced Font

LISTSERV Archives

LISTSERV Archives

CODE4LIB Home

CODE4LIB Home

CODE4LIB  January 2015

CODE4LIB January 2015

Subject:

Re: Checksums for objects and not embedded metadata

From:

Ronald Houk <[log in to unmask]>

Reply-To:

Code for Libraries <[log in to unmask]>

Date:

Wed, 28 Jan 2015 10:32:38 -0600

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (121 lines)

Hello,

I like Danielle's idea. I wonder if it wouldn't be a good idea to decouple
the metadata from the data permanently. Exiftool allows you to export the
metadata in lots of different formats like JSON. You could export the
metadata into JSON, run the checksums and then store the photo and the JSON
file in a single tar-ball. From there you could use a JSON editor to
modify/add metadata.

 It would be simple to reintroduce the metadata into the file when needed.

On Mon, Jan 26, 2015 at 10:27 AM, danielle plumer <[log in to unmask]>
wrote:

> Kyle,
>
> It's a bit of a hack, but you could write a script to delete all the
> metadata from images with ExifTool and then run checksums on the resulting
> image (see http://u88.n24.queensu.ca/exiftool/forum/index.php?topic=4902.0
> ).
> exiv2 might also work. I don't think you'd want to do that every time you
> audited the files, though; generating new checksums is a faster approach.
>
> I haven't tried this, but I know that there's a program called ssdeep
> developed for the digital forensics community that can do piecewise hashing
> -- it hashes chunks of content and then compares the hashes for the
> different chunks to find matches, in theory. It might be able to match
> files with embedded metadata vs. files without; the use cases described on
> the forensics wiki is finding altered (truncated) files, or reuse of source
> code. http://www.forensicswiki.org/wiki/Ssdeep
>
> Danielle Cunniff Plumer
>
> On Sun, Jan 25, 2015 at 9:44 AM, Kyle Banerjee <[log in to unmask]>
> wrote:
>
> > On Sat, Jan 24, 2015 at 11:07 AM, Rosalyn Metz <[log in to unmask]>
> > wrote:
> >
> > >
> > > - How is your content packaged?
> > > - Are you talking about the SIPs or the AIPs or both?
> > > - Is your content in an instance of Fedora, a unix file structure,
> or
> > > something else?
> > > - Are you generating checksums on the whole package, parts of it,
> > both?
> > >
> >
> > The quick answer to this is that this is a low tech operation. We're
> > currently on regular filesystems where we are limited to feeding md5
> > checksums into a list. I'm looking for a low tech way that makes it
> easier
> > to keep track of resources across a variety of platforms in a
> decentralized
> > environment and which will easily adopt to future technology transitions.
> > For example, we have a bunch of stuff in Bepress and Omeka. Neither of
> > those is good for preservation, so authoritative files live elsewhere as
> do
> > a huge number of resources that aren't in these platforms. Filenames are
> > terrible identifiers and things get moved around even if people don't
> mess
> > with the files.
> >
> > We also are trying to come up with something that deals with different
> > kinds of datasets (we're focusing on bioimaging at the moment) and fits
> in
> > the workflow of campus units, each of which needs to manage tens of
> > thousands of files with very little metadata on regular filesystems. Some
> > of the resources are enormous in terms of size or number of members.
> >
> > Simply embedding an identifier in the file is a really easy way to tell
> > which files have metadata and which metadata is there. In the case at
> hand,
> > I could just do that and generate new checksums. But I think the generic
> > problem of making better use of embedded metadata is an interesting one
> as
> > it can make objects more usable and understandable once they're removed.
> > For example, just this past Friday I received a request to use an image
> > someone downloaded for a book. Unfortunately, he just emailed me a copy
> of
> > the image, described what he wanted to do, and asked for permission but
> he
> > couldn't replicate how he found it. An identifier would have been handy
> as
> > would have been embedded rights info as this is not the same for all of
> our
> > images. The reason we're using DOI's is that they work well for anything
> > and can easily be recognized by syntax wherever they may appear.
> >
> > On Sat, Jan 24, 2015 at 7:06 PM, Joe Hourcle <
> > [log in to unmask]>
> > wrote:
> >
> > >
> > > The problems with 'metadata' in a lot of file formats is that they're
> > > just arbitrary segments -- you'd have to have a program that knew
> > > which segments were considered 'headers' vs. not. It might be easier
> > > to have it be able to compute a separate checksum for each segment,
> > > so that should the modifications change their order, they'd still
> > > be considered valid.
> > >
> >
> > This is what I seemed to be bumping up against so I was hoping there was
> an
> > easy workaround. But this is helpful information. Thanks,
> >
> > kyle
> >
>



--
Ronald Houk
Assistant Director
Ottumwa Public Library
102 W. Fourth Street
Ottumwa, IA 52501
(641)682-7563x203
[log in to unmask]

Top of Message | Previous Page | Permalink

Advanced Options


Options

Log In

Log In

Get Password

Get Password


Search Archives

Search Archives


Subscribe or Unsubscribe

Subscribe or Unsubscribe


Archives

March 2024
February 2024
January 2024
December 2023
November 2023
October 2023
September 2023
August 2023
July 2023
June 2023
May 2023
April 2023
March 2023
February 2023
January 2023
December 2022
November 2022
October 2022
September 2022
August 2022
July 2022
June 2022
May 2022
April 2022
March 2022
February 2022
January 2022
December 2021
November 2021
October 2021
September 2021
August 2021
July 2021
June 2021
May 2021
April 2021
March 2021
February 2021
January 2021
December 2020
November 2020
October 2020
September 2020
August 2020
July 2020
June 2020
May 2020
April 2020
March 2020
February 2020
January 2020
December 2019
November 2019
October 2019
September 2019
August 2019
July 2019
June 2019
May 2019
April 2019
March 2019
February 2019
January 2019
December 2018
November 2018
October 2018
September 2018
August 2018
July 2018
June 2018
May 2018
April 2018
March 2018
February 2018
January 2018
December 2017
November 2017
October 2017
September 2017
August 2017
July 2017
June 2017
May 2017
April 2017
March 2017
February 2017
January 2017
December 2016
November 2016
October 2016
September 2016
August 2016
July 2016
June 2016
May 2016
April 2016
March 2016
February 2016
January 2016
December 2015
November 2015
October 2015
September 2015
August 2015
July 2015
June 2015
May 2015
April 2015
March 2015
February 2015
January 2015
December 2014
November 2014
October 2014
September 2014
August 2014
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
November 2009
October 2009
September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009
December 2008
November 2008
October 2008
September 2008
August 2008
July 2008
June 2008
May 2008
April 2008
March 2008
February 2008
January 2008
December 2007
November 2007
October 2007
September 2007
August 2007
July 2007
June 2007
May 2007
April 2007
March 2007
February 2007
January 2007
December 2006
November 2006
October 2006
September 2006
August 2006
July 2006
June 2006
May 2006
April 2006
March 2006
February 2006
January 2006
December 2005
November 2005
October 2005
September 2005
August 2005
July 2005
June 2005
May 2005
April 2005
March 2005
February 2005
January 2005
December 2004
November 2004
October 2004
September 2004
August 2004
July 2004
June 2004
May 2004
April 2004
March 2004
February 2004
January 2004
December 2003
November 2003

ATOM RSS1 RSS2



LISTS.CLIR.ORG

CataList Email List Search Powered by the LISTSERV Email List Manager