[Metadatalibrarians] Editing embedded metadata in a tif

[Jon Stroop]

Ingrid,
How are you editing the DC now?  If you're just using a text editor 
maybe the text editor is changing something you can't see, or maybe 
you're corrupting IFD entries by changing the size or byte offset of the 
XMP?  I'm not sure if this could have a snowball effect and corrupt the 
rest of the image...but maybe, or something similar.

In any case, you can create and edit custom XMP fields within 
Photoshop[1].  Our Digital Initiatives Photographer here at Princeton 
has some experience with this; he says you can contact him[2]. (He is on 
this list as well.)

Another option, if you have some programming experience or support is to 
use a library like the Java Advanced Imaging tools[3] to manipulate the 
headers; any good library should encapsulate any adjustments that need 
to be made to the other parts of the image based on the changes you've 
made.  Obviously this is quite a bit more involved, but I'm not sure 
about the size of your project so maybe it's appropriate, maybe not.

Hope this helps,
-Jon

1. http://www.adobe.com/products/xmp/custompanel.html
2. Roel Munoz: rmunoz at princeton.edu
3. https://jai-imageio.dev.java.net/

Jon Stroop
Metadata Analyst
C-17-D2 Firestone Library
Princeton University
Princeton, NJ 08544

Email: jstroop at princeton.edu
Phone: (609)258-0059
Fax: (609)258-0441

http://diglib.princeton.edu
http://diglib.princeton.edu/ead



Ingrid Schneider wrote:
> Hello all!
>
> I'm creating metadata in CONTENTdm for a collaborative project we're 
> taking part in. I'd like to preserve this metadata for future use in 
> internal projects, and my original thinking was that I could make it a 
> part of the metadata embedded in our archival tifs. The embedded 
> metadata appears to have been built by Photoshop with human input on 
> the descriptive metadata and the file uses Adobe XMP Core, Exif, XAP, 
> Iptc 4xmp Core, CRS, TIFF, and DC. It's coded in RDF.
>
> I only want to modify the DC, but when I make and save changes to the 
> DC it messes the picture up. It won't open in Photoshop at all, I get 
> an error message that says it won't open because an "unexpected 
> end-of-file was encountered. I can open it in the Windows Office 
> Picture Manager but the image is distorted to the point where you 
> can't tell what it is.
>
> Does anyone know why this is happening, and if/how I can successfully 
> modify the metadata in the archival tif?
> Thank you,
> Ingrid Schneider