The GIF format does not support metadata. So the extra metadata cannot be saved in GIF.
That's just a limitation of that file format.
PNG has little or no standardized metadata, but supports some metadata.
Thanks, I assumed that was part of the answer. I guess the question is why my workflow allowed this in CS5.0 ... and/or whether there is a way for Ps to create a sidecar file for a GIF file?
If you have any ideas I could pursue, that would be great. I had a script that runs in bash (Mac OS X) that read these properties from a file using Photoshop (using osascript), and then generated "microdata" on pages containing those images to aid in search engine categorization. The artwork is originally generated in Ai - but I used Ps to tag the image files with the data.
(At this point, the easiest answer would be to make my own "pseudo-sidecar" files, but I try to find more standards-based methods. Unfortunately, like you said, GIF isn't naturally suited to this. By the way, CS6 Ps does read the metadata inserted by CS5 Ps.)
In CS5 it wouldn't work either EXCEPT that on Macintosh we'd save file info and other data in the resource fork. But that wouldn't transfer to Windows or unix servers (like web servers) and confused many people.
Also, resource forks were causing problems for many Apple file APIs, so we minimized use of resource forks.
Ahhh... that explains everything. I did have this working on the Mac, of course. You're right to drop the use of the resource fork.
Okay, thanks for that last bit of information. Is there any way to create an .XMP sidecar file using Ai or Ps that would serve the same function? I suspect now, but I figured this would be the last opportunity to ask.
Again, I appreciate the response! Thanks!
Just to follow up with some research that I performed...
The PNG standard defines two possibilities for including metadata. A chunk type iTXt with a keyword of 'XML:com.adobe.xmp' includes XMP metadata (from what I can tell, all available XMP metadata); alternately chunk type tEXt can contain metadata consisting of specified keywords (for example, Author, Description, Copyright, etc.) and their values.
My initial test document creation shows that Ps saves the XMP chunk, and Ai generates files with keyword/value chunks in them.
Seems to me that the best thing for me to do is modify my workflow to use PNG rather than GIF - although it also looks to me like Ps also has embedded a (non-standard?) XMP stream in the GIF as well.
You gave me enough information to ask the right questions here - thanks for helping me figure this out.
i was just searching for an answer to rather i can add a Copyright to my .png images. i gather after reading this that i cannot.
so, i have a question ... how can i go about protecting my art/images if i cannot attach a Copyright notice?
i'm new to all of this so i really have no idea.
thank you for your time and efforts
In Photoshop CC, you can - since PNG can include XMP metadata (which includes your copyright).
hi Chris & thank you for your response
it doesn't seem possible to add File > Info to a .png image in Photoshop itself. i've tried it a few different ways.
(shoot, actually i should try adding it again in Ps to a .png file and then see if Bridge can read it. hmmmm??)
in an other thread: [ http://forums.adobe.com/message/5642141#5642141 ] Gene told me that i could select Copyright and Contact Info from the Metadata drop down menu in the Save for Web panel to add the info to a .png image but this didn't work.
i don't know if Ps is having one of its "fits" or what but nothing seems to be working.
after a bit Gene was able to tell me that i can add File Info to .png files in the Bridge Cs6 or CC (no idea what the difference is between Ps Cs6 and Ps CC) and so i tried that and it worked.
however, it appears that Ps still cannot read the data/info when the .png image is opened in Ps itself. Only readable in Bridge.
which brings me to an other Q ... what's the point of Copyright info that can't be read? i am not being sarcastic i just really don't understand. granted, i need to read up on this topic but was hoping you could share your thoughts/knowledge w/me oh, and if you have any handy links i would also much appreciate it. thanx 4 ur help!!