2007.07.26 18:33 "[Tiff] Re: Writing custom TIFF tags to Photoshop saving TIFFs(withPhotoshop)", by Olumide
Currently you cannot tag individual layers with metadata -- there is no good guarantee on layer identity, or any metadata associated with each layer.
The workaround most commonly used is to rely on layer naming. But you are correct in that users can give multiple layers the same name, or rearrange layers as they please.
There are unique per document layer IDs associated with each layer, but I'm not sure how easily you can extract that from the layer data. If you can do that, then you have a unique mapping of the layers that you can use for metadata. But that still won't solve the problem of deleted or new layers.
Actually, I wasn't thinking of per-layer metadata but that would be perfect -- if it existed.
Sorry if the rest of this post is nonsense:
<thinking out loud>
Anyway, I could still store my custom metadata in the default location, right?... My external application should be able to get at it by finding the TIFF tag 700.
</thinking out loud>
The real question: is there a way to give a photoshop layer some sort of attribute, while the image is open, and later write it back as metadata when the image is saved?... and what would happen to the metadata when the image is opened and the layers edited???