HDR Composite Tag - Want to help?

[blue-j]

Hi everyone!  I hope you are well.  I'm looking at creating a composite tag that states whether an image is an HDR image or not.  This is not trivial - it is stated in a wide range of fields and namespaces.  I could use some help.  Anyone interested?  I'll go it alone if I must and certainly share the work, and if Phil approves, it might make a release.  - J