How can I place png data as a Key Value pair into an Annotation?

[Ryan]

To create a new stream you would use PDFDoc.CreateIndirectStream, and then on your annotation call something like annot.GetSDFObj().Put("IMAGE_A", objFromCreateIndirectStream)

Here are some guides that will help you the rest of the way.

Sdf | Apryse Documentation

How would I add XMP metadata to a PDF using PDFNet?

Q: How would I add XMP metadata to a PDF using PDFNet? // Using C# - Add XMP metadata to document catalog StdFile xmp_file = new StdFile("myxmp.xml", StdFile.OpenMode.e_read_mode); FilterReader reader = new FilterReader(xmp_file); Obj xmp_stm = pdfdoc.CreateIndirectStream(reader)); xmp_stm.Put("Subtype", Obj.CreateName("XML")); xmp_stm.Put("Type", Obj.CreateName("Metadata")); pdfdoc.GetRoot().Put("Metadata", xmp_stm); You can use the same approach to add XMP streams to any other object …