How Do I Create an Image Annotation?

To programmatically create an image annotation from a file, you first need to create an attachment in the document using a buffer and the content type. That will give you an ID for the attachment. Then you can construct an Image annotation and set the ImageAttachmentId and ContentType properties:

var buffer = await FileIO.ReadBufferAsync(file);

// Create an annotation attachment for the image in the document and get its ID.
var attachmentId = await PDFView.Controller.GetPdfDocument().CreateAttachmentAsync(buffer, file.ContentType);

// Next, define the bounding box of the annotation on the page.
var boundingBox = new Rect(100, 100, 100, 100);

// Create the annotation and set the image attachment ID and the content type.
var annotation = new Image
    BoundingBox = boundingBox,
    Description = "Logo",
    ImageAttachmentId = attachmentId,
    ContentType = file.ContentType,
    PageIndex = 0

// Add the annotation to the document.
annotation = await PDFView.Document.CreateAnnotationAsync(annotation) as Image;

For more information, refer to the example code in the Catalog.