Any image files can be inserted and commented with PDF Annotator.
Choose Edit Insert Image From File to select an image file and insert it into a PDF document. Alternatively, choose Edit Insert Image From Clipboard to insert an image you have previously copied to the clipboard.
This will first open the image in the Image Editor, where you can either modify the image before adding it to your document, or accept the image right away by clicking OK.
After inserting an image, you can change its position or its size by dragging one of the corners.