The Annotation Vocabulary JSON-LD context is defined to be at http://www.w3.org/ns/oa

Use that context document to convert the sample below into RDF triples. Did the conversion complete?

{
  "@context": "http://www.w3.org/ns/anno.jsonld",
  "id": "http://example.org/anno4",
  "type": "Annotation",
  "body": "http://example.org/description1",
  "target": {
    "id": "http://example.com/image1#xywh=100,100,300,300",
    "type": "Image",
    "format": "image/jpeg"
  }
}