You can find the reference for each property in the request object here: https://cloud.google.com/vision/docs/reference/rest/v1/images/annotate#AnnotateImageRequest.
- Face detection response: https://cloud.google.com/vision/docs/reference/rest/v1/images/annotate#FaceAnnotation
- Label detection response:
- https://cloud.google.com/vision/docs/reference/rest/v1/images/annotate#EntityAnnotation
- Safe search response: https://cloud.google.com/vision/docs/reference/rest/v1/images/annotate#safesearchannotation