How does Amazon Rekognition bill for face detection?

Question

I do have a sample registration system where they can upload image and scan it thru Amazon Rekognition.

I can't seem to find the exact answer on their documentation on how the billing works.

Does it charge every time you compare the image or every time you call the API?

Example: Uploaded image compared to 1000 Images. Does this count as 1000? Or only 1?

Answer 1

From Amazon Rekognition – frequently asked questions - AWS :

Q: How does Amazon Rekognition count the number of images processed?

For APIs that accept images as inputs, Amazon Rekognition counts the actual number of images analyzed as the number of images processed. DetectLabels, DetectModerationLabels, DetectFaces, IndexFaces, RecognizeCelebrities, and SearchFaceByImage belong to this category. For the CompareFaces API, where two images are passed as input, only the source image is counted as a unit of images processed.

For API calls that don't require an image as an input parameter, Amazon Rekognition counts each API call as one image processed. SearchFaces belongs to this category.

The remaining Amazon Rekognition APIs - ListFaces, DeleteFaces, CreateCollection, DeleteCollection, and ListCollections - do not count towards images processed.

See also: Amazon Rekognition – Pricing - AWS