AWS services or capabilities described in AWS Documentation may vary by region/location. Click Getting Started with Amazon AWS to see specific differences applicable to the China (Beijing) Region.
For a given input image, first detects the largest face in the image, and then searches
the specified collection for matching faces. The operation compares the features of
the input face with faces in the specified collection.
To search for all faces in an input image, you might first call the IndexFaces
operation, and then use the face IDs returned in subsequent calls to the SearchFaces
operation.
You can also call the DetectFaces operation and use the bounding boxes in
the response to make face crops, which then you can pass in to the SearchFacesByImage
operation.
You pass the input image either as base64-encoded image bytes or as a reference to an image in an Amazon S3 bucket. If you use the AWS CLI to call Amazon Rekognition operations, passing image bytes is not supported. The image must be either a PNG or JPEG formatted file.
The response returns an array of faces that match, ordered by similarity score with
the highest similarity first. More specifically, it is an array of metadata for each
face match found. Along with the metadata, the response also includes a similarity
indicating how similar the face is to the input face. In the response, the operation
also returns the bounding box (and a confidence level that the bounding box contains
a face) of the face that Amazon Rekognition used for the input image.
If no faces are detected in the input image, SearchFacesByImage returns an
InvalidParameterException error.
For an example, Searching for a Face Using an Image in the Amazon Rekognition Developer Guide.
The QualityFilter input parameter allows you to filter out detected faces that
don’t meet a required quality bar. The quality bar is based on a variety of common
use cases. Use QualityFilter to set the quality bar for filtering by specifying
LOW, MEDIUM, or HIGH. If you do not want to filter detected faces,
specify NONE. The default value is NONE.
To use quality filtering, you need a collection associated with version 3 of the face model or higher. To get the version of the face model associated with a collection, call DescribeCollection.
This operation requires permissions to perform the rekognition:SearchFacesByImage
action.
This is an asynchronous operation using the standard naming convention for .NET 4.5 or higher. For .NET 3.5 the operation is implemented as a pair of methods using the standard naming convention of BeginSearchFacesByImage and EndSearchFacesByImage.
Namespace: Amazon.Rekognition
Assembly: AWSSDK.Rekognition.dll
Version: 3.x.y.z
public virtual Task<SearchFacesByImageResponse> SearchFacesByImageAsync( SearchFacesByImageRequest request, CancellationToken cancellationToken )
Container for the necessary parameters to execute the SearchFacesByImage service method.
A cancellation token that can be used by other objects or threads to receive notice of cancellation.
| Exception | Condition |
|---|---|
| AccessDeniedException | You are not authorized to perform the action. |
| ImageTooLargeException | The input image size exceeds the allowed limit. If you are calling DetectProtectiveEquipment, the image size or resolution exceeds the allowed limit. For more information, see Guidelines and quotas in Amazon Rekognition in the Amazon Rekognition Developer Guide. |
| InternalServerErrorException | Amazon Rekognition experienced a service issue. Try your call again. |
| InvalidImageFormatException | The provided image format is not supported. |
| InvalidParameterException | Input parameter violated a constraint. Validate your parameter before calling the API operation again. |
| InvalidS3ObjectException | Amazon Rekognition is unable to access the S3 object specified in the request. |
| ProvisionedThroughputExceededException | The number of requests exceeded your throughput limit. If you want to increase this limit, contact Amazon Rekognition. |
| ResourceNotFoundException | The resource specified in the request cannot be found. |
| ThrottlingException | Amazon Rekognition is temporarily unable to process the request. Try your call again. |
.NET Core App:
Supported in: 3.1
.NET Standard:
Supported in: 2.0
.NET Framework:
Supported in: 4.5