compare-faces — AWS CLI 2.0.34 Command Reference

Description

Compares a face in the source input image with each of the 100 largest faces detected in the target input image.

Note

If the source image contains multiple faces, the service detects the largest face and compares it with each face detected in the target image.

You pass the input and target images either as base64-encoded image bytes or as references to images in an Amazon S3 bucket. If you use the AWS CLI to call Amazon Rekognition operations, passing image bytes isn’t supported. The image must be formatted as a PNG or JPEG file.

In response, the operation returns an array of face matches ordered by similarity score in descending order. For each face match, the response provides a bounding box of the face, facial landmarks, pose details (pitch, role, and yaw), quality (brightness and sharpness), and confidence value (indicating the level of confidence that the bounding box contains a face). The response also provides a similarity score, which indicates how closely the faces match.

Note

By default, only faces with a similarity score of greater than or equal to 80% are returned in the response. You can change this value by specifying the SimilarityThreshold parameter.

CompareFaces also returns an array of faces that don’t match the source image. For each face, it returns a bounding box, confidence value, landmarks, pose details, and quality. The response also returns information about the face in the source image, including the bounding box of the face and confidence value.

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 by specifying LOW , MEDIUM , or HIGH . If you do not want to filter detected faces, specify NONE . The default value is NONE .

Note

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 .

If the image doesn’t contain Exif metadata, CompareFaces returns orientation information for the source and target images. Use these values to display the images with the correct image orientation.

If no faces are detected in the source or target images, CompareFaces returns an InvalidParameterException error.

Note

This is a stateless API operation. That is, data returned by this operation doesn’t persist.

For an example, see Comparing Faces in Images in the Amazon Rekognition Developer Guide.

This operation requires permissions to perform the rekognition:CompareFaces action.

See also: AWS API Documentation

See ‘aws help’ for descriptions of global parameters.

Options

--source-image (structure)

The input image as base64-encoded bytes or an S3 object. If you use the AWS CLI to call Amazon Rekognition operations, passing base64-encoded image bytes is not supported.

If you are using an AWS SDK to call Amazon Rekognition, you might not need to base64-encode image bytes passed using the Bytes field. For more information, see Images in the Amazon Rekognition developer guide.

To specify a local file use --source-image-bytes instead.

Bytes -> (blob)

Blob of image bytes up to 5 MBs.

S3Object -> (structure)

Identifies an S3 object as the image source.

Bucket -> (string)

Name of the S3 bucket.

Name -> (string)

S3 object key name.

Version -> (string)

If the bucket is versioning enabled, you can specify the object version.

Shorthand Syntax:

Bytes=blob,S3Object={Bucket=string,Name=string,Version=string}

JSON Syntax:

{ "Bytes": blob, "S3Object": { "Bucket": "string", "Name": "string", "Version": "string" }}

--target-image (structure)

The target image as base64-encoded bytes or an S3 object. If you use the AWS CLI to call Amazon Rekognition operations, passing base64-encoded image bytes is not supported.

If you are using an AWS SDK to call Amazon Rekognition, you might not need to base64-encode image bytes passed using the Bytes field. For more information, see Images in the Amazon Rekognition developer guide.

To specify a local file use --target-image-bytes instead.

Bytes -> (blob)

Blob of image bytes up to 5 MBs.

S3Object -> (structure)

Identifies an S3 object as the image source.

Bucket -> (string)

Name of the S3 bucket.

Name -> (string)

S3 object key name.

Version -> (string)

If the bucket is versioning enabled, you can specify the object version.

Shorthand Syntax:

Bytes=blob,S3Object={Bucket=string,Name=string,Version=string}

JSON Syntax:

{ "Bytes": blob, "S3Object": { "Bucket": "string", "Name": "string", "Version": "string" }}

--similarity-threshold (float)

The minimum level of confidence in the face matches that a match must meet to be included in the FaceMatches array.

--quality-filter (string)

A filter that specifies a quality bar for how much filtering is done to identify faces. Filtered faces aren’t compared. If you specify AUTO , Amazon Rekognition chooses the quality bar. If you specify LOW , MEDIUM , or HIGH , filtering removes all faces that don’t meet the chosen quality bar. The quality bar is based on a variety of common use cases. Low-quality detections can occur for a number of reasons. Some examples are an object that’s misidentified as a face, a face that’s too blurry, or a face with a pose that’s too extreme to use. If you specify NONE , no filtering is performed. The default value is NONE .

To use quality filtering, the collection you are using must be associated with version 3 of the face model or higher.

Possible values:

• NONE

• AUTO

• LOW

• MEDIUM

• HIGH

--source-image-bytes (blob)

The content of the image to be uploaded. To specify the content of a local file use the fileb:// prefix. Example: fileb://image.png

--target-image-bytes (blob)

The content of the image to be uploaded. To specify the content of a local file use the fileb:// prefix. Example: fileb://image.png

--cli-input-json | --cli-input-yaml (string) Reads arguments from the JSON string provided. The JSON string follows the format provided by --generate-cli-skeleton. If other arguments are provided on the command line, those values will override the JSON-provided values. It is not possible to pass arbitrary binary values using a JSON-provided value as the string will be taken literally. This may not be specified along with --cli-input-yaml.

--generate-cli-skeleton (string) Prints a JSON skeleton to standard output without sending an API request. If provided with no value or the value input, prints a sample input JSON that can be used as an argument for --cli-input-json. Similarly, if provided yaml-input it will print a sample input YAML that can be used with --cli-input-yaml. If provided with the value output, it validates the command inputs and returns a sample output JSON for that command.

--cli-auto-prompt (boolean) Automatically prompt for CLI input parameters.

See ‘aws help’ for descriptions of global parameters.