AWS Tools for Windows PowerShell
Command Reference

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Synopsis

Calls the Amazon Rekognition CompareFaces API operation.

Syntax

Compare-REKFace
-SourceImageBucket <String>
-TargetImageBucket <String>
-SourceImageContent <Byte[]>
-TargetImageContent <Byte[]>
-SourceImageName <String>
-TargetImageName <String>
-QualityFilter <QualityFilter>
-SimilarityThreshold <Single>
-SourceImageVersion <String>
-TargetImageVersion <String>
-Select <String>
-Force <SwitchParameter>

Description

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

Parameters

This parameter overrides confirmation prompts to force the cmdlet to continue its operation. This parameter should always be used with caution.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-QualityFilter <QualityFilter>
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.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-Select <String>
Use the -Select parameter to control the cmdlet output. The default value is '*'. Specifying -Select '*' will result in the cmdlet returning the whole service response (Amazon.Rekognition.Model.CompareFacesResponse). Specifying the name of a property of type Amazon.Rekognition.Model.CompareFacesResponse will result in that property being returned. Specifying -Select '^ParameterName' will result in the cmdlet returning the selected cmdlet parameter value.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-SimilarityThreshold <Single>
The minimum level of confidence in the face matches that a match must meet to be included in the FaceMatches array.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-SourceImageBucket <String>
Name of the S3 bucket.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-SourceImageContent <Byte[]>
Blob of image bytes up to 5 MBs.The cmdlet will automatically convert the supplied parameter of type string, string[], System.IO.FileInfo or System.IO.Stream to byte[] before supplying it to the service.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-SourceImageName <String>
S3 object key name.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-SourceImageVersion <String>
If the bucket is versioning enabled, you can specify the object version.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-TargetImageBucket <String>
Name of the S3 bucket.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-TargetImageContent <Byte[]>
Blob of image bytes up to 5 MBs.The cmdlet will automatically convert the supplied parameter of type string, string[], System.IO.FileInfo or System.IO.Stream to byte[] before supplying it to the service.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-TargetImageName <String>
S3 object key name.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-TargetImageVersion <String>
If the bucket is versioning enabled, you can specify the object version.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)

Common Credential and Region Parameters

-AccessKey <String>
The AWS access key for the user account. This can be a temporary access key if the corresponding session token is supplied to the -SessionToken parameter.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesAK
-Credential <AWSCredentials>
An AWSCredentials object instance containing access and secret key information, and optionally a token for session-based credentials.
Required?False
Position?Named
Accept pipeline input?True (ByValue, ByPropertyName)
-EndpointUrl <String>
The endpoint to make the call against.Note: This parameter is primarily for internal AWS use and is not required/should not be specified for normal usage. The cmdlets normally determine which endpoint to call based on the region specified to the -Region parameter or set as default in the shell (via Set-DefaultAWSRegion). Only specify this parameter if you must direct the call to a specific custom endpoint.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
-NetworkCredential <PSCredential>
Used with SAML-based authentication when ProfileName references a SAML role profile. Contains the network credentials to be supplied during authentication with the configured identity provider's endpoint. This parameter is not required if the user's default network identity can or should be used during authentication.
Required?False
Position?Named
Accept pipeline input?True (ByValue, ByPropertyName)
-ProfileLocation <String>
Used to specify the name and location of the ini-format credential file (shared with the AWS CLI and other AWS SDKs)If this optional parameter is omitted this cmdlet will search the encrypted credential file used by the AWS SDK for .NET and AWS Toolkit for Visual Studio first. If the profile is not found then the cmdlet will search in the ini-format credential file at the default location: (user's home directory)\.aws\credentials.If this parameter is specified then this cmdlet will only search the ini-format credential file at the location given.As the current folder can vary in a shell or during script execution it is advised that you use specify a fully qualified path instead of a relative path.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesAWSProfilesLocation, ProfilesLocation
-ProfileName <String>
The user-defined name of an AWS credentials or SAML-based role profile containing credential information. The profile is expected to be found in the secure credential file shared with the AWS SDK for .NET and AWS Toolkit for Visual Studio. You can also specify the name of a profile stored in the .ini-format credential file used with the AWS CLI and other AWS SDKs.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesStoredCredentials, AWSProfileName
-Region <Object>
The system name of an AWS region or an AWSRegion instance. This governs the endpoint that will be used when calling service operations. Note that the AWS resources referenced in a call are usually region-specific.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesRegionToCall
-SecretKey <String>
The AWS secret key for the user account. This can be a temporary secret key if the corresponding session token is supplied to the -SessionToken parameter.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesSK, SecretAccessKey
-SessionToken <String>
The session token if the access and secret keys are temporary session-based credentials.
Required?False
Position?Named
Accept pipeline input?True (ByPropertyName)
AliasesST

Outputs

This cmdlet returns an Amazon.Rekognition.Model.CompareFacesResponse object containing multiple properties. The object can also be referenced from properties attached to the cmdlet entry in the $AWSHistory stack.

Supported Version

AWS Tools for PowerShell: 2.x.y.z