AWS SDK Version 3 for .NET
API Reference

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Detects instances of real-world entities within an image (JPEG or PNG) provided as input. This includes objects like flower, tree, and table; events like wedding, graduation, and birthday party; and concepts like landscape, evening, and nature. For an example, see images-s3.

DetectLabels does not support the detection of activities. However, activity detection is supported for label detection in videos. For more information, see .

You pass the input image as base64-encoded image bytes or as a reference to an image in an Amazon S3 bucket. If you use the Amazon CLI to call Amazon Rekognition operations, passing image bytes is not supported. The image must be either a PNG or JPEG formatted file.

For each object, scene, and concept the API returns one or more labels. Each label provides the object name, and the level of confidence that the image contains the object. For example, suppose the input image has a lighthouse, the sea, and a rock. The response will include all three labels, one for each object.

{Name: lighthouse, Confidence: 98.4629}

{Name: rock,Confidence: 79.2097}

{Name: sea,Confidence: 75.061}

In the preceding example, the operation returns one label for each of the three objects. The operation can also return multiple labels for the same object in the image. For example, if the input image shows a flower (for example, a tulip), the operation might return the following three labels.

{Name: flower,Confidence: 99.0562}

{Name: plant,Confidence: 99.0562}

{Name: tulip,Confidence: 99.0562}

In this example, the detection algorithm more precisely identifies the flower as a tulip.

In response, the API returns an array of labels. In addition, the response also includes the orientation correction. Optionally, you can specify MinConfidence to control the confidence threshold for the labels returned. The default is 50%. You can also add the MaxLabels parameter to limit the number of labels returned.

If the object detected is a person, the operation doesn't provide the same facial details that the DetectFaces operation provides.

This is a stateless API operation. That is, the operation does not persist any data.

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


For .NET Core and PCL this operation is only available in asynchronous form. Please refer to DetectLabelsAsync.

Namespace: Amazon.Rekognition
Assembly: AWSSDK.Rekognition.dll
Version: 3.x.y.z


public virtual DetectLabelsResponse DetectLabels(
         DetectLabelsRequest request
Type: Amazon.Rekognition.Model.DetectLabelsRequest

Container for the necessary parameters to execute the DetectLabels service method.

Return Value
The response from the DetectLabels service method, as returned by Rekognition.


AccessDeniedException You are not authorized to perform the action.
ImageTooLargeException The input image size exceeds the allowed limit. For more information, see limits.
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.
ThrottlingException Amazon Rekognition is temporarily unable to process the request. Try your call again.


This operation detects labels in the supplied image

To detect labels

var response = client.DetectLabels(new DetectLabelsRequest 
    Image = new Image { S3Object = new S3Object {
        Bucket = "mybucket",
        Name = "myphoto"
    } },
    MaxLabels = 123,
    MinConfidence = 70


Version Information

.NET Framework:
Supported in: 4.5, 4.0, 3.5

Portable Class Library:
Supported in: Windows Store Apps
Supported in: Windows Phone 8.1
Supported in: Xamarin Android
Supported in: Xamarin iOS (Unified)
Supported in: Xamarin.Forms

See Also