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[ aws . rekognition ]

detect-labels

Description

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 Analyzing Images Stored in an Amazon S3 Bucket in the Amazon Rekognition Developer Guide.

Note

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

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 AWS 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 includes 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.

Note

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

DetectLabels returns bounding boxes for instances of common object labels in an array of objects. An Instance object contains a object, for the location of the label on the image. It also includes the confidence by which the bounding box was detected.

DetectLabels also returns a hierarchical taxonomy of detected labels. For example, a detected car might be assigned the label car . The label car has two parent labels: Vehicle (its parent) and Transportation (its grandparent). The response returns the entire list of ancestors for a label. Each ancestor is a unique label in the response. In the previous example, Car , Vehicle , and Transportation are returned as unique labels in the response.

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.

See also: AWS API Documentation

See 'aws help' for descriptions of global parameters.

Synopsis

  detect-labels
[--image <value>]
[--max-labels <value>]
[--min-confidence <value>]
[--image-bytes <value>]
[--cli-input-json <value>]
[--generate-cli-skeleton <value>]

Options

--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.

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

Shorthand Syntax:

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

JSON Syntax:

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

--max-labels (integer)

Maximum number of labels you want the service to return in the response. The service returns the specified number of highest confidence labels.

--min-confidence (float)

Specifies the minimum confidence level for the labels to return. Amazon Rekognition doesn't return any labels with confidence lower than this specified value.

If MinConfidence is not specified, the operation returns labels with a confidence values greater than or equal to 50 percent.

--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 (string) Performs service operation based on the JSON string provided. The JSON string follows the format provided by --generate-cli-skeleton. If other arguments are provided on the command line, the CLI 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.

--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. If provided with the value output, it validates the command inputs and returns a sample output JSON for that command.

See 'aws help' for descriptions of global parameters.

Output

Labels -> (list)

An array of labels for the real-world objects detected.

(structure)

Structure containing details about the detected label, including the name, and level of confidence.

The Amazon Rekognition Image operation operation returns a hierarchical taxonomy (Parents ) for detected labels and also bounding box information (Instances ) for detected labels. Amazon Rekognition Video doesn't return this information and returns null for the Parents and Instances attributes.

Name -> (string)

The name (label) of the object or scene.

Confidence -> (float)

Level of confidence.

Instances -> (list)

If Label represents an object, Instances contains the bounding boxes for each instance of the detected object. Bounding boxes are returned for common object labels such as people, cars, furniture, apparel or pets.

Note

Amazon Rekognition Video does not support bounding box information for detected labels. The value of Instances is returned as null by GetLabelDetection .

(structure)

An instance of a label detected by .

BoundingBox -> (structure)

The position of the label instance on the image.

Width -> (float)

Width of the bounding box as a ratio of the overall image width.

Height -> (float)

Height of the bounding box as a ratio of the overall image height.

Left -> (float)

Left coordinate of the bounding box as a ratio of overall image width.

Top -> (float)

Top coordinate of the bounding box as a ratio of overall image height.

Confidence -> (float)

The confidence that Amazon Rekognition Image has in the accuracy of the bounding box.

Parents -> (list)

The parent labels for a label. The response includes all ancestor labels.

Note

Amazon Rekognition Video does not support a hierarchical taxonomy of detected labels. The value of Parents is returned as null by GetLabelDetection .

(structure)

A parent label for a label. A label can have 0, 1, or more parents.

Name -> (string)

The name of the parent label.

OrientationCorrection -> (string)

The value of OrientationCorrection is always null.

If the input image is in .jpeg format, it might contain exchangeable image file format (Exif) metadata that includes the image's orientation. Amazon Rekognition uses this orientation information to perform image correction. The bounding box coordinates are translated to represent object locations after the orientation information in the Exif metadata is used to correct the image orientation. Images in .png format don't contain Exif metadata.

Amazon Rekognition doesn’t perform image correction for images in .png format and .jpeg images without orientation information in the image Exif metadata. The bounding box coordinates aren't translated and represent the object locations before the image is rotated.

LabelModelVersion -> (string)

Version number of the label detection model that was used to detect labels.