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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 Analyzing images stored in an Amazon S3 bucket 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.
Optional Parameters
You can specify one or both of the GENERAL_LABELS
and IMAGE_PROPERTIES
feature types when calling the DetectLabels API. Including GENERAL_LABELS
will
ensure the response includes the labels detected in the input image, while including
IMAGE_PROPERTIES
will ensure the response includes information about the image
quality and color.
When using GENERAL_LABELS
and/or IMAGE_PROPERTIES
you can provide filtering
criteria to the Settings parameter. You can filter with sets of individual labels
or with label categories. You can specify inclusive filters, exclusive filters, or
a combination of inclusive and exclusive filters. For more information on filtering
see Detecting
Labels in an Image.
When getting labels, you can specify MinConfidence
to control the confidence
threshold for the labels returned. The default is 55%. You can also add the MaxLabels
parameter to limit the number of labels returned. The default and upper limit is 1000
labels. These arguments are only valid when supplying GENERAL_LABELS as a feature
type.
Response Elements
For each object, scene, and concept the API returns one or more labels. The API returns the following types of information about labels:
Name - The name of the detected label.
Confidence - The level of confidence in the label assigned to a detected object.
Parents - The ancestor labels for a detected label. DetectLabels 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 includes the all ancestors for a label, where every ancestor is a unique label. In the previous example, Car, Vehicle, and Transportation are returned as unique labels in the response.
Aliases - Possible Aliases for the label.
Categories - The label categories that the detected label belongs to.
BoundingBox — Bounding boxes are described for all instances of detected common object labels, returned in an array of Instance objects. An Instance object contains a BoundingBox object, describing the location of the label on the input image. It also includes the confidence for the accuracy of the detected bounding box.
The API returns the following information regarding the image, as part of the ImageProperties structure:
Quality - Information about the Sharpness, Brightness, and Contrast of the input image, scored between 0 to 100. Image quality is returned for the entire image, as well as the background and the foreground.
Dominant Color - An array of the dominant colors in the image.
Foreground - Information about the sharpness, brightness, and dominant colors of the input image’s foreground.
Background - Information about the sharpness, brightness, and dominant colors of the input image’s background.
The list of returned labels will include at least one label for every detected object, along with information about that label. In the following example, suppose the input image has a lighthouse, the sea, and a rock. The response includes all three labels, one for each object, as well as the confidence in the label:
{Name: lighthouse, Confidence: 98.4629}
{Name: rock,Confidence: 79.2097}
{Name: sea,Confidence: 75.061}
The list of labels can include multiple labels for the same object. 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.
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 doesn't return any data.
This operation requires permissions to perform the rekognition:DetectLabels
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 BeginDetectLabels and EndDetectLabels.
Namespace: Amazon.Rekognition
Assembly: AWSSDK.Rekognition.dll
Version: 3.x.y.z
public virtual Task<DetectLabelsResponse> DetectLabelsAsync( DetectLabelsRequest request, CancellationToken cancellationToken )
Container for the necessary parameters to execute the DetectLabels 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. |
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