AWS SDK Version 3 for .NET
API Reference

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Detects text in the input image and converts it into machine-readable text.

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, you must pass it as a reference to an image in an Amazon S3 bucket. For the AWS CLI, passing image bytes is not supported. The image must be either a .png or .jpeg formatted file.

The DetectText operation returns text in an array of elements, TextDetections. Each TextDetection element provides information about a single word or line of text that was detected in the image.

A word is one or more ISO basic latin script characters that are not separated by spaces. DetectText can detect up to 50 words in an image.

A line is a string of equally spaced words. A line isn't necessarily a complete sentence. For example, a driver's license number is detected as a line. A line ends when there is no aligned text after it. Also, a line ends when there is a large gap between words, relative to the length of the words. This means, depending on the gap between words, Amazon Rekognition may detect multiple lines in text aligned in the same direction. Periods don't represent the end of a line. If a sentence spans multiple lines, the DetectText operation returns multiple lines.

To determine whether a TextDetection element is a line of text or a word, use the TextDetection object Type field.

To be detected, text must be within +/- 30 degrees orientation of the horizontal axis.

For more information, see text-detection.


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

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


public abstract DetectTextResponse DetectText(
         DetectTextRequest request
Type: Amazon.Rekognition.Model.DetectTextRequest

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

Return Value
The response from the DetectText 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.

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