Analyzing an image with a trained model - Rekognition

Analyzing an image with a trained model

To analyze an image with a trained Amazon Rekognition Custom Labels model, you call the DetectCustomLabels API. The result from DetectCustomLabels is a prediction that the image contains specific objects, scenes, or concepts.

To call DetectCustomLabels, you specify the following:

  • The Amazon Resource Name (ARN) of the Amazon Rekognition Custom Labels model that you want to use.

  • The image that you want the model to make a prediction with. You can provide an input image as an image byte array (base64-encoded image bytes), or as an Amazon S3 object. For more information, see Image.

Custom labels are returned in an array of Custom Label objects. Each custom label represents a single object, scene, or concept found in the image. A custom label includes:

  • A label for the object, scene, or concept found in the image.

  • A bounding box for objects found in the image. The bounding box coordinates show where the object is located on the source image. The coordinate values are a ratio of the overall image size. For more information, see BoundingBox. DetectCustomLabels returns bounding boxes only if the model is trained to detect object locations.

  • The confidence that Amazon Rekognition Custom Labels has in the accuracy of the label and bounding box.

To filter labels based on the detection confidence, specify a value for MinConfidence that matches your desired confidence level. For example, if you need to be very confident of the prediction, specify a high value for MinConfidence. To get all labels, regardless of confidence, specify a MinConfidence value of 0.

The performance of your model is measured, in part, by the recall and precision metrics calculated during model training. For more information, see Metrics for evaluating your model.

To increase the precision of your model, set a higher value for MinConfidence. For more information, see Reducing false positives (better precision).

To increase the recall of your model, use a lower value for MinConfidence. For more information, see Reducing false negatives (better recall).

If you don't specify a value for MinConfidence, Amazon Rekognition Custom Labels returns a label based on the assumed threshold for that label. For more information, see Assumed threshold. You can get the value of the assumed threshold for a label from the model's training results. For more information, see Training a model (Console).

By using the MinConfidence input parameter, you are specifying a desired threshold for the call. Labels detected with a confidence below the value of MinConfidence aren't returned in the response. Also, the assumed threshold for a label doesn't affect the inclusion of the label in the response.

Note

Amazon Rekognition Custom Labels metrics express an assumed threshold as a floating point value between 0-1. The range of MinConfidence normalizes the threshold to a percentage value (0-100). Confidence responses from DetectCustomLabels are also returned as a percentage.

You might want to specify a threshold for specific labels. For example, when the precision metric is acceptable for Label A, but not for Label B. When specifying a different threshold (MinConfidence), consider the following.

  • If you're only interested in a single label (A), set the value of MinConfidence to the desired threshold value. In the response, predictions for label A are returned (along with other labels) only if the confidence is greater than MinConfidence. You need to filter out any other labels that are returned.

  • If you want to apply different thresholds to multiple labels, do the following:

    1. Use a value of 0 for MinConfidence. A value 0 ensures that all labels are returned, regardless of the detection confidence.

    2. For each label returned, apply the desired threshold by checking that the label confidence is greater than the threshold that you want for the label.

For more information, see Improving a trained Amazon Rekognition Custom Labels model.

If you're finding the confidence values returned by DetectCustomLabels are too low, consider retraining the model. For more information, see Training an Amazon Rekognition Custom Labels model. You can restrict the number of custom labels returned from DetectCustomLabels by specifying the MaxResults input parameter. The results are returned sorted from the highest confidence to the lowest.

For other examples that call DetectCustomLabels, see Examples.

For information about securing DetectCustomLabels, see Securing DetectCustomLabels.

To detect custom labels (API)

  1. If you haven't already:

    1. Create or update an IAM user with AmazonRekognitionFullAccess and AmazonS3ReadOnlyAccess permissions. For more information, see Step 2: Create an IAM administrator user and group.

    2. Install and configure the AWS CLI and the AWS SDKs. For more information, see Step 3: Set Up the AWS CLI and AWS SDKs.

  2. Train and deploy your model. For more information, see Creating an Amazon Rekognition Custom Labels model.

  3. Ensure the IAM user calling DetectCustomLabels has access to the model you used in step 2. For more information, see Securing DetectCustomLabels.

  4. Upload an image that you want to analyze to an S3 bucket.

    For instructions, see Uploading Objects into Amazon S3 in the Amazon Simple Storage Service User Guide. The Python, Java, and Java 2 examples also show you how to use a local image file to pass an image by using raw bytes. The file must be smaller than 4 MB.

  5. Use the following examples to call the DetectCustomLabels operation. The Python and Java examples show the image and overlay the analysis results, similar to the following image.

    AWS CLI

    This AWS CLI command displays the JSON output for the DetectCustomLabels CLI operation. Change the values of the following input parameters.

    • bucket with the name of Amazon S3 bucket that you used in step 4.

    • image with the name of the input image file you uploaded in step 4.

    • projectVersionArn with the ARN of the model that you want to use.

    aws rekognition detect-custom-labels --project-version-arn "model_arn"\ --image '{"S3Object":{"Bucket":"bucket","Name":"image"}}'\ --min-confidence 70
    Python

    The following example code displays bounding boxes and image level labels found in an image.

    To analyze a local image, run the program and supply the following command line arguments:

    • The ARN of the model with which you want to analyze the image.

    • The name and location of a local image file.

    To analyze an image stored in an Amazon S3 bucket, run the program and supply the following command line arguments:

    • The ARN of the model with which you want to analyze the image.

    • The name and location of an image within the Amazon S3 bucket that you used in step 4.

    • --bucket bucket name — The Amazon S3 bucket that you used in step 4.

    #Copyright 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved. #PDX-License-Identifier: MIT-0 (For details, see https://github.com/awsdocs/amazon-rekognition-custom-labels-developer-guide/blob/master/LICENSE-SAMPLECODE.) """ Purpose Amazon Rekognition Custom Labels detection example used in the service documentation: https://docs.aws.amazon.com/rekognition/latest/customlabels-dg/detecting-custom-labels.html Shows how to detect custom labels by using an Amazon Rekognition Custom Labels model. The image can be stored on your local computer or in an Amazon S3 bucket. """ import boto3 import io import logging import argparse from PIL import Image, ImageDraw, ImageFont from botocore.exceptions import ClientError logger = logging.getLogger(__name__) def analyze_local_image(rek_client, model, photo, min_confidence): """ Analyzes an image stored as a local file. :param rek_client: The Amazon Rekognition Boto3 client. :param s3_connection: The Amazon S3 Boto3 S3 connection object. :param model: The ARN of the Amazon Rekognition Custom Labels model that you want to use. :param photo: The name and file path of the photo that you want to analyze. :param min_confidence: The desired threshold/confidence for the call. """ try: logger.info ("Analyzing local file: %s", photo) image=Image.open(photo) image_type=Image.MIME[image.format] if (image_type == "image/jpeg" or image_type== "image/png") == False: logger.error("Invalid image type for %s", photo) raise ValueError( f"Invalid file format. Supply a jpeg or png format file: {photo}" ) # get images bytes for call to detect_anomalies image_bytes = io.BytesIO() image.save(image_bytes, format=image.format) image_bytes = image_bytes.getvalue() response = rek_client.detect_custom_labels(Image={'Bytes': image_bytes}, MinConfidence=min_confidence, ProjectVersionArn=model) show_image (image, response) return len(response['CustomLabels']) except ClientError as client_err: logger.error(format(client_err)) raise except FileNotFoundError as file_error: logger.error(format (file_error)) raise def analyze_s3_image(rek_client,s3_connection, model,bucket,photo, min_confidence): """ Analyzes an image stored in the specified S3 bucket. :param rek_client: The Amazon Rekognition Boto3 client. :param s3_connection: The Amazon S3 Boto3 S3 connection object. :param model: The ARN of the Amazon Rekognition Custom Labels model that you want to use. :param bucket: The name of the S3 bucket that contains the image that you want to analyze. :param photo: The name of the photo that you want to analyze. :param min_confidence: The desired threshold/confidence for the call. """ try: #Get image from S3 bucket. logger.info("analyzing bucket: %s image: %s", bucket, photo) s3_object = s3_connection.Object(bucket,photo) s3_response = s3_object.get() stream = io.BytesIO(s3_response['Body'].read()) image=Image.open(stream) image_type=Image.MIME[image.format] if (image_type == "image/jpeg" or image_type== "image/png") == False: logger.error("Invalid image type for %s", photo) raise ValueError( f"Invalid file format. Supply a jpeg or png format file: {photo}") img_width, img_height = image.size draw = ImageDraw.Draw(image) #Call DetectCustomLabels response = rek_client.detect_custom_labels(Image={'S3Object': {'Bucket': bucket, 'Name': photo}}, MinConfidence=min_confidence, ProjectVersionArn=model) show_image (image, response) return len(response['CustomLabels']) except ClientError as err: logger.error(format(err)) raise def show_image(image, response): """ Displays the analyzed image and overlays analysis results :param image: The analyzed image :param response: the response from DetectCustomLabels """ try: font_size=40 line_width=5 img_width, img_height = image.size draw = ImageDraw.Draw(image) # calculate and display bounding boxes for each detected custom label image_level_label_height = 0 for custom_label in response['CustomLabels']: confidence=int(round(custom_label['Confidence'],0)) label_text=f"{custom_label['Name']}:{confidence}%" fnt = ImageFont.truetype('Tahoma.ttf', font_size) text_width, text_height = draw.textsize(label_text,fnt) logger.info(f"Label: {custom_label['Name']}") logger.info(f"Confidence: {confidence}%") # Draw bounding boxes, if present if 'Geometry' in custom_label: box = custom_label['Geometry']['BoundingBox'] left = img_width * box['Left'] top = img_height * box['Top'] width = img_width * box['Width'] height = img_height * box['Height'] logger.info("Bounding box") logger.info("\tLeft: {0:.0f}".format(left)) logger.info("\tTop: {0:.0f}".format(top)) logger.info("\tLabel Width: {0:.0f}".format(width)) logger.info("\tLabel Height: {0:.0f}".format(height)) points = ( (left,top), (left + width, top), (left + width, top + height), (left , top + height), (left, top)) #Draw bounding box and label text draw.line(points, fill="limegreen", width=line_width) draw.rectangle([(left + line_width , top+line_width), (left + text_width + line_width, top + line_width + text_height)],fill="black") draw.text((left + line_width ,top +line_width), label_text, fill="limegreen", font=fnt) #draw image-level label text. else: draw.rectangle([(10 , image_level_label_height), (text_width + 10, image_level_label_height+text_height)],fill="black") draw.text((10,image_level_label_height), label_text, fill="limegreen", font=fnt) image_level_label_height += text_height image.show() except Exception as err: logger.error(format(err)) raise def add_arguments(parser): """ Adds command line arguments to the parser. :param parser: The command line parser. """ parser.add_argument( "model_arn", help="The ARN of the model that you want to use." ) parser.add_argument( "image", help="The path and file name of the image that you want to analyze" ) parser.add_argument( "--bucket", help="The bucket that contains the image. If not supplied, image is assumed to be a local file.", required=False ) def main(): try: logging.basicConfig(level=logging.INFO, format="%(levelname)s: %(message)s") #get command line arguments parser = argparse.ArgumentParser(usage=argparse.SUPPRESS) add_arguments(parser) args = parser.parse_args() label_count=0 min_confidence=50 rek_client=boto3.client('rekognition') if args.bucket==None: # Analyze local image label_count=analyze_local_image(rek_client, args.model_arn, args.image, min_confidence) else: #Analyze image in S3 bucket s3_connection = boto3.resource('s3') label_count=analyze_s3_image(rek_client, s3_connection, args.model_arn, args.bucket, args.image, min_confidence) print(f"Custom labels detected: {label_count}") except ClientError as client_err: print("A service client error occurred: " + format(client_err.response["Error"]["Message"])) except ValueError as value_err: print ("A value error occurred: " + format(value_err)) except FileNotFoundError as file_error: print("File not found error: " + format (file_error)) except Exception as err: print("An error occurred: " + format(err)) if __name__ == "__main__": main()
    Java

    The following example code displays bounding boxes and image level labels found in an image.

    To analyze a local image, run the program and supply the following command line arguments:

    • The ARN of the model with which you want to analyze the image.

    • The name and location of a local image file.

    To analyze an image stored in an Amazon S3 bucket, run the program and supply the following command line arguments:

    • The ARN of the model with which you want to analyze the image.

    • The name and location of an image within the Amazon S3 bucket that you used in step 4.

    • The Amazon S3 bucket that contains the image that you used in step 4.

    //Copyright 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved. //PDX-License-Identifier: MIT-0 (For details, see https://github.com/awsdocs/amazon-rekognition-custom-labels-developer-guide/blob/master/LICENSE-SAMPLECODE.) package com.example.rekognition; import java.awt.*; import java.awt.image.BufferedImage; import java.io.IOException; import java.util.List; import javax.imageio.ImageIO; import javax.swing.*; import java.io.FileNotFoundException; import java.awt.font.FontRenderContext; import java.util.logging.Level; import java.util.logging.Logger; import java.io.File; import java.io.FileInputStream; import java.io.InputStream; import java.nio.ByteBuffer; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import com.amazonaws.services.rekognition.AmazonRekognition; import com.amazonaws.services.rekognition.AmazonRekognitionClientBuilder; import com.amazonaws.services.rekognition.model.BoundingBox; import com.amazonaws.services.rekognition.model.CustomLabel; import com.amazonaws.services.rekognition.model.DetectCustomLabelsRequest; import com.amazonaws.services.rekognition.model.DetectCustomLabelsResult; import com.amazonaws.services.rekognition.model.Image; import com.amazonaws.services.rekognition.model.S3Object; import com.amazonaws.services.s3.AmazonS3; import com.amazonaws.services.s3.AmazonS3ClientBuilder; import com.amazonaws.services.s3.model.S3ObjectInputStream; import com.amazonaws.services.rekognition.model.AmazonRekognitionException; import com.amazonaws.services.s3.model.AmazonS3Exception; import com.amazonaws.util.IOUtils; // Calls DetectCustomLabels and displays a bounding box around each detected image. public class DetectCustomLabels extends JPanel { private transient DetectCustomLabelsResult response; private transient Dimension dimension; private transient BufferedImage image; public static final Logger logger = Logger.getLogger(DetectCustomLabels.class.getName()); // Finds custom labels in an image stored in an S3 bucket. public DetectCustomLabels(AmazonRekognition rekClient, AmazonS3 s3client, String projectVersionArn, String bucket, String key, Float minConfidence) throws AmazonRekognitionException, AmazonS3Exception, IOException { logger.log(Level.INFO, "Processing S3 bucket: {0} image {1}", new Object[] { bucket, key }); // Get image from S3 bucket and create BufferedImage com.amazonaws.services.s3.model.S3Object s3object = s3client.getObject(bucket, key); S3ObjectInputStream inputStream = s3object.getObjectContent(); image = ImageIO.read(inputStream); // Set image size setWindowDimensions(); DetectCustomLabelsRequest request = new DetectCustomLabelsRequest() .withProjectVersionArn(projectVersionArn) .withImage(new Image().withS3Object(new S3Object().withName(key).withBucket(bucket))) .withMinConfidence(minConfidence); // Call DetectCustomLabels response = rekClient.detectCustomLabels(request); logFoundLabels(response.getCustomLabels()); drawLabels(); } // Finds custom label in a local image file. public DetectCustomLabels(AmazonRekognition rekClient, String projectVersionArn, String photo, Float minConfidence) throws IOException, AmazonRekognitionException { logger.log(Level.INFO, "Processing local file: {0}", photo); // Get image bytes and buffered image ByteBuffer imageBytes; try (InputStream inputStream = new FileInputStream(new File(photo))) { imageBytes = ByteBuffer.wrap(IOUtils.toByteArray(inputStream)); } // Get image for display InputStream imageBytesStream; imageBytesStream = new ByteArrayInputStream(imageBytes.array()); ByteArrayOutputStream baos = new ByteArrayOutputStream(); image = ImageIO.read(imageBytesStream); ImageIO.write(image, "jpg", baos); // Set image size setWindowDimensions(); // Analyze image DetectCustomLabelsRequest request = new DetectCustomLabelsRequest() .withProjectVersionArn(projectVersionArn) .withImage(new Image() .withBytes(imageBytes)) .withMinConfidence(minConfidence); response = rekClient.detectCustomLabels(request); logFoundLabels(response.getCustomLabels()); drawLabels(); } // Log the labels found by DetectCustomLabels private void logFoundLabels(List<CustomLabel> customLabels) { logger.info("Custom labels found"); if (customLabels.isEmpty()) { logger.log(Level.INFO, "No Custom Labels found. Consider lowering min confidence."); } else { for (CustomLabel customLabel : customLabels) { logger.log(Level.INFO, " Label: {0} Confidence: {1}", new Object[] { customLabel.getName(), customLabel.getConfidence() }); } } } // Sets window dimensions to 1/2 screen size, unless image is smaller public void setWindowDimensions() { dimension = java.awt.Toolkit.getDefaultToolkit().getScreenSize(); dimension.width = (int) dimension.getWidth() / 2; if (image.getWidth() < dimension.width) { dimension.width = image.getWidth(); } dimension.height = (int) dimension.getHeight() / 2; if (image.getHeight() < dimension.height) { dimension.height = image.getHeight(); } setPreferredSize(dimension); } // Draws the image containing the bounding boxes and labels. @Override public void paintComponent(Graphics g) { Graphics2D g2d = (Graphics2D) g; // Create a Java2D version of g. // Draw the image. g2d.drawImage(image, 0, 0, dimension.width, dimension.height, this); } public void drawLabels() { // Draws bounding boxes (if present) and label text. int boundingBoxBorderWidth = 5; int imageHeight = image.getHeight(this); int imageWidth = image.getWidth(this); // Set up drawing Graphics2D g2d = image.createGraphics(); g2d.setColor(Color.GREEN); g2d.setFont(new Font("Tahoma", Font.PLAIN, 50)); Font font = g2d.getFont(); FontRenderContext frc = g2d.getFontRenderContext(); g2d.setStroke(new BasicStroke(boundingBoxBorderWidth)); List<CustomLabel> customLabels = response.getCustomLabels(); int imageLevelLabelHeight = 0; for (CustomLabel customLabel : customLabels) { String label = customLabel.getName(); int textWidth = (int) (font.getStringBounds(label, frc).getWidth()); int textHeight = (int) (font.getStringBounds(label, frc).getHeight()); // Draw bounding box, if present if (customLabel.getGeometry() != null) { BoundingBox box = customLabel.getGeometry().getBoundingBox(); float left = imageWidth * box.getLeft(); float top = imageHeight * box.getTop(); // Draw black rectangle g2d.setColor(Color.BLACK); g2d.fillRect(Math.round(left + (boundingBoxBorderWidth)), Math.round(top + (boundingBoxBorderWidth)), textWidth + boundingBoxBorderWidth, textHeight + boundingBoxBorderWidth); // Write label onto black rectangle g2d.setColor(Color.GREEN); g2d.drawString(label, left + boundingBoxBorderWidth, (top + textHeight)); // Draw bounding box around label location g2d.drawRect(Math.round(left), Math.round(top), Math.round((imageWidth * box.getWidth())), Math.round((imageHeight * box.getHeight()))); } // Draw image level labels. else { // Draw black rectangle g2d.setColor(Color.BLACK); g2d.fillRect(10, 10 + imageLevelLabelHeight, textWidth, textHeight); g2d.setColor(Color.GREEN); g2d.drawString(label, 10, textHeight + imageLevelLabelHeight); imageLevelLabelHeight += textHeight; } } g2d.dispose(); } public static void main(String args[]) throws Exception { String photo = null; String bucket = null; String projectVersionArn = null; float minConfidence = 50; final String USAGE = "\n" + "Usage: " + "<model_arn> <image> <bucket>\n\n" + "Where:\n" + " model_arn - The ARN of the model that you want to use. \n\n" + " image - The location of the image on your local file system or within an S3 bucket.\n\n" + " bucket - The S3 bucket that contains the image. Don't specify if image is local.\n\n"; // Collect the arguments. If 3 arguments are present, the image is assumed to be // in an S3 bucket. if (args.length < 2 || args.length > 3) { System.out.println(USAGE); System.exit(1); } projectVersionArn = args[0]; photo = args[1]; if (args.length == 3) { bucket = args[2]; } DetectCustomLabels panel = null; try { // Get the Rekognition client AmazonRekognition rekClient = AmazonRekognitionClientBuilder.defaultClient(); AmazonS3 s3client = AmazonS3ClientBuilder.defaultClient(); // Create frame and panel. JFrame frame = new JFrame("Custom Labels"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); if (args.length == 2) { // Analyze local image panel = new DetectCustomLabels(rekClient, projectVersionArn, photo, minConfidence); } else { // Analyze image in S3 bucket panel = new DetectCustomLabels(rekClient, s3client, projectVersionArn, bucket, photo, minConfidence); } frame.setContentPane(panel); frame.pack(); frame.setVisible(true); } catch (AmazonRekognitionException rekError) { String errorMessage = "Rekognition client error: " + rekError.getMessage(); logger.log(Level.SEVERE, errorMessage); System.out.println(errorMessage); System.exit(1); } catch (FileNotFoundException fileError) { String errorMessage = "File not found: " + photo; logger.log(Level.SEVERE, errorMessage); System.out.println(errorMessage); System.exit(1); } catch (IOException fileError) { String errorMessage = "Input output exception: " + fileError.getMessage(); logger.log(Level.SEVERE, errorMessage); System.out.println(errorMessage); System.exit(1); } catch (AmazonS3Exception s3Error) { String errorMessage = "S3 error: " + s3Error.getErrorMessage(); logger.log(Level.SEVERE, errorMessage); System.out.println(errorMessage); System.exit(1); } } }
    Java 2

    The following example code displays bounding boxes and image level labels found in an image.

    To analyze a local image, run the program and supply the following command line arguments:

    • projectVersionArn – The ARN of the model with which you want to analyze the image.

    • photo – the name and location of a local image file.

    To analyze an image stored in an S3 bucket, run the program and supply the following command line arguments:

    • The ARN of the model with which you want to analyze the image.

    • The name and location of an image within the S3 bucket that you used in step 4.

    • The Amazon S3 bucket that contains the image that you used in step 4.

    //Copyright 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved. //PDX-License-Identifier: MIT-0 (For details, see https://github.com/awsdocs/amazon-rekognition-custom-labels-developer-guide/blob/master/LICENSE-SAMPLECODE.) import software.amazon.awssdk.core.ResponseBytes; import software.amazon.awssdk.core.SdkBytes; import software.amazon.awssdk.core.sync.ResponseTransformer; import software.amazon.awssdk.services.rekognition.RekognitionClient; import software.amazon.awssdk.services.rekognition.model.S3Object; import software.amazon.awssdk.services.rekognition.model.Image; import software.amazon.awssdk.services.rekognition.model.DetectCustomLabelsRequest; import software.amazon.awssdk.services.rekognition.model.DetectCustomLabelsResponse; import software.amazon.awssdk.services.rekognition.model.CustomLabel; import software.amazon.awssdk.services.rekognition.model.RekognitionException; import software.amazon.awssdk.services.rekognition.model.BoundingBox; import software.amazon.awssdk.services.s3.S3Client; import software.amazon.awssdk.services.s3.model.GetObjectRequest; import software.amazon.awssdk.services.s3.model.GetObjectResponse; import software.amazon.awssdk.services.s3.model.NoSuchBucketException; import software.amazon.awssdk.services.s3.model.NoSuchKeyException; import java.io.ByteArrayInputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import java.util.List; import java.awt.*; import java.awt.font.FontRenderContext; import java.awt.image.BufferedImage; import javax.imageio.ImageIO; import javax.swing.*; import java.util.logging.Level; import java.util.logging.Logger; // Calls DetectCustomLabels on an image. Displays bounding boxes or // image level labels found in the image. public class DetectCustomLabels extends JPanel { private transient BufferedImage image; private transient DetectCustomLabelsResponse response; private transient Dimension dimension; public static final Logger logger = Logger.getLogger(DetectCustomLabels.class.getName()); // Finds custom labels in an image stored in an S3 bucket. public DetectCustomLabels(RekognitionClient rekClient, S3Client s3client, String projectVersionArn, String bucket, String key, Float minConfidence) throws RekognitionException, NoSuchBucketException, NoSuchKeyException, IOException { logger.log(Level.INFO, "Processing S3 bucket: {0} image {1}", new Object[] { bucket, key }); // Get image from S3 bucket and create BufferedImage GetObjectRequest requestObject = GetObjectRequest.builder().bucket(bucket).key(key).build(); ResponseBytes<GetObjectResponse> result = s3client.getObject(requestObject, ResponseTransformer.toBytes()); ByteArrayInputStream bis = new ByteArrayInputStream(result.asByteArray()); image = ImageIO.read(bis); // Set image size setWindowDimensions(); // Construct request parameter for DetectCustomLabels S3Object s3Object = S3Object.builder().bucket(bucket).name(key).build(); Image s3Image = Image.builder().s3Object(s3Object).build(); DetectCustomLabelsRequest request = DetectCustomLabelsRequest.builder().image(s3Image) .projectVersionArn(projectVersionArn).minConfidence(minConfidence).build(); response = rekClient.detectCustomLabels(request); logFoundLabels(response.customLabels()); drawLabels(); } // Finds custom label in a local image file. public DetectCustomLabels(RekognitionClient rekClient, String projectVersionArn, String photo, Float minConfidence) throws IOException, RekognitionException { logger.log(Level.INFO, "Processing local file: {0}", photo); // Get image bytes and buffered image InputStream sourceStream = new FileInputStream(new File(photo)); SdkBytes imageBytes = SdkBytes.fromInputStream(sourceStream); ByteArrayInputStream inputStream = new ByteArrayInputStream(imageBytes.asByteArray()); image = ImageIO.read(inputStream); setWindowDimensions(); // Construct request parameter for DetectCustomLabels Image localImageBytes = Image.builder().bytes(imageBytes).build(); DetectCustomLabelsRequest request = DetectCustomLabelsRequest.builder().image(localImageBytes) .projectVersionArn(projectVersionArn).minConfidence(minConfidence).build(); response = rekClient.detectCustomLabels(request); logFoundLabels(response.customLabels()); drawLabels(); } // Sets window dimensions to 1/2 screen size, unless image is smaller public void setWindowDimensions() { dimension = java.awt.Toolkit.getDefaultToolkit().getScreenSize(); dimension.width = (int) dimension.getWidth() / 2; if (image.getWidth() < dimension.width) { dimension.width = image.getWidth(); } dimension.height = (int) dimension.getHeight() / 2; if (image.getHeight() < dimension.height) { dimension.height = image.getHeight(); } setPreferredSize(dimension); } // Draws bounding boxes (if present) and label text. public void drawLabels() { int boundingBoxBorderWidth = 5; int imageHeight = image.getHeight(this); int imageWidth = image.getWidth(this); // Set up drawing Graphics2D g2d = image.createGraphics(); g2d.setColor(Color.GREEN); g2d.setFont(new Font("Tahoma", Font.PLAIN, 50)); Font font = g2d.getFont(); FontRenderContext frc = g2d.getFontRenderContext(); g2d.setStroke(new BasicStroke(boundingBoxBorderWidth)); List<CustomLabel> customLabels = response.customLabels(); int imageLevelLabelHeight = 0; for (CustomLabel customLabel : customLabels) { String label = customLabel.name(); int textWidth = (int) (font.getStringBounds(label, frc).getWidth()); int textHeight = (int) (font.getStringBounds(label, frc).getHeight()); // Draw bounding box, if present if (customLabel.geometry() != null) { BoundingBox box = customLabel.geometry().boundingBox(); float left = imageWidth * box.left(); float top = imageHeight * box.top(); // Draw black rectangle g2d.setColor(Color.BLACK); g2d.fillRect(Math.round(left + (boundingBoxBorderWidth)), Math.round(top + (boundingBoxBorderWidth)), textWidth + boundingBoxBorderWidth, textHeight + boundingBoxBorderWidth); // Write label onto black rectangle g2d.setColor(Color.GREEN); g2d.drawString(label, left + boundingBoxBorderWidth, (top + textHeight)); // Draw bounding box around label location g2d.drawRect(Math.round(left), Math.round(top), Math.round((imageWidth * box.width())), Math.round((imageHeight * box.height()))); } // Draw image level labels. else { // Draw black rectangle g2d.setColor(Color.BLACK); g2d.fillRect(10, 10 + imageLevelLabelHeight, textWidth, textHeight); g2d.setColor(Color.GREEN); g2d.drawString(label, 10, textHeight + imageLevelLabelHeight); imageLevelLabelHeight += textHeight; } } g2d.dispose(); } // Log the labels found by DetectCustomLabels private void logFoundLabels(List<CustomLabel> customLabels) { logger.info("Custom labels found:"); if (customLabels.isEmpty()) { logger.log(Level.INFO, "No Custom Labels found. Consider lowering min confidence."); } else { for (CustomLabel customLabel : customLabels) { logger.log(Level.INFO, " Label: {0} Confidence: {1}", new Object[] { customLabel.name(), customLabel.confidence() } ); } } } // Draws the image containing the bounding boxes and labels. @Override public void paintComponent(Graphics g) { Graphics2D g2d = (Graphics2D) g; // Create a Java2D version of g. // Draw the image. g2d.drawImage(image, 0, 0, dimension.width, dimension.height, this); } public static void main(String args[]) throws Exception { String photo = null; String bucket = null; String projectVersionArn = null; final String USAGE = "\n" + "Usage: " + "<model_arn> <image> <bucket>\n\n" + "Where:\n" + " model_arn - The ARN of the model that you want to use. \n\n" + " image - The location of the image on your local file system or within an S3 bucket.\n\n" + " bucket - The S3 bucket that contains the image. Don't specify if image is local.\n\n"; // Collect the arguments. If 3 arguments are present, the image is assumed to be // in an S3 bucket. if (args.length < 2 || args.length > 3) { System.out.println(USAGE); System.exit(1); } projectVersionArn = args[0]; photo = args[1]; if (args.length == 3) { bucket = args[2]; } float minConfidence = 50; DetectCustomLabels panel = null; try { // Get the Rekognition client RekognitionClient rekClient = RekognitionClient.builder().build(); S3Client s3client = S3Client.builder().build(); // Create frame and panel. JFrame frame = new JFrame("Custom Labels"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); if (args.length == 2) { // Analyze local image panel = new DetectCustomLabels(rekClient, projectVersionArn, photo, minConfidence); } else { // Analyze image in S3 bucket panel = new DetectCustomLabels(rekClient, s3client, projectVersionArn, bucket, photo, minConfidence); } frame.setContentPane(panel); frame.pack(); frame.setVisible(true); } catch (RekognitionException rekError) { String errorMessage = "Rekognition client error: " + rekError.getMessage(); logger.log(Level.SEVERE, errorMessage); System.out.println(errorMessage); System.exit(1); } catch (FileNotFoundException fileError) { String errorMessage = "File not found: " + photo; logger.log(Level.SEVERE, errorMessage); System.out.println(errorMessage); System.exit(1); } catch (IOException fileError) { String errorMessage = "Input output exception: " + fileError.getMessage(); logger.log(Level.SEVERE, errorMessage); System.out.println(errorMessage); System.exit(1); } catch (NoSuchKeyException bucketError) { String errorMessage = String.format("Image not found: %s in bucket %s.", photo, bucket); logger.log(Level.SEVERE, errorMessage); System.out.println(errorMessage); System.exit(1); } catch (NoSuchBucketException bucketError) { String errorMessage = "Bucket not found: " + bucket; logger.log(Level.SEVERE, errorMessage); System.out.println(errorMessage); System.exit(1); } } }

DetectCustomLabels operation request

In the DetectCustomLabels operation, you supply an input image either as a base64-encoded byte array or as an image stored in an Amazon S3 bucket. The following example JSON request shows the image loaded from an Amazon S3 bucket.

{ "ProjectVersionArn": "string", "Image":{ "S3Object":{ "Bucket":"string", "Name":"string", "Version":"string" } }, "MinConfidence": 90, "MaxLabels": 10, }

DetectCustomLabels operation response

The following JSON response from the DetectCustomLabels operation shows the custom labels that were detected in the following image.

{ "CustomLabels": [ { "Name": "MyLogo", "Confidence": 77.7729721069336, "Geometry": { "BoundingBox": { "Width": 0.198987677693367, "Height": 0.31296101212501526, "Left": 0.07924537360668182, "Top": 0.4037395715713501 } } } ] }