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# Rilevamento del testo del documento con Amazon Textract
<a name="detecting-document-text"></a>

Per rilevare il testo in un documento, si utilizza il[DetectDocumentText](API_DetectDocumentText.md)operazione e passa un file di documento come input.`DetectDocumentText`restituisce una struttura JSON che contiene righe e parole del testo rilevato, la posizione del testo nel documento e le relazioni tra il testo rilevato. Per ulteriori informazioni, consultare [Rilevamento del testo](how-it-works-detecting.md). 

Puoi fornire un documento di input come matrice di byte dell'immagine (byte dell'immagine codificata in formato Base64) o come oggetto Amazon S3. In questa procedura, viene caricato un file immagine nel bucket S3 e viene specificato il nome file. 

**Per rilevare il testo in un documento (API)**

1. Se non lo hai già fatto:

   1. Crea o aggiorna un utente IAM con`AmazonTextractFullAccess`e`AmazonS3ReadOnlyAccess`autorizzazioni. Per ulteriori informazioni, consultare [Fase 1: Impostazione di un account AWS e creazione di un utente IAM](setting-up.md#setting-up-iam).

   1. Installa e configura la AWS CLI e gli SDK AWS. Per ulteriori informazioni, consultare [Fase 2: Configurazione diAWS CLIeAWSSDK](setup-awscli-sdk.md).

1. Carica un documento nel bucket S3. 

   Per istruzioni, consulta[Caricamento di oggetti in Amazon S3](https://docs.aws.amazon.com/AmazonS3/latest/user-guide/UploadingObjectsintoAmazonS3.html)nella*Guida dell'utente Amazon Simple Storage Service*.

1. Utilizza i seguenti esempi per richiamare l'operazione `DetectDocumentText`.

------
#### [ Java ]

   Il codice di esempio seguente visualizza il documento e le caselle attorno alle righe di testo rilevato. 

   Nella funzione`main`, sostituire i valori di`bucket`e`document`con i nomi del bucket Amazon S3 e del documento utilizzati nella fase 2. 

   ```
   //Calls DetectDocumentText.
   //Loads document from S3 bucket. Displays the document and bounding boxes around detected lines/words of text.
   package com.amazonaws.samples;
   
   import java.awt.*;
   import java.awt.image.BufferedImage;
   import java.util.List;
   import javax.imageio.ImageIO;
   import javax.swing.*;
   import com.amazonaws.services.s3.AmazonS3;
   import com.amazonaws.services.s3.AmazonS3ClientBuilder;
   import com.amazonaws.services.s3.model.S3ObjectInputStream;
   import com.amazonaws.client.builder.AwsClientBuilder.EndpointConfiguration;
   import com.amazonaws.services.textract.AmazonTextract;
   import com.amazonaws.services.textract.AmazonTextractClientBuilder;
   import com.amazonaws.services.textract.model.Block;
   import com.amazonaws.services.textract.model.BoundingBox;
   import com.amazonaws.services.textract.model.DetectDocumentTextRequest;
   import com.amazonaws.services.textract.model.DetectDocumentTextResult;
   import com.amazonaws.services.textract.model.Document;
   import com.amazonaws.services.textract.model.S3Object;
   import com.amazonaws.services.textract.model.Point;
   import com.amazonaws.services.textract.model.Relationship;
   
   public class DocumentText extends JPanel {
   
       private static final long serialVersionUID = 1L;
   
       BufferedImage image;
       DetectDocumentTextResult result;
   
       public DocumentText(DetectDocumentTextResult documentResult, BufferedImage bufImage) throws Exception {
           super();
           
           result = documentResult; // Results of text detection.
           image = bufImage; // The image containing the document.
   
       }
   
       // Draws the image and text bounding box.
       public void paintComponent(Graphics g) {
   
           int height = image.getHeight(this);
           int width = image.getWidth(this);
   
           Graphics2D g2d = (Graphics2D) g; // Create a Java2D version of g.
   
           // Draw the image.
           g2d.drawImage(image, 0, 0, image.getWidth(this) , image.getHeight(this), this);
   
           // Iterate through blocks and display polygons around lines of detected text.
           List<Block> blocks = result.getBlocks();
           for (Block block : blocks) {
               DisplayBlockInfo(block);
               if ((block.getBlockType()).equals("LINE")) {
                   ShowPolygon(height, width, block.getGeometry().getPolygon(), g2d);
                   /*
                     ShowBoundingBox(height, width, block.getGeometry().getBoundingBox(), g2d);
                    */
               } else { // its a word, so just show vertical lines.
                   ShowPolygonVerticals(height, width, block.getGeometry().getPolygon(), g2d);
               }
           }
       }
   
       // Show bounding box at supplied location.
       private void ShowBoundingBox(int imageHeight, int imageWidth, BoundingBox box, Graphics2D g2d) {
   
           float left = imageWidth * box.getLeft();
           float top = imageHeight * box.getTop();
   
           // Display bounding box.
           g2d.setColor(new Color(0, 212, 0));
           g2d.drawRect(Math.round(left), Math.round(top),
                   Math.round(imageWidth * box.getWidth()), Math.round(imageHeight * box.getHeight()));
   
       }
   
       // Shows polygon at supplied location
       private void ShowPolygon(int imageHeight, int imageWidth, List<Point> points, Graphics2D g2d) {
   
           g2d.setColor(new Color(0, 0, 0));
           Polygon polygon = new Polygon();
   
           // Construct polygon and display
           for (Point point : points) {
               polygon.addPoint((Math.round(point.getX() * imageWidth)),
                       Math.round(point.getY() * imageHeight));
           }
           g2d.drawPolygon(polygon);
       }
   
       // Draws only the vertical lines in the supplied polygon.
       private void ShowPolygonVerticals(int imageHeight, int imageWidth, List<Point> points, Graphics2D g2d) {
   
           g2d.setColor(new Color(0, 212, 0));
           Object[] parry = points.toArray();
           g2d.setStroke(new BasicStroke(2));
   
           g2d.drawLine(Math.round(((Point) parry[0]).getX() * imageWidth),
                   Math.round(((Point) parry[0]).getY() * imageHeight), Math.round(((Point) parry[3]).getX() * imageWidth),
                   Math.round(((Point) parry[3]).getY() * imageHeight));
   
           g2d.setColor(new Color(255, 0, 0));
           g2d.drawLine(Math.round(((Point) parry[1]).getX() * imageWidth),
                   Math.round(((Point) parry[1]).getY() * imageHeight), Math.round(((Point) parry[2]).getX() * imageWidth),
                   Math.round(((Point) parry[2]).getY() * imageHeight));
   
       }
       //Displays information from a block returned by text detection and text analysis
       private void DisplayBlockInfo(Block block) {
           System.out.println("Block Id : " + block.getId());
           if (block.getText()!=null)
               System.out.println("    Detected text: " + block.getText());
           System.out.println("    Type: " + block.getBlockType());
           
           if (block.getBlockType().equals("PAGE") !=true) {
               System.out.println("    Confidence: " + block.getConfidence().toString());
           }
           if(block.getBlockType().equals("CELL"))
           {
               System.out.println("    Cell information:");
               System.out.println("        Column: " + block.getColumnIndex());
               System.out.println("        Row: " + block.getRowIndex());
               System.out.println("        Column span: " + block.getColumnSpan());
               System.out.println("        Row span: " + block.getRowSpan());
   
           }
           
           System.out.println("    Relationships");
           List<Relationship> relationships=block.getRelationships();
           if(relationships!=null) {
               for (Relationship relationship : relationships) {
                   System.out.println("        Type: " + relationship.getType());
                   System.out.println("        IDs: " + relationship.getIds().toString());
               }
           } else {
               System.out.println("        No related Blocks");
           }
   
           System.out.println("    Geometry");
           System.out.println("        Bounding Box: " + block.getGeometry().getBoundingBox().toString());
           System.out.println("        Polygon: " + block.getGeometry().getPolygon().toString());
           
           List<String> entityTypes = block.getEntityTypes();
           
           System.out.println("    Entity Types");
           if(entityTypes!=null) {
               for (String entityType : entityTypes) {
                   System.out.println("        Entity Type: " + entityType);
               }
           } else {
               System.out.println("        No entity type");
           }
           if(block.getPage()!=null)
               System.out.println("    Page: " + block.getPage());            
           System.out.println();
       }
   
       public static void main(String arg[]) throws Exception {
           
           // The S3 bucket and document
           String document = "";
           String bucket = "";
   
           
           AmazonS3 s3client = AmazonS3ClientBuilder.standard()
                   .withEndpointConfiguration( 
                           new EndpointConfiguration("https://s3.amazonaws.com","us-east-1"))
                   .build();
           
                  
           // Get the document from S3
           com.amazonaws.services.s3.model.S3Object s3object = s3client.getObject(bucket, document);
           S3ObjectInputStream inputStream = s3object.getObjectContent();
           BufferedImage image = ImageIO.read(inputStream);
   
           // Call DetectDocumentText
           EndpointConfiguration endpoint = new EndpointConfiguration(
                   "https://textract.us-east-1.amazonaws.com", "us-east-1");
           AmazonTextract client = AmazonTextractClientBuilder.standard()
                   .withEndpointConfiguration(endpoint).build();
   
   
           DetectDocumentTextRequest request = new DetectDocumentTextRequest()
               .withDocument(new Document().withS3Object(new S3Object().withName(document).withBucket(bucket)));
   
           DetectDocumentTextResult result = client.detectDocumentText(request);
           
           // Create frame and panel.
           JFrame frame = new JFrame("RotateImage");
           frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
           DocumentText panel = new DocumentText(result, image);
           panel.setPreferredSize(new Dimension(image.getWidth() , image.getHeight() ));
           frame.setContentPane(panel);
           frame.pack();
           frame.setVisible(true);
   
       }
   }
   ```

------
#### [ AWS CLI ]

   Questo comando AWS CLI visualizza l'output JSON dell'operazione CLI `detect-document-text`. 

   Sostituisci i valori di`Bucket`e`Name`con i nomi del bucket Amazon S3 e del documento utilizzati nella fase 2. 

   ```
   aws textract detect-document-text \
    --document '{"S3Object":{"Bucket":"bucket","Name":"document"}}'
   ```

------
#### [ Python ]

   Il codice di esempio seguente mostra il documento e le caselle attorno alle righe di testo rilevate. 

   Nella funzione`main`, sostituire i valori di`bucket`e`document`con i nomi del bucket Amazon S3 e del documento utilizzati nella fase 2. 

   ```
   #Detects text in a document stored in an S3 bucket. Display polygon box around text and angled text 
   import boto3
   import io
   from io import BytesIO
   import sys
   
   import psutil
   import time
   
   import math
   from PIL import Image, ImageDraw, ImageFont
   
   
   # Displays information about a block returned by text detection and text analysis
   def DisplayBlockInformation(block):
       print('Id: {}'.format(block['Id']))
       if 'Text' in block:
           print('    Detected: ' + block['Text'])
       print('    Type: ' + block['BlockType'])
      
       if 'Confidence' in block:
           print('    Confidence: ' + "{:.2f}".format(block['Confidence']) + "%")
   
       if block['BlockType'] == 'CELL':
           print("    Cell information")
           print("        Column: " + str(block['ColumnIndex']))
           print("        Row: " + str(block['RowIndex']))
           print("        ColumnSpan: " + str(block['ColumnSpan']))
           print("        RowSpan: " + str(block['RowSpan']))    
       
       if 'Relationships' in block:
           print('    Relationships: {}'.format(block['Relationships']))
       print('    Geometry: ')
       print('        Bounding Box: {}'.format(block['Geometry']['BoundingBox']))
       print('        Polygon: {}'.format(block['Geometry']['Polygon']))
       
       if block['BlockType'] == "KEY_VALUE_SET":
           print ('    Entity Type: ' + block['EntityTypes'][0])
       if 'Page' in block:
           print('Page: ' + block['Page'])
       print()
   
   def process_text_detection(bucket, document):
   
       
       #Get the document from S3
       s3_connection = boto3.resource('s3')
                             
       s3_object = s3_connection.Object(bucket,document)
       s3_response = s3_object.get()
   
       stream = io.BytesIO(s3_response['Body'].read())
       image=Image.open(stream)
   
      
       # Detect text in the document
       
       client = boto3.client('textract')
       #process using image bytes                      
       #image_binary = stream.getvalue()
       #response = client.detect_document_text(Document={'Bytes': image_binary})
   
       #process using S3 object
       response = client.detect_document_text(
           Document={'S3Object': {'Bucket': bucket, 'Name': document}})
   
       #Get the text blocks
       blocks=response['Blocks']
       width, height =image.size  
       draw = ImageDraw.Draw(image)  
       print ('Detected Document Text')
      
       # Create image showing bounding box/polygon the detected lines/text
       for block in blocks:
               print('Type: ' + block['BlockType'])
               if block['BlockType'] != 'PAGE':
                   print('Detected: ' + block['Text'])
                   print('Confidence: ' + "{:.2f}".format(block['Confidence']) + "%")
   
               print('Id: {}'.format(block['Id']))
               if 'Relationships' in block:
                   print('Relationships: {}'.format(block['Relationships']))
               print('Bounding Box: {}'.format(block['Geometry']['BoundingBox']))
               print('Polygon: {}'.format(block['Geometry']['Polygon']))
               print()
               draw=ImageDraw.Draw(image)
               # Draw WORD - Green -  start of word, red - end of word
               if block['BlockType'] == "WORD":
                   draw.line([(width * block['Geometry']['Polygon'][0]['X'],
                   height * block['Geometry']['Polygon'][0]['Y']),
                   (width * block['Geometry']['Polygon'][3]['X'],
                   height * block['Geometry']['Polygon'][3]['Y'])],fill='green',
                   width=2)
               
                   draw.line([(width * block['Geometry']['Polygon'][1]['X'],
                   height * block['Geometry']['Polygon'][1]['Y']),
                   (width * block['Geometry']['Polygon'][2]['X'],
                   height * block['Geometry']['Polygon'][2]['Y'])],
                   fill='red',
                   width=2)    
   
                    
               # Draw box around entire LINE  
               if block['BlockType'] == "LINE":
                   points=[]
   
                   for polygon in block['Geometry']['Polygon']:
                       points.append((width * polygon['X'], height * polygon['Y']))
   
                   draw.polygon((points), outline='black')    
     
                   # Uncomment to draw bounding box
                   #box=block['Geometry']['BoundingBox']                    
                   #left = width * box['Left']
                   #top = height * box['Top']           
                   #draw.rectangle([left,top, left + (width * box['Width']), top +(height * box['Height'])],outline='black') 
   
   
       # Display the image
       image.show()
       # display image for 10 seconds
   
       
       return len(blocks)
   
   def main():
   
       bucket = ''
       document = ''
       block_count=process_text_detection(bucket,document)
       print("Blocks detected: " + str(block_count))
       
   if __name__ == "__main__":
       main()
   ```

------
#### [ Node.js ]

   Il seguente codice di esempio Node.js visualizza il documento e le caselle attorno alle righe di testo rilevate, trasmettendo un'immagine dei risultati nella directory da cui si esegue il codice. Si avvale del`image-size`e`images`pacchetti.

   Nella funzione`main`, sostituire i valori di`bucket`e`document`con i nomi del bucket Amazon S3 e del documento utilizzati nella fase 2. Sostituisci il valore di`regionConfig`con il nome della regione in cui si trova il tuo account.

   ```
   async function main(){
   
   // Import AWS
   const AWS = require("aws-sdk")
   // Use Image-Size to get 
   const sizeOf = require('image-size');
   // Image tool to draw buffers
   const images = require("images");
   
   // Create a canvas and get the context
   const { createCanvas } = require('canvas')
   const canvas = createCanvas(200, 200)
   const ctx = canvas.getContext('2d')
   
   // Set variables
   const bucket = 'bucket-name' // the s3 bucket name
   const photo  = 'image-name' // the name of file
   const regionConfig = 'region'
   
   // Set region if needed
   AWS.config.update({region:regionConfig});
   
   // Connect to Textract
   const client = new AWS.Textract();
   // Connect to S3 to display image
   const s3 = new AWS.S3();
   
   // Define paramaters
   const params = {
     Document: {
       S3Object: {
         Bucket: bucket,
         Name: photo
       },
     },
   }
   
   // Function to display image
   async function getImage(){
     const imageData =  s3.getObject(
       {
           Bucket: bucket,
           Key: photo
         }
       
     ).promise();
     return imageData;
   }
   
   // get image
   var imageData = await getImage()
   
   // Get the height, width of the image
   const dimensions = sizeOf(imageData.Body)
   const width = dimensions.width
   const height = dimensions.height
   console.log(imageData.Body)
   console.log(width, height)
   
   canvas.width = width;
   canvas.height = height;
   
   try{
     // Call API and log response
     const res = await client.detectDocumentText(params).promise();
     var image = images(imageData.Body).size(width, height)
     //console.log the type of block, text, text type, and confidence
     res.Blocks.forEach(block => {
       console.log(`Block Type: ${block.BlockType}`),
       console.log(`Text: ${block.Text}`)
       console.log(`TextType: ${block.TextType}`)
       console.log(`Confidence: ${block.Confidence}`)
   
       // Draw box around detected text using polygons
       ctx.strokeStyle = 'rgba(0,0,0,0.5)';
       ctx.beginPath();
       block.Geometry.Polygon.forEach(({X, Y}) =>
       ctx.lineTo(width * X - 10, height * Y - 10)
       );
       ctx.closePath();
       ctx.stroke();
       console.log("-----")
     }) 
   
     // render image
     var buffer = canvas.toBuffer("image/png");
     image.draw(images(buffer), 10, 10)
     image.save("output-image.jpg");
     
   } catch (err){
   console.error(err);}
   
   }
   
   main()
   ```

------

1. Esegui l'esempio. Gli esempi di Python e Java visualizzano l'immagine del documento. Una casella nera circonda ogni riga di testo rilevato. Una linea verticale verde è l'inizio di una parola rilevata. Una linea verticale rossa è la fine di una parola rilevata. LaAWS CLIesempio visualizza solo l'output JSON per il`DetectDocumentText`operazione.