Rilevamento del testo del documento con Amazon Textract

Per rilevare il testo in un documento, si utilizza ilDetectDocumentTextoperazione e passa un file di documento come input.DetectDocumentTextrestituisce 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.

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)

Se non lo hai già fatto:
1. Crea o aggiorna un utente IAM conAmazonTextractFullAccesseAmazonS3ReadOnlyAccessautorizzazioni. Per ulteriori informazioni, consultare Fase 1: Impostazione di un account AWS e creazione di un utente IAM.
2. Installa e configura la AWS CLI e gli SDK AWS. Per ulteriori informazioni, consultare Fase 2: Configurazione diAWS CLIeAWSSDK.
Carica un documento nel bucket S3.

Per istruzioni, consultaCaricamento di oggetti in Amazon S3nellaGuida dell'utente Amazon Simple Storage Service.

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 funzionemain, sostituire i valori dibucketedocumentcon 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 diBucketeNamecon 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 funzionemain, sostituire i valori dibucketedocumentcon 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 delimage-sizeeimagespacchetti.

Nella funzionemain, sostituire i valori dibucketedocumentcon i nomi del bucket Amazon S3 e del documento utilizzati nella fase 2. Sostituisci il valore diregionConfigcon 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()

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 ilDetectDocumentTextoperazione.

Avvertimento JavaScript è disabilitato o non è disponibile nel tuo browser.

Per usare la documentazione AWS, JavaScript deve essere abilitato. Consulta le pagine della guida del browser per le istruzioni.

Convenzioni dei documenti

Chiamata di Amazon Textract Synchronous Operations

Analisi del testo del documento