Rilevamento del testo in un file video locale

Rileva il testo in un video archiviato localmente.

Per saperne di più

Per la documentazione dettagliata che include questo esempio di codice, vedi quanto segue:

Riconoscimento del testo

Esempio di codice

Go

Per eseguire l'autenticazione a Video Intelligence, configura Credenziali predefinite dell'applicazione. Per maggiori informazioni, consulta Configurare l'autenticazione per un ambiente di sviluppo locale.


import (
	"context"
	"fmt"
	"io"
	"io/ioutil"

	video "cloud.google.com/go/videointelligence/apiv1"
	videopb "cloud.google.com/go/videointelligence/apiv1/videointelligencepb"
	"github.com/golang/protobuf/ptypes"
)

// textDetection analyzes a video and extracts the text from the video's audio.
func textDetection(w io.Writer, filename string) error {
	// filename := "../testdata/googlework_short.mp4"

	ctx := context.Background()

	// Creates a client.
	client, err := video.NewClient(ctx)
	if err != nil {
		return fmt.Errorf("video.NewClient: %w", err)
	}
	defer client.Close()

	fileBytes, err := ioutil.ReadFile(filename)
	if err != nil {
		return fmt.Errorf("ioutil.ReadFile: %w", err)
	}

	op, err := client.AnnotateVideo(ctx, &videopb.AnnotateVideoRequest{
		InputContent: fileBytes,
		Features: []videopb.Feature{
			videopb.Feature_TEXT_DETECTION,
		},
	})
	if err != nil {
		return fmt.Errorf("AnnotateVideo: %w", err)
	}

	resp, err := op.Wait(ctx)
	if err != nil {
		return fmt.Errorf("Wait: %w", err)
	}

	// Only one video was processed, so get the first result.
	result := resp.GetAnnotationResults()[0]

	for _, annotation := range result.TextAnnotations {
		fmt.Fprintf(w, "Text: %q\n", annotation.GetText())

		// Get the first text segment.
		segment := annotation.GetSegments()[0]
		start, _ := ptypes.Duration(segment.GetSegment().GetStartTimeOffset())
		end, _ := ptypes.Duration(segment.GetSegment().GetEndTimeOffset())
		fmt.Fprintf(w, "\tSegment: %v to %v\n", start, end)

		fmt.Fprintf(w, "\tConfidence: %f\n", segment.GetConfidence())

		// Show the result for the first frame in this segment.
		frame := segment.GetFrames()[0]
		seconds := float32(frame.GetTimeOffset().GetSeconds())
		nanos := float32(frame.GetTimeOffset().GetNanos())
		fmt.Fprintf(w, "\tTime offset of the first frame: %fs\n", seconds+nanos/1e9)

		fmt.Fprintf(w, "\tRotated bounding box vertices:\n")
		for _, vertex := range frame.GetRotatedBoundingBox().GetVertices() {
			fmt.Fprintf(w, "\t\tVertex x=%f, y=%f\n", vertex.GetX(), vertex.GetY())
		}
	}

	return nil
}

Java

/**
 * Detect text in a video.
 *
 * @param filePath the path to the video file to analyze.
 */
public static VideoAnnotationResults detectText(String filePath) throws Exception {
  try (VideoIntelligenceServiceClient client = VideoIntelligenceServiceClient.create()) {
    // Read file
    Path path = Paths.get(filePath);
    byte[] data = Files.readAllBytes(path);

    // Create the request
    AnnotateVideoRequest request =
        AnnotateVideoRequest.newBuilder()
            .setInputContent(ByteString.copyFrom(data))
            .addFeatures(Feature.TEXT_DETECTION)
            .build();

    // asynchronously perform object tracking on videos
    OperationFuture<AnnotateVideoResponse, AnnotateVideoProgress> future =
        client.annotateVideoAsync(request);

    System.out.println("Waiting for operation to complete...");
    // The first result is retrieved because a single video was processed.
    AnnotateVideoResponse response = future.get(300, TimeUnit.SECONDS);
    VideoAnnotationResults results = response.getAnnotationResults(0);

    // Get only the first annotation for demo purposes.
    TextAnnotation annotation = results.getTextAnnotations(0);
    System.out.println("Text: " + annotation.getText());

    // Get the first text segment.
    TextSegment textSegment = annotation.getSegments(0);
    System.out.println("Confidence: " + textSegment.getConfidence());
    // For the text segment display it's time offset
    VideoSegment videoSegment = textSegment.getSegment();
    Duration startTimeOffset = videoSegment.getStartTimeOffset();
    Duration endTimeOffset = videoSegment.getEndTimeOffset();
    // Display the offset times in seconds, 1e9 is part of the formula to convert nanos to seconds
    System.out.println(
        String.format(
            "Start time: %.2f", startTimeOffset.getSeconds() + startTimeOffset.getNanos() / 1e9));
    System.out.println(
        String.format(
            "End time: %.2f", endTimeOffset.getSeconds() + endTimeOffset.getNanos() / 1e9));

    // Show the first result for the first frame in the segment.
    TextFrame textFrame = textSegment.getFrames(0);
    Duration timeOffset = textFrame.getTimeOffset();
    System.out.println(
        String.format(
            "Time offset for the first frame: %.2f",
            timeOffset.getSeconds() + timeOffset.getNanos() / 1e9));

    // Display the rotated bounding box for where the text is on the frame.
    System.out.println("Rotated Bounding Box Vertices:");
    List<NormalizedVertex> vertices = textFrame.getRotatedBoundingBox().getVerticesList();
    for (NormalizedVertex normalizedVertex : vertices) {
      System.out.println(
          String.format(
              "\tVertex.x: %.2f, Vertex.y: %.2f",
              normalizedVertex.getX(), normalizedVertex.getY()));
    }
    return results;
  }
}

Node.js

// Imports the Google Cloud Video Intelligence library + Node's fs library
const Video = require('@google-cloud/video-intelligence');
const fs = require('fs');
const util = require('util');
// Creates a client
const video = new Video.VideoIntelligenceServiceClient();

/**
 * TODO(developer): Uncomment the following line before running the sample.
 */
// const path = 'Local file to analyze, e.g. ./my-file.mp4';

// Reads a local video file and converts it to base64
const file = await util.promisify(fs.readFile)(path);
const inputContent = file.toString('base64');

const request = {
  inputContent: inputContent,
  features: ['TEXT_DETECTION'],
};
// Detects text in a video
const [operation] = await video.annotateVideo(request);
const results = await operation.promise();
console.log('Waiting for operation to complete...');

// Gets annotations for video
const textAnnotations = results[0].annotationResults[0].textAnnotations;
textAnnotations.forEach(textAnnotation => {
  console.log(`Text ${textAnnotation.text} occurs at:`);
  textAnnotation.segments.forEach(segment => {
    const time = segment.segment;
    if (time.startTimeOffset.seconds === undefined) {
      time.startTimeOffset.seconds = 0;
    }
    if (time.startTimeOffset.nanos === undefined) {
      time.startTimeOffset.nanos = 0;
    }
    if (time.endTimeOffset.seconds === undefined) {
      time.endTimeOffset.seconds = 0;
    }
    if (time.endTimeOffset.nanos === undefined) {
      time.endTimeOffset.nanos = 0;
    }
    console.log(
      `\tStart: ${time.startTimeOffset.seconds || 0}` +
        `.${(time.startTimeOffset.nanos / 1e6).toFixed(0)}s`
    );
    console.log(
      `\tEnd: ${time.endTimeOffset.seconds || 0}.` +
        `${(time.endTimeOffset.nanos / 1e6).toFixed(0)}s`
    );
    console.log(`\tConfidence: ${segment.confidence}`);
    segment.frames.forEach(frame => {
      const timeOffset = frame.timeOffset;
      console.log(
        `Time offset for the frame: ${timeOffset.seconds || 0}` +
          `.${(timeOffset.nanos / 1e6).toFixed(0)}s`
      );
      console.log('Rotated Bounding Box Vertices:');
      frame.rotatedBoundingBox.vertices.forEach(vertex => {
        console.log(`Vertex.x:${vertex.x}, Vertex.y:${vertex.y}`);
      });
    });
  });
});

PHP

use Google\Cloud\VideoIntelligence\V1\AnnotateVideoRequest;
use Google\Cloud\VideoIntelligence\V1\Client\VideoIntelligenceServiceClient;
use Google\Cloud\VideoIntelligence\V1\Feature;

/**
 * @param string $path   File path to a video file to analyze
 * @param int $pollingIntervalSeconds
 */
function analyze_text_detection_file(string $path, int $pollingIntervalSeconds = 0)
{
    # Instantiate a client.
    $video = new VideoIntelligenceServiceClient();

    # Read the local video file
    $inputContent = file_get_contents($path);

    # Execute a request.
    $features = [Feature::TEXT_DETECTION];
    $request = (new AnnotateVideoRequest())
        ->setInputContent($inputContent)
        ->setFeatures($features);
    $operation = $video->annotateVideo($request);

    # Wait for the request to complete.
    $operation->pollUntilComplete([
        'pollingIntervalSeconds' => $pollingIntervalSeconds
    ]);

    # Print the results.
    if ($operation->operationSucceeded()) {
        $results = $operation->getResult()->getAnnotationResults()[0];

        # Process video/segment level label annotations
        foreach ($results->getTextAnnotations() as $text) {
            printf('Video text description: %s' . PHP_EOL, $text->getText());
            foreach ($text->getSegments() as $segment) {
                $start = $segment->getSegment()->getStartTimeOffset();
                $end = $segment->getSegment()->getEndTimeOffset();
                printf('  Segment: %ss to %ss' . PHP_EOL,
                    $start->getSeconds() + $start->getNanos() / 1000000000.0,
                    $end->getSeconds() + $end->getNanos() / 1000000000.0);
                printf('  Confidence: %f' . PHP_EOL, $segment->getConfidence());
            }
        }
        print(PHP_EOL);
    } else {
        print_r($operation->getError());
    }
}

Python

import io

from google.cloud import videointelligence

def video_detect_text(path):
    """Detect text in a local video."""
    video_client = videointelligence.VideoIntelligenceServiceClient()
    features = [videointelligence.Feature.TEXT_DETECTION]
    video_context = videointelligence.VideoContext()

    with io.open(path, "rb") as file:
        input_content = file.read()

    operation = video_client.annotate_video(
        request={
            "features": features,
            "input_content": input_content,
            "video_context": video_context,
        }
    )

    print("\nProcessing video for text detection.")
    result = operation.result(timeout=300)

    # The first result is retrieved because a single video was processed.
    annotation_result = result.annotation_results[0]

    for text_annotation in annotation_result.text_annotations:
        print("\nText: {}".format(text_annotation.text))

        # Get the first text segment
        text_segment = text_annotation.segments[0]
        start_time = text_segment.segment.start_time_offset
        end_time = text_segment.segment.end_time_offset
        print(
            "start_time: {}, end_time: {}".format(
                start_time.seconds + start_time.microseconds * 1e-6,
                end_time.seconds + end_time.microseconds * 1e-6,
            )
        )

        print("Confidence: {}".format(text_segment.confidence))

        # Show the result for the first frame in this segment.
        frame = text_segment.frames[0]
        time_offset = frame.time_offset
        print(
            "Time offset for the first frame: {}".format(
                time_offset.seconds + time_offset.microseconds * 1e-6
            )
        )
        print("Rotated Bounding Box Vertices:")
        for vertex in frame.rotated_bounding_box.vertices:
            print("\tVertex.x: {}, Vertex.y: {}".format(vertex.x, vertex.y))

Passaggi successivi

Per cercare e filtrare esempi di codice per altri prodotti Google Cloud, consulta il browser di esempio Google Cloud.