偵測圖片中的標籤

對圖片執行標籤偵測。

深入探索

如需包含這個程式碼範例的詳細說明文件，請參閱下列文章：

• 快速入門導覽課程：使用用戶端程式庫偵測圖片中的標籤
• Vision 用戶端程式庫

程式碼範例

Go

在試用這個範例之前，請先按照「使用用戶端程式庫的 Vision 快速入門導覽課程」中的 Go 設定說明操作。詳情請參閱 Vision Go API 參考文件。

如要向 Vision 進行驗證，請設定應用程式預設憑證。詳情請參閱「為本機開發環境設定驗證機制」。

// Sample vision-quickstart uses the Google Cloud Vision API to label an image.
package main

import (
	"context"
	"fmt"
	"log"
	"os"

	vision "cloud.google.com/go/vision/apiv1"
)

func main() {
	ctx := context.Background()

	// Creates a client.
	client, err := vision.NewImageAnnotatorClient(ctx)
	if err != nil {
		log.Fatalf("Failed to create client: %v", err)
	}
	defer client.Close()

	// Sets the name of the image file to annotate.
	filename := "../testdata/cat.jpg"

	file, err := os.Open(filename)
	if err != nil {
		log.Fatalf("Failed to read file: %v", err)
	}
	defer file.Close()
	image, err := vision.NewImageFromReader(file)
	if err != nil {
		log.Fatalf("Failed to create image: %v", err)
	}

	labels, err := client.DetectLabels(ctx, image, nil, 10)
	if err != nil {
		log.Fatalf("Failed to detect labels: %v", err)
	}

	fmt.Println("Labels:")
	for _, label := range labels {
		fmt.Println(label.Description)
	}
}

Java

在試用這個範例之前，請先按照「使用用戶端程式庫的 Vision 快速入門導覽課程」中的 Java 設定說明操作。詳情請參閱 Vision Java API 參考文件。

如要向 Vision 進行驗證，請設定應用程式預設憑證。詳情請參閱「為本機開發環境設定驗證機制」。

// Imports the Google Cloud client library

import com.google.cloud.vision.v1.AnnotateImageRequest;
import com.google.cloud.vision.v1.AnnotateImageResponse;
import com.google.cloud.vision.v1.BatchAnnotateImagesResponse;
import com.google.cloud.vision.v1.EntityAnnotation;
import com.google.cloud.vision.v1.Feature;
import com.google.cloud.vision.v1.Feature.Type;
import com.google.cloud.vision.v1.Image;
import com.google.cloud.vision.v1.ImageAnnotatorClient;
import com.google.protobuf.ByteString;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;

public class QuickstartSample {
  public static void main(String... args) throws Exception {
    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests. After completing all of your requests, call
    // the "close" method on the client to safely clean up any remaining background resources.
    try (ImageAnnotatorClient vision = ImageAnnotatorClient.create()) {

      // The path to the image file to annotate
      String fileName = "./resources/wakeupcat.jpg";

      // Reads the image file into memory
      Path path = Paths.get(fileName);
      byte[] data = Files.readAllBytes(path);
      ByteString imgBytes = ByteString.copyFrom(data);

      // Builds the image annotation request
      List<AnnotateImageRequest> requests = new ArrayList<>();
      Image img = Image.newBuilder().setContent(imgBytes).build();
      Feature feat = Feature.newBuilder().setType(Type.LABEL_DETECTION).build();
      AnnotateImageRequest request =
          AnnotateImageRequest.newBuilder().addFeatures(feat).setImage(img).build();
      requests.add(request);

      // Performs label detection on the image file
      BatchAnnotateImagesResponse response = vision.batchAnnotateImages(requests);
      List<AnnotateImageResponse> responses = response.getResponsesList();

      for (AnnotateImageResponse res : responses) {
        if (res.hasError()) {
          System.out.format("Error: %s%n", res.getError().getMessage());
          return;
        }

        for (EntityAnnotation annotation : res.getLabelAnnotationsList()) {
          annotation
              .getAllFields()
              .forEach((k, v) -> System.out.format("%s : %s%n", k, v.toString()));
        }
      }
    }
  }
}

Kotlin

import com.google.api.gax.rpc.ApiException
import com.google.api.gax.rpc.InvalidArgumentException
import com.google.cloud.vision.v1.AnnotateImageRequest
import com.google.cloud.vision.v1.Feature
import com.google.cloud.vision.v1.Image
import com.google.cloud.vision.v1.ImageAnnotatorClient
import com.google.cloud.vision.v1.ImageSource
import java.io.IOException

/**
 * Detects labels in an image stored in Google Cloud Storage using Cloud Vision.
 * Referencing a Cloud Storage URI avoids transferring raw image bytes from the
 * client workstation.
 *
 * @param gcsUri Cloud Storage URI of the target image (for example, "gs://example-bucket/example-image.jpg").
 */
fun annotateImage(gcsUri: String) {
  val imageSource = ImageSource.newBuilder().setGcsImageUri(gcsUri).build()
  val image = Image.newBuilder().setSource(imageSource).build()

  // Limit label detection to 5 results to return only high-confidence annotations.
  val feature =
    Feature.newBuilder()
      .setType(Feature.Type.LABEL_DETECTION)
      .setMaxResults(5)
      .build()
  val request =
      AnnotateImageRequest.newBuilder()
        .addFeatures(feature)
        .setImage(image)
        .build()

  try {
    ImageAnnotatorClient.create().use { client ->
      val response = client.batchAnnotateImages(listOf(request))
      val imageResponse = response.responsesList.firstOrNull()

      if (imageResponse == null) {
        System.err.println(
          "error: no response received from Vision API for image '$gcsUri'"
        )
      } else if (imageResponse.hasError()) {
        System.err.println(
          "error: annotation failed for image '$gcsUri': ${imageResponse.error.message}"
        )
      } else {
        println("Resource ID: $gcsUri")
        println("Annotation Count: ${imageResponse.labelAnnotationsCount}")
        for (annotation in imageResponse.labelAnnotationsList) {
          println("Description: ${annotation.description}")
          println("Mid: ${annotation.mid}")
          println("Score: ${annotation.score}")
        }
      }
    }
  } catch (err: InvalidArgumentException) {
    System.err.println(
      "error: invalid annotation request for image '$gcsUri': ${err.message}"
    )
  } catch (err: ApiException) {
    System.err.println(
      "error: failed to annotate image '$gcsUri': ${err.message}"
    )
  } catch (err: IOException) {
    System.err.println(
      "error: failed to initialize Vision client for image '$gcsUri': ${err.message}"
    )
  }
}

Node.js

在試用這個範例之前，請先按照「使用用戶端程式庫的 Vision 快速入門導覽課程」中的 Node.js 設定說明操作。詳情請參閱 Vision Node.js API 參考文件。

如要向 Vision 進行驗證，請設定應用程式預設憑證。詳情請參閱「為本機開發環境設定驗證機制」。

async function quickstart() {
  // Imports the Google Cloud client library
  const vision = require('@google-cloud/vision');

  // Creates a client
  const client = new vision.ImageAnnotatorClient();

  // Performs label detection on the image file
  const [result] = await client.labelDetection('./resources/wakeupcat.jpg');
  const labels = result.labelAnnotations;
  console.log('Labels:');
  labels.forEach(label => console.log(label.description));
}
quickstart();

PHP

在試用這個範例之前，請先按照「使用用戶端程式庫的 Vision 快速入門導覽課程」中的 PHP 設定說明操作。詳情請參閱 Vision PHP API 參考文件。

如要向 Vision 進行驗證，請設定應用程式預設憑證。詳情請參閱「為本機開發環境設定驗證機制」。

# includes the autoloader for libraries installed with composer
require __DIR__ . '/vendor/autoload.php';

# imports the Google Cloud client library
use Google\Cloud\Vision\V1\Client\ImageAnnotatorClient;

# instantiates a client
$imageAnnotator = new ImageAnnotatorClient();

# the name of the image file to annotate
$fileName = 'test/data/wakeupcat.jpg';

# prepare the image to be annotated
$image = file_get_contents($fileName);

# performs label detection on the image file
$response = $imageAnnotator->labelDetection($image);
$labels = $response->getLabelAnnotations();

if ($labels) {
    echo('Labels:' . PHP_EOL);
    foreach ($labels as $label) {
        echo($label->getDescription() . PHP_EOL);
    }
} else {
    echo('No label found' . PHP_EOL);
}

Python

在試用這個範例之前，請先按照「使用用戶端程式庫的 Vision 快速入門導覽課程」中的 Python 設定說明操作。詳情請參閱 Vision Python API 參考文件。

如要向 Vision 進行驗證，請設定應用程式預設憑證。詳情請參閱「為本機開發環境設定驗證機制」。

# Imports the Google Cloud client library
from google.cloud import vision



def run_quickstart() -> vision.EntityAnnotation:
    """Provides a quick start example for Cloud Vision."""

    # Instantiates a client
    client = vision.ImageAnnotatorClient()

    # The URI of the image file to annotate
    file_uri = "gs://cloud-samples-data/vision/label/wakeupcat.jpg"

    image = vision.Image()
    image.source.image_uri = file_uri

    # Performs label detection on the image file
    response = client.label_detection(image=image)
    labels = response.label_annotations

    print("Labels:")
    for label in labels:
        print(label.description)

    return labels

後續步驟

如要搜尋及篩選其他 Google Cloud 產品的程式碼範例，請參閱Google Cloud 範例瀏覽工具。