离线批量图片注释

Vision API 可以使用任何 Vision 特征类型运行离线（异步）检测服务和大批量图片文件注释。例如，您可以为一批图片指定一个或多个 Vision API 特征（例如 TEXT_DETECTION、LABEL_DETECTION 和 LANDMARK_DETECTION）。

离线批量请求的输出将写入在指定 Cloud Storage 存储桶中创建的 JSON 文件中。

注意：所有 Vision API 特征类型还提供在线同步批量图片注释。在线同步请求会立即响应注释请求。如需了解详情，请参阅方法页面。

• 在线（同步）请求 - 在线注释请求（images:annotate 或 files:annotate）会立即将内嵌注释返回给用户。在线注释请求限制了您可以在单个请求中添加注释的文件数量。使用 images:annotate 请求时，您只能指定少量要添加注释的图片 (<=16)；使用 files:annotate 请求时，您只能指定单个文件，并指定该文件中要添加注释的少量页面 (<=5)。
• 离线（异步）请求 - 离线注释请求（images:asyncBatchAnnotate 或 files:asyncBatchAnnotate）会启动长时间运行的操作 (LRO)，并且不会立即向调用方返回响应。当 LRO 完成后，注释会作为文件存储在您指定的 Cloud Storage 存储桶中。通过 images:asyncBatchAnnotate 请求，您可以为每个请求指定最多 2000 张图片；与在线请求相比，files:asyncBatchAnnotate 请求允许您指定更大批量的文件，并且一次可以为每个文件指定更多页面（<=2000）进行注释。

限制

Vision API 最多可接受 2000 个图片文件。批量图片文件数量超过该限制会返回错误。

注意：如果批量请求中有 Cloud Vision 未成功处理的文件，请重新提交处理失败的文件，以避免为成功处理的文件付费。

目前支持的特征类型

特征类型
CROP_HINTS	确定图片的建议剪裁区域顶点。
DOCUMENT_TEXT_DETECTION	对文档 (PDF/TIFF) 等包含密集文本的图片和包含手写内容的图片执行 OCR。TEXT_DETECTION 可用于包含稀疏文本的图片。 如果同时存在 DOCUMENT_TEXT_DETECTION 和 TEXT_DETECTION，则优先考虑。
FACE_DETECTION	检测图片中的人脸。
IMAGE_PROPERTIES	计算一组图片属性，例如图片的主色。
LABEL_DETECTION	根据图片内容添加标签。
LANDMARK_DETECTION	检测图片中的地标。
LOGO_DETECTION	检测图片中的公司徽标。
OBJECT_LOCALIZATION	检测并提取图片中的多个对象。
SAFE_SEARCH_DETECTION	运行安全搜索可检测可能不安全的内容或不良内容。
TEXT_DETECTION	对图片中的文本执行光学字符识别 (OCR)。 文本检测针对大型图片中的稀疏文本区域进行了优化。 如果图片为文档 (PDF/TIFF)、包含密集文本或包含手写内容，请改用 DOCUMENT_TEXT_DETECTION。
WEB_DETECTION	检测图片中的新闻、事件或名人等主题实体，并借助强大的 Google 图片搜索在网络上查找相似的图片。

示例代码

使用以下代码示例对 Cloud Storage 中的一批图片文件运行离线注释服务。

注意：在以下代码示例中，每个请求元素 (requests_element/requestsElement) 对应一张图片。如果要为更多图片添加注释，请为每个图片创建一个请求元素，并将其添加到请求数组 (requests) 中。

Java

在试用此示例之前，请按照Vision API 快速入门：使用客户端库中的 Java 设置说明进行操作。如需了解详情，请参阅 Vision API Java 参考文档。

注意：对于 Java Spring 框架用户，Spring Cloud Google Cloud 提供了一种身份验证设置和客户端对象的自动配置方法来使用 Vision API。

import com.google.cloud.vision.v1.AnnotateImageRequest;
import com.google.cloud.vision.v1.AsyncBatchAnnotateImagesRequest;
import com.google.cloud.vision.v1.AsyncBatchAnnotateImagesResponse;
import com.google.cloud.vision.v1.Feature;
import com.google.cloud.vision.v1.GcsDestination;
import com.google.cloud.vision.v1.Image;
import com.google.cloud.vision.v1.ImageAnnotatorClient;
import com.google.cloud.vision.v1.ImageSource;
import com.google.cloud.vision.v1.OutputConfig;
import java.io.IOException;
import java.util.concurrent.ExecutionException;

public class AsyncBatchAnnotateImages {

  public static void asyncBatchAnnotateImages()
      throws InterruptedException, ExecutionException, IOException {
    String inputImageUri = "gs://cloud-samples-data/vision/label/wakeupcat.jpg";
    String outputUri = "gs://YOUR_BUCKET_ID/path/to/save/results/";
    asyncBatchAnnotateImages(inputImageUri, outputUri);
  }

  public static void asyncBatchAnnotateImages(String inputImageUri, String outputUri)
      throws IOException, ExecutionException, InterruptedException {
    // 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 imageAnnotatorClient = ImageAnnotatorClient.create()) {

      // You can send multiple images to be annotated, this sample demonstrates how to do this with
      // one image. If you want to use multiple images, you have to create a `AnnotateImageRequest`
      // object for each image that you want annotated.
      // First specify where the vision api can find the image
      ImageSource source = ImageSource.newBuilder().setImageUri(inputImageUri).build();
      Image image = Image.newBuilder().setSource(source).build();

      // Set the type of annotation you want to perform on the image
      // https://cloud.google.com/vision/docs/reference/rpc/google.cloud.vision.v1#google.cloud.vision.v1.Feature.Type
      Feature feature = Feature.newBuilder().setType(Feature.Type.LABEL_DETECTION).build();

      // Build the request object for that one image. Note: for additional images you have to create
      // additional `AnnotateImageRequest` objects and store them in a list to be used below.
      AnnotateImageRequest imageRequest =
          AnnotateImageRequest.newBuilder().setImage(image).addFeatures(feature).build();

      // Set where to store the results for the images that will be annotated.
      GcsDestination gcsDestination = GcsDestination.newBuilder().setUri(outputUri).build();
      OutputConfig outputConfig =
          OutputConfig.newBuilder()
              .setGcsDestination(gcsDestination)
              .setBatchSize(2) // The max number of responses to output in each JSON file
              .build();

      // Add each `AnnotateImageRequest` object to the batch request and add the output config.
      AsyncBatchAnnotateImagesRequest request =
          AsyncBatchAnnotateImagesRequest.newBuilder()
              .addRequests(imageRequest)
              .setOutputConfig(outputConfig)
              .build();

      // Make the asynchronous batch request.
      AsyncBatchAnnotateImagesResponse response =
          imageAnnotatorClient.asyncBatchAnnotateImagesAsync(request).get();

      // The output is written to GCS with the provided output_uri as prefix
      String gcsOutputUri = response.getOutputConfig().getGcsDestination().getUri();
      System.out.format("Output written to GCS with prefix: %s%n", gcsOutputUri);
    }
  }
}

Node.js

试用此示例之前，请按照《Vision 快速入门：使用客户端库》中的 Node.js 设置说明进行操作。 如需了解详情，请参阅 Vision Node.js API 参考文档。

如需向 Vision 进行身份验证，请设置应用默认凭据。 如需了解详情，请参阅为本地开发环境设置身份验证。

/**
 * TODO(developer): Uncomment these variables before running the sample.
 */
// const inputImageUri = 'gs://cloud-samples-data/vision/label/wakeupcat.jpg';
// const outputUri = 'gs://YOUR_BUCKET_ID/path/to/save/results/';

// Imports the Google Cloud client libraries
const {ImageAnnotatorClient} = require('@google-cloud/vision').v1;

// Instantiates a client
const client = new ImageAnnotatorClient();

// You can send multiple images to be annotated, this sample demonstrates how to do this with
// one image. If you want to use multiple images, you have to create a request object for each image that you want annotated.
async function asyncBatchAnnotateImages() {
  // Set the type of annotation you want to perform on the image
  // https://cloud.google.com/vision/docs/reference/rpc/google.cloud.vision.v1#google.cloud.vision.v1.Feature.Type
  const features = [{type: 'LABEL_DETECTION'}];

  // Build the image request object for that one image. Note: for additional images you have to create
  // additional image request objects and store them in a list to be used below.
  const imageRequest = {
    image: {
      source: {
        imageUri: inputImageUri,
      },
    },
    features: features,
  };

  // Set where to store the results for the images that will be annotated.
  const outputConfig = {
    gcsDestination: {
      uri: outputUri,
    },
    batchSize: 2, // The max number of responses to output in each JSON file
  };

  // Add each image request object to the batch request and add the output config.
  const request = {
    requests: [
      imageRequest, // add additional request objects here
    ],
    outputConfig,
  };

  // Make the asynchronous batch request.
  const [operation] = await client.asyncBatchAnnotateImages(request);

  // Wait for the operation to complete
  const [filesResponse] = await operation.promise();

  // The output is written to GCS with the provided output_uri as prefix
  const destinationUri = filesResponse.outputConfig.gcsDestination.uri;
  console.log(`Output written to GCS with prefix: ${destinationUri}`);
}

asyncBatchAnnotateImages();

Python

试用此示例之前，请按照《Vision 快速入门：使用客户端库》中的 Python 设置说明进行操作。 如需了解详情，请参阅 Vision Python API 参考文档。

如需向 Vision 进行身份验证，请设置应用默认凭据。 如需了解详情，请参阅为本地开发环境设置身份验证。

from google.cloud import vision_v1


def sample_async_batch_annotate_images(
    input_image_uri="gs://cloud-samples-data/vision/label/wakeupcat.jpg",
    output_uri="gs://your-bucket/prefix/",
):
    """Perform async batch image annotation."""
    client = vision_v1.ImageAnnotatorClient()

    source = {"image_uri": input_image_uri}
    image = {"source": source}
    features = [
        {"type_": vision_v1.Feature.Type.LABEL_DETECTION},
        {"type_": vision_v1.Feature.Type.IMAGE_PROPERTIES},
    ]

    # Each requests element corresponds to a single image.  To annotate more
    # images, create a request element for each image and add it to
    # the array of requests
    requests = [{"image": image, "features": features}]
    gcs_destination = {"uri": output_uri}

    # The max number of responses to output in each JSON file
    batch_size = 2
    output_config = {"gcs_destination": gcs_destination, "batch_size": batch_size}

    operation = client.async_batch_annotate_images(
        requests=requests, output_config=output_config
    )

    print("Waiting for operation to complete...")
    response = operation.result(90)

    # The output is written to GCS with the provided output_uri as prefix
    gcs_output_uri = response.output_config.gcs_destination.uri
    print(f"Output written to GCS with prefix: {gcs_output_uri}")

响应

如果请求成功，则将响应 JSON 文件返回到代码示例所指定的 Cloud Storage 存储桶中。每个 JSON 文件的响应数量由代码示例中的 batch_size 决定。

返回的响应与常规 Vision API 特征响应类似，具体取决于您请求的图片特征。

以下响应显示了 image1.png 的 LABEL_DETECTION 和 TEXT_DETECTION 注释、image2.jpg 的 IMAGE_PROPERTIES 的注释以及 image3.jpg 的 OBJECT_LOCALIZATION 注释。

该响应还包含一个显示文件 URI 的 context 字段。

offline_batch_output/output-1-to-2.json

{
  "responses": [
    {
      "labelAnnotations": [
        {
          "mid": "/m/07s6nbt",
          "description": "Text",
          "score": 0.93413997,
          "topicality": 0.93413997
        },
        {
          "mid": "/m/0dwx7",
          "description": "Logo",
          "score": 0.8733531,
          "topicality": 0.8733531
        },
        ...
        {
          "mid": "/m/03bxgrp",
          "description": "Company",
          "score": 0.5682425,
          "topicality": 0.5682425
        }
      ],
      "textAnnotations": [
        {
          "locale": "en",
          "description": "Google\n",
          "boundingPoly": {
            "vertices": [
              {
                "x": 72,
                "y": 40
              },
              {
                "x": 613,
                "y": 40
              },
              {
                "x": 613,
                "y": 233
              },
              {
                "x": 72,
                "y": 233
              }
            ]
          }
        },
        ...
                ],
                "blockType": "TEXT"
              }
            ]
          }
        ],
        "text": "Google\n"
      },
      "context": {
        "uri": "gs://cloud-samples-data/vision/document_understanding/image1.png"
      }
    },
    {
      "imagePropertiesAnnotation": {
        "dominantColors": {
          "colors": [
            {
              "color": {
                "red": 229,
                "green": 230,
                "blue": 238
              },
              "score": 0.2744754,
              "pixelFraction": 0.075339235
            },
            ...
            {
              "color": {
                "red": 86,
                "green": 87,
                "blue": 95
              },
              "score": 0.025770646,
              "pixelFraction": 0.13109145
            }
          ]
        }
      },
      "cropHintsAnnotation": {
        "cropHints": [
          {
            "boundingPoly": {
              "vertices": [
                {},
                {
                  "x": 1599
                },
                {
                  "x": 1599,
                  "y": 1199
                },
                {
                  "y": 1199
                }
              ]
            },
            "confidence": 0.79999995,
            "importanceFraction": 1
          }
        ]
      },
      "context": {
        "uri": "gs://cloud-samples-data/vision/document_understanding/image2.jpg"
      }
    }
  ]
}

offline_batch_output/output-3-to-3.json

{
  "responses": [
    {
      "context": {
        "uri": "gs://cloud-samples-data/vision/document_understanding/image3.jpg"
      },
      "localizedObjectAnnotations": [
        {
          "mid": "/m/0bt9lr",
          "name": "Dog",
          "score": 0.9669734,
          "boundingPoly": {
            "normalizedVertices": [
              {
                "x": 0.6035543,
                "y": 0.1357359
              },
              {
                "x": 0.98546547,
                "y": 0.1357359
              },
              {
                "x": 0.98546547,
                "y": 0.98426414
              },
              {
                "x": 0.6035543,
                "y": 0.98426414
              }
            ]
          }
        },
        ...
        {
          "mid": "/m/0jbk",
          "name": "Animal",
          "score": 0.58003056,
          "boundingPoly": {
            "normalizedVertices": [
              {
                "x": 0.014534635,
                "y": 0.1357359
              },
              {
                "x": 0.37197515,
                "y": 0.1357359
              },
              {
                "x": 0.37197515,
                "y": 0.98426414
              },
              {
                "x": 0.014534635,
                "y": 0.98426414
              }
            ]
          }
        }
      ]
    }
  ]
}