使用命令行检测图片中的标签

使用命令行检测图片中的标签

本页面展示如何使用 REST 接口和 curl 命令向 Vision API 发送三个特征检测和注释请求。

通过 Vision API，可将 Google 视觉识别技术轻松集成到开发者应用中。您可以将图片数据和所需的特征类型发送给 Vision API，后者会根据您感兴趣的图片特性返回相应的响应。如需详细了解 Vision API 提供的特征类型，请参阅所有 Vision API 特征列表。

准备工作

1. Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.
2. Install the Google Cloud CLI.

3. To initialize the gcloud CLI, run the following command:

   gcloud init

4. Create or select a Google Cloud project.

   Note: If you don't plan to keep the resources that you create in this procedure, create a project instead of selecting an existing project. After you finish these steps, you can delete the project, removing all resources associated with the project.

   • Create a Google Cloud project:

     gcloud projects create PROJECT_ID

     Replace PROJECT_ID with a name for the Google Cloud project you are creating.

   • Select the Google Cloud project that you created:

     gcloud config set project PROJECT_ID

     Replace PROJECT_ID with your Google Cloud project name.

5. Make sure that billing is enabled for your Google Cloud project.

6. Enable the Vision API:

   gcloud services enable vision.googleapis.com

7. Grant roles to your user account. Run the following command once for each of the following IAM roles: roles/storage.objectViewer

   gcloud projects add-iam-policy-binding PROJECT_ID --member="user:USER_IDENTIFIER" --role=ROLE

   • Replace PROJECT_ID with your project ID.

   • Replace USER_IDENTIFIER with the identifier for your user account. For example, user:[e-mail].

   • Replace ROLE with each individual role.
8. Install the Google Cloud CLI.

9. To initialize the gcloud CLI, run the following command:

   gcloud init

10. Create or select a Google Cloud project.

    Note: If you don't plan to keep the resources that you create in this procedure, create a project instead of selecting an existing project. After you finish these steps, you can delete the project, removing all resources associated with the project.

    • Create a Google Cloud project:

      gcloud projects create PROJECT_ID

      Replace PROJECT_ID with a name for the Google Cloud project you are creating.

    • Select the Google Cloud project that you created:

      gcloud config set project PROJECT_ID

      Replace PROJECT_ID with your Google Cloud project name.

11. Make sure that billing is enabled for your Google Cloud project.

12. Enable the Vision API:

    gcloud services enable vision.googleapis.com

13. Grant roles to your user account. Run the following command once for each of the following IAM roles: roles/storage.objectViewer

    gcloud projects add-iam-policy-binding PROJECT_ID --member="user:USER_IDENTIFIER" --role=ROLE

    • Replace PROJECT_ID with your project ID.

    • Replace USER_IDENTIFIER with the identifier for your user account. For example, user:[e-mail].

    • Replace ROLE with each individual role.

发出图片注释请求

完成准备工作步骤后，就可以使用 Vision API 对图片文件进行注释了。

在以下示例中，您将使用下面的图片，通过 curl 向 Vision API 发送请求：

Cloud Storage URI：

gs://cloud-samples-data/vision/using_curl/shanghai.jpeg

HTTPS 网址：

https://console.cloud.google.com/storage/browser/cloud-samples-data/vision/using_curl/shanghai.jpeg

图片来源：Steve Long (Unsplash)。

创建请求 JSON

以下 request.json 文件演示了如何请求三个 images:annotate 特征并限制响应中的结果。

创建包含以下文本的 JSON 请求文件，然后将其以 request.json 纯文本文件的格式保存在工作目录下：

request.json

{
  "requests": [
    {
      "image": {
        "source": {
          "imageUri": "gs://cloud-samples-data/vision/using_curl/shanghai.jpeg"
        }
      },
      "features": [
        {
          "type": "LABEL_DETECTION",
          "maxResults": 3
        },
        {
          "type": "OBJECT_LOCALIZATION",
          "maxResults": 1
        },
        {
          "type": "TEXT_DETECTION",
          "maxResults": 1,
          "model": "builtin/latest"
        }
      ]
    }
  ]
}

字段值详细信息

• image.source.gcsImageUri - 表示存储在 Cloud Storage 存储桶中的图片。您可以将此请求更改为 image.source.imageUri（如果图片 URI 为公开可用的 URI），或者更改为 image.content 以传递图片的 base64 编码字符串。
• features - 表示特定特征类型的对象。 您可以为单张图片请求多种特征类型。
• type - 用于指定特征的枚举值。
• maxResults（可选）- 用于限制返回结果的值。
• model（可选）- 如果适用，您可以指定 builtin/stable（如果未设置，则为默认值）或 builtin/latest 来选择模型。如需查看最近更新的模型列表，请参阅版本说明主题。

发送请求

您可以使用 request.json 中的正文内容和 curl 工具向 Vision API 发送请求。在命令行中输入以下内容：

curl -X POST \
    -H "Authorization: Bearer $(gcloud auth print-access-token)" \
    -H "x-goog-user-project: PROJECT_ID" \
    -H "Content-Type: application/json; charset=utf-8" \
    https://vision.googleapis.com/v1/images:annotate -d @request.json

• 示例 curl 命令使用 gcloud auth print-access-token 命令来获取身份验证令牌。
• 请注意，如需将文件名传递给 curl，您可以使用 -d 选项（表示“data”），并在文件名前面加上 @ 符号。此文件应该与您执行的 curl 命令位于同一目录中。

解读响应

您应该看到和下方类似的 JSON 响应。

该 JSON 格式的请求正文为每种注释类型指定了 maxResults。 因此，您将在响应 JSON 中看到以下内容：

• 三条 labelAnnotations 返回结果
• 一条 textAnnotations 返回结果（为简洁起见，这里省略了部分响应）
• 一条 localizedObjectAnnotations 返回结果

响应

Note: Zero coordinate values omitted. When the API detects a coordinate ("x" or "y") value of 0, that coordinate is omitted in the JSON response. Thus, a response with a bounding poly around the entire image would be
[{},{"x": 100},{"x": 100,"y": 100},{"y": 100}] for an image that is 100 pixels by 100 pixels. For more information, see the API Reference documentation.

{
  "responses": [
    {
      "labelAnnotations": [
        {
          "mid": "/m/09g5pq",
          "description": "People",
          "score": 0.9504782,
          "topicality": 0.9504782
        },
        {
          "mid": "/m/01c8br",
          "description": "Street",
          "score": 0.8911568,
          "topicality": 0.8911568
        },
        {
          "mid": "/m/079bkr",
          "description": "Mode of transport",
          "score": 0.89089024,
          "topicality": 0.89089024
        }
      ],
      "textAnnotations": [
        {
          "locale": "zh",
          "description": "牛牛面馆\n",
          "boundingPoly": {
            "vertices": [
              {
                "x": 159,
                "y": 212
              },
              {
                "x": 947,
                "y": 212
              },
              {
                "x": 947,
                "y": 354
              },
              {
                "x": 159,
                "y": 354
              }
            ]
          }
        },
        ...
      ],
      "fullTextAnnotation": {
        "pages": [
          {
            ...
                "paragraphs": [
                  {
                    ...
                    "words": [
                      {
                        ...
                        "symbols": [
                          {
                            ...
                ],
                "blockType": "TEXT"
              }
            ]
          }
        ],
        "text": "牛牛面馆\n"
      },
      "localizedObjectAnnotations": [
        {
          "mid": "/m/01g317",
          "name": "Person",
          "score": 0.94413143,
          "boundingPoly": {
            "normalizedVertices": [
              {
                "x": 0.26063988,
                "y": 0.46869153
              },
              {
                "x": 0.40736017,
                "y": 0.46869153
              },
              {
                "x": 0.40736017,
                "y": 0.8957791
              },
              {
                "x": 0.26063988,
                "y": 0.8957791
              }
            ]
          }
        }
      ]
    }
  ]
}

标签检测结果

1. 说明：“人物”，得分：0.950
2. 说明：“街道”，得分：0.891
3. 说明：“交通方式”，得分：0.890

图片来源：Steve Long (Unsplash)（已添加注释）。

文本检测结果

• 文本：牛牛面馆\n
• 顶点：(x: 159, y: 212)、(x: 947, y: 212)、(x: 947, y: 354)、(x: 159, y: 354)

图片来源：Steve Long (Unsplash)（已添加注释）。

对象检测结果

• 名称：“人”，得分：0.944
• 归一化顶点：(x: 0.260, y: 0.468)、(x: 0.407, y: 0.468)、(x: 0.407, y: 0.895)、(x: 0.260, y: 0.895)

图片来源：Steve Long (Unsplash)（已添加注释）。

恭喜！您已向 Vision API 发送了自己的第一个请求！

清理

为避免因本页面中使用的资源导致您的 Google Cloud 账号产生费用，请删除包含这些资源的 Google Cloud 项目。

Optional: Revoke credentials from the gcloud CLI.

gcloud auth revoke

后续步骤

• 查看所有特征类型及其用途的列表。
• 通过 Vision API 客户端库，以您选择的语言开始使用 Vision API。
• 通过方法指南详细了解特定特征，查看示例注释以及获取单个文件或图片的注释。
• 了解批量图片和文件 (PDF/TIFF/GIF) 注释。
• 浏览客户端库代码示例的完整列表。