使用扩绘功能扩展图片内容

本页介绍了如何使用扩绘功能将图片的内容扩展到更大的区域或者具有不同尺寸的区域。

以下模型支持扩图：

• imagen-3.0-capability-001

扩绘示例

扩绘是一种基于蒙版的修改方法，可让您扩展基础图片的内容，以适合更大或不同大小的蒙版画布。

查看 Imagen for Editing and Customization 模型卡片

准备工作

登录您的 Google Cloud 账号。如果您是 Google Cloud新手，请 创建一个账号来评估我们的产品在实际场景中的表现。新客户还可获享 $300 赠金，用于运行、测试和部署工作负载。

In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

Roles required to select or create a project

• Select a project: Selecting a project doesn't require a specific IAM role—you can select any project that you've been granted a role on.
• Create a project: To create a project, you need the Project Creator role (roles/resourcemanager.projectCreator), which contains the resourcemanager.projects.create permission. Learn how to grant roles.

Go to project selector

Verify that billing is enabled for your Google Cloud project.

Enable the Vertex AI API, if it is not already enabled.

Roles required to enable APIs

To enable APIs, you need the serviceusage.services.enable permission. If you created the project, then you likely already have this permission through the Owner role (roles/owner). Otherwise, you can get this permission through the Service Usage Admin role (roles/serviceusage.serviceUsageAdmin). Learn how to grant roles.

Enable the API

In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

Roles required to select or create a project

• Select a project: Selecting a project doesn't require a specific IAM role—you can select any project that you've been granted a role on.
• Create a project: To create a project, you need the Project Creator role (roles/resourcemanager.projectCreator), which contains the resourcemanager.projects.create permission. Learn how to grant roles.

Go to project selector

Verify that billing is enabled for your Google Cloud project.

Enable the Vertex AI API, if it is not already enabled.

Roles required to enable APIs

To enable APIs, you need the serviceusage.services.enable permission. If you created the project, then you likely already have this permission through the Owner role (roles/owner). Otherwise, you can get this permission through the Service Usage Admin role (roles/serviceusage.serviceUsageAdmin). Learn how to grant roles.

Enable the API

1. 为您的环境设置身份验证。

   选择标签页以了解您打算如何使用本页面上的示例：

   控制台

   当您使用 Google Cloud 控制台访问 Google Cloud 服务和 API 时，无需设置身份验证。

   REST

   如需在本地开发环境中使用本页面上的 REST API 示例，请使用您提供给 gcloud CLI 的凭证。

   安装 Google Cloud CLI。

   如果您使用的是外部身份提供方 (IdP)，则必须先使用联合身份登录 gcloud CLI。

   如需了解详情，请参阅 Google Cloud 身份验证文档中的使用 REST 时进行身份验证。

扩展图片的内容

使用以下代码示例扩展现有图片的内容。

POST https://LOCATION-aiplatform.googleapis.com/v1/projects/PROJECT_ID/locations/LOCATION/publishers/google/models/imagen-3.0-capability-001:predict

{
  "instances": [
    {
      "prompt": "",
      "referenceImages": [
        {
          "referenceType": "REFERENCE_TYPE_RAW",
          "referenceId": 1,
          "referenceImage": {
            "bytesBase64Encoded": "B64_BASE_IMAGE"
          }
        },
        {
          "referenceType": "REFERENCE_TYPE_MASK",
          "referenceId": 2,
          "referenceImage": {
            "bytesBase64Encoded": "B64_OUTPAINTING_MASK"
          },
          "maskImageConfig": {
            "maskMode": "MASK_MODE_USER_PROVIDED",
            "dilation": MASK_DILATION
          }
        }
      ]
    }
  ],
  "parameters": {
    "editConfig": {
      "baseSteps": EDIT_STEPS
    },
    "editMode": "EDIT_MODE_OUTPAINT",
    "sampleCount": EDIT_IMAGE_COUNT
  }
}

curl -X POST \
     -H "Authorization: Bearer $(gcloud auth print-access-token)" \
     -H "Content-Type: application/json; charset=utf-8" \
     -d @request.json \
     "https://LOCATION-aiplatform.googleapis.com/v1/projects/PROJECT_ID/locations/LOCATION/publishers/google/models/imagen-3.0-capability-001:predict"

$cred = gcloud auth print-access-token
$headers = @{ "Authorization" = "Bearer $cred" }

Invoke-WebRequest `
    -Method POST `
    -Headers $headers `
    -ContentType: "application/json; charset=utf-8" `
    -InFile request.json `
    -Uri "https://LOCATION-aiplatform.googleapis.com/v1/projects/PROJECT_ID/locations/LOCATION/publishers/google/models/imagen-3.0-capability-001:predict" | Select-Object -Expand Content

{
  "predictions": [
    {
      "bytesBase64Encoded": "BASE64_IMG_BYTES",
      "mimeType": "image/png"
    },
    {
      "mimeType": "image/png",
      "bytesBase64Encoded": "BASE64_IMG_BYTES"
    }
  ]
}

限制

如果扩绘后的图片扩大到原始图片大小的 200% 或更大，模型可能会生成失真的细节。根据最佳实践，我们建议添加一个后处理步骤，以对扩绘后的图片运行 Alpha 混合。

以下代码展示了后处理的示例：

parameters = {
   "editConfig": {
       "outpaintingConfig": {
         "blendingMode": "alpha-blending",
         "blendingFactor": 0.01,
       },
   },
}

后续步骤

阅读有关 Imagen 和其他 Vertex AI 上的生成式 AI 产品的文章：

• Imagen 3 on Vertex AI 开发者入门指南
• 与创作者一起为创作者打造的全新生成式媒体模型和工具
• Gemini 中的新功能：自定义 Gem 以及通过 Imagen 3 改进的图片生成
• Google DeepMind：Imagen 3 - 我们质量最高的文本转图片模型