进行单个预测

创建（训练）模型并将其部署后，您可以向它发出在线（或同步）预测请求。

在 GA 版本中，自定义模型的最长寿命为 18 个月。该时间期限过后，您必须创建并训练新模型，才能继续对内容进行分类。

在线（单个）预测示例

部署训练好的模型后，您可以使用 predict 方法请求图片预测，或使用界面获取预测注释。predict 方法将标签应用于图片中的对象边界框。

如果预测的框小于 10 x 10 像素，则模型预测性能会受到影响。

模型部署后即会产生费用。使用经过训练的模型进行预测后，如果您希望不再产生模型托管使用费，可以取消部署模型。

网页界面

1. 打开 AutoML Vision Object Detection 界面，然后点击左侧导航栏中的模型标签页（带有灯泡图标）以显示可用的模型。

   如需查看其他项目的模型，请从标题栏右上角的下拉列表中选择该项目。

2. 点击要用于为图片添加标签的模型所对应的行。

3. 如果模型尚未部署，请选择部署模型立即进行部署。

   您必须先部署模型才能使用在线预测。部署模型会产生费用。如需了解详情，请参阅价格页面。

4. 点击标题栏正下方的测试和使用标签页。

   

5. 点击上传图片，上传要标记的图片。

   

REST

如需测试预测，您必须先部署云托管的模型。

在使用任何请求数据之前，请先进行以下替换：

• project-id：您的 GCP 项目 ID。
• model-id：您的模型的 ID（从创建模型时返回的响应中获取）。此 ID 是模型名称的最后一个元素。 例如：
  • 模型名称：projects/project-id/locations/location-id/models/IOD4412217016962778756
  • 模型 ID：IOD4412217016962778756
• base64-encoded-image：二进制图片数据的 base64 表示（ASCII 字符串）。此字符串应类似于以下字符串：/9j/4QAYRXhpZgAA...9tAVx/zDQDlGxn//2Q==。如需了解详情，请访问 base64 编码主题。

特定于字段的注意事项：

• scoreThreshold - 一个介于 0 到 1 之间的值。系统将只显示分数阈值不小于此值的值。默认值为 0.5。
• maxBoundingBoxCount - 在响应中返回的边界框的最大数目（上限）。默认值为 100，最大值为 500。 该值受资源限制，并且可能会受到服务器的限制。

HTTP 方法和网址：

POST https://automl.googleapis.com/v1/projects/PROJECT_ID/locations/us-central1/models/MODEL_ID:predict

请求 JSON 正文：

{
  "payload": {
    "image": {
      "imageBytes": "BASE64_ENCODED_IMAGE"
    }
  },
  "params": {
    "scoreThreshold": "0.5",
    "maxBoundingBoxCount": "100"
  }
}

如需发送请求，请选择以下方式之一：

curl

注意：以下命令假定您已使用您的用户账号通过运行 gcloud init 或 gcloud auth login 登录 gcloud CLI，或者使用了 Cloud Shell，这会使您自动登录 gcloud CLI。您可以运行 gcloud auth list 来检查当前活跃的账号。

将请求正文保存在名为 request.json 的文件中，然后执行以下命令：

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" \
     -d @request.json \
     "https://automl.googleapis.com/v1/projects/PROJECT_ID/locations/us-central1/models/MODEL_ID:predict"

PowerShell

注意：以下命令假定您已使用您的用户账号通过运行 gcloud init 或 gcloud auth login 登录 gcloud CLI。您可以运行 gcloud auth list 来检查当前活跃的账号。

将请求正文保存在名为 request.json 的文件中，然后执行以下命令：

$cred = gcloud auth print-access-token
$headers = @{ "Authorization" = "Bearer $cred"; "x-goog-user-project" = "project-id" }

Invoke-WebRequest `
    -Method POST `
    -Headers $headers `
    -ContentType: "application/json; charset=utf-8" `
    -InFile request.json `
    -Uri "https://automl.googleapis.com/v1/projects/PROJECT_ID/locations/us-central1/models/MODEL_ID:predict" | Select-Object -Expand Content

输出以 JSON 格式返回。来自您的 AutoML Vision Object Detection 模型的预测包含在 payload 字段中：

• 对象的 boundingBox 由对角顶点指定。
• displayName 是由 AutoML Vision Object Detection 模型预测的对象标签。
• score 表示指定标签适用于图片的置信度。它的范围为 0（零置信度）到 1（高置信度）。

注意：零坐标值会被省略。当 API 检测到坐标（“x”或“y”）值为 0 时，该坐标值将在 JSON 响应中被省略。因此，整个图片周围的边界多边形所对应的响应将为
[{},{"x": 1,"y": 1}]。如需了解详情，请参阅方法：projects.locations.models.predict。

{
  "payload": [
    {
      "imageObjectDetection": {
        "boundingBox": {
          "normalizedVertices": [
            {
              "x": 0.034553755,
              "y": 0.015524037
            },
            {
              "x": 0.941527,
              "y": 0.9912563
            }
          ]
        },
        "score": 0.9997793
      },
      "displayName": "Salad"
    },
    {
      "imageObjectDetection": {
        "boundingBox": {
          "normalizedVertices": [
            {
              "x": 0.11737197,
              "y": 0.7098793
            },
            {
              "x": 0.510878,
              "y": 0.87987
            }
          ]
        },
        "score": 0.63219965
      },
      "displayName": "Tomato"
    }
  ]
}

Go

在试用此示例之前，请按照客户端库页面中与此编程语言对应的设置说明执行操作。

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

	automl "cloud.google.com/go/automl/apiv1"
	"cloud.google.com/go/automl/apiv1/automlpb"
)

// visionObjectDetectionPredict does a prediction for image classification.
func visionObjectDetectionPredict(w io.Writer, projectID string, location string, modelID string, filePath string) error {
	// projectID := "my-project-id"
	// location := "us-central1"
	// modelID := "IOD123456789..."
	// filePath := "path/to/image.jpg"

	ctx := context.Background()
	client, err := automl.NewPredictionClient(ctx)
	if err != nil {
		return fmt.Errorf("NewPredictionClient: %w", err)
	}
	defer client.Close()

	file, err := os.Open(filePath)
	if err != nil {
		return fmt.Errorf("Open: %w", err)
	}
	defer file.Close()
	bytes, err := ioutil.ReadAll(file)
	if err != nil {
		return fmt.Errorf("ReadAll: %w", err)
	}

	req := &automlpb.PredictRequest{
		Name: fmt.Sprintf("projects/%s/locations/%s/models/%s", projectID, location, modelID),
		Payload: &automlpb.ExamplePayload{
			Payload: &automlpb.ExamplePayload_Image{
				Image: &automlpb.Image{
					Data: &automlpb.Image_ImageBytes{
						ImageBytes: bytes,
					},
				},
			},
		},
		// Params is additional domain-specific parameters.
		Params: map[string]string{
			// score_threshold is used to filter the result.
			"score_threshold": "0.8",
		},
	}

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

	for _, payload := range resp.GetPayload() {
		fmt.Fprintf(w, "Predicted class name: %v\n", payload.GetDisplayName())
		fmt.Fprintf(w, "Predicted class score: %v\n", payload.GetImageObjectDetection().GetScore())
		boundingBox := payload.GetImageObjectDetection().GetBoundingBox()
		fmt.Fprintf(w, "Normalized vertices:\n")
		for _, vertex := range boundingBox.GetNormalizedVertices() {
			fmt.Fprintf(w, "\tX: %v, Y: %v\n", vertex.GetX(), vertex.GetY())
		}
	}

	return nil
}

Java

在试用此示例之前，请按照客户端库页面中与此编程语言对应的设置说明执行操作。

import com.google.cloud.automl.v1.AnnotationPayload;
import com.google.cloud.automl.v1.BoundingPoly;
import com.google.cloud.automl.v1.ExamplePayload;
import com.google.cloud.automl.v1.Image;
import com.google.cloud.automl.v1.ModelName;
import com.google.cloud.automl.v1.NormalizedVertex;
import com.google.cloud.automl.v1.PredictRequest;
import com.google.cloud.automl.v1.PredictResponse;
import com.google.cloud.automl.v1.PredictionServiceClient;
import com.google.protobuf.ByteString;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;

class VisionObjectDetectionPredict {

  static void predict() throws IOException {
    // TODO(developer): Replace these variables before running the sample.
    String projectId = "YOUR_PROJECT_ID";
    String modelId = "YOUR_MODEL_ID";
    String filePath = "path_to_local_file.jpg";
    predict(projectId, modelId, filePath);
  }

  static void predict(String projectId, String modelId, String filePath) throws IOException {
    // 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 (PredictionServiceClient client = PredictionServiceClient.create()) {
      // Get the full path of the model.
      ModelName name = ModelName.of(projectId, "us-central1", modelId);
      ByteString content = ByteString.copyFrom(Files.readAllBytes(Paths.get(filePath)));
      Image image = Image.newBuilder().setImageBytes(content).build();
      ExamplePayload payload = ExamplePayload.newBuilder().setImage(image).build();
      PredictRequest predictRequest =
          PredictRequest.newBuilder()
              .setName(name.toString())
              .setPayload(payload)
              .putParams(
                  "score_threshold", "0.5") // [0.0-1.0] Only produce results higher than this value
              .build();

      PredictResponse response = client.predict(predictRequest);
      for (AnnotationPayload annotationPayload : response.getPayloadList()) {
        System.out.format("Predicted class name: %s\n", annotationPayload.getDisplayName());
        System.out.format(
            "Predicted class score: %.2f\n",
            annotationPayload.getImageObjectDetection().getScore());
        BoundingPoly boundingPoly = annotationPayload.getImageObjectDetection().getBoundingBox();
        System.out.println("Normalized Vertices:");
        for (NormalizedVertex vertex : boundingPoly.getNormalizedVerticesList()) {
          System.out.format("\tX: %.2f, Y: %.2f\n", vertex.getX(), vertex.getY());
        }
      }
    }
  }
}

Node.js

在试用此示例之前，请按照客户端库页面中与此编程语言对应的设置说明执行操作。

/**
 * TODO(developer): Uncomment these variables before running the sample.
 */
// const projectId = 'YOUR_PROJECT_ID';
// const location = 'us-central1';
// const modelId = 'YOUR_MODEL_ID';
// const filePath = 'path_to_local_file.jpg';

// Imports the Google Cloud AutoML library
const {PredictionServiceClient} = require('@google-cloud/automl').v1;
const fs = require('fs');

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

// Read the file content for translation.
const content = fs.readFileSync(filePath);

async function predict() {
  // Construct request
  // params is additional domain-specific parameters.
  // score_threshold is used to filter the result
  const request = {
    name: client.modelPath(projectId, location, modelId),
    payload: {
      image: {
        imageBytes: content,
      },
    },
    params: {
      score_threshold: '0.8',
    },
  };

  const [response] = await client.predict(request);

  for (const annotationPayload of response.payload) {
    console.log(`Predicted class name: ${annotationPayload.displayName}`);
    console.log(
      `Predicted class score: ${annotationPayload.imageObjectDetection.score}`
    );
    console.log('Normalized vertices:');
    for (const vertex of annotationPayload.imageObjectDetection.boundingBox
      .normalizedVertices) {
      console.log(`\tX: ${vertex.x}, Y: ${vertex.y}`);
    }
  }
}

predict();

Python

在试用此示例之前，请按照客户端库页面中与此编程语言对应的设置说明执行操作。

from google.cloud import automl

# TODO(developer): Uncomment and set the following variables
# project_id = "YOUR_PROJECT_ID"
# model_id = "YOUR_MODEL_ID"
# file_path = "path_to_local_file.jpg"

prediction_client = automl.PredictionServiceClient()

# Get the full path of the model.
model_full_id = automl.AutoMlClient.model_path(project_id, "us-central1", model_id)

# Read the file.
with open(file_path, "rb") as content_file:
    content = content_file.read()

image = automl.Image(image_bytes=content)
payload = automl.ExamplePayload(image=image)

# params is additional domain-specific parameters.
# score_threshold is used to filter the result
# https://cloud.google.com/automl/docs/reference/rpc/google.cloud.automl.v1#predictrequest
params = {"score_threshold": "0.8"}

request = automl.PredictRequest(name=model_full_id, payload=payload, params=params)

response = prediction_client.predict(request=request)
print("Prediction results:")
for result in response.payload:
    print(f"Predicted class name: {result.display_name}")
    print(f"Predicted class score: {result.image_object_detection.score}")
    bounding_box = result.image_object_detection.bounding_box
    print("Normalized Vertices:")
    for vertex in bounding_box.normalized_vertices:
        print(f"\tX: {vertex.x}, Y: {vertex.y}")

其他语言

C#： 请按照客户端库页面上的 C# 设置说明操作，然后访问 .NET 版 AutoML Vision Object Detection 参考文档。

PHP： 请按照客户端库页面上的 PHP 设置说明操作，然后访问 PHP 版 AutoML Vision Object Detection 参考文档。

Ruby 版： 请按照客户端库页面上的 Ruby 设置说明操作，然后访问 Ruby 版 AutoML Vision Object Detection 参考文档。

重要提示：错误消息“Model is warming up. Please try again later.”（模型正在预热。请稍后重试。）表示您应该等待几分钟后再尝试查询模型。在首次查询模型时，或向最近一直未查询的模型发出请求时，可能会发生这种预热延迟。