本文档适用于 AutoML Vision,它与 Vertex AI 有所不同。如果您使用的是 Vertex AI,请参阅 Vertex AI 文档

进行单个预测

创建(训练)模型后,可以使用 predict 方法请求对图片执行预测。predict 方法基于模型预测的图片的主对象将标签应用于图片。

在线(逐一)预测

本部分介绍了如何发送单个文件进行注释。该请求将立即返回响应。

您还可以发送一批文件进行注释。批量文件注释是一项长时间运行的操作,并将结果存储在您选择的 Cloud Storage 存储分区中。

网页界面

  1. 打开 Vision Dashboard,然后点击左侧导航栏中的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. 点击标题栏正下方的测试和使用标签页。

  4. 点击上传图片以上传要标记的图片。

    updated predict page

REST 和命令行

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。

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"
  }
}

如需发送请求,请选择以下方式之一:

curl

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 application-default print-access-token) \
-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

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 application-default print-access-token
$headers = @{ "Authorization" = "Bearer $cred" }

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。AutoML Vision 模型的预测包含在 payload 字段中:

  • displayName 是由 AutoML Vision 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)。
{
  "payload": [
    {
      "annotationSpecId": "7922029656637702144",
      "classification": {
        "score": 0.9960259
      },
      "displayName": "roses"
    }
  ]
}

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"
	automlpb "google.golang.org/genproto/googleapis/cloud/automl/v1"
)

// visionClassificationPredict does a prediction for image classification.
func visionClassificationPredict(w io.Writer, projectID string, location string, modelID string, filePath string) error {
	// projectID := "my-project-id"
	// location := "us-central1"
	// modelID := "ICN123456789..."
	// filePath := "path/to/image.jpg"

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

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

	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.ExamplePayload;
import com.google.cloud.automl.v1.Image;
import com.google.cloud.automl.v1.ModelName;
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 VisionClassificationPredict {

  public static void main(String[] args) 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", "0.8") // [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.getClassification().getScore());
      }
    }
  }
}

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,
      },
    },
  };

  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.classification.score}`
    );
  }
}

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("Predicted class name: {}".format(result.display_name))
    print("Predicted class score: {}".format(result.classification.score))

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 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 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 参考文档。