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。