检测图片属性

图片属性功能可检测图片的一般属性,如主色。

巴厘岛图片
图片来源:Unsplash 用户 Jeremy Bishop

检测到主色

在巴厘岛图片中检测到的主色

图片属性检测请求

设置您的 GCP 项目和身份验证

检测本地图片中的图片属性

Vision API 可以将本地图片文件的内容作为 base64 编码的字符串在请求正文中发送,从而对此图片文件执行特征检测。

ColorInfo 字段不包含用于解释 RGB 值的绝对颜色空间(例如 sRGB、Adobe RGB、DCI-P3、BT.2020 等等)的相关信息。默认情况下,应用应采用 sRGB 颜色空间。

REST 和命令行

在使用任何请求数据之前,请先进行以下替换:

  • 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,请参阅 base64 编码主题。

HTTP 方法和网址:

POST https://vision.googleapis.com/v1/images:annotate

请求 JSON 正文:

{
  "requests": [
    {
      "image": {
        "content": "base64-encoded-image"
      },
      "features": [
        {
          "maxResults": 10,
          "type": "IMAGE_PROPERTIES"
        },
      ]
    }
  ]
}

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://vision.googleapis.com/v1/images:annotate"

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://vision.googleapis.com/v1/images:annotate" | Select-Object -Expand Content

如果请求成功,服务器将返回一个 200 OK HTTP 状态代码以及 JSON 格式的响应。

响应

Go

试用此示例之前,请按照《Vision 快速入门:使用客户端库》中的 Go 设置说明进行操作。如需了解详情,请参阅 Vision Go API 参考文档


// detectProperties gets image properties from the Vision API for an image at the given file path.
func detectProperties(w io.Writer, file string) error {
	ctx := context.Background()

	client, err := vision.NewImageAnnotatorClient(ctx)
	if err != nil {
		return err
	}

	f, err := os.Open(file)
	if err != nil {
		return err
	}
	defer f.Close()

	image, err := vision.NewImageFromReader(f)
	if err != nil {
		return err
	}
	props, err := client.DetectImageProperties(ctx, image, nil)
	if err != nil {
		return err
	}

	fmt.Fprintln(w, "Dominant colors:")
	for _, quantized := range props.DominantColors.Colors {
		color := quantized.Color
		r := int(color.Red) & 0xff
		g := int(color.Green) & 0xff
		b := int(color.Blue) & 0xff
		fmt.Fprintf(w, "%2.1f%% - #%02x%02x%02x\n", quantized.PixelFraction*100, r, g, b)
	}

	return nil
}

Java

在试用此示例之前,请按照Vision API 快速入门:使用客户端库中的 Java 设置说明进行操作。如需了解详情,请参阅 Vision API Java API 参考文档


import com.google.cloud.vision.v1.AnnotateImageRequest;
import com.google.cloud.vision.v1.AnnotateImageResponse;
import com.google.cloud.vision.v1.BatchAnnotateImagesResponse;
import com.google.cloud.vision.v1.ColorInfo;
import com.google.cloud.vision.v1.DominantColorsAnnotation;
import com.google.cloud.vision.v1.Feature;
import com.google.cloud.vision.v1.Image;
import com.google.cloud.vision.v1.ImageAnnotatorClient;
import com.google.protobuf.ByteString;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class DetectProperties {
  public static void detectProperties() throws IOException {
    // TODO(developer): Replace these variables before running the sample.
    String filePath = "path/to/your/image/file.jpg";
    detectProperties(filePath);
  }

  // Detects image properties such as color frequency from the specified local image.
  public static void detectProperties(String filePath) throws IOException {
    List<AnnotateImageRequest> requests = new ArrayList<>();

    ByteString imgBytes = ByteString.readFrom(new FileInputStream(filePath));

    Image img = Image.newBuilder().setContent(imgBytes).build();
    Feature feat = Feature.newBuilder().setType(Feature.Type.IMAGE_PROPERTIES).build();
    AnnotateImageRequest request =
        AnnotateImageRequest.newBuilder().addFeatures(feat).setImage(img).build();
    requests.add(request);

    // 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 (ImageAnnotatorClient client = ImageAnnotatorClient.create()) {
      BatchAnnotateImagesResponse response = client.batchAnnotateImages(requests);
      List<AnnotateImageResponse> responses = response.getResponsesList();

      for (AnnotateImageResponse res : responses) {
        if (res.hasError()) {
          System.out.format("Error: %s%n", res.getError().getMessage());
          return;
        }

        // For full list of available annotations, see http://g.co/cloud/vision/docs
        DominantColorsAnnotation colors = res.getImagePropertiesAnnotation().getDominantColors();
        for (ColorInfo color : colors.getColorsList()) {
          System.out.format(
              "fraction: %f%nr: %f, g: %f, b: %f%n",
              color.getPixelFraction(),
              color.getColor().getRed(),
              color.getColor().getGreen(),
              color.getColor().getBlue());
        }
      }
    }
  }
}

Node.js

试用此示例之前,请按照《Vision 快速入门:使用客户端库》中的 Node.js 设置说明进行操作。如需了解详情,请参阅 Vision Node.js API 参考文档

const vision = require('@google-cloud/vision');

// Creates a client
const client = new vision.ImageAnnotatorClient();

/**
 * TODO(developer): Uncomment the following line before running the sample.
 */
// const fileName = 'Local image file, e.g. /path/to/image.png';

// Performs property detection on the local file
const [result] = await client.imageProperties(fileName);
const colors = result.imagePropertiesAnnotation.dominantColors.colors;
colors.forEach(color => console.log(color));

Python

试用此示例之前,请按照《Vision 快速入门:使用客户端库》中的 Python 设置说明进行操作。如需了解详情,请参阅 Vision Python API 参考文档

def detect_properties(path):
    """Detects image properties in the file."""
    from google.cloud import vision
    import io
    client = vision.ImageAnnotatorClient()

    with io.open(path, 'rb') as image_file:
        content = image_file.read()

    image = vision.Image(content=content)

    response = client.image_properties(image=image)
    props = response.image_properties_annotation
    print('Properties:')

    for color in props.dominant_colors.colors:
        print('fraction: {}'.format(color.pixel_fraction))
        print('\tr: {}'.format(color.color.red))
        print('\tg: {}'.format(color.color.green))
        print('\tb: {}'.format(color.color.blue))
        print('\ta: {}'.format(color.color.alpha))

    if response.error.message:
        raise Exception(
            '{}\nFor more info on error messages, check: '
            'https://cloud.google.com/apis/design/errors'.format(
                response.error.message))

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 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 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 Vision 参考文档。

检测远程图片中的图片属性

为方便起见,Vision API 可以直接对位于 Google Cloud Storage 或网络中的图片文件执行特征检测,无需在请求正文中发送图片文件的内容。

ColorInfo 字段不包含用于解释 RGB 值的绝对颜色空间(例如 sRGB、Adobe RGB、DCI-P3、BT.2020 等等)的相关信息。默认情况下,应用应采用 sRGB 颜色空间。

REST 和命令行

在使用任何请求数据之前,请先进行以下替换:

  • cloud-storage-image-uri:Cloud Storage 存储分区中有效图片文件的路径。您必须至少拥有该文件的读取权限。 示例:
    • gs://cloud-samples-data/vision/image_properties/bali.jpeg

HTTP 方法和网址:

POST https://vision.googleapis.com/v1/images:annotate

请求 JSON 正文:

{
  "requests": [
    {
      "image": {
        "source": {
          "gcsImageUri": "cloud-storage-image-uri"
        }
      },
      "features": [
        {
          "maxResults": 10,
          "type": "IMAGE_PROPERTIES"
        },
      ]
    }
  ]
}

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://vision.googleapis.com/v1/images:annotate"

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://vision.googleapis.com/v1/images:annotate" | Select-Object -Expand Content

如果请求成功,服务器将返回一个 200 OK HTTP 状态代码以及 JSON 格式的响应。

响应

Go

试用此示例之前,请按照《Vision 快速入门:使用客户端库》中的 Go 设置说明进行操作。如需了解详情,请参阅 Vision Go API 参考文档


// detectProperties gets image properties from the Vision API for an image at the given file path.
func detectPropertiesURI(w io.Writer, file string) error {
	ctx := context.Background()

	client, err := vision.NewImageAnnotatorClient(ctx)
	if err != nil {
		return err
	}

	image := vision.NewImageFromURI(file)
	props, err := client.DetectImageProperties(ctx, image, nil)
	if err != nil {
		return err
	}

	fmt.Fprintln(w, "Dominant colors:")
	for _, quantized := range props.DominantColors.Colors {
		color := quantized.Color
		r := int(color.Red) & 0xff
		g := int(color.Green) & 0xff
		b := int(color.Blue) & 0xff
		fmt.Fprintf(w, "%2.1f%% - #%02x%02x%02x\n", quantized.PixelFraction*100, r, g, b)
	}

	return nil
}

Java

试用此示例之前,请按照《Vision 快速入门:使用客户端库》中的 Java 设置说明进行操作。如需了解详情,请参阅 Vision Java API 参考文档


import com.google.cloud.vision.v1.AnnotateImageRequest;
import com.google.cloud.vision.v1.AnnotateImageResponse;
import com.google.cloud.vision.v1.BatchAnnotateImagesResponse;
import com.google.cloud.vision.v1.ColorInfo;
import com.google.cloud.vision.v1.DominantColorsAnnotation;
import com.google.cloud.vision.v1.Feature;
import com.google.cloud.vision.v1.Image;
import com.google.cloud.vision.v1.ImageAnnotatorClient;
import com.google.cloud.vision.v1.ImageSource;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class DetectPropertiesGcs {

  public static void detectPropertiesGcs() throws IOException {
    // TODO(developer): Replace these variables before running the sample.
    String filePath = "gs://your-gcs-bucket/path/to/image/file.jpg";
    detectPropertiesGcs(filePath);
  }

  // Detects image properties such as color frequency from the specified remote image on Google
  // Cloud Storage.
  public static void detectPropertiesGcs(String gcsPath) throws IOException {
    List<AnnotateImageRequest> requests = new ArrayList<>();

    ImageSource imgSource = ImageSource.newBuilder().setGcsImageUri(gcsPath).build();
    Image img = Image.newBuilder().setSource(imgSource).build();
    Feature feat = Feature.newBuilder().setType(Feature.Type.IMAGE_PROPERTIES).build();
    AnnotateImageRequest request =
        AnnotateImageRequest.newBuilder().addFeatures(feat).setImage(img).build();
    requests.add(request);

    // 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 (ImageAnnotatorClient client = ImageAnnotatorClient.create()) {
      BatchAnnotateImagesResponse response = client.batchAnnotateImages(requests);
      List<AnnotateImageResponse> responses = response.getResponsesList();

      for (AnnotateImageResponse res : responses) {
        if (res.hasError()) {
          System.out.format("Error: %s%n", res.getError().getMessage());
          return;
        }

        // For full list of available annotations, see http://g.co/cloud/vision/docs
        DominantColorsAnnotation colors = res.getImagePropertiesAnnotation().getDominantColors();
        for (ColorInfo color : colors.getColorsList()) {
          System.out.format(
              "fraction: %f%nr: %f, g: %f, b: %f%n",
              color.getPixelFraction(),
              color.getColor().getRed(),
              color.getColor().getGreen(),
              color.getColor().getBlue());
        }
      }
    }
  }
}

Node.js

试用此示例之前,请按照《Vision 快速入门:使用客户端库》中的 Node.js 设置说明进行操作。如需了解详情,请参阅 Vision Node.js API 参考文档

// Imports the Google Cloud client libraries
const vision = require('@google-cloud/vision');

// Creates a client
const client = new vision.ImageAnnotatorClient();

/**
 * TODO(developer): Uncomment the following lines before running the sample.
 */
// const bucketName = 'Bucket where the file resides, e.g. my-bucket';
// const fileName = 'Path to file within bucket, e.g. path/to/image.png';

// Performs property detection on the gcs file
const [result] = await client.imageProperties(
  `gs://${bucketName}/${fileName}`
);
const colors = result.imagePropertiesAnnotation.dominantColors.colors;
colors.forEach(color => console.log(color));

Python

试用此示例之前,请按照《Vision 快速入门:使用客户端库》中的 Python 设置说明进行操作。如需了解详情,请参阅 Vision Python API 参考文档

def detect_properties_uri(uri):
    """Detects image properties in the file located in Google Cloud Storage or
    on the Web."""
    from google.cloud import vision
    client = vision.ImageAnnotatorClient()
    image = vision.Image()
    image.source.image_uri = uri

    response = client.image_properties(image=image)
    props = response.image_properties_annotation
    print('Properties:')

    for color in props.dominant_colors.colors:
        print('frac: {}'.format(color.pixel_fraction))
        print('\tr: {}'.format(color.color.red))
        print('\tg: {}'.format(color.color.green))
        print('\tb: {}'.format(color.color.blue))
        print('\ta: {}'.format(color.color.alpha))

    if response.error.message:
        raise Exception(
            '{}\nFor more info on error messages, check: '
            'https://cloud.google.com/apis/design/errors'.format(
                response.error.message))

gcloud

如需执行图片属性检测操作,请使用 gcloud ml vision detect-image-properties 命令,如以下示例所示:

gcloud ml vision detect-image-properties gs://cloud-samples-data/vision/image_properties/bali.jpeg

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 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 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 Vision 参考文档。

试试看

接下来,请尝试执行图片属性检测。您可以使用已指定的图片 (gs://cloud-samples-data/vision/image_properties/bali.jpeg) 或指定您自己的图片。选择执行即可发送请求。

巴厘岛图片
图片来源:Unsplash 用户 Jeremy Bishop

请求正文:

{
  "requests": [
    {
      "features": [
        {
          "maxResults": 10,
          "type": "IMAGE_PROPERTIES"
        }
      ],
      "image": {
        "source": {
          "imageUri": "gs://cloud-samples-data/vision/image_properties/bali.jpeg"
        }
      }
    }
  ]
}