Send a request for face detection

Send a request to the Cloud Vision API to detected faces in an image.

Explore further

For detailed documentation that includes this code sample, see the following:

• Face detection tutorial
• Send a request for face detection

Code sample

Java

To learn how to install and use the client library for Vision API Product Search, see Vision API Product Search client libraries. For more information, see the Vision API Product Search Java API reference documentation.

To authenticate to Vision API Product Search, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

/** Gets up to {@code maxResults} faces for an image stored at {@code path}. */
public List<FaceAnnotation> detectFaces(Path path, int maxResults) throws IOException {
  byte[] data = Files.readAllBytes(path);

  AnnotateImageRequest request =
      new AnnotateImageRequest()
          .setImage(new Image().encodeContent(data))
          .setFeatures(
              ImmutableList.of(
                  new Feature().setType("FACE_DETECTION").setMaxResults(maxResults)));
  Vision.Images.Annotate annotate =
      vision
          .images()
          .annotate(new BatchAnnotateImagesRequest().setRequests(ImmutableList.of(request)));
  // Due to a bug: requests to Vision API containing large images fail when GZipped.
  annotate.setDisableGZipContent(true);

  BatchAnnotateImagesResponse batchResponse = annotate.execute();
  assert batchResponse.getResponses().size() == 1;
  AnnotateImageResponse response = batchResponse.getResponses().get(0);
  if (response.getFaceAnnotations() == null) {
    throw new IOException(
        response.getError() != null
            ? response.getError().getMessage()
            : "Unknown error getting image annotations");
  }
  return response.getFaceAnnotations();
}

Node.js

To learn how to install and use the client library for Vision API Product Search, see Vision API Product Search client libraries. For more information, see the Vision API Product Search Node.js API reference documentation.

To authenticate to Vision API Product Search, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

async function detectFaces(inputFile) {
  // Make a call to the Vision API to detect the faces
  const request = {image: {source: {filename: inputFile}}};
  const results = await client.faceDetection(request);
  const faces = results[0].faceAnnotations;
  const numFaces = faces.length;
  console.log(`Found ${numFaces} face${numFaces === 1 ? '' : 's'}.`);
  return faces;
}

PHP

To learn how to install and use the client library for Vision API Product Search, see Vision API Product Search client libraries.

To authenticate to Vision API Product Search, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

# annotate the image
// $path = 'path/to/your/image.jpg'
$image = file_get_contents($path);
$response = $imageAnnotator->faceDetection($image);
$faces = $response->getFaceAnnotations();

Python

To learn how to install and use the client library for Vision API Product Search, see Vision API Product Search client libraries. For more information, see the Vision API Product Search Python API reference documentation.

To authenticate to Vision API Product Search, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

def detect_face(face_file, max_results=4):
    """Uses the Vision API to detect faces in the given file.

    Args:
        face_file: A file-like object containing an image with faces.

    Returns:
        An array of Face objects with information about the picture.
    """
    client = vision.ImageAnnotatorClient()

    content = face_file.read()
    image = vision.Image(content=content)

    return client.face_detection(image=image, max_results=max_results).face_annotations

What's next

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