Detect labels in an image by using the command line
This page shows you how to send three feature detection and annotation requests
to the Vision API using the REST interface
and the curl
command.
Vision API enables easy integration of Google vision recognition technologies into developer applications. You can send image data and desired feature types to the Vision API, which then returns a corresponding response based on the image attributes you are interested in. For more information about the feature types offered, see the List of all Vision API features.
Before you begin
- Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.
- Install the Google Cloud CLI.
-
To initialize the gcloud CLI, run the following command:
gcloud init
-
Create or select a Google Cloud project.
-
Create a Google Cloud project:
gcloud projects create PROJECT_ID
Replace
PROJECT_ID
with a name for the Google Cloud project you are creating. -
Select the Google Cloud project that you created:
gcloud config set project PROJECT_ID
Replace
PROJECT_ID
with your Google Cloud project name.
-
-
Make sure that billing is enabled for your Google Cloud project.
-
Enable the Vision API:
gcloud services enable vision.googleapis.com
-
Grant roles to your user account. Run the following command once for each of the following IAM roles:
roles/storage.objectViewer
gcloud projects add-iam-policy-binding PROJECT_ID --member="USER_IDENTIFIER" --role=ROLE
- Replace
PROJECT_ID
with your project ID. -
Replace
USER_IDENTIFIER
with the identifier for your user account. For example,user:myemail@example.com
. - Replace
ROLE
with each individual role.
- Replace
- Install the Google Cloud CLI.
-
To initialize the gcloud CLI, run the following command:
gcloud init
-
Create or select a Google Cloud project.
-
Create a Google Cloud project:
gcloud projects create PROJECT_ID
Replace
PROJECT_ID
with a name for the Google Cloud project you are creating. -
Select the Google Cloud project that you created:
gcloud config set project PROJECT_ID
Replace
PROJECT_ID
with your Google Cloud project name.
-
-
Make sure that billing is enabled for your Google Cloud project.
-
Enable the Vision API:
gcloud services enable vision.googleapis.com
-
Grant roles to your user account. Run the following command once for each of the following IAM roles:
roles/storage.objectViewer
gcloud projects add-iam-policy-binding PROJECT_ID --member="USER_IDENTIFIER" --role=ROLE
- Replace
PROJECT_ID
with your project ID. -
Replace
USER_IDENTIFIER
with the identifier for your user account. For example,user:myemail@example.com
. - Replace
ROLE
with each individual role.
- Replace
Make an image annotation request
After completing the Before you begin steps you can use the Vision API to annotate an image file.
In this example you use curl to send a request to the Vision API using the following image:
Cloud Storage URI:
gs://cloud-samples-data/vision/using_curl/shanghai.jpeg
HTTPS URL:
https://console.cloud.google.com/storage/browser/cloud-samples-data/vision/using_curl/shanghai.jpeg
Create the request JSON
The following request.json
file demonstrates how
to request three images:annotate
features
and limit the results in the response.
Create the JSON request file with the following text, and save it as a
request.json
plain text file in your working directory:
request.json
{ "requests": [ { "image": { "source": { "imageUri": "gs://cloud-samples-data/vision/using_curl/shanghai.jpeg" } }, "features": [ { "type": "LABEL_DETECTION", "maxResults": 3 }, { "type": "OBJECT_LOCALIZATION", "maxResults": 1 }, { "type": "TEXT_DETECTION", "maxResults": 1, "model": "builtin/latest" } ] } ] }
Send the request
You use curl and the body content from request.json
to send the request
to the Vision API. Enter the following on your
command line:
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" \ https://vision.googleapis.com/v1/images:annotate -d @request.json
Interpret the response
You should see a JSON response similar to the one below.
The request JSON body specified maxResults
for each annotation type.
Consequently, you will see the following in the response JSON:
- three
labelAnnotations
results - one
textAnnotations
result (shortened for clarity) - one
localizedObjectAnnotations
result
Label detection results
- description: "People", score: 0.950
- description: "Street", score: 0.891
- description: "Mode of transport", score: 0.890
Text detection results
- text: 牛牛面馆\n
- vertices: (x: 159, y: 212), (x: 947, y: 212), (x: 947, y: 354), (x: 159, y: 354 )
Object detection results
- name: "Person", score: 0.944
- normalized vertices: (x: 0.260, y: 0.468), (x: 0.407, y: 0.468), (x: 0.407, y: 0.895), (x: 0.260, y: 0.895)
Congratulations! You've sent your first request to the Vision API.
Clean up
To avoid incurring charges to your Google Cloud account for the resources used on this page, delete the Google Cloud project with the resources.
Optional: Revoke credentials from the gcloud CLI.
gcloud auth revoke
What's next
- See a list of all feature types and their uses.
- Get started with the Vision API in your language of choice by using a Vision API Client Library.
- Use the How-to guides to learn more about specific features, see example annotations, and get annotations for an individual file or image.
- Learn about batch image and file (PDF/TIFF/GIF) annotation.
- Browse through a comprehensive list of client library code samples.