# Google Cloud Vision API Java examples

This directory contains [Cloud Vision API](https://cloud.google.com/vision/) Java samples.

For Android samples, check out the [mobile samples](https://cloud.google.com/vision/docs/samples#mobile_platform_examples) for the Cloud Vision API. ([Source code for Android sample](https://github.com/GoogleCloudPlatform/cloud-vision/tree/master/android))

## Prerequisites

### Download Maven

This sample uses the [Apache Maven][maven] build system. Before getting started, be
sure to [download][maven-download] and [install][maven-install] it. When you use
Maven as described here, it will automatically download the needed client
libraries.

[maven]: https://maven.apache.org
[maven-download]: https://maven.apache.org/download.cgi
[maven-install]: https://maven.apache.org/install.html

### Setup

* Create a project with the [Google Cloud Console][cloud-console], and enable
  the [Vision API][vision-api].
* Set up your environment with [Application Default Credentials][adc]. For
    example, from the Cloud Console, you might create a service account,
    download its json credentials file, then set the appropriate environment
    variable:

    ```bash
    export GOOGLE_APPLICATION_CREDENTIALS=/path/to/your-project-credentials.json
    ```

[cloud-console]: https://console.cloud.google.com
[vision-api]: https://console.cloud.google.com/apis/api/vision.googleapis.com/overview?project=_
[adc]: https://cloud.google.com/docs/authentication#developer_workflow

## Samples

### Label Detection

This sample annotates an image with labels based on its content.

- [Java Code](label)

### Face Detection

This sample identifies faces within an image.

- [Quickstart Walkthrough](https://cloud.google.com/vision/docs/face-tutorial)
- [Java Code](face-detection)

### Landmark Detection Using Google Cloud Storage

This sample identifies a landmark within an image stored on
Google Cloud Storage.

- [Documentation and Java Code](landmark_detection)

### Text Detection Using the Vision API

This sample uses `TEXT_DETECTION` Vision API requests to build an inverted index
from the stemmed words found in the images, and stores that index in a
[Redis](redis.io) database.  The example uses the
[OpenNLP](https://opennlp.apache.org/) library (Open Natural Language
Processing) for finding stopwords and doing stemming. The resulting index can be
queried to find images that match a given set of words, and to list text that
was found in each matching image.

[Documentation and Java Code](text)