Author: Google Cloud (https://cloud.google.com)

Description: Extracts text from images and saves to Firestore using Cloud Vision API.

Details: This extension extracts text from jpg or png images uploaded to Cloud Storage and writes the extracted text to Firestore, using the Cloud Vision API.

On install, you will be asked to provide a Cloud Storage bucket where files will be uploaded, and a Firestore collection to write extracted text back to.

When a JPG or PNG file is uploaded to the designated bucket, the extension automatically triggers a Cloud Function. This function then employs the Google Cloud Vision API to process the image, effectively extracting any discernible text. Following this extraction process, the resulting text is saved in a specific Firestore collection. In this collection, each document will have a field named 'file' whose value matches the full storage path of the uploaded image.

• Optical character recognition (OCR) for scanned documents: Extract and store text from scanned documents to make them searchable and accessible in your application.
• Reading text from images in a social media app: Automatically extract and analyze text from user images to identify trends or inappropriate content.
• Extracting menu items from restaurant images: Create a food ordering app that allows users to upload images of menus and automatically extracts and displays the menu items in a structured format.

The extension provides a include path list parameter. Setting this parameter will restrict the extension to only extract text from images in specific locations in your Storage bucket.

If this parameter is not set, then images uploaded to all paths from the given bucket will trigger text extraction.

For example, specifying the paths /users/pictures,/restaurants/menuItems will extract text from any images found in any subdirectories of /users/pictures and /restaurants/menuItems. You may also use wildcard notation for directories in the path.

### Excluding Cloud Storage paths

Alternatively, the extension also provides a exclude path list parameter. This parameter is a list of absolute paths not included for extract text from images.

Setting is will ensure the extension does not extract text from images in the specific locations.

For example, to exclude the images stored in the /foo/alpha and its subdirectories and /bar/beta and its subdirectories, specify the paths /foo/alpha,/bar/beta.

The extension also allows you to control whether you would like to store just extracted text, or all returned metadata from Cloud Vision AI. If set to "basic" the extension will simply write the extracted text as a string field. If set to "full" then the full information returned from Cloud Vision AI will be written to the Firestore document.

Ensure you have a Cloud Firestore database and Cloud Storage bucket set up in your Firebase project.

This extension uses other Firebase or Google Cloud Platform services which may have associated charges:

• Cloud Vision AI
• Cloud Storage
• Cloud Firestore
• Cloud Functions (See FAQs)

When you use Firebase Extensions, you're only charged for the underlying resources that you use. A paid-tier (Blaze) billing plan is required because the extension uses Cloud Vision API.

Configuration Parameters:

• Cloud Functions location: Where do you want to deploy the functions created for this extension? You usually want a location close to your database. Realtime Database instances are located in us-central1. For help selecting a location, refer to the location selection guide.

• Cloud Storage bucket for images: To which Cloud Storage bucket will you upload images from which you want to extract text?

• Collection path: What is the path to the collection where extracted text will be written to.

• Paths that contain images you want to extract text from: Restrict storage-image-text-extraction to only extract text from images in specific locations in your Storage bucket by supplying a comma-separated list of absolute paths. For example, specifying the paths /users/pictures,/restaurants/menuItems will process any images found in any subdirectories of /users/pictures and /restaurants/menuItems. If you prefer not to explicitly exclude any directories of your Storage bucket, leave this field empty.

• List of absolute paths not included for image text extraction: Ensure storage-image-text-extraction does not process images in specific locations in your Storage bucket by supplying a comma-separated list of absolute paths. For example, to exclude the images stored in the /foo/alpha and its subdirectories and /bar/beta and its subdirectories, specify the paths /foo/alpha,/bar/beta. If you prefer to process every image uploaded to your Storage bucket, leave this field empty.

• Amount of text extraction information to write to firestore.: How much information should be written to firestore? Do you want just the extracted text written to firestore, or the full data of the annotation? Select "basic" for the former, "full" for the later.

Cloud Functions:

• extractText: Listens to incoming Storage documents, executes OCR on them and writes extracted text to Firestore into a preconfigured collection.

APIs Used:

• vision.googleapis.com (Reason: Powers all Vision tasks performed by the extension.)

Access Required:

This extension will operate with the following project IAM roles:

• storage.admin (Reason: Allows the extension to write to your Cloud Storage.)

• datastore.user (Reason: Allows the extension to write to your Firestore Database instance.)