Tutorial: How to Send Images for Font Identification

Learning Objectives

In this tutorial, you’ll learn:

• How to prepare images for font identification
• How to construct the API request for font identification
• How to configure image preprocessing settings
• How to handle the API response

Prerequisites

• Basic understanding of REST APIs
• Familiarity with JSON
• An active Aspose Cloud account with valid credentials
• An image with clear text for testing

Preparing Your Environment

Before we begin sending images for font identification, you need to set up your environment:

1. Sign in to your Aspose Cloud Dashboard
2. Note your Client ID and Client Secret or generate new ones if needed
3. Ensure you have an image file ready for testing

Understanding the Font Identification Endpoint

The Aspose.OCR Cloud API provides a dedicated endpoint for font identification:

POST https://api.aspose.cloud/v5.0/ocr/IdentifyFont

This endpoint accepts a JSON payload containing your image and configuration settings.

Step 1: Obtain an Access Token

Before sending an image for font identification, you need to authenticate with the Aspose.OCR Cloud service. Let’s see how to get an access token:

curl -X POST "https://api.aspose.cloud/connect/token" \
  -d "grant_type=client_credentials&client_id=YOUR_CLIENT_ID&client_secret=YOUR_CLIENT_SECRET" \
  -H "Content-Type: application/x-www-form-urlencoded"

The response will include an access_token that you’ll use in subsequent requests.

Step 2: Prepare Your Image

For font identification to work effectively, your image should:

• Contain clearly visible text
• Have good contrast between text and background
• Be in a common format (JPEG, PNG, BMP, etc.)

You’ll need to encode your image as a Base64 string to include it in the API request. Here’s how to do it in different languages:

Try It Yourself: Encode an Image to Base64

base64 -i your_image.png
# On Windows PowerShell, use:
# [Convert]::ToBase64String([IO.File]::ReadAllBytes("your_image.png"))

import base64

with open("your_image.png", "rb") as image_file:
    encoded_string = base64.b64encode(image_file.read()).decode('utf-8')
    print(encoded_string)

using System;
using System.IO;

string filePath = "your_image.png";
byte[] imageBytes = File.ReadAllBytes(filePath);
string base64String = Convert.ToBase64String(imageBytes);
Console.WriteLine(base64String);

Step 3: Configure Font Identification Settings

The API allows you to configure various preprocessing options to improve font identification accuracy. Here are the available settings:

Image Preprocessing Order

When multiple preprocessing options are enabled, they’re applied in this order:

1. Contrast correction
2. Skew correction
3. Upsampling

Step 4: Send the Image for Font Identification

Now, let’s build the request to send an image for font identification:

{
  "image": "YOUR_BASE64_ENCODED_IMAGE",
  "settings": {
    "language": "English",
    "makeSkewCorrect": true,
    "rotate": 0,
    "makeBinarization": false,
    "makeContrastCorrection": true,
    "makeUpsampling": false,
    "resultType": "Text"
  }
}

Try It Yourself: Complete cURL Example

Let’s put everything together in a complete cURL example:

curl --request POST --location 'https://api.aspose.cloud/v5.0/ocr/IdentifyFont' \
--header 'Accept: text/plain' \
--header 'Content-Type: application/json' \
--header 'Authorization: Bearer YOUR_ACCESS_TOKEN' \
--data-raw '{
  "image": "YOUR_BASE64_ENCODED_IMAGE",
  "settings": {
    "makeSkewCorrect": true,
    "resultType": "Text"
  }
}'

Step 5: Handle the API Response

If your request is successful, the API will return a unique identifier (GUID) for your font identification task:

c11c975d-5124-4555-9561-af40fb95ba07

This ID will be used in the next tutorial to retrieve the font identification results.

Troubleshooting Tips

If you encounter issues when sending images for font identification, check these common problems:

• Error 401: Your access token may be invalid or expired. Generate a new one.
• Error 400: Check your request payload for formatting issues.
• Command too long: For very large images, the Base64 string can exceed command line limits. Consider using a programming language instead of cURL.

What You’ve Learned

In this tutorial, you’ve learned:

• How to authenticate with the Aspose.OCR Cloud API
• How to prepare and encode images for font identification
• How to configure preprocessing settings for optimal results
• How to send images to the API and handle the response

Next Steps

Now that you’ve successfully submitted an image for font identification, continue to the next tutorial: How to Fetch Font Identification Results to learn how to retrieve and interpret the results.

Further Practice

• Try sending different types of images with various fonts
• Experiment with different preprocessing settings
• Create a script that automates the image encoding and submission process

Helpful Resources

• Product Page
• Documentation
• Live Demo
• API Reference
• Blog
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