How to Read Screenshots with IronOCR in C#

What Types of Screenshots Work Best?

Below is our input for the code example; we demonstrate the versatility of this method by mixing different text fonts and sizes. The ReadScreenshot method excels at recognizing:

• System UI fonts (Windows, macOS, Linux)
• Anti-aliased text from modern applications
• Mixed font sizes and styles
• Text overlaid on complex backgrounds
• Console output and terminal screenshots
• Browser content with various web fonts

For optimal results, capture screenshots at native resolution without compression. The method handles various image formats, but PNG format preserves text clarity best due to its lossless compression.

How Do I Implement the ReadScreenshot Method?

:path=/static-assets/ocr/content-code-examples/how-to/read-screenshot-read-screenshot.cs

using IronOcr;
using System;
using System.Linq;

// Instantiate OCR engine
var ocr = new IronTesseract();

using var inputScreenshot = new OcrInput();
inputScreenshot.LoadImage("screenshotOCR.png");

// Perform OCR
OcrPhotoResult result = ocr.ReadScreenShot(inputScreenshot);

// Output screenshot information
Console.WriteLine(result.Text);
Console.WriteLine(result.TextRegions.First().Region.X);
Console.WriteLine(result.TextRegions.Last().Region.Width);
Console.WriteLine(result.Confidence);

Imports IronOcr
Imports System
Imports System.Linq

' Instantiate OCR engine
Private ocr = New IronTesseract()

Private inputScreenshot = New OcrInput()
inputScreenshot.LoadImage("screenshotOCR.png")

' Perform OCR
Dim result As OcrPhotoResult = ocr.ReadScreenShot(inputScreenshot)

' Output screenshot information
Console.WriteLine(result.Text)
Console.WriteLine(result.TextRegions.First().Region.X)
Console.WriteLine(result.TextRegions.Last().Region.Width)
Console.WriteLine(result.Confidence)

For complex scenarios, enhance the screenshot reading process with additional preprocessing:

using IronOcr;
using System;

// Configure OCR engine with specific settings for screenshots
var ocr = new IronTesseract()
{
    // Set language for better accuracy with non-English content
    Language = OcrLanguage.English,
    // Configure for screen-resolution images
    Configuration = new TesseractConfiguration()
    {
        PageSegmentationMode = TesseractPageSegmentationMode.AutoOsd,
        // Enable whitelist for specific characters if needed
        WhiteListCharacters = null
    }
};

using var inputScreenshot = new OcrInput();
// Load screenshot with specific DPI setting for consistency
inputScreenshot.LoadImage("screenshotOCR.png", 96); // Standard screen DPI

// Apply preprocessing for better accuracy
inputScreenshot.DeNoise(); // Remove screenshot artifacts
inputScreenshot.Sharpen(); // Enhance text edges

// Perform OCR with error handling
try
{
    OcrPhotoResult result = ocr.ReadScreenShot(inputScreenshot);

    // Process results with confidence threshold
    if (result.Confidence > 0.8)
    {
        Console.WriteLine($"High confidence text extraction: {result.Text}");
    }
    else
    {
        Console.WriteLine("Low confidence - consider image preprocessing");
    }
}
catch (Exception ex)
{
    Console.WriteLine($"OCR Error: {ex.Message}");
}

using IronOcr;
using System;

// Configure OCR engine with specific settings for screenshots
var ocr = new IronTesseract()
{
    // Set language for better accuracy with non-English content
    Language = OcrLanguage.English,
    // Configure for screen-resolution images
    Configuration = new TesseractConfiguration()
    {
        PageSegmentationMode = TesseractPageSegmentationMode.AutoOsd,
        // Enable whitelist for specific characters if needed
        WhiteListCharacters = null
    }
};

using var inputScreenshot = new OcrInput();
// Load screenshot with specific DPI setting for consistency
inputScreenshot.LoadImage("screenshotOCR.png", 96); // Standard screen DPI

// Apply preprocessing for better accuracy
inputScreenshot.DeNoise(); // Remove screenshot artifacts
inputScreenshot.Sharpen(); // Enhance text edges

// Perform OCR with error handling
try
{
    OcrPhotoResult result = ocr.ReadScreenShot(inputScreenshot);

    // Process results with confidence threshold
    if (result.Confidence > 0.8)
    {
        Console.WriteLine($"High confidence text extraction: {result.Text}");
    }
    else
    {
        Console.WriteLine("Low confidence - consider image preprocessing");
    }
}
catch (Exception ex)
{
    Console.WriteLine($"OCR Error: {ex.Message}");
}

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What Properties Does OcrPhotoResult Return?

The console output shows extraction of all text instances from the screenshot. Let's explore the properties of OcrPhotoResult and how to leverage them effectively:

• Text: The extracted text from OCR Input. This property contains all recognized text as a single string, preserving the original layout with line breaks and spacing.
• Confidence: A double property indicating statistical accuracy confidence on a scale from 0 to 1, where 1 represents highest confidence. Use this to implement quality control in your application.
• TextRegion: An array of TextRegion objects holding properties that return areas where text is found on the screenshot. By default, all TextRegion is a derived Rectangle class from IronOCR models. It includes x and y coordinates plus height and width of the rectangle.

Working with TextRegions allows you to:

• Extract text from specific screenshot areas
• Identify UI element locations
• Create clickable overlays based on text positions
• Implement region-specific OCR processing

Here's an example of processing individual text regions:

using IronOcr;
using System;
using System.Linq;

var ocr = new IronTesseract();
using var input = new OcrInput();
input.LoadImage("screenshot.png");

OcrPhotoResult result = ocr.ReadScreenShot(input);

// Process each text region individually
foreach (var region in result.TextRegions)
{
    Console.WriteLine($"Text: {region.Text}");
    Console.WriteLine($"Location: X={region.Region.X}, Y={region.Region.Y}");
    Console.WriteLine($"Size: {region.Region.Width}x{region.Region.Height}");
    Console.WriteLine($"Confidence: {region.Confidence:P2}");
    Console.WriteLine("---");
}

// Find specific UI elements by text content
var buttonRegion = result.TextRegions
    .FirstOrDefault(r => r.Text.Contains("Submit", StringComparison.OrdinalIgnoreCase));

if (buttonRegion != null)
{
    Console.WriteLine($"Found button at: {buttonRegion.Region.X}, {buttonRegion.Region.Y}");
}

using IronOcr;
using System;
using System.Linq;

var ocr = new IronTesseract();
using var input = new OcrInput();
input.LoadImage("screenshot.png");

OcrPhotoResult result = ocr.ReadScreenShot(input);

// Process each text region individually
foreach (var region in result.TextRegions)
{
    Console.WriteLine($"Text: {region.Text}");
    Console.WriteLine($"Location: X={region.Region.X}, Y={region.Region.Y}");
    Console.WriteLine($"Size: {region.Region.Width}x{region.Region.Height}");
    Console.WriteLine($"Confidence: {region.Confidence:P2}");
    Console.WriteLine("---");
}

// Find specific UI elements by text content
var buttonRegion = result.TextRegions
    .FirstOrDefault(r => r.Text.Contains("Submit", StringComparison.OrdinalIgnoreCase));

if (buttonRegion != null)
{
    Console.WriteLine($"Found button at: {buttonRegion.Region.X}, {buttonRegion.Region.Y}");
}

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Handling Multi-Language Screenshots

When working with screenshots containing multiple languages, IronOCR provides robust multi-language support. This is useful for international applications or screenshots from multilingual user interfaces:

using IronOcr;

// Configure for multiple languages
var ocr = new IronTesseract();
ocr.AddSecondaryLanguage(OcrLanguage.ChineseSimplified);
ocr.AddSecondaryLanguage(OcrLanguage.Japanese);

using var input = new OcrInput();
input.LoadImage("multilingual-screenshot.png");

// Process with language detection
OcrPhotoResult result = ocr.ReadScreenShot(input);
Console.WriteLine($"Extracted multilingual text: {result.Text}");

using IronOcr;

// Configure for multiple languages
var ocr = new IronTesseract();
ocr.AddSecondaryLanguage(OcrLanguage.ChineseSimplified);
ocr.AddSecondaryLanguage(OcrLanguage.Japanese);

using var input = new OcrInput();
input.LoadImage("multilingual-screenshot.png");

// Process with language detection
OcrPhotoResult result = ocr.ReadScreenShot(input);
Console.WriteLine($"Extracted multilingual text: {result.Text}");

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Performance Optimization for Batch Processing

When processing multiple screenshots, implement these optimization strategies:

using IronOcr;
using System.Collections.Generic;
using System.Threading.Tasks;

public async Task ProcessScreenshotBatchAsync(List<string> screenshotPaths)
{
    var ocr = new IronTesseract();

    // Process screenshots in parallel for better performance
    var tasks = screenshotPaths.Select(async path =>
    {
        using var input = new OcrInput();
        input.LoadImage(path);

        // Apply consistent preprocessing
        input.DeNoise();

        var result = await Task.Run(() => ocr.ReadScreenShot(input));
        return new { Path = path, Result = result };
    });

    var results = await Task.WhenAll(tasks);

    // Process results
    foreach (var item in results)
    {
        Console.WriteLine($"File: {item.Path}");
        Console.WriteLine($"Text: {item.Result.Text}");
        Console.WriteLine($"Confidence: {item.Result.Confidence:P2}");
    }
}

using IronOcr;
using System.Collections.Generic;
using System.Threading.Tasks;

public async Task ProcessScreenshotBatchAsync(List<string> screenshotPaths)
{
    var ocr = new IronTesseract();

    // Process screenshots in parallel for better performance
    var tasks = screenshotPaths.Select(async path =>
    {
        using var input = new OcrInput();
        input.LoadImage(path);

        // Apply consistent preprocessing
        input.DeNoise();

        var result = await Task.Run(() => ocr.ReadScreenShot(input));
        return new { Path = path, Result = result };
    });

    var results = await Task.WhenAll(tasks);

    // Process results
    foreach (var item in results)
    {
        Console.WriteLine($"File: {item.Path}");
        Console.WriteLine($"Text: {item.Result.Text}");
        Console.WriteLine($"Confidence: {item.Result.Confidence:P2}");
    }
}

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