Font detection

Aspose.OCR for .NET can detect font information for each recognized text line. This is useful when you need to preserve visual characteristics of recognized content or analyze documents by typography.

Font detection is enabled through RecognitionSettings.DetectFonts. When the setting is enabled, each non-empty item in RecognitionResult.RecognitionLinesResult can contain a FontLineResult object in its Font property.

Font detection is designed for recognized text lines. Enable line-level recognition output and use clear, sufficiently large text images for best results.

Font information

FontLineResult contains the following information:

Property	Type	Description
LineIndex	int	Zero-based line index in the processed font batch.
SizePx	int	Detected line height in pixels.
SizePtEstimate	double?	Estimated font size in points.
Style	string	Detected font style, for example regular, italic, or bold_italic.
StyleConfidence	double	Confidence score for the detected style.
Font	string	Detected font family name.
FontConfidence	double	Confidence score for the detected font family.

Detecting fonts

Set RecognitionSettings.DetectFonts to true, recognize the image, and read the Font property of each recognized line.

using Aspose.OCR;
using System;
using System.Linq;

AsposeOcr api = new AsposeOcr();

OcrInput input = new OcrInput(InputType.SingleImage);
input.Add("source.png");

RecognitionSettings settings = new RecognitionSettings
{
	DetectFonts = true,
	DetectAreasMode = DetectAreasMode.LEAN,
	Language = Language.Latin,
	ThreadsCount = 1
};

RecognitionResult result = api.Recognize(input, settings)[0];

foreach (RecognitionResult.LinesResult line in result.RecognitionLinesResult
	.Where(line => !string.IsNullOrWhiteSpace(line.TextInLine)))
{
	FontLineResult font = line.Font;

	Console.WriteLine(line.TextInLine);
	Console.WriteLine($"Font: {font.Font} ({font.FontConfidence:P0})");
	Console.WriteLine($"Style: {font.Style} ({font.StyleConfidence:P0})");
	Console.WriteLine($"Size: {font.SizePx}px / {font.SizePtEstimate}pt");
}

Processing multiple images

Font detection works with batches. Each RecognitionResult contains line-level font data for the corresponding input image or page.

using Aspose.OCR;
using System;
using System.Linq;

AsposeOcr api = new AsposeOcr();

OcrInput input = new OcrInput(InputType.SingleImage);
input.Add("arial.png");
input.Add("calibri.png");

RecognitionSettings settings = new RecognitionSettings
{
	DetectFonts = true,
	DetectAreasMode = DetectAreasMode.LEAN,
	Language = Language.Latin,
	ThreadsCount = 1
};

foreach (RecognitionResult result in api.Recognize(input, settings))
{
	foreach (RecognitionResult.LinesResult line in result.RecognitionLinesResult
		.Where(line => !string.IsNullOrWhiteSpace(line.TextInLine)))
	{
		Console.WriteLine($"{line.TextInLine}: {line.Font.Font}, {line.Font.Style}");
	}
}