ByteScout Text Recognition SDK – C# – Use Image Preprocessing Filters

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ByteScout Text Recognition SDK – C# – Use Image Preprocessing Filters

Program.cs

using System;
using System.Diagnostics;
using ByteScout.TextRecognition;

namespace TextRecognitionExample
{
    class Program
    {
        static void Main(string[] args)
        {
            string inputDocument = @".\skewed.png";
            string outputDocument = @".\result.txt";

            // Create and activate TextRecognizer instance
            using (TextRecognizer textRecognizer = new TextRecognizer("demo", "demo"))
            {
                try
                {
                    // Load document (image or PDF)
                    textRecognizer.LoadDocument(inputDocument);

                    // Set location of "tessdata" folder containing language data files
                    textRecognizer.OCRLanguageDataFolder = @"c:\Program Files\ByteScout Text Recognition SDK\tessdata\";

                    // Set OCR language.
                    // "eng" for english, "deu" for German, "fra" for French, "spa" for Spanish etc - according to files in "tessdata" folder
                    // Find more language files at https://github.com/tesseract-ocr/tessdata/tree/3.04.00
                    textRecognizer.OCRLanguage = "eng"; 
                    

                    // Add deskew filter that automatically rotates the image to make the text horizontal.
                    // Note, it analyzes the left edge of scanned text. Any dark artifacts may prevent 
                    // the correct angle detection.
                    textRecognizer.ImagePreprocessingFilters.AddDeskew();

                    // Other filters that may be useful to improve recognition
                    // (note, the filters are applied in the order they were added):

                    // Improve image contrast.
                    //textRecognizer.ImagePreprocessingFilters.AddContrast();

                    // Apply gamma correction.
                    //textRecognizer.ImagePreprocessingFilters.AddGammaCorrection();

                    // Apply median filter. Helps to remove noise.
                    //textRecognizer.ImagePreprocessingFilters.AddMedian();

                    // Apply dilate filter. Helps to cure symbols erosion.
                    //textRecognizer.ImagePreprocessingFilters.AddDilate();

                    // Lines removers. Removing borders of some tables may improve the recognition.
                    //textRecognizer.ImagePreprocessingFilters.AddHorizontalLinesRemover();
                    //textRecognizer.ImagePreprocessingFilters.AddVerticalLinesRemover();

                    
                    // Recognize text from all pages and save it to file
                    textRecognizer.SaveText(outputDocument);

                    // Open the result file in default associated application (for demo purposes)
                    Process.Start(outputDocument);
                }
                catch (Exception exception)
                {
                    Console.WriteLine(exception);
                }
            }

//            Console.WriteLine();
//            Console.WriteLine("Press any key...");
//            Console.ReadKey();
        }
    }
}


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