thesis-src/Implementation/Ocr.OneShot.Postprocessing/Program.cs

// See https://aka.ms/new-console-template for more information

using System.Text.Json;
using System.Text.RegularExpressions;
using ImageMagick;
using Ocr.Tesseract;
using Ocr.Tesseract.Models;
using Ocr.Tesseract.Screenshots;
using Ocr.Tesseract.Screenshots.Configuration;
using Ocr.Tesseract.Screenshots.Threshold;
using Process.Abstract.Configuration;
using Process.Interface;

var wordRegex = new Regex(
    @"[\w'\-]{2,}",
    RegexOptions.Compiled | RegexOptions.Multiline | RegexOptions.IgnoreCase
);
var tesseractConfig = new TesseractScreenshotConfiguration
{
    DataPath = "tessdata",
    Languages = new[] { "eng", "deu" }
};

var jsonOptions = new JsonSerializerOptions()
{
    WriteIndented = true,
    Encoder = System.Text.Encodings.Web.JavaScriptEncoder.UnsafeRelaxedJsonEscaping
};

var processor = MakeProcessor();
processor.Process(new[] { new MagickImage(args.Single()) });

return;

IProcessorChain<MagickImage, ScanResult> MakeProcessor()
{
    var preprocessing = new ProcessorChainConfiguration<MagickImage, MagickImage>()
        .Use(new CloneImageProcessor())
        .Use(new ResizeProcessor(FilterType.Lanczos2Sharp, PixelInterpolateMethod.Mesh))
        .Use(new NormalizeProcessor())
        .Use(new ThresholdAdaptiveProcessor(15, 15))
        .Use(new AddBorderProcessor(10))
        .Use(new BinarizeProcessor())
        .Complete(new NegateCloneProcessor());

    var postprocessing = new ProcessorChainConfiguration<ScanResult, ScanResult>()
        .Use(new ProcessingEvent<ScanResult>((_, data) => WriteToFile(data, "source")))
        .Use(new ConfidenceFilter(50))
        .Use(new ProcessingEvent<ScanResult>((_, data) => WriteToFile(data, "confidence")))
        .Use(new ToLowerProcessor())
        .Use(new ProcessingEvent<ScanResult>((_, data) => WriteToFile(data, "normalize")))
        .Use(new DuplicateFilter())
        .Use(new ProcessingEvent<ScanResult>((_, data) => WriteToFile(data, "duplicates")))
        .Use(new RegexFilter(wordRegex))
        .Complete(new ProcessingEvent<ScanResult>((_, data) => WriteToFile(data, "regex")));

    var scan = new TesseractProcessor(tesseractConfig);

    return new ProcessorChainConfiguration<MagickImage, ScanResult>()
        .Use(preprocessing)
        .Use(scan)
        .Complete(postprocessing);
}

void WriteToFile(ICollection<ScanResult> data, string name)
{
    using var file1 = File.Open($"{name}.detailed.json", FileMode.Create);
    JsonSerializer.Serialize(file1, data.Select(WordInfo.Create), jsonOptions);

    using var file2 = File.Open($"{name}.json", FileMode.Create);
    JsonSerializer.Serialize(file2, data.Select(d => d.Word.Text), jsonOptions);
}

struct WordInfo
{
    public string Text { get; set; }

    public double Confidence { get; set; }

    public static WordInfo Create(ScanResult result) => new()
    {
        Text = result.Word.Text,
        Confidence = result.Word.Confidence
    };
}