POC for OCR PDF output. Yay it works!

NAPS2.Core/ImportExport/Pdf/TestOcrExporter.cs

@@ -0,0 +1,121 @@
+/*
+    NAPS2 (Not Another PDF Scanner 2)
+    http://sourceforge.net/projects/naps2/
+    
+    Copyright (C) 2009       Pavel Sorejs
+    Copyright (C) 2012       Michael Adams
+    Copyright (C) 2013       Peter De Leeuw
+    Copyright (C) 2012-2013  Ben Olden-Cooligan
+
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License
+    as published by the Free Software Foundation; either version 2
+    of the License, or (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+*/
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Drawing;
+using System.IO;
+using System.Linq;
+using System.Xml.Linq;
+using Clock.Pdf;
+using NAPS2.Scan.Images;
+using PdfSharp.Drawing;
+using PdfSharp.Drawing.Layout;
+using PdfSharp.Pdf;
+using PdfSharp.Pdf.IO;
+
+namespace NAPS2.ImportExport.Pdf
+{
+    public class TestOcrExporter : IPdfExporter
+    {
+        public bool Export(string path, IEnumerable<IScannedImage> images, PdfInfo info, Func<int, bool> progressCallback)
+        {
+            var document = new PdfDocument { Layout = PdfWriterLayout.Compact };
+            document.Info.Author = info.Author;
+            document.Info.Creator = info.Creator;
+            document.Info.Keywords = info.Keywords;
+            document.Info.Subject = info.Subject;
+            document.Info.Title = info.Title;
+
+            var hocrFiles = new List<string>();
+
+            int i = 1;
+            foreach (IScannedImage scannedImage in images)
+            {
+                using (Image img = scannedImage.GetImage())
+                {
+                    string tempImageFilePath = Path.Combine(Paths.Temp, Path.GetRandomFileName());
+                    string tempHocrFilePath = Path.Combine(Paths.Temp, Path.GetRandomFileName());
+                    XDocument hocrDocument;
+                    try
+                    {
+                        img.Save(tempImageFilePath);
+                        var tesseractProcess = Process.Start(@"C:\Program Files (x86)\Tesseract-OCR\tesseract.exe",
+                            string.Format("\"{0}\" \"{1}\" hocr -l {2}", tempImageFilePath, tempHocrFilePath, "eng"));
+                        if (tesseractProcess == null)
+                        {
+                            // Couldn't start tesseract for some reason
+                            throw new Exception();
+                        }
+                        tesseractProcess.WaitForExit();
+                        hocrDocument = XDocument.Load(tempHocrFilePath + ".html");
+                    }
+                    finally
+                    {
+                        File.Delete(tempImageFilePath);
+                        File.Delete(tempHocrFilePath + ".html");
+                    }
+
+                    if (!progressCallback(i))
+                    {
+                        return false;
+                    }
+                    float hAdjust = 72 / img.HorizontalResolution;
+                    float vAdjust = 72 / img.VerticalResolution;
+                    double realWidth = img.Width * hAdjust;
+                    double realHeight = img.Height * vAdjust;
+                    PdfPage newPage = document.AddPage();
+                    newPage.Width = (int)realWidth;
+                    newPage.Height = (int)realHeight;
+                    XGraphics gfx = XGraphics.FromPdfPage(newPage);
+                    XTextFormatter tf = new XTextFormatter(gfx);
+                    foreach (
+                        var wordElement in
+                            hocrDocument.Descendants()
+                                .Where(x => x.Attributes("class").Any(y => y.Value == "ocrx_word")))
+                    {
+                        string word = wordElement.Value;
+                        var bounds = new RectangleF();
+                        string bbox = wordElement.Attributes("title").Select(x => x.Value).SingleOrDefault();
+                        int fontSize = 10;
+                        if (bbox != null)
+                        {
+                            string[] parts = bbox.Split(' ');
+                            if (parts.Length == 5 && parts[0] == "bbox")
+                            {
+                                float x1 = int.Parse(parts[1]) * hAdjust, y1 = int.Parse(parts[2]) * vAdjust;
+                                float x2 = int.Parse(parts[3]) * hAdjust, y2 = int.Parse(parts[4]) * vAdjust;
+                                bounds = new RectangleF(x1, y1, x2 - x1, y2 - y1);
+                                fontSize = Math.Max(10, (int)(y2 - y1));
+                            }
+                        }
+                        tf.DrawString(word, new XFont("Times New Roman", fontSize, XFontStyle.Regular), XBrushes.Transparent, bounds);
+                    }
+                    gfx.DrawImage(img, 0, 0, (int)realWidth, (int)realHeight);
+                    i++;
+                }
+            }
+            document.Save(path);
+
+            return true;
+        }
+    }
+}

NAPS2.Core/NAPS2.Core.csproj

@@ -52,6 +52,7 @@
     <Compile Include="Config\ProfileManager.cs" />
     <Compile Include="Config\UserConfig.cs" />
     <Compile Include="Config\UserConfigManager.cs" />
+    <Compile Include="ImportExport\Pdf\TestOcrExporter.cs" />
     <Compile Include="Log.cs" />
     <Compile Include="NullLogger.cs" />
     <Compile Include="Scan\IScanDriverFactory.cs" />

NAPS2/DI/CommonModule.cs

@@ -29,7 +29,7 @@ namespace NAPS2.DI
             Bind<IImageImporter>().To<ImageImporter>();
 
             // Export
-            Bind<IPdfExporter>().To<PdfSharpExporter>();
+            Bind<IPdfExporter>().To<TestOcrExporter>();
             Bind<IEmailer>().To<MapiEmailer>();
 
             // Scan