public static void processImage(Tesseract.TesseractEngine engine, Tesseract.Pix img, string testImagePath, int pageNum)
{
System.IO.FileInfo mfile = new System.IO.FileInfo(testImagePath);
string hocrPath = mfile.DirectoryName + "\\" + System.IO.Path.GetFileNameWithoutExtension(testImagePath) + "_p" + pageNum.ToString() + ".xhtml";
using (var page = engine.Process(img, PageSegMode.AutoOsd))
{
page.AnalyseLayout();
string hocr = page.GetHOCRText(0, true);
System.IO.File.AppendAllText(hocrPath, hocr);
var text = page.GetText();
Console.WriteLine("Mean confidence: {0}", page.GetMeanConfidence());
Console.WriteLine("Text (GetText): \r\n{0}", text);
Console.WriteLine("Text (iterator):");
using (var iter = page.GetIterator())
{
iter.Begin();
do
{
do
{
do
{
do
{
if (iter.IsAtBeginningOf(PageIteratorLevel.Block))
{
Console.WriteLine("<BLOCK>");
Rect currentBlock;
iter.TryGetBoundingBox(PageIteratorLevel.Block, out currentBlock);
Console.WriteLine(iter.BlockType.ToString());
Console.WriteLine("(" + currentBlock.X1.ToString() + "," + currentBlock.Y1.ToString() + ") (" + currentBlock.X2.ToString() + "," + currentBlock.Y2.ToString() + ")");
Console.WriteLine("");
}
Console.Write(iter.GetText(PageIteratorLevel.Word));
Console.Write(" ");
if (iter.IsAtFinalOf(PageIteratorLevel.TextLine, PageIteratorLevel.Word))
{
Console.WriteLine(iter.BlockType.ToString());
}
} while (iter.Next(PageIteratorLevel.TextLine, PageIteratorLevel.Word));
if (iter.IsAtFinalOf(PageIteratorLevel.Para, PageIteratorLevel.TextLine))
{
Console.WriteLine();
}
} while (iter.Next(PageIteratorLevel.Para, PageIteratorLevel.TextLine));
} while (iter.Next(PageIteratorLevel.Block, PageIteratorLevel.Para));
} while (iter.Next(PageIteratorLevel.Block));
}
}
}
public static byte[] PerformOCRTesseract(byte[] image)
{
// Specify that Tesseract use three 3 languages: English, Russian and Vietnamese.
string tesseractLanguages = "rus+eng+vie";
// A path to a folder which contains languages data files and font file "pdf.ttf".
// Language data files can be found here:
// Good and fast: https://github.com/tesseract-ocr/tessdata_fast
// or
// Best and slow: https://github.com/tesseract-ocr/tessdata_best
// Also this folder must have write permissions.
string tesseractData = Path.GetFullPath(@"..\..\tessdata\");
// A path for a temporary PDF file (because Tesseract returns OCR result as PDF document)
string tempFile = Path.Combine(tesseractData, Path.GetRandomFileName());
try
{
using (Tesseract.IResultRenderer renderer = Tesseract.PdfResultRenderer.CreatePdfRenderer(tempFile, tesseractData, true))
{
using (renderer.BeginDocument("Serachablepdf"))
{
using (Tesseract.TesseractEngine engine = new Tesseract.TesseractEngine(tesseractData, tesseractLanguages, Tesseract.EngineMode.Default))
{
engine.DefaultPageSegMode = Tesseract.PageSegMode.Auto;
using (MemoryStream msImg = new MemoryStream(image))
{
System.Drawing.Image imgWithText = System.Drawing.Image.FromStream(msImg);
for (int i = 0; i < imgWithText.GetFrameCount(System.Drawing.Imaging.FrameDimension.Page); i++)
{
imgWithText.SelectActiveFrame(System.Drawing.Imaging.FrameDimension.Page, i);
using (MemoryStream ms = new MemoryStream())
{
imgWithText.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
byte[] imgBytes = ms.ToArray();
using (Tesseract.Pix img = Tesseract.Pix.LoadFromMemory(imgBytes))
{
using (var page = engine.Process(img, "Serachablepdf"))
{
renderer.AddPage(page);
}
}
}
}
}
}
}
}
PdfLoadOptions pl = new PdfLoadOptions();
pl.ShowInvisibleText = true;
pl.PreserveEmbeddedFonts = false;
pl.ConversionMode = PdfConversionMode.Continuous;
DocumentCore dc = DocumentCore.Load(File.OpenRead(tempFile + @".pdf"), pl);
byte[] returnPdf;
using (MemoryStream ms = new MemoryStream())
{
PdfSaveOptions ps = new PdfSaveOptions();
dc.Save(ms, ps);
returnPdf = ms.ToArray();
}
return(returnPdf);
}
catch (Exception e)
{
Console.WriteLine();
Console.WriteLine("Please be sure that you have Language data files (*.traineddata) in your folder \"tessdata\"");
Console.WriteLine("The Language data files can be download from here: https://github.com/tesseract-ocr/tessdata_fast");
Console.ReadKey();
throw new Exception("Error Tesseract: " + e.Message);
}
finally
{
if (File.Exists(tempFile + ".pdf"))
{
File.Delete(tempFile + ".pdf");
}
}
}
