private bool InitOcr(String path, String lang, OcrEngineMode mode)
{
try
{
if (_ocr != null)
{
_ocr.Dispose();
_ocr = null;
}
if (String.IsNullOrEmpty(path))
{
path = Emgu.CV.OCR.Tesseract.DefaultTesseractDirectory;
}
TesseractDownloadLangFile(path, lang);
TesseractDownloadLangFile(path, "osd"); //script orientation detection
/*
* String pathFinal = path.Length == 0 || path.Substring(path.Length - 1, 1).Equals(Path.DirectorySeparatorChar.ToString())
* ? path
* : String.Format("{0}{1}", path, System.IO.Path.DirectorySeparatorChar);
*/
_ocr = new Tesseract(path, lang, mode);
languageNameLabel.Text = String.Format("{0} : {1} (tesseract version {2})", lang, mode.ToString(), Emgu.CV.OCR.Tesseract.VersionString);
return(true);
}
catch (Exception e)
{
_ocr = null;
MessageBox.Show(e.Message, "Failed to initialize tesseract OCR engine", MessageBoxButtons.OK);
languageNameLabel.Text = "Failed to initialize tesseract OCR engine";
return(false);
}
}
public OCRForm()
{
InitializeComponent();
_ocr = new Tesseract("tessdata", "eng", Tesseract.OcrEngineMode.OEM_TESSERACT_CUBE_COMBINED);
languageNameLabel.Text = "eng : tesseract + cube";
}
private static String OcrImage(Tesseract ocr, Mat image, OCRMode mode, Mat imageColor)
{
Bgr drawCharColor = new Bgr(Color.Red);
if (image.NumberOfChannels == 1)
{
CvInvoke.CvtColor(image, imageColor, ColorConversion.Gray2Bgr);
}
else
{
image.CopyTo(imageColor);
}
if (mode == OCRMode.FullPage)
{
ocr.SetImage(imageColor);
if (ocr.Recognize() != 0)
{
throw new Exception("Failed to recognizer image");
}
Tesseract.Character[] characters = ocr.GetCharacters();
if (characters.Length == 0)
{
Mat imgGrey = new Mat();
CvInvoke.CvtColor(image, imgGrey, ColorConversion.Bgr2Gray);
Mat imgThresholded = new Mat();
CvInvoke.Threshold(imgGrey, imgThresholded, 65, 255, ThresholdType.Binary);
ocr.SetImage(imgThresholded);
characters = ocr.GetCharacters();
imageColor = imgThresholded;
if (characters.Length == 0)
{
CvInvoke.Threshold(image, imgThresholded, 190, 255, ThresholdType.Binary);
ocr.SetImage(imgThresholded);
characters = ocr.GetCharacters();
imageColor = imgThresholded;
}
}
foreach (Tesseract.Character c in characters)
{
CvInvoke.Rectangle(imageColor, c.Region, drawCharColor.MCvScalar);
}
return(ocr.GetUTF8Text());
}
else
{
bool checkInvert = true;
Rectangle[] regions;
using (
ERFilterNM1 er1 = new ERFilterNM1("trained_classifierNM1.xml", 8, 0.00025f, 0.13f, 0.4f, true, 0.1f))
using (ERFilterNM2 er2 = new ERFilterNM2("trained_classifierNM2.xml", 0.3f))
{
int channelCount = image.NumberOfChannels;
UMat[] channels = new UMat[checkInvert ? channelCount * 2 : channelCount];
for (int i = 0; i < channelCount; i++)
{
UMat c = new UMat();
CvInvoke.ExtractChannel(image, c, i);
channels[i] = c;
}
if (checkInvert)
{
for (int i = 0; i < channelCount; i++)
{
UMat c = new UMat();
CvInvoke.BitwiseNot(channels[i], c);
channels[i + channelCount] = c;
}
}
VectorOfERStat[] regionVecs = new VectorOfERStat[channels.Length];
for (int i = 0; i < regionVecs.Length; i++)
{
regionVecs[i] = new VectorOfERStat();
}
try
{
for (int i = 0; i < channels.Length; i++)
{
er1.Run(channels[i], regionVecs[i]);
er2.Run(channels[i], regionVecs[i]);
}
using (VectorOfUMat vm = new VectorOfUMat(channels))
{
regions = ERFilter.ERGrouping(image, vm, regionVecs, ERFilter.GroupingMethod.OrientationHoriz,
"trained_classifier_erGrouping.xml", 0.5f);
}
}
finally
{
foreach (UMat tmp in channels)
{
if (tmp != null)
{
tmp.Dispose();
}
}
foreach (VectorOfERStat tmp in regionVecs)
{
if (tmp != null)
{
tmp.Dispose();
}
}
}
Rectangle imageRegion = new Rectangle(Point.Empty, imageColor.Size);
for (int i = 0; i < regions.Length; i++)
{
Rectangle r = ScaleRectangle(regions[i], 1.1);
r.Intersect(imageRegion);
regions[i] = r;
}
}
List <Tesseract.Character> allChars = new List <Tesseract.Character>();
String allText = String.Empty;
foreach (Rectangle rect in regions)
{
using (Mat region = new Mat(image, rect))
{
ocr.SetImage(region);
if (ocr.Recognize() != 0)
{
throw new Exception("Failed to recognize image");
}
Tesseract.Character[] characters = ocr.GetCharacters();
//convert the coordinates from the local region to global
for (int i = 0; i < characters.Length; i++)
{
Rectangle charRegion = characters[i].Region;
charRegion.Offset(rect.Location);
characters[i].Region = charRegion;
}
allChars.AddRange(characters);
allText += ocr.GetUTF8Text() + Environment.NewLine;
}
}
Bgr drawRegionColor = new Bgr(Color.Red);
foreach (Rectangle rect in regions)
{
CvInvoke.Rectangle(imageColor, rect, drawRegionColor.MCvScalar);
}
foreach (Tesseract.Character c in allChars)
{
CvInvoke.Rectangle(imageColor, c.Region, drawCharColor.MCvScalar);
}
return(allText);
}
}
public OCRForm()
{
InitializeComponent();
_ocr = new Tesseract("", "eng", OcrEngineMode.TesseractCubeCombined);
languageNameLabel.Text = "eng : tesseract + cube";
}
