/// <summary>
/// try to give resources free
/// TODO: most likely, this method is not used
/// </summary>
/// <param name="ce"></param>
private static void DisposeData(ContextEntry ce)
{
if (ce == null || ce.Screenshot == null) return;
if (ce.Screenshot.Image != null) ce.Screenshot.Image.Dispose();
if (ce.Screenshot != null) ce.Screenshot.Dispose();
ce = null;
}
/// <summary>
/// Gets a screenshot of the active window (already optimised for OCR),
/// calculates the thresholded image,
/// runs the OCR,
/// and returns the result as a context entry.
/// </summary>
/// <param name="ce"></param>
/// <returns></returns>
public ContextEntry RunOcr(ContextEntry ce)
{
if (_tEngine == null) return null;
try
{
// run OCR preprocessing
RunOcrPreProcessing(ce.Screenshot);
// processed screenshot
var processedScreenshot = ce.Screenshot.Image;
// threshold
//screenshot = _tEngine.GetThresholdedImage(screenshot, Rectangle.Empty); //TODO: enable or disable?
//Screenshot.SaveImage(screenshot, "thresholded"); //TEMP
_tEngine.OcrDone += OcrFinished;
//var result = _tEngine.DoOCR(screenshot, Rectangle.Empty); // used for single-threading OCR processing
_tEngine.DoOCR(processedScreenshot, Rectangle.Empty);
processedScreenshot.Dispose();
_mEvent = new ManualResetEvent(false);
_mEvent.WaitOne(); // wait here until it's finished
// add ocr'd text to context entry
ce.OcrText = _temporaryOcrText;
ce.Confidence = _tempConfidence;
// reset temp values
_temporaryOcrText = string.Empty;
_tempConfidence = Settings.OcrConfidenceAcceptanceThreshold;
// release sources
ce.Screenshot.Dispose();
ce.Screenshot = null;
}
catch (Exception e)
{
Logger.WriteToLogFile(e);
}
return ce;
}
private static void SaveContextEntryToDatabase(ContextEntry contextEntry)
{
if (contextEntry == null ||
contextEntry.OcrText == string.Empty || // no text recognized
contextEntry.Confidence < 0.5) // makes no sense to save if recognition is too in-accurate
return;
var query = "INSERT INTO " + Settings.DbTable +
" (time, timestamp, ocrText, confidentality, windowName, processName) VALUES (strftime('%Y-%m-%d %H:%M:%S', 'now', 'localtime'), " +
Database.GetInstance().QTime(contextEntry.Timestamp) + ", " +
Database.GetInstance().Q(contextEntry.OcrText) + ", " +
Database.GetInstance().Q(contextEntry.Confidence.ToString()) + ", " +
Database.GetInstance().Q(contextEntry.WindowName) + ", " +
Database.GetInstance().Q(contextEntry.ProcessName) + ");";
Database.GetInstance().ExecuteDefaultQuery(query);
}
/// <summary>
/// Every x seconds the Context Recognition algorithm is run if the window has changed.
/// Some info about the context is added (currently: process + windows information)
/// Then, the background worker is started for OCR recognition
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void RunContextRecognition(object sender, EventArgs e)
{
// determine whether store or not
if (_screenshotChangedTracker == null || !_screenshotChangedTracker.WindowChanged()) return;
// capture the screenshot
var sc = ScreenCapture.CaptureActiveWindowHq();
if (sc == null || sc.Image == null) return; // screenshot capture unsuccessful
// get window & process names (additional contextual information)
var currentWindowName = _screenshotChangedTracker.GetWindowText();
var currentProcessName = _screenshotChangedTracker.GetProcessName();
var ce = new ContextEntry
{
Timestamp = DateTime.Now,
WindowName = currentWindowName,
ProcessName = currentProcessName,
Confidence = OcrLibrary.Settings.OcrConfidenceAcceptanceThreshold, // so it won't be saved if it isn't overwritten
OcrText = string.Empty,
Screenshot = sc
};
// runs the OCR process and get's the result as a context entry
ce = OcrEngine.GetInstance().RunOcr(ce);
// only save in database if useful accuracy & enough content
if (ce != null &&
ce.Confidence < OcrLibrary.Settings.OcrConfidenceAcceptanceThreshold &&
ce.OcrText.Length > OcrLibrary.Settings.OcrTextLengthAcceptanceThreshold)
{
SaveContextEntryToDatabase(ce);
}
// dispose data (to free up RAM)
DisposeData(ce);
}
