void VGAWorker::processImage() {
// If this is the first time processing, initialize VGA processing fields and return
// without further processing
if(!oldScreen.data) {
oldScreen = currentScreen.clone();
if(lastStableScreen.data)
lastStableScreen.release();
lastStableScreen = Mat::zeros(currentScreen.size(), currentScreen.type());
return;
}
// Get difference between last and current images
float percentDifference = PAOLProcUtils::getVGADifferences(oldScreen, currentScreen);
// If computer image has not changed significantly
if(percentDifference < COMP_DIFF_THRESHOLD) {
// Update stable screen count
stableScreenCount++;
//copy the current image to the last stable image location
if(lastStableScreen.data)
lastStableScreen.release();
lastStableScreen = currentScreen.clone();
}
else {
// If there has been a change and the number of images stable before the change
// were enough, save the last stable image
if(stableScreenCount >= COMP_REPEAT_THRESHOLD) {
saveImageWithTimestamp(lastStableScreen);
realImageIsStored = true;
}
stableScreenCount = 0;
stableTime=currentImageTime;
}
}
void VGAWorker::saveLastImage() {
//if(stableScreenCount>0)
saveImageWithTimestamp(lastStableScreen);
}
void MainWindow::processImage() {
// If this is the first time processing, initialize WB processing fields and return
// without further processing
if(!oldFrame.data) {
oldRefinedBackground = Mat::zeros(currentFrame.size(), currentFrame.type());
oldMarkerModel = Mat::zeros(currentFrame.size(), currentFrame.type());
return;
}
// Get rectified versions of old and current frames
Mat oldRectified = PAOLProcUtils::rectifyImage(oldFrame, corners);
Mat currentRectified = PAOLProcUtils::rectifyImage(currentFrame, corners);
//compare picture to previous picture and store differences in allDiffs
float numDif;
Mat allDiffs;
PAOLProcUtils::findAllDiffsMini(allDiffs, numDif, oldRectified, currentRectified, 40, 1);
// If there is a large enough difference, reset the stable whiteboard image count and do further processing
if(numDif > .03) {
// Reset stable whiteboard image count
stableWhiteboardCount = 0;
// Find true differences (ie. difference pixels with enough differences surrounding them)
float refinedNumDif;
Mat filteredDiffs;
PAOLProcUtils::filterNoisyDiffs(filteredDiffs, refinedNumDif, allDiffs);
displayMat(filteredDiffs, *ui->imDisplay4);
// Find if there are enough true differences to update the current marker and whiteboard models
// (ie. professor movement or lighting change detected)
if(refinedNumDif > .04) {
// Identify where the motion (ie. the professor) is
Mat movement = PAOLProcUtils::expandDifferencesRegion(filteredDiffs);
// Rescale movement info to full size
Mat mvmtFullSize = PAOLProcUtils::enlarge(movement);
displayMat(mvmtFullSize, *ui->imDisplay5);
// Find marker candidates
Mat markerCandidates = PAOLProcUtils::findMarkerStrokeCandidates(currentRectified);
// Find marker locations
Mat markerLocations = PAOLProcUtils::findMarkerStrokeLocations(currentRectified);
// Keep marker candidates intersecting with marker locations
Mat currentMarkerWithProf = PAOLProcUtils::filterConnectedComponents(markerCandidates, markerLocations);
// Use the movement information to erase the professor
Mat currentMarkerModel = PAOLProcUtils::updateModel(
oldMarkerModel, currentMarkerWithProf, mvmtFullSize);
displayMat(currentMarkerModel, *ui->imDisplay6);
// Find how much the current marker model differs from the stored one
float markerDiffs = PAOLProcUtils::findMarkerModelDiffs(oldMarkerModel, currentMarkerModel);
qDebug("numDif: %f", numDif);
qDebug("refinedNumDif: %f", refinedNumDif);
qDebug("markerDiffs: %f", markerDiffs);
// Save and update the models if the marker content changed enough
if(markerDiffs > .008) {
// Save the smooth marker version of the old background image
Mat oldRefinedBackgroundSmooth = PAOLProcUtils::smoothMarkerTransition(oldRefinedBackground);
saveImageWithTimestamp(oldRefinedBackgroundSmooth);
// Update marker model
oldMarkerModel = currentMarkerModel.clone();
// Update enhanced version of background
Mat whiteWhiteboard = PAOLProcUtils::whitenWhiteboard(currentRectified, currentMarkerModel);
oldRefinedBackground = PAOLProcUtils::updateModel(
oldRefinedBackground, whiteWhiteboard, mvmtFullSize);
displayMat(oldRefinedBackground, *ui->imDisplay2);
}
}
}
// Otherwise, check if the frames are basically identical (ie. stable)
else if(numDif < .000001) {
stableWhiteboardCount++;
// If the image has been stable for exactly twenty frames, the lecturer is not present, so we
// can update the marker and whiteboard models without movement information
if(stableWhiteboardCount == 20) {
// Save the smooth marker version of the old background image
Mat oldRefinedBackgroundSmooth = PAOLProcUtils::smoothMarkerTransition(oldRefinedBackground);
saveImageWithTimestamp(oldRefinedBackgroundSmooth);
// Update marker model
// Find marker candidates
Mat markerCandidates = PAOLProcUtils::findMarkerStrokeCandidates(currentRectified);
// Find marker locations
Mat markerLocations = PAOLProcUtils::findMarkerStrokeLocations(currentRectified);
// Keep marker candidates intersecting with marker locations
Mat currentMarkerModel = PAOLProcUtils::filterConnectedComponents(markerCandidates, markerLocations);
oldMarkerModel = currentMarkerModel.clone();
// Update enhanced version of background
Mat whiteWhiteboard = PAOLProcUtils::whitenWhiteboard(currentRectified, currentMarkerModel);
oldRefinedBackground = whiteWhiteboard.clone();
displayMat(oldRefinedBackground, *ui->imDisplay2);
}
}
}
