From aafe4beac48dd6bb192f4a65af463f485ea88b96 Mon Sep 17 00:00:00 2001
From: matlabbe <matlabbe@620bd6b2-0a58-f614-fd9a-1bd335dccda9>
Date: Thu, 5 Jan 2012 00:31:29 +0000
Subject: [PATCH] Fixed a crash (Windows) after adding an object. This may be
 related to issue 1. The cause is that the first image acquired from the
 camera is blank, so no features are extracted and the code not handled this
 case, crashing during nearest neighbor search.

git-svn-id: http://find-object.googlecode.com/svn/trunk/find_object@67 620bd6b2-0a58-f614-fd9a-1bd335dccda9
---
 src/MainWindow.cpp | 35 ++++++++++++++++++++---------------
 src/ObjWidget.cpp  | 14 ++++++++++++++
 2 files changed, 34 insertions(+), 15 deletions(-)

diff --git a/src/MainWindow.cpp b/src/MainWindow.cpp
index 2d8b0dde..0f516ef0 100644
--- a/src/MainWindow.cpp
+++ b/src/MainWindow.cpp
@@ -353,31 +353,38 @@ void MainWindow::update(const cv::Mat & image)
 		delete detector;
 		ui_->label_timeDetection->setText(QString::number(time.restart()));
 
-		// EXTRACT DESCRIPTORS
 		cv::Mat descriptors;
-		cv::DescriptorExtractor * extractor = Settings::createDescriptorsExtractor();
-		extractor->compute(img, keypoints, descriptors);
-		delete extractor;
-		if((int)keypoints.size() != descriptors.rows)
+		if(keypoints.size())
 		{
-			printf("ERROR : kpt=%d != descriptors=%d\n", (int)keypoints.size(), descriptors.rows);
+			// EXTRACT DESCRIPTORS
+			cv::DescriptorExtractor * extractor = Settings::createDescriptorsExtractor();
+			extractor->compute(img, keypoints, descriptors);
+			delete extractor;
+			if((int)keypoints.size() != descriptors.rows)
+			{
+				printf("ERROR : kpt=%d != descriptors=%d\n", (int)keypoints.size(), descriptors.rows);
+			}
+			if(imageGrayScale)
+			{
+				cvReleaseImage(&imageGrayScale);
+			}
+			ui_->label_timeExtraction->setText(QString::number(time.restart()));
 		}
-		if(imageGrayScale)
+		else
 		{
-			cvReleaseImage(&imageGrayScale);
+			printf("WARNING: no features detected !?!\n");
+			ui_->label_timeExtraction->setText(QString::number(0));
 		}
-		ui_->label_timeExtraction->setText(QString::number(time.restart()));
 
 		// COMPARE
-		int alpha = 20*255/100;
-		if(!dataTree_.empty() && (Settings::getNearestNeighbor_nndrRatioUsed() || Settings::getNearestNeighbor_minDistanceUsed()))
+		if(!dataTree_.empty() && keypoints.size() && (Settings::getNearestNeighbor_nndrRatioUsed() || Settings::getNearestNeighbor_minDistanceUsed()))
 		{
 			// CREATE INDEX
 			cv::Mat environment(descriptors.rows, descriptors.cols, CV_32F);
 			descriptors.convertTo(environment, CV_32F);
 			cv::flann::Index treeFlannIndex(environment, cv::flann::KDTreeIndexParams());
 			ui_->label_timeIndexing->setText(QString::number(time.restart()));
-
+			
 			// DO NEAREST NEIGHBOR
 			int k = 1;
 			if(Settings::getNearestNeighbor_nndrRatioUsed())
@@ -390,7 +397,6 @@ void MainWindow::update(const cv::Mat & image)
 			treeFlannIndex.knnSearch(dataTree_, results, dists, k, cv::flann::SearchParams(emax) ); // maximum number of leafs checked
 			ui_->label_timeMatching->setText(QString::number(time.restart()));
 
-
 			// PROCESS RESULTS
 			if(this->isVisible())
 			{
@@ -406,7 +412,6 @@ void MainWindow::update(const cv::Mat & image)
 			for(int i=0; i<dataTree_.rows; ++i)
 			{
 				QColor color((Qt::GlobalColor)(j % 12 + 7 ));
-				color.setAlpha(alpha);
 				bool matched = false;
 				// Check if this descriptor matches with those of the objects
 				if(Settings::getNearestNeighbor_nndrRatioUsed() &&
@@ -497,7 +502,7 @@ void MainWindow::update(const cv::Mat & image)
 										}
 										else
 										{
-											objects_.at(j)->setKptColor(indexes_1.at(k), QColor(0,0,0,alpha));
+											objects_.at(j)->setKptColor(indexes_1.at(k), QColor(0,0,0));
 										}
 									}
 								}
diff --git a/src/ObjWidget.cpp b/src/ObjWidget.cpp
index df737740..6404af97 100644
--- a/src/ObjWidget.cpp
+++ b/src/ObjWidget.cpp
@@ -20,6 +20,7 @@
 #include <QtGui/QVBoxLayout>
 #include <QtGui/QGraphicsRectItem>
 #include <QtGui/QInputDialog>
+#include <QtGui/QPen>
 
 #include <QtCore/QDir>
 
@@ -201,6 +202,14 @@ void ObjWidget::setAlpha(int alpha)
 				color.setAlpha(alpha_);
 				keypointItems_.at(i)->setColor(color);
 			}
+			for(int i=0; i<rectItems_.size(); ++i)
+			{
+				QPen pen = rectItems_.at(i)->pen();
+				QColor color = pen.color();
+				color.setAlpha(alpha_);
+				pen.setColor(color);
+				rectItems_.at(i)->setPen(pen);
+			}
 		}
 		if(!_graphicsViewMode->isChecked())
 		{
@@ -282,6 +291,11 @@ void ObjWidget::addRect(QGraphicsRectItem * rect)
 		graphicsView_->scene()->addItem(rect);
 	}
 	rect->setZValue(2);
+	QPen pen = rect->pen();
+	QColor color = pen.color();
+	color.setAlpha(alpha_);
+	pen.setColor(color);
+	rect->setPen(pen);
 	rectItems_.append(rect);
 }