diff --git a/imageviewer-qt4.cpp b/imageviewer-qt4.cpp
index be1cd0e..7ea2c01 100644
--- a/imageviewer-qt4.cpp
+++ b/imageviewer-qt4.cpp
@@ -212,11 +212,11 @@ void ImageViewer::analyzeImage() {
     renewLogging();
     for(int x=0; x<image->width(); x++) {
       for(int y=0; y<image->height(); y++) {
-	int r,g,b;
-	QColor color = QColor::fromRgb(image->pixel(x, y));
-	color.getRgb(&r,&g,&b);
-	int intensity = calcIntensity(r, g, b);
-	grayscale_absolute_histogramm[intensity] += 1;
+        int r,g,b;
+        QColor color = QColor::fromRgb(image->pixel(x, y));
+        color.getRgb(&r,&g,&b);
+        int intensity = calcIntensity(r, g, b);
+        grayscale_absolute_histogramm[intensity] += 1;
       }
     }
     
@@ -553,8 +553,8 @@ void ImageViewer::open() {
       return;
     } else {
       if(original_image!=NULL) {
-	delete original_image;
-	original_image = NULL;
+        delete original_image;
+        original_image = NULL;
       }
       original_image = new QImage(fileName);
     }