diff --git a/src/apps/showimage/Filter.cpp b/src/apps/showimage/Filter.cpp
index 43a38e3a11..b9521bd7f9 100644
--- a/src/apps/showimage/Filter.cpp
+++ b/src/apps/showimage/Filter.cpp
@@ -1068,7 +1068,7 @@ ImageProcessor::Run(int32 i, int32 n)
 				}
 			}
 			break;
-		case kMirrorHorizontal:
+		case kFlipUpsideDown:
 			for (y = from; y <= to; y ++) {
 				for (x = 0; x <= fWidth; x ++) {
 					destX = x;
@@ -1077,7 +1077,7 @@ ImageProcessor::Run(int32 i, int32 n)
 				}
 			}
 			break;
-		case kMirrorVertical:
+		case kFlipSideways:
 			for (y = from; y <= to; y ++) {
 				for (x = 0; x <= fWidth; x ++) {
 					destX = fWidth - x;
diff --git a/src/apps/showimage/Filter.h b/src/apps/showimage/Filter.h
index aeb45b37dd..d1faa19d32 100644
--- a/src/apps/showimage/Filter.h
+++ b/src/apps/showimage/Filter.h
@@ -189,8 +189,8 @@ public:
 	enum operation {
 		kRotateClockwise,
 		kRotateAntiClockwise,
-		kMirrorVertical,
-		kMirrorHorizontal,
+		kFlipSideways,
+		kFlipUpsideDown,
 		kInvert,
 		kNumberOfAffineTransformations = 4
 	};
diff --git a/src/apps/showimage/ShowImageConstants.h b/src/apps/showimage/ShowImageConstants.h
index 380658edb2..a8c5bd5ff3 100644
--- a/src/apps/showimage/ShowImageConstants.h
+++ b/src/apps/showimage/ShowImageConstants.h
@@ -40,8 +40,8 @@ const uint32 MSG_SHRINK_TO_WINDOW   = 'mSTW';
 const uint32 MSG_ZOOM_TO_WINDOW     = 'mZTW';
 const uint32 MSG_ROTATE_90			= 'mR90';
 const uint32 MSG_ROTATE_270			= 'mR27';
-const uint32 MSG_MIRROR_VERTICAL    = 'mMIV';
-const uint32 MSG_MIRROR_HORIZONTAL  = 'mMIH';
+const uint32 MSG_FLIP_SIDEWAYS    	= 'mFSW';
+const uint32 MSG_FLIP_UPSIDE_DOWN  	= 'mFUD';
 const uint32 MSG_INVERT             = 'mINV';
 const uint32 MSG_SLIDE_SHOW         = 'mSSW';
 const uint32 MSG_SLIDE_SHOW_DELAY   = 'mSSD';
diff --git a/src/apps/showimage/ShowImageView.cpp b/src/apps/showimage/ShowImageView.cpp
index 0075ea3c13..40b32cfe0b 100644
--- a/src/apps/showimage/ShowImageView.cpp
+++ b/src/apps/showimage/ShowImageView.cpp
@@ -497,18 +497,18 @@ ShowImageView::SetImage(const entry_ref *ref)
 				DoImageOperation(ImageProcessor::kRotateAntiClockwise, true);
 				break;
 			case k0V:
-				DoImageOperation(ImageProcessor::ImageProcessor::kMirrorHorizontal, true);
+				DoImageOperation(ImageProcessor::ImageProcessor::kFlipUpsideDown, true);
 				break;
 			case k90V:
 				DoImageOperation(ImageProcessor::kRotateClockwise, true);
-				DoImageOperation(ImageProcessor::ImageProcessor::kMirrorHorizontal, true);
+				DoImageOperation(ImageProcessor::ImageProcessor::kFlipUpsideDown, true);
 				break;
 			case k0H:
-				DoImageOperation(ImageProcessor::ImageProcessor::kMirrorVertical, true);
+				DoImageOperation(ImageProcessor::ImageProcessor::kFlipSideways, true);
 				break;
 			case k270V:
 				DoImageOperation(ImageProcessor::kRotateAntiClockwise, true);
-				DoImageOperation(ImageProcessor::ImageProcessor::kMirrorHorizontal, true);
+				DoImageOperation(ImageProcessor::ImageProcessor::kFlipUpsideDown, true);
 				break;
 		}
 	}
@@ -741,6 +741,10 @@ ShowImageView::AlignBitmap()
 		rect.right = floorf(bitmapWidth * zoom) - 1; 
 		rect.bottom = floorf(bitmapHeight * zoom) - 1;
 
+		// update the bitmap size after the zoom
+		bitmapWidth = rect.Width() + 1.0;
+		bitmapHeight = rect.Height() + 1.0;
+
 		// align
 		switch (fHAlignment) {
 			case B_ALIGN_CENTER:
@@ -2388,8 +2392,8 @@ ShowImageView::DoImageOperation(ImageProcessor::operation op, bool quiet)
 		// Note: If one of these fails, check its definition in class ImageProcessor.
 		ASSERT(ImageProcessor::kRotateClockwise < ImageProcessor::kNumberOfAffineTransformations);
 		ASSERT(ImageProcessor::kRotateAntiClockwise < ImageProcessor::kNumberOfAffineTransformations);
-		ASSERT(ImageProcessor::kMirrorVertical < ImageProcessor::kNumberOfAffineTransformations);
-		ASSERT(ImageProcessor::kMirrorHorizontal < ImageProcessor::kNumberOfAffineTransformations);
+		ASSERT(ImageProcessor::kFlipSideways < ImageProcessor::kNumberOfAffineTransformations);
+		ASSERT(ImageProcessor::kFlipUpsideDown < ImageProcessor::kNumberOfAffineTransformations);
 		fImageOrientation = fTransformation[op][fImageOrientation];
 	} else {
 		fInverted = !fInverted;
@@ -2440,12 +2444,12 @@ ShowImageView::Rotate(int degree)
 
 
 void
-ShowImageView::Mirror(bool vertical) 
+ShowImageView::Flip(bool vertical) 
 {
 	if (vertical) {
-		UserDoImageOperation(ImageProcessor::kMirrorVertical);
+		UserDoImageOperation(ImageProcessor::kFlipSideways);
 	} else {
-		UserDoImageOperation(ImageProcessor::kMirrorHorizontal);
+		UserDoImageOperation(ImageProcessor::kFlipUpsideDown);
 	}
 }
 
diff --git a/src/apps/showimage/ShowImageView.h b/src/apps/showimage/ShowImageView.h
index 881032ae1c..8bec416624 100644
--- a/src/apps/showimage/ShowImageView.h
+++ b/src/apps/showimage/ShowImageView.h
@@ -101,7 +101,7 @@ class ShowImageView : public BView {
 
 		// Image manipulation
 		void Rotate(int degree); // 90 and 270 only
-		void Mirror(bool vertical);
+		void Flip(bool vertical);
 		void Invert();
 
 		void SetIcon(bool clear);
diff --git a/src/apps/showimage/ShowImageWindow.cpp b/src/apps/showimage/ShowImageWindow.cpp
index d14136dd3e..7ec4aaa3cd 100644
--- a/src/apps/showimage/ShowImageWindow.cpp
+++ b/src/apps/showimage/ShowImageWindow.cpp
@@ -329,8 +329,8 @@ ShowImageWindow::AddMenus(BMenuBar *bar)
 	AddItemMenu(menu, "Rotate -90°", MSG_ROTATE_270, '[', 0, 'W', true);
 	AddItemMenu(menu, "Rotate +90°", MSG_ROTATE_90, ']', 0, 'W', true);
 	menu->AddSeparatorItem();
-	AddItemMenu(menu, "Mirror Vertical", MSG_MIRROR_VERTICAL, 0, 0, 'W', true);
-	AddItemMenu(menu, "Mirror Horizontal", MSG_MIRROR_HORIZONTAL, 0, 0, 'W', true);
+	AddItemMenu(menu, "Flip Sideways", MSG_FLIP_SIDEWAYS, 0, 0, 'W', true);
+	AddItemMenu(menu, "Flip Upside Down", MSG_FLIP_UPSIDE_DOWN, 0, 0, 'W', true);
 	menu->AddSeparatorItem();
 	AddItemMenu(menu, "Invert", MSG_INVERT, 0, 0, 'W', true);
 	bar->AddItem(menu);
@@ -717,11 +717,11 @@ ShowImageWindow::MessageReceived(BMessage *message)
 		case MSG_ROTATE_270:
 			fImageView->Rotate(270);
 			break;
-		case MSG_MIRROR_VERTICAL:
-			fImageView->Mirror(true);
+		case MSG_FLIP_SIDEWAYS:
+			fImageView->Flip(true);
 			break;
-		case MSG_MIRROR_HORIZONTAL:
-			fImageView->Mirror(false);
+		case MSG_FLIP_UPSIDE_DOWN:
+			fImageView->Flip(false);
 			break;
 		case MSG_INVERT:
 			fImageView->Invert();