diff --git a/source/app/ModulesHandle.cpp b/source/app/ModulesHandle.cpp
index decd84b..44cbc9e 100644
--- a/source/app/ModulesHandle.cpp
+++ b/source/app/ModulesHandle.cpp
@@ -77,7 +77,7 @@ SubWindowHandle* ModulesHandle::toggleSelectedModuleIf()
   if( currModuleIf->m_pcAction->isChecked() )
   {
     currModuleIf->m_pcDisplaySubWindow = NULL;
-    if( currModuleIf->m_cModuleDef.m_bRequiresNewWindow || bShowModulesNewWindow )
+    if( ( currModuleIf->m_cModuleDef.m_uiModuleRequirements & MODULE_REQUIRES_NEW_WINDOW ) || bShowModulesNewWindow )
     {
       QString windowName;
       interfaceChild = new SubWindowHandle( m_pcParent );
diff --git a/source/app/PlaYUVerModuleIf.h b/source/app/PlaYUVerModuleIf.h
index 67b81e2..f8d3bcc 100644
--- a/source/app/PlaYUVerModuleIf.h
+++ b/source/app/PlaYUVerModuleIf.h
@@ -49,7 +49,9 @@ enum __PlaYUVerModuleRequirements
 {
   MODULE_REQUIRES_FRAME = 1,
   MODULE_REQUIRES_TWOFRAMES = 2,
-  MODULE_REQUIRES_SIDEBAR = 4,
+  MODULE_REQUIRES_NEW_WINDOW = 4,
+  MODULE_REQUIRES_SIDEBAR = 8,
+  MODULES_REQUIREMENTS_TOTAL,
 };
 
 #define REGISTER_MODULE(X)                      \
@@ -63,39 +65,41 @@ enum __PlaYUVerModuleRequirements
 
 typedef struct __PlaYUVerModuleDefinition
 {
-  int   m_iModuleType;
-  const char* m_pchModuleCategory;
-  const char* m_pchModuleName;
-  const char* m_pchModuleTooltip;
-  bool  m_bRequiresNewWindow;
-}PlaYUVerModuleDefinition;
+  Int m_iModuleType;
+  const Char* m_pchModuleCategory;
+  const Char* m_pchModuleName;
+  const Char* m_pchModuleTooltip;
+  UInt m_uiModuleRequirements;
+} PlaYUVerModuleDefinition;
 
 class SubWindowHandle;
 
 class PlaYUVerModuleIf
 {
   friend class ModulesHandle;
-
-public:
-  PlaYUVerModuleDefinition m_cModuleDef;
 private:
   QAction* m_pcAction;
   SubWindowHandle* m_pcSubWindow;
   SubWindowHandle* m_pcDisplaySubWindow;
-
+  PlaYUVerModuleDefinition m_cModuleDef;
 public:
-  PlaYUVerModuleIf() {  }
+  PlaYUVerModuleIf() :
+          m_pcAction( NULL ),
+          m_pcSubWindow( NULL ),
+          m_pcDisplaySubWindow( NULL )
+  { }
   virtual ~PlaYUVerModuleIf() { }
 
-  virtual Void create() {};
-  virtual Void create( PlaYUVerFrame* ) {};
+  virtual Void create()                 { }
+  virtual Void create( PlaYUVerFrame* ) { }
 
-  virtual Void            process() {};
-  virtual PlaYUVerFrame*  process( PlaYUVerFrame* )                   { return NULL; };
-  virtual PlaYUVerFrame*  process( PlaYUVerFrame* , PlaYUVerFrame* )  { return NULL; };
+  virtual Void              process()                                 {               }
+  virtual PlaYUVerFrame*    process( PlaYUVerFrame* )                 { return NULL;  }
+  virtual PlaYUVerFrame*    process( PlaYUVerFrame*, PlaYUVerFrame* ) { return NULL;  }
 
-  virtual Void destroy() {};
+  virtual Void destroy(){ }
 
+  Void setModuleDefinition( PlaYUVerModuleDefinition def )  { m_cModuleDef = def; }
 };
 
 }  // NAMESPACE
diff --git a/source/modules/FilterFrame.cpp b/source/modules/FilterFrame.cpp
index 28bfa49..6a40d0a 100644
--- a/source/modules/FilterFrame.cpp
+++ b/source/modules/FilterFrame.cpp
@@ -35,12 +35,12 @@ PlaYUVerModuleDefinition FilterFrameDef = {
     "Filters",
     "Y_Filter",
     "Filter Y matrix of YUV frame",
-    false,
+    MODULE_REQUIRES_FRAME,
 };
 
 FilterFrame::FilterFrame()
 {
-  m_cModuleDef = FilterFrameDef;
+  setModuleDefinition( FilterFrameDef );
   m_pcFilteredFrame = NULL;
 }
 
diff --git a/source/modules/FrameDifference.cpp b/source/modules/FrameDifference.cpp
index 16b2add..7199c2c 100644
--- a/source/modules/FrameDifference.cpp
+++ b/source/modules/FrameDifference.cpp
@@ -36,12 +36,13 @@ static PlaYUVerModuleDefinition FrameDifferenceDef =
     "Measurements",
     "FrameDifference",
     "Measure the difference between two images (Y plane)",
-    true, };
+    MODULE_REQUIRES_TWOFRAMES | MODULE_REQUIRES_NEW_WINDOW,
+};
 
 FrameDifference::FrameDifference()
 {
   m_pcFrameDifference = NULL;
-  m_cModuleDef = FrameDifferenceDef;
+  setModuleDefinition( FrameDifferenceDef );
 }
 
 Void FrameDifference::create( PlaYUVerFrame* Input )
diff --git a/source/modules/MeasurePSNR.cpp b/source/modules/MeasurePSNR.cpp
index 3843fba..9cf2b0c 100644
--- a/source/modules/MeasurePSNR.cpp
+++ b/source/modules/MeasurePSNR.cpp
@@ -35,13 +35,14 @@ static PlaYUVerModuleDefinition MeasurePSNRDef =
     FRAME_LEVEL_MODULE,
     "Measurements",
     "PSNR",
-    "MEasure the PSNR between two images",
-    true, };
+    "Measure the PSNR between two images",
+    MODULE_REQUIRES_TWOFRAMES | MODULE_REQUIRES_SIDEBAR,
+};
 
 MeasurePSNR::MeasurePSNR()
 {
   m_pcFilteredFrame = NULL;
-  m_cModuleDef = MeasurePSNRDef;
+  setModuleDefinition( MeasurePSNRDef );
 }
 
 Void MeasurePSNR::create( PlaYUVerFrame* InputFrame )