diff --git a/src/osg/ImageUtils.cpp b/src/osg/ImageUtils.cpp
index 4075ebc52..b40c23b31 100644
--- a/src/osg/ImageUtils.cpp
+++ b/src/osg/ImageUtils.cpp
@@ -636,7 +636,7 @@ struct ReplaceAlphaWithLuminanceOperator
 
     inline void luminance(float&) const {}
     inline void alpha(float&) const {}
-    inline void luminance_alpha(float& l,float& a) const { a= l; }
+    inline void luminance_alpha(float& l,float& a) const { a = l; }
     inline void rgb(float&,float&,float&) const { }
     inline void rgba(float& r,float& g,float& b,float& a) const { float l = (r+g+b)*0.3333333; a = l; }
 };
@@ -660,12 +660,24 @@ osg::Image* colorSpaceConversion(ColorSpaceOperation op, osg::Image* image, cons
         case (REPLACE_ALPHA_WITH_LUMINANCE):
         {
             OSG_NOTICE<<"doing conversion REPLACE_ALPHA_WITH_LUMINANCE"<<std::endl;
-            osg::modifyImage(image, ReplaceAlphaWithLuminanceOperator());
+            if (image->getPixelFormat()==GL_RGB || image->getPixelFormat()==GL_BGR)
+            {
+                osg::Image* newImage = new osg::Image;
+                newImage->allocateImage(image->s(), image->t(), image->r(), GL_RGBA, image->getDataType());
+                osg::copyImage(image, 0, 0, 0, image->s(), image->t(), image->r(),
+                            newImage, 0, 0, 0, false);
+                osg::modifyImage(newImage, ReplaceAlphaWithLuminanceOperator());
+                return newImage;
+            }
+            else
+            {
+                osg::modifyImage(image, ReplaceAlphaWithLuminanceOperator());
+            }
             return image;
         }
         case (REPLACE_RGB_WITH_LUMINANCE):
         {
-            OSG_NOTICE<<"doing conversion REPLACE_ALPHA_WITH_LUMINANCE"<<std::endl;
+            OSG_NOTICE<<"doing conversion REPLACE_RGB_WITH_LUMINANCE"<<std::endl;
             osg::Image* newImage = new osg::Image;
             newImage->allocateImage(image->s(), image->t(), image->r(), GL_LUMINANCE, image->getDataType());
             osg::copyImage(image, 0, 0, 0, image->s(), image->t(), image->r(),