my $pname = 'C:\WINNT\Web\Wallpaper\Fall Memories.jpg';
my $shape = $slide->Shapes->AddPicture( $pname, msoFalse, 
                                        msoTrue, 20, 1 );
# scale to 50% of original size
$shape->ScaleHeight( 0.5, msoTrue, msoScaleFromTopLeft );
$shape->ScaleWidth( 0.5, msoTrue, msoScaleFromTopLeft );
$ppt->SaveAs($filename);