my $app_w = 400;
my $app_h = 300;

my $image_w = 600;
my $image_h = 200;

my $y_scale = $app_w / $image_w;
my $x_scale = $app_h / $image_h;

if( $y_scale > $x_scale ) {
	print "scale on x axis(scale y < scale x ==> $y_scale < $x_scale)\n";
	printf("y-axis overlap: %s\n", int(int($image_h - $app_h) / 2));
	
}elsif( $y_scale < $x_scale ) {
	print "scale on y axis(scale y < scale x ==> $y_scale < $x_scale)\n";
	printf("x-axis overlap: %s\n", int(int($image_w - $app_w) / 2));
	
}else{
	print 'doesn\'t matter, it will fit. It has the same aspect ratio as the window.';
}