function image_rgb2hsv ($R,$G,$B) {
	$var_R = ( $R / 255 ) ;                    //Where RGB values = 0 ÷ 255
	$var_G = ( $G / 255 );
	$var_B = ( $B / 255 );

	$var_Min = min( $var_R, $var_G, $var_B ) ;   //Min. value of RGB
	$var_Max = max( $var_R, $var_G, $var_B ) ;   //Max. value of RGB
	$del_Max = $var_Max - $var_Min  ;           //Delta RGB value

	$V = $var_Max;
	$L = ( $var_Max + $var_Min ) / 2;
	
	if ( $del_Max == 0 )                     //This is a gray, no chroma...
	{
	   $H = 0 ;                            //HSL results = 0 ÷ 1
	   $S = 0 ;
	}
	else                                    //Chromatic data...
	{
	   $S = $del_Max / $var_Max;
	
	   $del_R = ( ( ( $var_Max - $var_R ) / 6 ) + ( $del_Max / 2 ) ) / $del_Max;
	   $del_G = ( ( ( $var_Max - $var_G ) / 6 ) + ( $del_Max / 2 ) ) / $del_Max;
	   $del_B = ( ( ( $var_Max - $var_B ) / 6 ) + ( $del_Max / 2 ) ) / $del_Max;
	
	   if      ( $var_R == $var_Max ) $H = $del_B - $del_G;
	   else if ( $var_G == $var_Max ) $H = ( 1 / 3 ) + $del_R - $del_B;
	   else if ( $var_B == $var_Max ) $H = ( 2 / 3 ) + $del_G - $del_R;
	
	   if ( $H < 0 )  $H =  $H + 1;
	   if ( $H > 1 )  $H = $H - 1;
	}
				
	$ret["h"] = $H;
	$ret["s"] = $S;
	$ret["v"] = $V;
	
	return $ret;
}