function image_courbe($im, $couche, $courb="") {

	$numargs = func_num_args();
	$arg_list = func_get_args();
	$texte = $arg_list[0];
	for ($i = 1; $i < $numargs; $i++) {
		if (ereg("\=", $arg_list[$i])) {
			$nom_variable = substr($arg_list[$i], 0, strpos($arg_list[$i], "="));
			$val_variable = substr($arg_list[$i], strpos($arg_list[$i], "=")+1, strlen($arg_list[$i]));
			$courbe[$nom_variable] = $val_variable;
		}
	}

	$image = valeurs_image_trans($im, "courbe-$couche-".serialize($courbe));
	if (!$image) return("");

	$x_i = $image["largeur"];
	$y_i = $image["hauteur"];
	
	$im = $image["fichier"];
	$dest = $image["fichier_dest"];
	$creer = $image["creer"];

	if ($creer) {
		$courbe[0] = 0;
		$courbe[255] = 255;
	
		ksort($courbe);
		while (list($key, $val) = each($courbe)) {
			if ($key > 0) {
				$key1 = $key_old;
				$val1 = $val_old;
				$prop = ($val - $val1) / ($key-$key1);
				for ($i = $key1; $i < $key; $i++) {
					$valeur = round($prop * ($i - $key1) + $val1);
					$courbe[$i] = $valeur;
				}
				$key_old = $key;
				$val_old = $val;
			} else {
				$key_old = $key;
				$val_old = $val;
			}
		}

		$im = $image["fonction_imagecreatefrom"]($im);
		$im_ = imagecreatetruecolor($x_i, $y_i);
		@imagealphablending($im_, false);
		@imagesavealpha($im_,true);
		$color_t = ImageColorAllocateAlpha( $im_, 255, 255, 255 , 0 );
		imagefill ($im_, 0, 0, $color_t);

		for ($x = 0; $x < $x_i; $x++) {
			for ($y=0; $y < $y_i; $y++) {
				$rgb = ImageColorAt($im, $x, $y);
				$a = ($rgb >> 24) & 0xFF;
				$r = ($rgb >> 16) & 0xFF;
				$v = ($rgb >> 8) & 0xFF;
				$b = $rgb & 0xFF;
				
				if ($couche == "rvb" OR $couche == "r") $r = $courbe[$r];
				if ($couche == "rvb" OR $couche == "v") $v = $courbe[$v];
				if ($couche == "rvb" OR $couche == "b") $b = $courbe[$b];
				
				$color = ImageColorAllocateAlpha( $im_, $r, $v, $b , $a );
				imagesetpixel ($im_, $x, $y, $color);			
			}
		}

		$image["fonction_image"]($im_, "$dest");
		imagedestroy($im_);
		imagedestroy($im);
	}

	$class = $image["class"];
	if (strlen($class) > 1) $tags=" class='$class'";
	$tags = "$tags alt='".$image["alt"]."'";
	$style = $image["style"];
	if (strlen($style) > 1) $tags="$tags style='$style'";
	return "<img src='$dest'$tags />";
}