Using keywords in Alt description

[cardsup]

I am using to generate thumbnails on the fly. Is there a way to add dynamic keywords to the image alt description?

 

For example, if someone searches for "Black shoes", the alt will have "Black shoes" in addition to the normal ' . htmlspecialchars(StripSlashes($alt)) . alt text?

 

				 // Generate thumbnail on the fly
							$image = '<img src="product_thumb.php?img='.$src.'&w='.intval($width).'&h='.intval($height).'" border="0" alt=" ' . htmlspecialchars(StripSlashes($alt)) . ' "';

		} else { 
			$rx = $image_size[0] / $width; 
			$ry = $image_size[1] / $height; 

			if ($rx < $ry) { 
				$width = $height / $ratio; 
			} else { 
				$height = $width * $ratio; 
			} 

		} 
	} 
} 

if ( ($width) && ($height) ) { 
	$image .= ' width="' . intval($width) . '" height="' . intval($height) . '"'; 
} 

if ($params != '') { 
	$image .= ' ' . $params; 
}