Content-type的image类型是不是每种图片都对应着一个？

<?php
$mime_type_match['jpg'] = array("image/jpeg", "image/pjpeg");
$mime_type_match['jpeg'] = array("image/jpeg", "image/pjpeg");$mime_type_match['gif'] = array("image/gif");$mime_type_match['png'] = array("image/png", "image/x-png");$mime_type_match['tif'] = array("image/tiff");
$mime_type_match['tiff'] = array("image/tiff");$mime_type_match['bmp'] = array("image/x-ms-bmp");$mime_type_match['aif'] = array("audio/x-aiff");$mime_type_match['aiff'] = array("audio/x-aiff");$mime_type_match['au'] = array("audio/basic");$mime_type_match['snd'] = array("audio/basic");$mime_type_match['mid'] = array("audio/x-midi", "audio/mid", "audio/midi");$mime_type_match['mp3'] = array("audio/mpeg", "audio/x-mpeg", "audio/mp3", "audio/mpg");$mime_type_match['ra'] = array("audio/x-pn-realaudio");$mime_type_match['ram'] = array("audio/x-pn-realaudio");$mime_type_match['rm'] = array("audio/vnd.rn-realmedia", "application/vnd.rn-realmedia", "video/vnd.rn-realvideo", "application/vnd");$mime_type_match['rpm'] = array("audio/x-pn-realaudio-plugin");$mime_type_match['wav'] = array("audio/x-wav");$mime_type_match['avi'] = array("video/x-msvideo", "video/avi");$mime_type_match['mpg'] = array("video/mpeg");
$mime_type_match['mpeg'] = array("video/mpeg");
$mime_type_match['mpe'] = array("video/mpeg");$mime_type_match['mov'] = array("video/quicktime");
$mime_type_match['qt'] = array("video/quicktime");$mime_type_match['swf'] = array("application/x-shockwave-flash");$mime_type_match['psd'] = array("application/octet-stream");
$mime_type_match['fla'] = array("application/octet-stream");
$mime_type_match['ani'] = array("application/octet-stream");$mime_type_match['gz'] = array("application/gzip", "application/x-gzip-compressed");
$mime_type_match['rar'] = array("application/x-rar-compressed");
$mime_type_match['tar'] = array("application/x-tar");
$mime_type_match['gtar'] = array("application/x-gtar");
$mime_type_match['zip'] = array("application/zip", "application/x-zip-compressed");
$mime_type_match['sit'] = array("application/x-stuffit");$mime_type_match['pdf'] = array("application/pdf", "application/x-pdf");$mime_type_match['ai'] = array("application/postscript");
$mime_type_match['eps'] = array("application/postscript");
$mime_type_match['ps'] = array("application/postscript");$mime_type_match['txt'] = array("text/plain", "text/richtext", "text/rtf", "text/html");
$mime_type_match['rtf'] = array("text/plain", "text/richtext", "text/rtf");
$mime_type_match['rtx'] = array("text/plain", "text/richtext", "text/rtf");$mime_type_match['doc'] = array("application/msword");
$mime_type_match['xls'] = array("application/vnd", "application/x-msexcel");
$mime_type_match['ppt'] = array("application/vnd");$mime_type_match['css'] = array("text/css");
$mime_type_match['csv'] = array("text/comma-separated-values");
$mime_type_match['js'] = array("text/javascript");
?>
不是太完整，不过多数类型都有了