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PHP用GD库生成高质量的缩略图片,PHP一般情况下生成的缩略图都比较不理想。今天试用PHP,GD库来生成缩略图。虽然并不100%完美。可是也应该可以满足缩略图的要求了。- <?php
8 k/ k! ?: |; C+ {# F - $FILENAME="image.thumb"; ; F o" X0 z6 `% c9 k. z$ {# e; a
- // 生成图片的宽度
4 l5 `1 \* ?9 X0 E+ E9 q W/ E5 f - $RESIZEWIDTH=400; / g! c( `0 s* j
- // 生成图片的高度
! f: G2 p* b1 ?5 @, \2 X - $RESIZEHEIGHT=400;. i, q; f( d0 O3 z/ t3 D
- % D2 j6 T/ R: ?7 Y8 h
- function ResizeImage($im,$maxwidth,$maxheight,$name){
( F4 N4 A ~) B& F* ` - $width = imagesx($im);
4 d# ?7 d u& z1 v5 g0 Z; S5 t - $height = imagesy($im);
) T% J3 L7 F2 Q/ h# A w9 P! r w - if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){
" L1 s/ \- c; K$ I2 ]7 p - if($maxwidth && $width > $maxwidth){ 4 _" m8 {6 P. w* x+ ^! M
- $widthratio = $maxwidth/$width; / h, V }' |/ ]
- $RESIZEWIDTH=true; ( D4 B2 `5 Y& U) s/ n
- }
* ]( r" ~, v& M" Z: S - if($maxheight && $height > $maxheight){ + Y$ [/ W6 |" Y9 S
- $heightratio = $maxheight/$height;
" M- W6 o2 {- l- c' X - $RESIZEHEIGHT=true; 5 l( j. A$ X1 L0 _: @
- }
: X+ e5 I o! o - if($RESIZEWIDTH && $RESIZEHEIGHT){ + N, L1 n6 U c
- if($widthratio < $heightratio){ 8 V9 h# z. U/ i! {( t0 x W6 {
- $ratio = $widthratio;
. J8 B8 V5 W5 r+ L- s: I" ^ - }else{
! x& B, A, I8 `+ V9 c8 {" W - $ratio = $heightratio; + ?6 n3 m$ e v6 [# [
- } $ U( m$ z8 |- D z" ^
- }elseif($RESIZEWIDTH){
% H' q& M8 M' n# [" [3 w - $ratio = $widthratio; 3 V$ r1 D% M" N, H$ Q3 h
- }elseif($RESIZEHEIGHT){
5 B& K! p8 l5 d2 u" A - $ratio = $heightratio; 0 a% `: S- p' N
- } . L; Z+ I2 q, V
- $newwidth = $width * $ratio;
/ l8 |( i$ [7 G% P& t - $newheight = $height * $ratio;
1 W9 E H ^) ]8 F* L" M - if(function_exists("imagecopyresampled")){
2 o2 E" v# j) j7 n - $newim = imagecreatetruecolor($newwidth, $newheight);
" I5 @4 ?4 Z/ y2 `+ S0 g - imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); % e1 \" d$ x, {2 @! P. Y
- }else{ $ x8 U% b: U& W$ i# Z/ h, a
- $newim = imagecreate($newwidth, $newheight); $ U) ]! W7 ]( q' Z8 n
- imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); % K4 |0 P# `% _3 s; N1 ]
- } / R+ j3 N' o; D, @6 K* k
- ImageJpeg ($newim,$name . ".jpg");
# L6 A4 f* e) U% I% x1 } - ImageDestroy ($newim); ( L% w" c- p2 _5 c! ?, X2 x
- }else{
) k2 Y: W& |6 }( N8 `( a - ImageJpeg ($im,$name . ".jpg"); 2 e: v2 K# O- a! \' }- |' U
- }
$ B2 |; W$ z: V+ |6 g9 G) t - }) A" h# I b1 q, t
- p! h- @! f% z: b' `
- if($_FILES['image']['size']){
' C( w1 R0 s7 ?: u - if($_FILES['image']['type'] == "image/pjpeg"){ 5 z# }. w6 x. W2 Q5 P
- $im = imagecreatefromjpeg($_FILES['image']['tmp_name']); ( ^2 k' P3 E0 p- l6 g: w3 p
- }elseif($_FILES['image']['type'] == "image/x-png"){
Y$ @* O& T, k - $im = imagecreatefrompng($_FILES['image']['tmp_name']); * Q8 ?: j7 A7 J- w$ n
- }elseif($_FILES['image']['type'] == "image/gif"){
4 a( D t+ h: a+ U! J - $im = imagecreatefromgif($_FILES['image']['tmp_name']); & _" |, S# ]: \% m
- } 2881064151' f( o% Z0 l& ?7 e/ Z! X9 y* @
- if($im){ / f b- R4 \5 n, P0 \) {
- if(file_exists("$FILENAME.jpg")){ 1 h/ l, U6 \* A2 K5 f4 ^
- unlink("$FILENAME.jpg"); 3 m4 F8 m9 b& h7 n' I% n
- } 3 j7 O+ f. n% a& P1 Y
- ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,$FILENAME); ) b1 y9 X$ N" s h8 q& J' N- F7 `( ^/ K
- ImageDestroy ($im);
* u+ w/ g! D* e* ]3 A' Q - }
; f! L+ `& ]+ T! Y - } # ?! I% H; t& A9 L4 c9 j& O' j
- ?>
复制代码 以下是测试代码(demo.php)
) X5 y I2 `% `2 {' \7 q' s" X+ ~' D* X' ~/ [9 O
代码如下:
" Z4 k% ?! \9 v4 {( X3 f9 }; q |% s) t) v8 l* E
- <?php
1 P o5 r. D7 V# j$ f - include('ResizeImage.php');
2 t2 e: x; _# U/ e+ { - if(!empty($_POST)){ : D$ E1 J* _ G t$ t0 |# n
- echo($FILENAME.".jpg?cache=".rand(0,999999)); 9 C3 g+ f% R' y8 E: c8 s" G' D$ l
- } ' f$ ^$ P: o2 ~' z+ l
- ?>
6 Y( B9 W9 y" k - <form name="test" action="?submit=true" enctype="multipart/form-data" method="post" >
# u' X7 ?" }0 V - <input type="file" name="image" size="50" value="浏览"><p>
# }+ C- }, \' h3 I' l7 s1 [ - <input type="submit" value="上传图片"> " q4 L5 N" Z2 E' w7 y/ Z$ K5 p
- </form>
复制代码 4 A& X8 t" N3 j8 ^
0 T( v, N1 ~: d* \. }5 L9 g/ r
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