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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
; \+ E* m! _ J; y( A - $FILENAME="image.thumb"; 7 x4 z% p6 b- e8 |* b4 W
- // 生成图片的宽度 0 d5 I, S, c$ x1 w5 M
- $RESIZEWIDTH=400; ' w) f1 w- F, N; m
- // 生成图片的高度 % r X2 e7 E+ K9 b, c$ o
- $RESIZEHEIGHT=400;. `0 [ j; V9 Y, W
- 3 I, d, k6 I7 Z. I9 _1 D
- function ResizeImage($im,$maxwidth,$maxheight,$name){ 3 ^ O7 {6 f ^& _3 n/ v. {( ]
- $width = imagesx($im); * ?5 ]- B% I2 x9 m9 n$ N. u
- $height = imagesy($im); - Q; n8 ]) W/ ^' I1 p
- if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){
. B2 u! [) q5 s( G G% C, @ - if($maxwidth && $width > $maxwidth){
0 N. {8 a- d, e0 f0 k V - $widthratio = $maxwidth/$width; 2 n4 J1 A, t; \3 ~+ n [; `$ H
- $RESIZEWIDTH=true; % v" D( r( A" M- d0 y- a
- }
: c+ p5 m* A+ ]+ [$ o - if($maxheight && $height > $maxheight){
9 I# \ h% L8 d' l5 n) t3 n/ @- g - $heightratio = $maxheight/$height; 6 P% Q- I2 D5 S( T. o
- $RESIZEHEIGHT=true; * J; c1 _, C9 x; Z
- }
) n$ A; {0 q$ I6 R: i- M- K - if($RESIZEWIDTH && $RESIZEHEIGHT){ $ \ ~5 O9 k, J8 c
- if($widthratio < $heightratio){ 6 t, `9 k5 a) N. u) R4 T
- $ratio = $widthratio;
) q4 \/ O* i: B, j% t- b - }else{ ( v: o% x4 F+ _( L9 r
- $ratio = $heightratio;
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- }elseif($RESIZEWIDTH){ _5 H2 h; W3 E' i! b4 U
- $ratio = $widthratio; " M$ w/ U* P: V4 d0 L6 x! K
- }elseif($RESIZEHEIGHT){
6 N" t Y0 A3 d, U - $ratio = $heightratio;
6 q; _5 {0 V: V) c" t6 L - }
. V9 q: R& Q& S1 g6 N - $newwidth = $width * $ratio; & ~- ^* U- a: h. ?( h% {( r3 w/ t- F
- $newheight = $height * $ratio; $ I9 r4 a7 W' R$ b
- if(function_exists("imagecopyresampled")){
5 o- n u7 E* m: B2 ], ?- I* v - $newim = imagecreatetruecolor($newwidth, $newheight);
8 B8 c' T( p$ ` p5 z - imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); : S/ ^) B0 C' q+ @5 Z) P
- }else{ 9 P) C( ^: E; b
- $newim = imagecreate($newwidth, $newheight);
" i2 d9 G' p4 ?" y' N, C8 r - imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); 6 H7 R% P! z6 i9 \
- } 0 {, i" B% n. s+ A' T# p- I: T: q
- ImageJpeg ($newim,$name . ".jpg");
* ?' v3 L' P7 z - ImageDestroy ($newim); ( {/ V4 p- w* L, H* F9 i2 |
- }else{ 2 g; ]( k# E' l* d [2 Z6 L0 J: m
- ImageJpeg ($im,$name . ".jpg");
/ r5 p% `' n. B8 x# w4 v/ L - } + i- b1 k1 H( k9 |
- }+ [% R4 [5 p3 A" A
7 d# w* S _5 n% w: ?0 M- J- if($_FILES['image']['size']){
0 n- s* f7 ~) u- z+ ^ - if($_FILES['image']['type'] == "image/pjpeg"){
" p9 P+ @ r( e* N8 E - $im = imagecreatefromjpeg($_FILES['image']['tmp_name']);
% ]- x8 n, s' v1 U - }elseif($_FILES['image']['type'] == "image/x-png"){
! A4 ~$ D. }9 a8 h, b( m; Q - $im = imagecreatefrompng($_FILES['image']['tmp_name']); * }$ P# \3 V' q# ]
- }elseif($_FILES['image']['type'] == "image/gif"){
+ {& y2 B1 D# X0 I# |1 o - $im = imagecreatefromgif($_FILES['image']['tmp_name']); : u# b& ]5 `0 ^! l9 T3 v4 f
- } 2881064151
3 a$ I. Q% A, } - if($im){ 7 e+ J) T O8 o- D0 N3 g1 ^
- if(file_exists("$FILENAME.jpg")){
3 ?. s' s) a2 I( i# Z - unlink("$FILENAME.jpg"); 9 z0 H j2 @ ~3 T+ c5 `+ O
- } 7 w; {" U: l/ U+ i# d' R
- ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,$FILENAME);
7 W( z7 ^9 \$ u - ImageDestroy ($im); $ m# x1 o7 [/ F+ f G& P+ [* m: N
- } " h5 F, _0 ^! @; _
- }
0 g0 T. F& h* ~( D' M - ?>
复制代码 以下是测试代码(demo.php)
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$ N' [8 b' W" b/ V代码如下:4 C" f, I* k* | B- J4 c! V
# W7 L1 }" w7 l* k- <?php 3 E7 ^8 \; y5 A0 ?) u
- include('ResizeImage.php'); 5 Z! N1 @' j! u& I/ V. O2 b2 l% g
- if(!empty($_POST)){ , X! N9 I G* g6 ` y# p/ g
- echo($FILENAME.".jpg?cache=".rand(0,999999)); % {; {- j& v* p5 d& Y
- } 8 |9 C0 }' a* Y! `3 n" Z$ f2 B) Y
- ?>
6 D! R3 ]) r5 b$ Y( M - <form name="test" action="?submit=true" enctype="multipart/form-data" method="post" > - A1 I: D) l/ D# x
- <input type="file" name="image" size="50" value="浏览"><p> 9 m( h, u. J5 Z! ?
- <input type="submit" value="上传图片"> & b5 _" q) z( M. X1 k( N! z2 `
- </form>
复制代码
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