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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 ' y+ ^; L8 X# w. F0 ?+ x
- $FILENAME="image.thumb";
8 s7 F( U( g) M1 q! m# V - // 生成图片的宽度
! [5 z9 y6 z. R. A( V9 j& z9 k; a - $RESIZEWIDTH=400; ) j l! {! ]+ i" y* O+ q% Y
- // 生成图片的高度
' u) ]5 ^- g0 k - $RESIZEHEIGHT=400;
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- function ResizeImage($im,$maxwidth,$maxheight,$name){ 3 a9 }% Z j' l/ e
- $width = imagesx($im);
! n6 ~. L. ]/ I& M; Q' F$ x0 T( j - $height = imagesy($im);
8 c. g; x" H& m# L! v - if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){
4 e) H$ \- h. ` - if($maxwidth && $width > $maxwidth){
; B7 ~6 `/ ^6 w6 u. [/ z1 d" d - $widthratio = $maxwidth/$width;
+ j# X( Q+ M( ]! a# }4 G - $RESIZEWIDTH=true;
' a: s5 i- H1 W7 c% | - }
$ ]4 i! ~7 S1 H% \, t4 A3 R3 v/ C - if($maxheight && $height > $maxheight){
1 n) w0 \; L2 E, U0 N& o - $heightratio = $maxheight/$height;
' q1 o% _3 M$ V! T. l - $RESIZEHEIGHT=true;
' r# [: m U0 q7 X& p' }& d! o - }
2 q/ W( }* r7 P" e9 S7 c - if($RESIZEWIDTH && $RESIZEHEIGHT){
+ Q" |4 U0 A: X( s" m) J - if($widthratio < $heightratio){
* r8 K0 F9 d# K1 f! e* o. V+ }: c - $ratio = $widthratio; 4 ]- Y% w: t" M, A* R$ c- j' T7 `2 Z
- }else{
, b2 Z+ \! J8 y' T - $ratio = $heightratio; 6 l9 Z) B, N; i% B7 l
- }
, \0 N, f/ v! J5 ~# z - }elseif($RESIZEWIDTH){ |; v& c0 A' {* l" ~- y c( W
- $ratio = $widthratio;
4 J2 Y& P3 C# E - }elseif($RESIZEHEIGHT){ 9 ~4 j7 J0 n' W2 i" N% u
- $ratio = $heightratio; c2 x4 X; f% }) x" \
- } $ n1 T/ ]# _- m$ A
- $newwidth = $width * $ratio; ' M# J+ R/ |2 g* e3 a/ ^1 ~1 F
- $newheight = $height * $ratio; ^! B& b5 M7 ~- U! Z }
- if(function_exists("imagecopyresampled")){
4 [5 j% X. M' z% r. ~ - $newim = imagecreatetruecolor($newwidth, $newheight);
: r& O- s. C. j9 Q! z. P - imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
: r7 F) W# N; @ [4 [3 S - }else{ ; l$ A6 L1 y; P5 [ Y
- $newim = imagecreate($newwidth, $newheight); 1 z b4 b" P* Y- ?' z
- imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
% d$ ?5 w6 u8 W# n- P1 s; V - } * w7 `3 Y# `) H: P& V
- ImageJpeg ($newim,$name . ".jpg");
: U* T* U& V( W2 F - ImageDestroy ($newim);
) J) J q3 L. c8 ]% V - }else{
8 v* t; L# J- X4 S) V$ e6 {* h - ImageJpeg ($im,$name . ".jpg");
% z! _2 f( _8 V/ k - }
2 M( d0 x; P9 h$ J" r - }. E2 O" {- i0 Y: [! B' z4 R0 [1 t
- 5 g) O' c% R7 F2 p
- if($_FILES['image']['size']){
/ J+ V0 ?: _# B7 q: e' o - if($_FILES['image']['type'] == "image/pjpeg"){ 5 {5 h; k% R) S0 |: P
- $im = imagecreatefromjpeg($_FILES['image']['tmp_name']);
& x. {: s" X* t, l4 D" N" R - }elseif($_FILES['image']['type'] == "image/x-png"){ ) z; n( d6 J+ k
- $im = imagecreatefrompng($_FILES['image']['tmp_name']);
3 E# \" R% l0 s! J) m' v9 g2 _ - }elseif($_FILES['image']['type'] == "image/gif"){
- V, Y' E$ e' o+ t* } - $im = imagecreatefromgif($_FILES['image']['tmp_name']); # o [2 k+ S7 h4 i
- } 2881064151
9 E6 j8 {- }- G& p5 f - if($im){ / j/ `& H. [3 N* V
- if(file_exists("$FILENAME.jpg")){ . h* [& K+ v9 R5 V( N4 g) q
- unlink("$FILENAME.jpg"); 1 u: e0 P" |6 X8 I% o( Q
- } ; F! J" m. y% D
- ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,$FILENAME); % w8 S9 y, l, g; U) T3 m
- ImageDestroy ($im);
. [7 d# V x0 ]& r, `: N - } ; i( @: g i& {6 U; r
- }
6 M j9 _4 q/ y3 ?: A& D - ?>
复制代码 以下是测试代码(demo.php) 8 d; }9 z* m5 f I, Z5 Q1 u
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代码如下:! K1 B1 P! c h
! H3 s; A( b8 x- <?php
X0 i; ]# A/ ]! t - include('ResizeImage.php'); 6 ]0 ~6 i; S4 W
- if(!empty($_POST)){ 5 c8 J% K( `! E$ t
- echo($FILENAME.".jpg?cache=".rand(0,999999));
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- ?> & t& | b' p+ v, k+ ~) s' x1 Z- D
- <form name="test" action="?submit=true" enctype="multipart/form-data" method="post" >
2 w; l: Y& [4 ?5 B* q- l/ ? - <input type="file" name="image" size="50" value="浏览"><p> # k! W7 n4 T4 m3 W& M8 i
- <input type="submit" value="上传图片">
! s! f) f' y8 M3 o" N$ Q* w - </form>
复制代码 + q% v6 d. i2 d8 h z, d/ g/ d! ^7 v
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