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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
: }' v; L+ A: N/ {2 K* C - $FILENAME="image.thumb"; ! Y+ A5 j& T) {3 T- q0 M
- // 生成图片的宽度 ( Q$ |% ]0 w- y
- $RESIZEWIDTH=400;
( q, m- W1 `% V - // 生成图片的高度 8 m, J7 K) T( ^2 e: l" B; k
- $RESIZEHEIGHT=400;" A+ J2 F: L! ] m
- . `! `6 A1 d1 M9 {
- function ResizeImage($im,$maxwidth,$maxheight,$name){
) D) i* s' f9 H |" u4 [# q& P - $width = imagesx($im); : x) q# A: B' P1 e8 J
- $height = imagesy($im);
2 H& t3 t; w/ }1 ]/ k, i - if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){ " ?+ X/ o" a. ~; _& Y) d, B
- if($maxwidth && $width > $maxwidth){
5 ~) D/ U) J# [( Y - $widthratio = $maxwidth/$width;
5 ~" n% m! |$ d' m1 q4 G - $RESIZEWIDTH=true; & F: v! a) F: g M& d! _' l5 M( a$ V
- } ( D, s9 m# w& A% B- [2 Q
- if($maxheight && $height > $maxheight){ " I3 `. r- p) P0 ^' n
- $heightratio = $maxheight/$height;
! y6 C4 m! L s3 f; C - $RESIZEHEIGHT=true;
) \0 X+ S! m; m* q: Z4 a$ E: p: S1 k - } @- @. K* p u4 ~6 P3 h
- if($RESIZEWIDTH && $RESIZEHEIGHT){
+ a6 G+ h* D" }# C( `' V$ m - if($widthratio < $heightratio){
7 {8 A3 f% W G8 \, ~2 t/ [ - $ratio = $widthratio;
8 \' b6 V5 |! R( s - }else{ , j. ~/ f- V. l3 z
- $ratio = $heightratio; 6 K* A/ x: d' v5 M7 Q( e3 ]
- } + ~$ x' D. |) d& z# ^3 h. ^% n$ i
- }elseif($RESIZEWIDTH){ 7 U1 e7 Y8 G, s: A: ^/ ~
- $ratio = $widthratio;
+ E2 r% ?8 f, T% @2 n5 b2 K - }elseif($RESIZEHEIGHT){ ! z+ T$ H! C3 Q. j$ [; k# j
- $ratio = $heightratio;
. q3 H* } w8 c8 \; f4 s - }
% N9 I" O8 E' Y Z9 K) m - $newwidth = $width * $ratio;
! g: A- p6 @0 x! \0 T3 k$ P1 Y+ F' O - $newheight = $height * $ratio; Z s* w/ z, i& ]! Z, X# [9 e
- if(function_exists("imagecopyresampled")){
" @; p- ?7 i( d! Z - $newim = imagecreatetruecolor($newwidth, $newheight);
% h% E6 P& u) ^1 R - imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
F. r+ f- q. H, t( M* m! [ - }else{ 6 z7 N! |. f* D4 Z! W! T. Y
- $newim = imagecreate($newwidth, $newheight); $ }) L2 i9 [3 Z" d. O
- imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
! e) i o! J/ U7 A' y6 g. Y3 p+ K$ a - } ; U% q4 k% \8 z2 Z1 `$ @* x% u! h
- ImageJpeg ($newim,$name . ".jpg");
$ m, }+ R b0 Z0 C, ] - ImageDestroy ($newim); # @+ t$ p; E6 E
- }else{ ( I2 @, ?- K: y. ^8 e
- ImageJpeg ($im,$name . ".jpg");
$ @) o+ {) j: S7 y; @/ U( }$ {/ Q+ ` - } 6 b$ J% [1 o0 L
- } l1 `, m' _; d7 {5 K6 u
- * R) u$ @# m5 `1 ~! M9 [# F0 _
- if($_FILES['image']['size']){
2 J! v* h! C9 Y9 v* @% J - if($_FILES['image']['type'] == "image/pjpeg"){
2 G1 P {. i& M1 Z - $im = imagecreatefromjpeg($_FILES['image']['tmp_name']); 5 v3 R7 a4 _; G/ v
- }elseif($_FILES['image']['type'] == "image/x-png"){ . t3 c/ `. Q8 i! K
- $im = imagecreatefrompng($_FILES['image']['tmp_name']);
$ K2 _+ M s5 K2 e2 i& T! \4 a - }elseif($_FILES['image']['type'] == "image/gif"){
" L; d: U) I2 y9 V - $im = imagecreatefromgif($_FILES['image']['tmp_name']); 3 d6 I% H) f. J5 q! z( o5 b- G
- } 2881064151# A. C6 F9 T |' j: {& S$ j
- if($im){ ' w7 }7 K' E5 ~* f$ ^6 d0 s2 W/ A1 y
- if(file_exists("$FILENAME.jpg")){ 2 p" P3 y4 G V L( [9 |
- unlink("$FILENAME.jpg");
( g% V9 H) ?/ N - }
w% C; U( \- \6 m/ D; I - ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,$FILENAME); % g' M/ E$ q1 K' {; E m; u
- ImageDestroy ($im); $ ~, ]. r5 n1 l4 @3 K
- }
" [+ o' |' l8 P9 ?# K7 I- Q3 R - }
/ D- @2 p& s6 f" i, T - ?>
复制代码 以下是测试代码(demo.php) , K" q5 J8 V* S1 w6 X
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代码如下:- i" y/ J8 {5 ?/ s5 m8 L- g8 Y$ Q& M
7 u2 v I) l7 _& O) ~4 W- <?php
+ K% x# {/ A# I& ]; e1 m7 v - include('ResizeImage.php'); * U3 F- n1 F0 w$ v X! O& G3 ^
- if(!empty($_POST)){
: c8 c& r: L. e0 a) _' G - echo($FILENAME.".jpg?cache=".rand(0,999999));
5 q( {' ^- c8 J - }
0 a) @- G4 O- N4 B# w. R! Z - ?> ( k0 D: e) U- U- ^) m
- <form name="test" action="?submit=true" enctype="multipart/form-data" method="post" >
: U9 f; z2 \) F/ U, t0 g* E1 F( E1 ?% x - <input type="file" name="image" size="50" value="浏览"><p>
3 J5 \# Y5 q' F4 w w9 E - <input type="submit" value="上传图片"> 3 \( g$ d* S: D, b
- </form>
复制代码
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