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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 $ N: S; X6 b$ o9 ?' W+ T% F- J
- $FILENAME="image.thumb";
8 } O/ k7 M( W* m0 g' p* V3 H* Q - // 生成图片的宽度
, {, ` ]+ \. c3 ~! g; @8 C! Z - $RESIZEWIDTH=400; ! G* p9 ?7 _; Y, P' h3 |
- // 生成图片的高度 a3 q H4 A$ m0 J3 Y6 `
- $RESIZEHEIGHT=400;/ n! n% M0 y; G% @$ ?# l
B; W+ R+ Y {- Z( H6 \3 s- function ResizeImage($im,$maxwidth,$maxheight,$name){ % m6 i0 o0 p$ S3 f$ M
- $width = imagesx($im);
; \( x6 S/ w8 s& p+ x' X7 ~- k. j, R - $height = imagesy($im); 1 J* g3 m: v2 ?) Y, D
- if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){ . B% m% I! h. P$ }. c
- if($maxwidth && $width > $maxwidth){ + M+ o. d6 v8 P/ y6 x
- $widthratio = $maxwidth/$width; : ?6 M2 S$ x z7 \" f
- $RESIZEWIDTH=true;
5 v9 U$ |, Y/ J( h4 A) e - }
" _; F/ t6 l: q% @ - if($maxheight && $height > $maxheight){
* v+ [+ w! ]: A1 L- R) p - $heightratio = $maxheight/$height; / Q7 o0 t# S$ v
- $RESIZEHEIGHT=true; 6 H+ Q' [7 o, z6 \, O4 {! H. `' ~
- }
8 k" P. C$ g9 q4 R - if($RESIZEWIDTH && $RESIZEHEIGHT){
3 a& {/ K8 Y+ _; B - if($widthratio < $heightratio){
3 p/ _, V8 l m$ X& L, @ - $ratio = $widthratio; ! Z4 _/ \4 I6 }8 q. N
- }else{
! V7 d& r7 L1 E8 ^5 o# \ - $ratio = $heightratio; 6 m# {9 W$ A0 j. V2 I, t# G0 [* d
- } : y- }0 X5 B; A
- }elseif($RESIZEWIDTH){ / k" z' } O4 y$ e+ `' {# S4 N$ n
- $ratio = $widthratio; " p6 D5 J. R/ O# k0 o
- }elseif($RESIZEHEIGHT){ L- l5 _3 T- g# w3 ?1 M
- $ratio = $heightratio;
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- $newwidth = $width * $ratio;
3 c. l8 c6 g+ z0 j6 ^+ M" K/ Y: ? - $newheight = $height * $ratio;
$ _, [; C! p4 I5 ?2 ~ - if(function_exists("imagecopyresampled")){
; G- l7 O* k1 \0 w7 U - $newim = imagecreatetruecolor($newwidth, $newheight);
2 C) Z! d% H ?& v% e - imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); , X) ^0 M# W1 {, Y2 [/ W% a
- }else{ , ^$ v+ @! v5 J& f0 o% S, |9 t& P
- $newim = imagecreate($newwidth, $newheight); . j" H6 j: m( w; i. I
- imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
4 A( U0 L/ V9 T" Y" g/ A - } % r! X: T# c$ M7 W
- ImageJpeg ($newim,$name . ".jpg"); 2 Q! V3 |# d' X. [5 `2 k9 e
- ImageDestroy ($newim); - N7 b3 D! |7 b2 g
- }else{ 3 Q5 F$ B$ t6 K$ A# [
- ImageJpeg ($im,$name . ".jpg");
. h7 N" g4 h* m0 l8 {( s/ h: q - }
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- 4 A: T6 ^/ @/ A- U
- if($_FILES['image']['size']){ . j: V d4 o: z& u% ]; c
- if($_FILES['image']['type'] == "image/pjpeg"){ & Y" H0 C* k0 T9 H
- $im = imagecreatefromjpeg($_FILES['image']['tmp_name']);
* d- n9 w# Y Y6 i2 T- n+ t0 c4 `/ U - }elseif($_FILES['image']['type'] == "image/x-png"){
1 A- j8 H" z. O& B! A& [1 m) { - $im = imagecreatefrompng($_FILES['image']['tmp_name']); : d) i: I3 e& P2 A
- }elseif($_FILES['image']['type'] == "image/gif"){ 9 T: k+ `* i4 I; Z
- $im = imagecreatefromgif($_FILES['image']['tmp_name']);
. M0 D5 g- a6 S) H6 r, w% g# U$ R - } 28810641513 c$ h$ A' d q, T; t; ^, t
- if($im){
# e; k, Y5 R9 g% `% M3 S9 q- \9 H - if(file_exists("$FILENAME.jpg")){
% i9 k5 D0 v/ L( o4 o; N V0 @, P( A8 M - unlink("$FILENAME.jpg"); # `7 _ z6 }" |2 s
- }
" I* T/ V$ `# G, f/ i) Q - ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,$FILENAME); - Z, }9 o% S' Y
- ImageDestroy ($im); & j, [/ o; d9 Y; y4 w
- }
5 x- o2 k8 I# }6 ? - } # ^8 E0 f/ c0 V5 S1 ~7 w$ ?: T
- ?>
复制代码 以下是测试代码(demo.php) 6 g7 ^ J' i( [$ T4 s6 E6 }
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代码如下:$ K5 o( T6 i) }' `: h. `
+ U# v! a/ c& R9 \ h* a
- <?php
9 l5 E$ Q9 h3 N2 C8 U' \; ` - include('ResizeImage.php'); ) R7 w: E+ f' k2 j/ T8 X& |
- if(!empty($_POST)){ / W& _1 o+ y) i: [" C
- echo($FILENAME.".jpg?cache=".rand(0,999999));
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- ?> $ X6 P# T# q2 q- _3 ^% h; Y
- <form name="test" action="?submit=true" enctype="multipart/form-data" method="post" >
/ h+ N5 I" Q5 y" L+ z! L- ] - <input type="file" name="image" size="50" value="浏览"><p> 6 i, X9 T$ G6 j6 y" u/ z* n4 z
- <input type="submit" value="上传图片">
7 t% S2 N, g# t" o5 z& z - </form>
复制代码 $ m( E! G: Z2 I& y2 v. t) `+ C
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