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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' Y6 l. m3 R* f
- $FILENAME="image.thumb"; z8 }( Q5 d: K3 c
- // 生成图片的宽度
* K0 y( P, C) o' H' X. u5 ` - $RESIZEWIDTH=400;
0 G2 V' J1 ?7 a - // 生成图片的高度
# i# ?1 P4 j! [8 d4 G - $RESIZEHEIGHT=400;4 ?4 }1 G3 u1 K' j
- 2 j) w# z" x) E" x9 O" X! _! J
- function ResizeImage($im,$maxwidth,$maxheight,$name){ 8 X" c8 J8 w" E* M
- $width = imagesx($im); , M0 f2 T! E2 r. L K8 x: {
- $height = imagesy($im);
# n1 ^9 m- x, C! A8 q0 V" } - if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){
6 @! H, z$ e3 |# e# c. [" O6 @ - if($maxwidth && $width > $maxwidth){ " j; Q G, ^2 h
- $widthratio = $maxwidth/$width; + D: Y4 G% T9 O9 i: B
- $RESIZEWIDTH=true; - {5 ^3 s" O" ]0 f$ S: l
- } 4 w0 P) u- Z* ]+ T" ]# x
- if($maxheight && $height > $maxheight){ ; T8 H3 {& n" R, H, h
- $heightratio = $maxheight/$height; " t1 L. Z( L* ~( M8 A0 r7 O; G4 G
- $RESIZEHEIGHT=true;
3 @, g7 |5 J- Z0 Q4 D; V8 } - }
6 J1 s( m; J7 m3 \+ k, J - if($RESIZEWIDTH && $RESIZEHEIGHT){
' d$ E& f( d8 ~. ~' [$ |! X: t - if($widthratio < $heightratio){ & e( w3 E; n! |& v4 {3 A
- $ratio = $widthratio; ?" c+ F: D- b' J5 {0 O3 K8 h
- }else{
7 D, |" E6 V7 R: } G - $ratio = $heightratio;
- v! }& ~0 g% T0 s6 H/ u, H* Z- s - }
. a( g/ U* K' \" G* t) ?" b - }elseif($RESIZEWIDTH){ + c* @# a# D0 T0 u5 r# P
- $ratio = $widthratio;
- D: g- O3 r; M" T' Z3 p+ ? - }elseif($RESIZEHEIGHT){ . T o1 |( F0 _$ A
- $ratio = $heightratio; , E- j, H5 L# Y2 X
- } 5 m/ c' g _" Q/ H5 N5 D- |
- $newwidth = $width * $ratio; # d @3 u% R' L) z! P& K6 O
- $newheight = $height * $ratio; ! _: ^6 z$ } f7 q
- if(function_exists("imagecopyresampled")){ 0 ^3 r( ^3 J& b3 I' a
- $newim = imagecreatetruecolor($newwidth, $newheight);
( q, J$ Q( \" {0 J8 @# } - imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); 9 ?8 F% l# n+ R9 |
- }else{
( c, X0 V3 h3 ~8 z - $newim = imagecreate($newwidth, $newheight); 1 Y& U- Y3 R2 n+ T& q7 s; m3 m2 f; x
- imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); # Q7 B& j# I5 `' B$ H/ {& G
- }
# R$ {% X/ |" l - ImageJpeg ($newim,$name . ".jpg"); 0 H7 w6 R! D x7 |) S
- ImageDestroy ($newim); ; L% e* w6 D/ L8 e. l
- }else{ 2 H" }" {7 O6 v5 s" }9 l
- ImageJpeg ($im,$name . ".jpg");
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- }
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- if($_FILES['image']['size']){ 9 S! G) P7 r8 J
- if($_FILES['image']['type'] == "image/pjpeg"){
j; _) Z6 O8 l6 | - $im = imagecreatefromjpeg($_FILES['image']['tmp_name']);
+ l$ U0 |- |7 l }5 i. f! x - }elseif($_FILES['image']['type'] == "image/x-png"){ 2 U8 x! S# O6 q5 |$ A9 f
- $im = imagecreatefrompng($_FILES['image']['tmp_name']);
, ]5 h' }$ b7 R: \% Y. |7 s9 u z - }elseif($_FILES['image']['type'] == "image/gif"){
3 a6 H; @+ B/ b5 u9 ^ - $im = imagecreatefromgif($_FILES['image']['tmp_name']); + X/ @7 k3 Y4 e* o
- } 2881064151
8 q( I, j: v7 t+ _7 } - if($im){
7 j! A& o3 u8 t4 i3 o - if(file_exists("$FILENAME.jpg")){
/ u! r$ w# i. i$ t% k - unlink("$FILENAME.jpg"); 8 q5 I- p5 E( a6 B0 }1 S
- }
1 y; _8 ^, ~3 M$ o( k - ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,$FILENAME); 1 J9 g" O! }( t6 Y6 k" _
- ImageDestroy ($im);
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- } 3 _$ U. g0 a% B3 T
- ?>
复制代码 以下是测试代码(demo.php)
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/ M) N' q/ ^* m w. H+ z% }/ J" d代码如下:5 @; {& W; z( X) w1 ]1 @
/ w Y3 p) R2 q6 @( ~( I8 y- <?php 0 s+ _. _$ j, H2 `
- include('ResizeImage.php'); $ l9 o8 f2 k2 ?7 s1 E
- if(!empty($_POST)){
& i- J$ t- }- j8 C- }) [ - echo($FILENAME.".jpg?cache=".rand(0,999999));
2 B2 s, B* J# i - }
3 ]. p Y4 G% [ - ?>
" R% t- J6 E7 t& @* Z. A - <form name="test" action="?submit=true" enctype="multipart/form-data" method="post" >
0 {3 g/ R3 Y" n5 V" ]9 | - <input type="file" name="image" size="50" value="浏览"><p> 0 n; b W" N X0 [' `4 `% P
- <input type="submit" value="上传图片"> + v) E, y+ k. d8 y6 F" s) B9 y
- </form>
复制代码 / {( l* ?8 m2 l; R4 r- X, z: v
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