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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 5 Y3 u( L. R0 o
- $FILENAME="image.thumb";
0 I% i+ `! m p' _7 {+ s - // 生成图片的宽度
0 V, `6 a* {$ l m6 V - $RESIZEWIDTH=400;
0 z% E9 @+ `. _0 Y4 A - // 生成图片的高度 $ z3 o& d+ e* b3 q# b! [* N
- $RESIZEHEIGHT=400;4 [' o. |. F" ^* j/ Z% ~
* a; Q) ^/ c+ a- function ResizeImage($im,$maxwidth,$maxheight,$name){ ) M' ~' W; e, y
- $width = imagesx($im); 0 y3 C: _& k: e) D2 [3 |
- $height = imagesy($im);
c7 t/ o" ?7 }# `9 d4 [7 s5 m - if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){
. ? j1 H" r, o9 B+ C4 r - if($maxwidth && $width > $maxwidth){
8 L* i& `. q& _8 Z/ q+ q' F( t; l - $widthratio = $maxwidth/$width;
- G c2 o: C7 _# r - $RESIZEWIDTH=true;
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- if($maxheight && $height > $maxheight){ , U" q7 Q6 M% H2 c7 l4 _
- $heightratio = $maxheight/$height;
2 ]5 O7 ^* j8 M5 x! o) W/ h7 ? - $RESIZEHEIGHT=true; 7 M" k, c0 S2 l+ l* }; L
- }
1 {% B. q2 M" y1 x( A - if($RESIZEWIDTH && $RESIZEHEIGHT){
- l' K* i% o! P7 e; ^) ]) ^ - if($widthratio < $heightratio){ " Z. T2 b. f( Q
- $ratio = $widthratio;
( E4 n, X" j, o8 n2 o* R- d2 K; X - }else{
: m: a1 T, j2 w: h2 y - $ratio = $heightratio; ?" l" j' I- C4 Z8 N
- }
! F2 p: F8 o, n" T h% [ - }elseif($RESIZEWIDTH){
8 Q/ H o) K6 _& p8 b - $ratio = $widthratio; ' F+ ] P" V* a
- }elseif($RESIZEHEIGHT){ 6 b. l1 s" G1 d/ O; E# J9 a0 ~
- $ratio = $heightratio; 4 k4 T. g) y9 j" Z Q: |" t9 ~3 @
- } : W" i" D& p7 W9 N5 ^
- $newwidth = $width * $ratio;
$ B: ]2 O$ ^' S6 r - $newheight = $height * $ratio; . P9 [8 l" g8 z2 j* v9 I" v: d
- if(function_exists("imagecopyresampled")){
" `; P0 S8 S2 ^ X" f - $newim = imagecreatetruecolor($newwidth, $newheight); 8 G3 [/ }4 Y' U t
- imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
i) d; J4 p5 H4 c8 G6 c7 j3 T - }else{
9 R9 o9 Y- ?4 T, v - $newim = imagecreate($newwidth, $newheight); ) z4 K, D) ]9 n/ f% C+ ]
- imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
8 Y& m' m" V( B; k- b; I# m8 ~ - }
2 x( y& J- m i4 e2 x$ n - ImageJpeg ($newim,$name . ".jpg"); 7 u" M' k$ T1 T' j' t# y s3 D
- ImageDestroy ($newim);
6 a! s; e0 ?" {4 } j) v% n - }else{
G! j7 O" g1 H; S3 H& L9 P - ImageJpeg ($im,$name . ".jpg");
& @- o: N8 y/ Z( N6 }: a. t" @ - }
3 D0 [8 \* g/ b& M - }9 m) `3 ?) M9 @- X' }$ B
- 7 ~- R z% f/ {6 ~
- if($_FILES['image']['size']){ . z' A& z$ F" [$ L1 T% q
- if($_FILES['image']['type'] == "image/pjpeg"){ . k& {7 s/ j- }. [
- $im = imagecreatefromjpeg($_FILES['image']['tmp_name']);
9 B# R/ W' l% Y - }elseif($_FILES['image']['type'] == "image/x-png"){ 9 G: }0 X y& O. C* x0 K: a" B: I3 }
- $im = imagecreatefrompng($_FILES['image']['tmp_name']); + E" O7 f. `9 k) S/ v
- }elseif($_FILES['image']['type'] == "image/gif"){ % K4 |7 X7 t1 M3 s0 X* z* j9 Y1 h
- $im = imagecreatefromgif($_FILES['image']['tmp_name']);
0 K& _7 W+ E& g% G/ N0 h: ]- c0 P - } 2881064151+ _! `1 j- o2 B. s' l3 t3 c
- if($im){
1 B* U- B) g ?; F1 ^, D - if(file_exists("$FILENAME.jpg")){ " D1 B& Z% I$ \4 w- e5 a B% g
- unlink("$FILENAME.jpg");
. r" d/ H/ @9 u1 i- }/ D - } 7 S& F9 o* m- G$ v
- ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,$FILENAME); 6 Z6 t, [0 c9 T3 ?4 N/ o
- ImageDestroy ($im); ( T) u+ d$ D# s2 K# W$ d, ^% e
- } 3 ~- X6 d% I9 \
- }
- s. i* {0 d) K9 H% s9 R5 z - ?>
复制代码 以下是测试代码(demo.php)
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1 k" J, w# r! ?& i$ i1 E3 t: d代码如下:2 X- Q3 P) x8 C9 P5 @
8 @/ L' q) Z' o4 |/ R8 c( U- <?php
+ m. Y# R/ E3 b/ o% V - include('ResizeImage.php'); W8 F# V* T: u* p- f M% @% y$ P
- if(!empty($_POST)){
1 @' j4 v. k: A+ y& [0 y T - echo($FILENAME.".jpg?cache=".rand(0,999999));
+ j2 B; y) u) I k5 c - } 0 J9 t* j4 C" Y1 ~: z6 s; e- h
- ?> - m) ~- i2 m6 w9 v7 ^. ?6 O9 T
- <form name="test" action="?submit=true" enctype="multipart/form-data" method="post" >
! Y5 e- Y' l4 v; v% G. C - <input type="file" name="image" size="50" value="浏览"><p> 9 P$ [* g+ a6 e, H' O
- <input type="submit" value="上传图片">
% q3 {3 j& g4 U, s* q1 j% x8 s - </form>
复制代码
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