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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
" o4 `& ~% J( W4 k+ n/ I - $FILENAME="image.thumb";
" |+ C5 o& y! K. P1 K) { - // 生成图片的宽度 7 W$ u" A4 M% Y: S8 y
- $RESIZEWIDTH=400; , X6 u# T) C& r9 Z
- // 生成图片的高度
' j- z" ?9 M; f - $RESIZEHEIGHT=400;9 e0 q( |6 c. W6 y3 l) B5 @, W# Q9 v
/ g; Q! q, ~- D5 V; X* _2 x7 K- function ResizeImage($im,$maxwidth,$maxheight,$name){
3 _, ?) W2 t" b" L6 ~/ \ - $width = imagesx($im);
' w" g, I) {" ^, ] - $height = imagesy($im); ! w9 }* l& @/ f6 A& s. u; B
- if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){ \; b) U9 H5 p( ?
- if($maxwidth && $width > $maxwidth){
4 q3 P2 w: N; m6 Q- u+ ~* H - $widthratio = $maxwidth/$width; - S) c: p$ ?- I( G
- $RESIZEWIDTH=true;
$ V* h: T2 }9 y4 l% K - } 9 a* t! {2 i1 D9 P2 ~- n7 e
- if($maxheight && $height > $maxheight){
$ | o4 p6 j$ C9 M* D- y/ Y% Z - $heightratio = $maxheight/$height; , C |6 V' p4 u6 \' |4 `5 K
- $RESIZEHEIGHT=true; ( t% U6 \& _* z
- }
* { E/ J$ Y1 R+ H x; J6 Y! n - if($RESIZEWIDTH && $RESIZEHEIGHT){
6 A; x9 _: A( }; L1 o! N+ w% e - if($widthratio < $heightratio){
# y9 W" s; ]# Q. [+ x& B - $ratio = $widthratio; 0 K3 F5 f6 R; j$ v
- }else{ & z/ r3 F" a3 F* w
- $ratio = $heightratio; . D. `( W8 ]( V
- }
$ g2 o7 { \$ |6 X7 q1 B - }elseif($RESIZEWIDTH){ / n8 l4 ^$ a& s1 X/ |$ A
- $ratio = $widthratio;
( U" x8 D" h6 q& ` - }elseif($RESIZEHEIGHT){
$ T7 U+ g2 \6 s' f, X - $ratio = $heightratio; 0 o1 I- r4 _; \4 y5 V/ y
- }
3 k. _) X( Y0 P4 B1 W/ I2 {- } - $newwidth = $width * $ratio; 9 g& Q, P" N! J) W3 m: d4 k
- $newheight = $height * $ratio;
5 o N! u/ l, K6 D) O& d: v8 e& K - if(function_exists("imagecopyresampled")){ % J( W+ ?( v/ [; q
- $newim = imagecreatetruecolor($newwidth, $newheight);
" b$ q, r) s1 y% I3 U; o - imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); A; G6 ^( `- e2 N
- }else{
* ?# W6 o0 u8 [! k4 M - $newim = imagecreate($newwidth, $newheight); 9 y% m: A4 z8 Q. B3 G
- imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); 2 X, p* J1 L; c! A8 `5 Q: S$ M5 v
- } & S b6 k6 @1 o% I+ Q1 Z5 S$ L0 d
- ImageJpeg ($newim,$name . ".jpg"); 9 A/ h1 I& M) \0 ?2 I, r3 j u- i2 L
- ImageDestroy ($newim);
2 k* @, X7 A" c- s# U" Y' I - }else{
0 V$ V8 v3 U/ L - ImageJpeg ($im,$name . ".jpg"); % n2 j# @# }2 h+ E
- } + m% F+ u: M3 k/ a( w1 w
- }+ [6 h" l* @, q" p! V) k
# @5 q7 R- R$ E1 A- p: B- if($_FILES['image']['size']){
7 x% W8 A" X S! [7 v' L" x$ J1 r { - if($_FILES['image']['type'] == "image/pjpeg"){
8 \. g2 D: ~' h6 a - $im = imagecreatefromjpeg($_FILES['image']['tmp_name']); 2 K. ?# Q) ]+ D5 Y! E* s
- }elseif($_FILES['image']['type'] == "image/x-png"){ 6 t' ]$ W3 H9 M
- $im = imagecreatefrompng($_FILES['image']['tmp_name']); , H R4 C+ {( Y$ N! H& O6 ~
- }elseif($_FILES['image']['type'] == "image/gif"){
, T/ H4 u* x, \ - $im = imagecreatefromgif($_FILES['image']['tmp_name']);
9 O2 [4 N J5 ~( C) n8 n% V - } 2881064151
& [# Z* {5 p' L b# P: }4 D6 j - if($im){ + i; U8 w, z) o' `4 F/ x% u( w: x
- if(file_exists("$FILENAME.jpg")){
3 v. Q, U. ~5 U1 Y. M/ D - unlink("$FILENAME.jpg"); 4 A8 ?# c0 n5 w4 t" v' P
- }
9 {$ d2 X# Y" F4 A1 ]; I - ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,$FILENAME);
( K6 n6 P+ w, C - ImageDestroy ($im); ( L8 T1 ^& _! X% X3 _, N" _
- } 6 o. T3 Z) ~ l
- }
3 k6 _' I$ D; m9 j - ?>
复制代码 以下是测试代码(demo.php) ( |; p9 P% |% a7 F
6 n& i$ d' g( T4 b
代码如下:
3 v9 i- i, n4 r& X; b
1 d" ~0 A6 z5 P. `- <?php
( X9 Z# g6 E2 t" _ - include('ResizeImage.php');
" T( ]3 i7 O- X0 E( F - if(!empty($_POST)){
0 x) w9 J$ q, G4 ]0 [5 m - echo($FILENAME.".jpg?cache=".rand(0,999999)); ' B# N) l; n. T$ q0 Y1 d! S5 z
- }
3 H2 l0 d. r7 R9 f/ t1 W6 j - ?>
2 v0 A2 r/ T- g - <form name="test" action="?submit=true" enctype="multipart/form-data" method="post" > 9 x! Y+ F9 N1 y9 y3 O
- <input type="file" name="image" size="50" value="浏览"><p> / |& z: p+ r b
- <input type="submit" value="上传图片">
& y3 s# z% Z7 b) q7 B - </form>
复制代码 2 g8 Q* @- U5 H0 [9 o
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