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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
, u) @0 d: V$ ^# m1 h - $FILENAME="image.thumb"; 1 s' Y: B- @% E
- // 生成图片的宽度
# [ }* `5 V; D) E+ S, ]+ [ - $RESIZEWIDTH=400;
0 g& k/ j/ a: b2 v% T' n* H - // 生成图片的高度
* Y5 ~3 w6 r! v9 z7 k - $RESIZEHEIGHT=400;
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" m" {) A; l9 {" `* m" ^- function ResizeImage($im,$maxwidth,$maxheight,$name){
4 N0 ^* r5 }) [( g9 z - $width = imagesx($im); * }# ~0 _9 c% N" I A
- $height = imagesy($im);
C/ [' A$ q' I6 F2 p7 C+ z! L - if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){ + Y# t5 X. r! k2 D; ?1 F! S/ F
- if($maxwidth && $width > $maxwidth){ - D4 M" e @% T# @
- $widthratio = $maxwidth/$width; * t9 u$ ~, f8 J8 ]
- $RESIZEWIDTH=true;
& W% v9 e7 k1 j( Y - }
$ W, v& W4 |4 D4 }" Y# r2 e - if($maxheight && $height > $maxheight){ 5 P& r% d8 T: e$ e
- $heightratio = $maxheight/$height;
8 z, [ p: ~! w - $RESIZEHEIGHT=true; & a1 Z6 @3 E6 [" m) g; r
- } / ]5 l+ a( K7 V7 p2 t4 l7 U, b
- if($RESIZEWIDTH && $RESIZEHEIGHT){
7 Z% z: `, o. c: O) a4 M+ g8 H - if($widthratio < $heightratio){ # I, g8 o5 s2 S& P
- $ratio = $widthratio; 1 Q" B3 n6 J R! Q
- }else{ " x( O) g/ H0 }$ S. U. c- c+ s
- $ratio = $heightratio; 4 d: E5 h+ C3 u
- }
6 F, i; W, ?. v: X - }elseif($RESIZEWIDTH){ 5 t' Z- p. H7 y2 e7 S1 @& l
- $ratio = $widthratio;
7 z7 g p M4 \3 y! G! u - }elseif($RESIZEHEIGHT){ * D9 n/ V/ K# u7 G/ N2 f0 I: x
- $ratio = $heightratio;
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- $newwidth = $width * $ratio; ' [# x/ F3 w9 c- W) z
- $newheight = $height * $ratio; 6 q" e0 W! w, N9 l: `
- if(function_exists("imagecopyresampled")){ 7 f M+ |% V% P1 B/ ^0 C! S- \
- $newim = imagecreatetruecolor($newwidth, $newheight);
% g! ~9 T, @6 m# |6 u; B - imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); * ^4 U3 K2 M9 f
- }else{
4 P t+ q& Q+ W- G- E - $newim = imagecreate($newwidth, $newheight); # B9 y8 f% e1 f8 j/ S
- imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); * I4 T1 b/ p+ e
- } ) J( ^$ X7 u$ x; _0 E3 J9 I
- ImageJpeg ($newim,$name . ".jpg");
. s4 W. r% S- }' @0 t4 ?* A4 L - ImageDestroy ($newim); 1 |% k, ?+ m: J
- }else{ 9 G; ?6 C, C( K# z' h- U
- ImageJpeg ($im,$name . ".jpg"); 3 ]. J9 H2 @# [* t6 e9 B4 K* i; c
- }
1 ^/ {5 Y" g0 e7 A3 i+ p4 l0 z - }2 [3 j/ K: W2 K) T- E0 U6 T
7 ~+ V- U, Y R) I- if($_FILES['image']['size']){ 8 C7 D4 r# D' y0 ?0 ]6 D
- if($_FILES['image']['type'] == "image/pjpeg"){ 5 s) ?; I3 g( r4 V
- $im = imagecreatefromjpeg($_FILES['image']['tmp_name']); % H1 j1 ?* j' U2 `6 |5 B) M6 }2 v
- }elseif($_FILES['image']['type'] == "image/x-png"){ + [, s; ]! a5 a) Q
- $im = imagecreatefrompng($_FILES['image']['tmp_name']); $ X! U3 v, Z& b7 R
- }elseif($_FILES['image']['type'] == "image/gif"){ v; J: W1 ] @! Q
- $im = imagecreatefromgif($_FILES['image']['tmp_name']);
0 D" E7 A# \5 ?+ N# t% @ - } 2881064151
3 r# l R! D1 M3 `( t3 ]: z" Q - if($im){
+ Y# r: N6 D: u: o5 D! \ - if(file_exists("$FILENAME.jpg")){ 5 ]* d( b0 i& ` G2 n
- unlink("$FILENAME.jpg");
9 t0 g" w0 I$ L5 p - }
7 {3 g+ b! d' s, x+ f1 G - ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,$FILENAME); , U& ?4 e) D, g8 o7 A2 [
- ImageDestroy ($im); 3 ?8 I6 Q6 G6 D5 E; q" s0 [
- }
1 Z8 [* ^+ K. p: R - }
1 f& r f2 F, U! M# a7 F - ?>
复制代码 以下是测试代码(demo.php) 8 P0 l; r( b8 n: f* f6 A" V
. M. V( k$ z9 e% F1 L1 ?& c代码如下:
) l) t" _( N H4 W8 |/ I1 H, K& s6 W7 u3 ]$ U
- <?php
: ^7 S. \2 `, B( c( u - include('ResizeImage.php');
, c4 Y# R7 c, b0 C# O/ R - if(!empty($_POST)){
% l5 z5 }6 O8 k6 q - echo($FILENAME.".jpg?cache=".rand(0,999999));
0 ]& d$ I6 a8 y3 x5 D - } % m' F$ T0 q9 u, W
- ?> 2 N* n# o- N$ W4 W6 o) t' l( i
- <form name="test" action="?submit=true" enctype="multipart/form-data" method="post" >
, M( h5 n. Q* z, Z0 o: i - <input type="file" name="image" size="50" value="浏览"><p> # V) J y/ }( X& A
- <input type="submit" value="上传图片">
7 ]5 ]9 I4 C4 b5 d4 e - </form>
复制代码
* U3 G, l2 R; k& H. R5 N3 {% X5 M$ t. Q: ~
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