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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
& ^8 P/ ]( u6 A2 f% A' P - $FILENAME="image.thumb"; 2 f+ d& l# X# F# _3 c, f
- // 生成图片的宽度 , _ ?3 _" {! Y: k$ I$ p
- $RESIZEWIDTH=400; 6 D% r' {8 ?5 K* u9 Y, f1 X8 v
- // 生成图片的高度 7 t( z( L X6 C: @8 L8 v0 e ?
- $RESIZEHEIGHT=400;6 @/ ]/ A0 d. ^1 V f. X+ C% M
( ^ r* P: O9 j, G5 q" X9 Y- function ResizeImage($im,$maxwidth,$maxheight,$name){
3 p+ D! v# x/ v" Q - $width = imagesx($im); ( I, \; z. K4 j
- $height = imagesy($im);
; v' u* n; I) \" v - if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){
1 T- v1 p9 {/ ?8 t. X& K8 Q - if($maxwidth && $width > $maxwidth){
2 G1 Q/ {, g, T: \7 N! B - $widthratio = $maxwidth/$width; 0 F. w6 V8 H8 K3 m# G
- $RESIZEWIDTH=true; " Z" w9 E9 q* T& v+ s. l& X
- }
3 t3 Q( o; B; e( T' x - if($maxheight && $height > $maxheight){
6 e8 S# P# Q( k3 k+ _ - $heightratio = $maxheight/$height; 5 E" N8 c$ O7 h
- $RESIZEHEIGHT=true; 8 j( i o% ?1 }( O
- }
5 c% a( y! q: n& [+ W& z: G - if($RESIZEWIDTH && $RESIZEHEIGHT){
l4 _5 p+ P- V - if($widthratio < $heightratio){ " ?; P( s! E1 H$ s
- $ratio = $widthratio; * c7 O1 y: t! B# d0 b
- }else{ # l) D7 w1 Y3 a! g8 z
- $ratio = $heightratio;
! v, ?) H$ s+ x% }6 j) t - } & U+ S3 }: t4 P9 u
- }elseif($RESIZEWIDTH){ 3 a& r$ p [( n4 p4 S6 ^* w6 |
- $ratio = $widthratio;
/ a- K) f2 [* F5 F# O - }elseif($RESIZEHEIGHT){ . n j: [) {* t% x: G4 s/ [
- $ratio = $heightratio; 4 [7 H9 W3 u. W7 B, G
- }
* O% [1 s7 m- {& T( ^ - $newwidth = $width * $ratio;
% ]% \. T) ?; b+ Q" p - $newheight = $height * $ratio; 2 Q3 N* _5 P1 u
- if(function_exists("imagecopyresampled")){ % A: v+ ^" s/ s: v0 ~5 ~
- $newim = imagecreatetruecolor($newwidth, $newheight);
5 P! j. d: T; m# R7 y6 l - imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
3 X$ ^5 v( A6 @; j" i - }else{
9 A3 l" s$ a3 X4 d2 C - $newim = imagecreate($newwidth, $newheight); & z4 I5 h$ M' P
- imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); $ U( w; X+ m& U! j( T, Q# t
- } 9 d# u4 B# F! A$ p! u$ y8 p7 j
- ImageJpeg ($newim,$name . ".jpg"); + ]1 h2 u* |3 S% ^; ^5 l
- ImageDestroy ($newim);
. k$ D+ G. D+ e' |, i' ~ - }else{
$ D! O! a0 C( _: N) t - ImageJpeg ($im,$name . ".jpg");
# F- }/ ]. ?7 _ - } : l$ e0 _. P& {7 l' o
- } I0 s. n. W$ G1 X* A, t7 u* J7 P
- ! Q; i( {6 F* G/ t1 V
- if($_FILES['image']['size']){ - ?. g; c/ k ^: v& e- b" N
- if($_FILES['image']['type'] == "image/pjpeg"){ 7 i' D: [. y8 |) _7 F; _- t: q
- $im = imagecreatefromjpeg($_FILES['image']['tmp_name']);
% P* S( {+ V/ l5 L, V$ _ - }elseif($_FILES['image']['type'] == "image/x-png"){
, C9 }# B* C+ f0 h! o2 o/ m - $im = imagecreatefrompng($_FILES['image']['tmp_name']);
3 ` b. A. R! I( w4 h - }elseif($_FILES['image']['type'] == "image/gif"){
y* D0 J. D8 V1 u! R# L - $im = imagecreatefromgif($_FILES['image']['tmp_name']); ! ^% Y* d( n0 C& Q
- } 2881064151
. a4 f+ q3 ~( J# o) q0 L - if($im){
1 s4 B6 d' F- R0 d. g - if(file_exists("$FILENAME.jpg")){ ; j) ~! r) y/ c9 @2 v. n
- unlink("$FILENAME.jpg"); ! j8 i/ `( H2 o4 I9 f; a6 y8 {9 j
- } 5 `; F4 ~0 _" D4 d
- ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,$FILENAME); % f! B4 Z" g( n6 q
- ImageDestroy ($im); ( K% \/ O3 O: z5 ?( u( A
- } + }6 Y3 C2 m, F1 t% R! q' V" z7 C
- } # d) ]0 z' y: o
- ?>
复制代码 以下是测试代码(demo.php) . F9 \& _7 Z: p1 E3 q/ k
, A8 ]$ K% o5 S# a$ k代码如下:: Y6 v$ s& g& g4 H6 D4 I
0 w# `3 w" m4 Y0 E/ I
- <?php
8 Y6 M5 J, T6 ? - include('ResizeImage.php'); 8 j! L, U) f! }
- if(!empty($_POST)){ & J- y6 Y# T7 w% ^: c+ Y
- echo($FILENAME.".jpg?cache=".rand(0,999999));
( @; f7 M6 ?" V: y* |+ x$ w; d" @ - } 0 K7 H2 z/ S3 Q- V7 M3 I
- ?> ' F1 w* @& C$ t" J1 T7 J+ @+ X
- <form name="test" action="?submit=true" enctype="multipart/form-data" method="post" > ' |; I- u( P0 u/ m, N$ K
- <input type="file" name="image" size="50" value="浏览"><p>
& x/ f4 x2 W6 T) S. e - <input type="submit" value="上传图片"> ( v0 k9 J. \7 Q( x
- </form>
复制代码
- \% E2 _% z, ~, \& W; z/ b; Q: Q7 k! I2 Q C7 q4 w, C) ~
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