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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
! b5 s9 H% G+ j - $FILENAME="image.thumb";
8 a9 R( V+ H8 s8 Q ~" w- j6 Z. a: |3 d - // 生成图片的宽度 # N# p8 L) L( ^6 ^
- $RESIZEWIDTH=400;
, s4 Q4 F& j$ K$ h - // 生成图片的高度 - ^+ ~% X) k$ a' K. C; _
- $RESIZEHEIGHT=400;- ` O7 z& s( w$ f: Z( t! {$ [
- : @9 S- @% l% R; A, h
- function ResizeImage($im,$maxwidth,$maxheight,$name){
Y- b- I5 X1 G6 m% l5 z - $width = imagesx($im); 3 l0 f9 n' Z5 }) k9 z5 i8 V
- $height = imagesy($im); ( P) K! p* T; [8 W8 [" q/ {7 b
- if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){ . R( {1 T# o ^: O1 }
- if($maxwidth && $width > $maxwidth){
' a- t1 A: L: A+ e* }" w - $widthratio = $maxwidth/$width; , s( U& E2 F) ?8 W# H8 B9 k' M
- $RESIZEWIDTH=true; " G6 O( J5 d8 F. ~
- }
* p/ s4 q. j) R& D9 w - if($maxheight && $height > $maxheight){
0 u7 _0 j8 I! I$ |. u - $heightratio = $maxheight/$height;
0 x4 l+ g. X3 M) `! ^2 x - $RESIZEHEIGHT=true;
: [4 T C2 w! z# w- Z2 K- e# T - } 1 _' l, @# |. u( L/ F6 C
- if($RESIZEWIDTH && $RESIZEHEIGHT){
3 U5 a3 I Q0 y: ~ - if($widthratio < $heightratio){
; V, r9 C. I3 u4 R( ~ - $ratio = $widthratio;
9 p$ l+ V9 B1 U0 N/ J9 M - }else{ 4 M' r$ J" j2 S* g+ [9 p& ^( \$ b9 b
- $ratio = $heightratio;
- ^+ e- }2 K0 \1 R: I7 [. }2 Q# F* x - } - ^4 p% l8 p {6 ?4 Z
- }elseif($RESIZEWIDTH){
1 ]% }7 P* z4 n \8 J% n, t9 o - $ratio = $widthratio;
5 W) Q2 v( f* ?5 ]: ~7 l - }elseif($RESIZEHEIGHT){
4 K& `: F( }5 G' W5 a6 W- V - $ratio = $heightratio; 2 X, c# a* n' R3 h/ Z% h
- }
0 T! X6 m( m. }0 s0 V J - $newwidth = $width * $ratio;
# X( R I% K0 Z7 W" | - $newheight = $height * $ratio;
4 D1 L# ^9 c- w2 [: i$ D& @9 o - if(function_exists("imagecopyresampled")){ 9 m5 t. N3 v6 T; G. `
- $newim = imagecreatetruecolor($newwidth, $newheight);
% o; A+ W$ ~) Z2 A/ z - imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
! a6 n) k5 B A - }else{ " Z- f; G1 j# q: N9 A9 C# o; v
- $newim = imagecreate($newwidth, $newheight); * D0 n& l9 H' n6 |
- imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
- y" V2 t- l$ ?( m0 i - }
& ~. F i: _3 m" C; o) M# ?- S$ [ - ImageJpeg ($newim,$name . ".jpg");
. U$ v4 b- k# I9 E/ w$ m - ImageDestroy ($newim);
6 t+ ]5 ^/ J8 F - }else{ 6 E+ v; t# t2 C* o9 y
- ImageJpeg ($im,$name . ".jpg");
2 [. ]. V' Y) N - } / x8 Y+ |/ L9 Y' `; w
- }
+ B; o& Y( p# n: j7 f - 5 g# {" u; K& W+ }, I& i( [ r
- if($_FILES['image']['size']){
+ R6 q% F# J) a' J - if($_FILES['image']['type'] == "image/pjpeg"){
- Z8 O7 s, e3 U$ b0 j& ?0 Y7 D - $im = imagecreatefromjpeg($_FILES['image']['tmp_name']);
& N/ u6 a- y+ E) x8 t - }elseif($_FILES['image']['type'] == "image/x-png"){ / E( ?0 g) x3 p, n
- $im = imagecreatefrompng($_FILES['image']['tmp_name']);
6 a# P' t6 i" R% o* f+ c - }elseif($_FILES['image']['type'] == "image/gif"){
% {5 U- c/ z4 ?2 h* S7 ~; F - $im = imagecreatefromgif($_FILES['image']['tmp_name']); $ B( C) R, @) s) j6 m' `
- } 2881064151
! g% b& U2 P _' C - if($im){
5 w c( o/ B7 {0 Q - if(file_exists("$FILENAME.jpg")){
$ {1 M# z1 I& }! {: c; y: ? - unlink("$FILENAME.jpg"); ) B6 d. ]# M. M( O+ V9 i
- }
( J. G2 r* O' ~. S) t - ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,$FILENAME);
# d% i! i- X' `3 A- m - ImageDestroy ($im);
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- } " u; }/ l: {4 z" F/ R8 ?
- ?>
复制代码 以下是测试代码(demo.php)
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8 Z. q" s4 ^7 G; \( C7 L代码如下:
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- <?php
8 s1 `2 U2 _) x - include('ResizeImage.php');
( j( y9 C2 J; O% }' @, S2 z - if(!empty($_POST)){ ; w; C" w- q/ h# Q# P* H# Y
- echo($FILENAME.".jpg?cache=".rand(0,999999)); ! l: I' z7 q# c
- } ' q" Z! Q/ V' c7 ]' F8 m
- ?>
8 k* K p* l4 x7 g - <form name="test" action="?submit=true" enctype="multipart/form-data" method="post" > 8 Q. r( m0 N7 c3 {% n1 t& f, P
- <input type="file" name="image" size="50" value="浏览"><p>
6 y5 Y' F5 Z3 |% B - <input type="submit" value="上传图片"> & N( Q; _- G4 M$ N
- </form>
复制代码
+ U" z/ Y" J, ?* { J% T4 ]* d2 Z4 `1 p$ T D2 i4 F6 E
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