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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
! V5 x' j: q% r3 X1 C0 Q3 ? - $FILENAME="image.thumb"; * Y$ M9 _9 ]! w% Q
- // 生成图片的宽度
& M9 H, `6 T9 p! H! G3 r - $RESIZEWIDTH=400;
+ G7 ?! r$ J0 c8 w4 U2 u k6 N& K - // 生成图片的高度 1 E. ^3 d. @) W% W) I8 U
- $RESIZEHEIGHT=400;
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# X( l2 H+ y# P# ?& ?- function ResizeImage($im,$maxwidth,$maxheight,$name){
% ^" U- e/ z' m) C - $width = imagesx($im);
) Q. C6 W3 x$ Z" H0 e% Z2 s7 D) l - $height = imagesy($im); 4 Q2 c# |# `2 `) s8 j
- if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){
: l" q6 J3 x7 c! S! s - if($maxwidth && $width > $maxwidth){ 1 k9 u% c2 L7 t. i+ _* }1 Q! [$ D
- $widthratio = $maxwidth/$width; 5 A6 L3 J( K4 P. X8 m. O; D8 [# T% t
- $RESIZEWIDTH=true;
' X7 g6 |+ U1 H/ E) V - }
" s( C5 m; z \/ u" z& J) V. g0 S- J9 g - if($maxheight && $height > $maxheight){ - z& x# H8 N1 Q4 w: L G" ^
- $heightratio = $maxheight/$height;
% k% N- \# F% C7 {3 D - $RESIZEHEIGHT=true;
9 p; M6 Y) J8 d. u# j( h - }
8 \9 C, p9 S. N" a$ m, C - if($RESIZEWIDTH && $RESIZEHEIGHT){
N% @+ C* [% t" Q' ~1 A - if($widthratio < $heightratio){ . \7 A i* j6 S% ^
- $ratio = $widthratio;
3 S) {: |" {5 k2 e5 I6 b$ M7 x - }else{ - {6 f, C; s4 X
- $ratio = $heightratio;
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- }elseif($RESIZEWIDTH){ * ?- @/ H# m! _, L0 D
- $ratio = $widthratio;
. W# A& j/ K2 d6 e9 a - }elseif($RESIZEHEIGHT){ , L( ?7 H' [+ T% t, m
- $ratio = $heightratio;
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- $newwidth = $width * $ratio; 5 Y9 j/ N2 k: _
- $newheight = $height * $ratio;
, D( C7 i+ U( @- ]2 f, W9 { - if(function_exists("imagecopyresampled")){
7 A( _8 t1 q( n0 }# w& ^$ T - $newim = imagecreatetruecolor($newwidth, $newheight); 6 E$ C7 I3 M5 v2 o5 H9 a
- imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); ! s$ Y# p+ h5 K7 v/ \
- }else{ $ i# p2 m( j) A: X# y5 G# B
- $newim = imagecreate($newwidth, $newheight); 2 U8 m |$ |2 Y
- imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); 0 z6 I% i' f3 h6 z: t. z
- }
- F) p4 j& u' W4 n2 j - ImageJpeg ($newim,$name . ".jpg"); $ }; M( b M* h, v
- ImageDestroy ($newim); 2 Z4 `5 ~# [. S4 y5 b7 ^
- }else{
0 F7 X% S. |0 G# T' a6 [ - ImageJpeg ($im,$name . ".jpg"); * @6 w3 U# A% m
- }
3 l+ P" Q$ z! q$ q$ G3 \, g# O - }) D5 F2 E8 l' {9 J
- 9 |% I: s/ K; G# s
- if($_FILES['image']['size']){ * O" I m+ F7 S E5 b7 e S
- if($_FILES['image']['type'] == "image/pjpeg"){
5 B* O( U0 o7 W! X. {# v - $im = imagecreatefromjpeg($_FILES['image']['tmp_name']);
& P4 V: }* C5 W0 Z - }elseif($_FILES['image']['type'] == "image/x-png"){ 3 k) f- U8 ]; }6 H
- $im = imagecreatefrompng($_FILES['image']['tmp_name']); + _6 w/ T5 \ _; T8 g2 U* A4 Z! n0 q
- }elseif($_FILES['image']['type'] == "image/gif"){
3 x3 M- m( h: p3 a9 J - $im = imagecreatefromgif($_FILES['image']['tmp_name']);
1 Q& y7 ^* ?- ?7 G$ ^ - } 2881064151+ y# {$ m/ O1 S9 g7 h7 b# d! t% C
- if($im){
. ]$ T$ u3 w6 j) y5 a% C( u - if(file_exists("$FILENAME.jpg")){
2 ^& R, f9 t) t$ K - unlink("$FILENAME.jpg"); : F5 t, l! _7 `( a: J
- }
" U7 ?) R t. c - ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,$FILENAME); # _8 w0 D1 @% F. D# d; d
- ImageDestroy ($im); 9 q8 w0 j4 R6 Y1 ]
- }
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- ?>
复制代码 以下是测试代码(demo.php)
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& H' y' }- u9 Q7 t8 z6 N. ~0 d代码如下:. |7 k$ m& Q9 i0 \) H
1 B) n+ Z- [) D1 G9 l& ` ^& D' G- <?php ) g. {7 x! {/ V) F9 a2 _5 p. U% i. i
- include('ResizeImage.php');
! s, ?2 Y+ q. D# U* A3 | - if(!empty($_POST)){
4 l- k& S6 ?: F - echo($FILENAME.".jpg?cache=".rand(0,999999)); 5 `* j$ I# r! [
- } - t3 N! P3 f) v- c' R
- ?> : @$ ^, C6 Z2 i8 K6 D
- <form name="test" action="?submit=true" enctype="multipart/form-data" method="post" > - P1 w, B0 y5 Y: u4 y9 M
- <input type="file" name="image" size="50" value="浏览"><p>
. b0 n9 C3 g6 v$ e8 l" q - <input type="submit" value="上传图片"> ; y0 w$ ^ |4 x. ?) \
- </form>
复制代码
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