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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
% ]: p+ x4 f9 g - $FILENAME="image.thumb"; , o: ]2 K- m" o4 i
- // 生成图片的宽度
7 C* r! |; A) [9 H% S - $RESIZEWIDTH=400; 0 ~* t q. L9 ~( R
- // 生成图片的高度 & ^, T5 _- @8 Y; G2 \/ c" S3 N
- $RESIZEHEIGHT=400;- h$ S) |6 v8 ` a9 n
" N1 ~1 F8 i# Y. K, S% B- function ResizeImage($im,$maxwidth,$maxheight,$name){ " T7 D) \/ e6 l% R( G# X
- $width = imagesx($im); G9 [7 u4 ^ T$ `+ m
- $height = imagesy($im); : J! I1 I5 ]/ I
- if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){
5 D8 ~6 A/ j4 J1 ^# }0 S7 E - if($maxwidth && $width > $maxwidth){
7 P/ _& H: Q1 Z) k: i - $widthratio = $maxwidth/$width; 8 s* e3 Y4 f9 Y( j3 |( i
- $RESIZEWIDTH=true; # x! e4 D' X3 s3 M5 v3 f
- } : w9 W+ H4 m( Q/ l/ Q" N3 B
- if($maxheight && $height > $maxheight){ $ o# O" w# C* L4 c8 u3 L2 v
- $heightratio = $maxheight/$height; " ^# z! A$ m6 A! r4 y, W
- $RESIZEHEIGHT=true; 3 _% A; p1 N! d; s; P
- } 7 C1 Q% @) j* z5 m# V" q- D
- if($RESIZEWIDTH && $RESIZEHEIGHT){ ) V! {* F0 @" k9 P6 `4 \: e3 X
- if($widthratio < $heightratio){ ! M7 ^8 |3 ]8 W, ]- L U% |
- $ratio = $widthratio; 9 Z: }( Z3 C+ e; T
- }else{
6 H4 ~. ~3 N% b% q& ~2 O - $ratio = $heightratio;
4 E, u- A4 ~- N- B - }
& N8 d# H0 i( j- e) N9 _ - }elseif($RESIZEWIDTH){ ( K/ R( j" z/ x8 i: a
- $ratio = $widthratio; 5 u' z6 M5 d( Y- @/ ?# z! F
- }elseif($RESIZEHEIGHT){ / v1 b: ^ |. Q
- $ratio = $heightratio;
1 o6 i3 x* G( w - }
5 b6 O- R+ x9 I F - $newwidth = $width * $ratio;
+ Q1 j: `- L) u L - $newheight = $height * $ratio;
! I2 K( P, c4 p7 p9 z; s( q - if(function_exists("imagecopyresampled")){
# c% T4 ~' a/ C$ n - $newim = imagecreatetruecolor($newwidth, $newheight);
% T8 M3 W5 D8 z1 h: u - imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); & q2 ^$ X0 W6 ~
- }else{ 9 k6 |% l$ }( B
- $newim = imagecreate($newwidth, $newheight); 5 ~+ S7 ?% u2 Q7 r, a! z$ i
- imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
3 g& E' j! p8 p$ _2 g2 i; y- B - }
N3 r. c5 j. D6 U" i! N - ImageJpeg ($newim,$name . ".jpg"); 1 y) q' F, X# I
- ImageDestroy ($newim); ) {8 Q7 B5 \) j, [/ c" k" W1 [
- }else{
" V4 }- b+ A+ V0 d* L5 T - ImageJpeg ($im,$name . ".jpg"); . i" D0 u$ u. x. o
- }
7 I# Y. Z* n2 Q! y! K1 H/ {% r - }. J8 J- a6 O+ \' \
- % e& {3 ^* m3 j1 X! R- Z$ L
- if($_FILES['image']['size']){ 9 Z } K+ K" ~: [! h
- if($_FILES['image']['type'] == "image/pjpeg"){ R/ j+ @% j7 q! H+ K/ U: t
- $im = imagecreatefromjpeg($_FILES['image']['tmp_name']);
1 z4 R& w1 R! F7 X' ~% V: ? W - }elseif($_FILES['image']['type'] == "image/x-png"){
* T1 ]/ X0 _: o u9 ]" U - $im = imagecreatefrompng($_FILES['image']['tmp_name']);
0 @: ?: `2 |" k6 {9 \- c. N - }elseif($_FILES['image']['type'] == "image/gif"){
3 T/ D. \& l$ e: u( T1 b - $im = imagecreatefromgif($_FILES['image']['tmp_name']); 1 w* W, a3 L4 j2 k1 \
- } 2881064151- T. B% N) P. D# v
- if($im){ ' g. | }" A, \: b o" C
- if(file_exists("$FILENAME.jpg")){
) @$ x$ \+ J$ p. F6 V# P1 m/ { - unlink("$FILENAME.jpg");
( c& \* z, L ~2 Z - }
' ]- R" _; U3 r; i! j J - ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,$FILENAME); ) R: _8 G+ e3 v; f: e
- ImageDestroy ($im); * ^) ?' O4 @9 U) g8 h
- } " I3 d1 Q z: c0 f2 v
- }
+ C5 D6 o; [) x4 }& V" t - ?>
复制代码 以下是测试代码(demo.php)
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代码如下:& v" `7 @7 c" }* M
7 S6 L. c+ _: _* r
- <?php
0 { k9 ~' p D, C' Z: D - include('ResizeImage.php');
& Q. R3 G8 O/ [8 {* d/ ^ - if(!empty($_POST)){
! |/ v9 A2 H% W; R - echo($FILENAME.".jpg?cache=".rand(0,999999));
6 u2 r3 W ?2 [# V$ v% _ - }
4 P# s7 D: \8 c0 v$ ~ - ?> 0 a8 [6 h% {2 I
- <form name="test" action="?submit=true" enctype="multipart/form-data" method="post" > - |" z8 @5 ^7 D) F0 q
- <input type="file" name="image" size="50" value="浏览"><p>
( M; X1 N* q" A% h! v$ ?7 J - <input type="submit" value="上传图片">
4 v; ?) e+ V3 @+ J3 r7 h4 X - </form>
复制代码
+ u" v/ {/ s, R) |$ d, K! t. U: z" C6 C% D x8 r5 Q
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