cncml手绘网

标题: PHP一般情况下生成的缩略图都比较不理想 [打印本页]
作者: admin    时间: 2018-7-7 23:52
标题: PHP一般情况下生成的缩略图都比较不理想
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。
  1. <?php 4 ^) ?/ A1 \# O# R8 M) X4 q! w
  2. $FILENAME="image.thumb";
      r% _$ ^3 H5 H9 L9 d1 l
  3. // 生成图片的宽度 3 d- t4 Q  Z1 k5 I& l- G+ T8 A# e+ P" \
  4. $RESIZEWIDTH=400;
    ; R' b6 C: k! V) W. w
  5. // 生成图片的高度 1 [+ Z' _" o( W
  6. $RESIZEHEIGHT=400;
    % V! i& m7 d  r* y

  7. & X* n6 ~% i  c& F' m+ V/ n1 _/ I
  8. function ResizeImage($im,$maxwidth,$maxheight,$name){ 1 j1 g* O) o8 t1 m( w& I
  9. $width = imagesx($im); . D# ?( g% ~$ y! x0 ?
  10. $height = imagesy($im); " k* g7 q# c- i( a0 s
  11. if(($maxwidth && $width > $maxwidth) || ($maxheight && $height > $maxheight)){ ; T8 R1 O( `$ Z* B4 s
  12. if($maxwidth && $width > $maxwidth){
    / y8 z" Z3 Y. w; o
  13. $widthratio = $maxwidth/$width; ( j) \/ ^% a! E& @3 ~
  14. $RESIZEWIDTH=true; # P4 v) L. M* ]
  15. } : l: j7 ]5 ]% S
  16. if($maxheight && $height > $maxheight){ 0 W8 _3 g% {; @7 b  f+ Y5 T
  17. $heightratio = $maxheight/$height;
    2 K( `5 u! J) t! ], W/ ^
  18. $RESIZEHEIGHT=true; & _, E8 A5 n% w$ P
  19. } * S4 ]4 ^: }0 R1 [8 q2 m# x
  20. if($RESIZEWIDTH && $RESIZEHEIGHT){ & J, N7 f# u' V/ y+ ^- u2 j
  21. if($widthratio < $heightratio){
    1 z0 [8 ?! C) V" H+ z
  22. $ratio = $widthratio;
    6 e( b) A$ r' l5 l- ~. a
  23. }else{ " s$ L# D2 V. w
  24. $ratio = $heightratio; 3 |( X( L, M" P, B) }' z3 _: M
  25. }
    4 ]2 h( U) W; T2 L
  26. }elseif($RESIZEWIDTH){
    ( J3 t* ]0 k2 d; f0 R' `5 F
  27. $ratio = $widthratio;
    / a! U8 p8 u/ V, Y7 n
  28. }elseif($RESIZEHEIGHT){
    ; e: U, A" W- R9 c( P2 x7 E
  29. $ratio = $heightratio; - S3 q7 {0 u$ x4 @2 j$ n( x
  30. }
      P) y" A/ \) F- h) u/ |  C& E9 T3 M
  31. $newwidth = $width * $ratio; 1 E; M0 @+ R0 u+ D  @2 Y
  32. $newheight = $height * $ratio;
    : S! g3 b. _. t& c: Q
  33. if(function_exists("imagecopyresampled")){ ( y7 U+ V, H$ W& }& P& {# i  @
  34. $newim = imagecreatetruecolor($newwidth, $newheight);
    : V# B. Y- M: j0 m3 |
  35. imagecopyresampled($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); ; Z3 m/ _) ]% [- O# B( Q1 Q$ ]
  36. }else{ 0 _) V+ J* {4 s2 K  i  @. A
  37. $newim = imagecreate($newwidth, $newheight); # D" {( c( p0 {: {
  38. imagecopyresized($newim, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height); : D* j+ c/ C8 a- u
  39. }
    ; S9 Q. R( U, F5 J  A2 r
  40. ImageJpeg ($newim,$name . ".jpg");
    ; m% x7 N7 b9 {% \" E. ]  S
  41. ImageDestroy ($newim); * T3 e% Z4 D, Z7 w+ `& l, q
  42. }else{ & n3 h8 P6 K8 d) \3 r+ X* j
  43. ImageJpeg ($im,$name . ".jpg");
    / p7 H% @& Q% G& Z# B# |
  44. } # F  z, C& g* b- K: M1 R( j
  45. }
    4 _7 U8 U9 {' [" g- l
  46. 8 A7 I2 l$ L1 m+ X
  47. if($_FILES['image']['size']){ 9 k8 ]( b* U# S; l/ [) A
  48. if($_FILES['image']['type'] == "image/pjpeg"){ ) `$ }4 {* V/ w- s9 y( o- h1 \
  49. $im = imagecreatefromjpeg($_FILES['image']['tmp_name']); * u; C. x' Y+ z, k0 W
  50. }elseif($_FILES['image']['type'] == "image/x-png"){
      [/ X! Z: C4 U5 w3 L' s4 `
  51. $im = imagecreatefrompng($_FILES['image']['tmp_name']);
    6 S, x5 H: p. `8 U& m
  52. }elseif($_FILES['image']['type'] == "image/gif"){ + f: Y8 y9 ?/ |5 J& r/ R
  53. $im = imagecreatefromgif($_FILES['image']['tmp_name']); ; ]7 U9 N4 T  j. g* m, a' Z/ T
  54. } 2881064151/ z, j4 @9 w" @* V( K$ A
  55. if($im){
    # b% O: k( J! `
  56. if(file_exists("$FILENAME.jpg")){ ! ~& v' @. I% ^
  57. unlink("$FILENAME.jpg"); ( B) R# Z+ R/ i
  58. } 9 z" l4 @# H: ]$ Q; A  }- o% ~
  59. ResizeImage($im,$RESIZEWIDTH,$RESIZEHEIGHT,$FILENAME);
    & `3 f1 w4 |% a% A$ i3 i' f. P
  60. ImageDestroy ($im);
    5 F) w2 a' H, ]3 A4 w
  61. }
    0 Z$ P( ~9 J) H* i+ y; ~3 I& \7 n
  62. } 8 S( w- A4 m, V/ C( y/ {8 R, {. k: P
  63. ?>
复制代码
以下是测试代码(demo.php) 5 ~& h1 k3 k/ u
7 L. M! C% y" }& `
代码如下:
  U8 ]; d# [0 a
: v5 S, r5 U! d+ o
  1. <?php
    0 O$ u. f! ~9 U: H4 J
  2. include('ResizeImage.php');
    ( Z; {. ^- R/ w- v
  3. if(!empty($_POST)){
    1 q; ?. `' D7 A2 J+ D4 g7 W6 S
  4. echo($FILENAME.".jpg?cache=".rand(0,999999));
    + ]7 |1 P: q' b, L) c: x3 c9 e. ?
  5. } ; f7 a/ }. F% g8 M0 b" U
  6. ?>
    ' J' c5 T. a* i) U9 P% Z
  7. <form name="test" action="?submit=true" enctype="multipart/form-data" method="post" > 7 G/ B: E0 |( ?. Y  _4 V6 s
  8. <input type="file" name="image" size="50" value="浏览"><p> 3 J( U; V% O- }( [% F
  9. <input type="submit" value="上传图片">
    4 a% Y( T+ y0 Y! b: W8 r7 m# I/ Q
  10. </form>
复制代码

: h! d" `) R: V8 p: k7 c4 X7 i3 }" {+ y$ o7 x




欢迎光临 cncml手绘网 (http://www.cncml.com/) Powered by Discuz! X3.2