php生成图片缩略图功能示例

<?php

/*

 * Created on 2011-3-18

 *

 * To change the template for this generated file go to

 * Window - Preferences - PHPeclipse - PHP - Code Templates

*/

/*构造函数-生成缩略图+水印,参数说明:

$srcFile-图片文件名,

$dstFile-另存文件名,

$markwords-水印文字,

$markimage-水印图片,

$dstW-图片保存宽度,

$dstH-图片保存高度,

$rate-图片保存品质*/

makethumb("1.jpg","aa/b.jpg","50","50");

functionmakethumb($srcFile,$dstFile,$dstW,$dstH,$rate= 100,$markwords= null,$markimage= null) {

  $data=GetImageSize($srcFile);

  switch($data[2]) {

    case1:

      $im= @ImageCreateFromGIF($srcFile);

    break;

    case2:

      $im= @ImageCreateFromJPEG($srcFile);

    break;

    case3:

      $im= @ImageCreateFromPNG($srcFile);

    break;

  }

  if(!$im)returnFalse;

  $srcW= ImageSX($im);

  $srcH= ImageSY($im);

  $dstX= 0;

  $dstY= 0;

  if($srcW*$dstH>$srcH*$dstW) {

    $fdstH=round($srcH*$dstW/$srcW);

    $dstY=floor(($dstH-$fdstH) / 2);

    $fdstW=$dstW;

  }else{

    $fdstW=round($srcW*$dstH/$srcH);

    $dstX=floor(($dstW-$fdstW) / 2);

    $fdstH=$dstH;

  }

  $ni= ImageCreateTrueColor($dstW,$dstH);

  $dstX= ($dstX< 0) ? 0 :$dstX;

  $dstY= ($dstX< 0) ? 0 :$dstY;

  $dstX= ($dstX> ($dstW/ 2)) ?floor($dstW/ 2) :$dstX;

  $dstY= ($dstY> ($dstH/ 2)) ?floor($dstH/ s) :$dstY;

  $white= ImageColorAllocate($ni, 255, 255, 255);

  $black= ImageColorAllocate($ni, 0, 0, 0);

  imagefilledrectangle($ni, 0, 0,$dstW,$dstH,$white);// 填充背景色

  ImageCopyResized($ni,$im,$dstX,$dstY, 0, 0,$fdstW,$fdstH,$srcW,$srcH);

  if($markwords!= null) {

    $markwords= iconv("gb2312","UTF-8",$markwords);

    //转换文字编码

    ImageTTFText($ni, 20, 30, 450, 560,$black,"simhei.ttf",$markwords);//写入文字水印

    //参数依次为，文字大小|偏转度|横坐标|纵坐标|文字颜色|文字类型|文字内容

  }elseif($markimage!= null) {

    $wimage_data=GetImageSize($markimage);

    switch($wimage_data[2]) {

      case1:

        $wimage= @ImageCreateFromGIF($markimage);

      break;

      case2:

        $wimage= @ImageCreateFromJPEG($markimage);

      break;

      case3:

        $wimage= @ImageCreateFromPNG($markimage);

      break;

    }

    imagecopy($ni,$wimage, 500, 560, 0, 0, 88, 31);//写入图片水印,水印图片大小默认为88*31

    imagedestroy($wimage);

  }

  ImageJpeg($ni,$dstFile,$rate);

  ImageJpeg($ni,$srcFile,$rate);

  imagedestroy($im);

  imagedestroy($ni);

}

?>

<!-- ajax文件上传开始 -->

<scripttype="text/javascript"src="/imageupload/jquery-1.10.2.min.js"></script>

<scripttype="text/javascript"src="/imageupload/layer/layer.js"></script>

<scripttype="text/javascript"src="/imageupload/ajaxupload.js"></script>

<!--ajax文件上传结束-->

<!--上传文件按钮列表开始-->

<inputid="requesturl"type="hidden"value="{:U('admin/upload/uploadfile')}"/>

<inputid="ajaxuploadfile"type="file"onchange="filechange()"/>

<inputid="filepathurl"type="hidden"value=""/>

<inputtype="button"value="第一张"pathurl="./Uploads/admin/trailer/"class="uploadclass"/>

<inputtype="button"value="第二张"pathurl="./Uploads/admin/fdfdfd/"class="uploadclass"/>

<inputtype="button"value="第三张"pathurl="./Uploads/admin/cdcdfd/"class="uploadclass"/>

<!--上传文件按钮列表结束-->

/**

* 文件上传方法

*/

publicfunctionuploadfile(){

//单文件上传

$upload=new\Think\Upload();// 实例化上传类

$upload->maxSize = 100000000 ;// 设置附件上传大小

$upload->exts =array('jpg','gif','png','jpeg');// 设置附件上传类型

$url=$_POST['filepathurl'];

if(!file_exists($url)){

mkdir($url,0777,true);

}

$upload->rootPath =$url;// 设置附件上传根目录

// 上传单个文件

$info=$upload->uploadOne($_FILES['postfilename']);

if(!$info) {

echojson_encode(array('bool'=>false,'error'=>$upload->getError()));

}else{

$path=$info['savepath'].$info['savename'];

echojson_encode(array('bool'=>true,'path'=>$path));

}

}