<?php
class image{
//生成随机字符
static protected function randName($n){
$str = "123456789abcdefghijkmnpqrstuvwxyz";
return substr(str_shuffle($str),0,$n);
}
//生成验证码
static public function chekcode(){
$im = imagecreatetruecolor(50,25);
$gray = imagecolorallocate($im,100,100,100);
$blue = imagecolorallocate($im,0,0,255);
imagefill($im,0,0,$gray);
$str = self::randName(4);
$_SESSION['chekcode']=$str;
imagestring($im,5,10,10,$str,$blue);
header('content-type:image/png');
return imagepng($im);
}
//获取图片信息长,宽,等
static public function getInfo($ori){
$arr = getimagesize($ori);
//判断文件的格式是不是图片
if(strstr($arr['mime'],'/',true)!=='image'){
echo '文件不是图片';
return false;
}
$info = array();
//获取长宽
$info['width'] = $arr['0'];
$info['height'] = $arr['1'];
//获取图片格式
switch($arr['2']){
case 1:$info['postfix'] = 'gif';break;
case 2:$info['postfix'] = 'jpeg';break;
case 3:$info['postfix'] = 'png';break;
case 6:$info['postfix'] = 'bmp';break;
default :$info['postfix'] = false;
}
return $info;
}
//等比生成缩略图
static public function thumb($ori,$w=200,$h=200 ){
$info = image::getInfo($ori);
//获取原图
$func1 = 'imagecreatefrom' . $info['postfix'];
$big = $func1($ori);
//生成缩略图模板
$small = imagecreatetruecolor($w,$h);
$gray = imagecolorallocate($small,100,100,100);
imagefill($small,0,0,$gray);
//获取缩放比例
$k = min($w/$info['width'],$h/$info['height']);
$width = $info['width']*$k;
$height = $info['height']*$k;
// 计算留白
$lw = round(($w - $width)/2); // 计算左侧留的宽度
$lh = round(($h - $height)/2); // 计算上部留的高度
//生成缩略图
imagecopyresampled($small,$big,$lw,$lh,0,0,$width,$height,$info['width'],$info['height']);
//保存缩略图
// 计算小图片的存储路径
$thumburl = str_replace('.','_thumb.',$ori);
$func2 = 'image' . $info['postfix'];
if($func2($small,$thumburl)){
return str_replace(ROOT,'',$thumburl);
}else{
return false;
}
}
}
//$dd = "../resource/uediter/php/upload/20151121/14480943825639.jpg";
//cho image::thumb($dd);
//image::chekcode();
?>
