php图片处理类（生成缩略图,增加水印，获取图片信息)_PHP教程

class image
{
public $info=array();

function __construct()
{
!extension_loaded('gd') && exit("www.bKjia.c0m提示：服务器环境不支持gd库");
return true;
}

function image()
{
$this->__construct();
}

function thumb($image,$thumb_width=300,$thumb_height=225)
{
$info=$this->info($image);
$scale=min(1,min($thumb_width/$info['width'],$thumb_height/$info['height'])); //按比例缩放
$thumb_width=intval($info['width']*$scale);
$thumb_height=intval($info['height']*$scale);
$createfunc='imagecreatefrom'.($info['type']=='jpg'?'jpeg':$info['type']);
$im=$createfunc($image);
$thumb_im=$info['type']!='gif' && function_exists('imagecreatetruecolor')?imagecreatetruecolor($thumb_width,$thumb_height):imagecreate($thumb_width,$thumb_height);
imagecopyresampled($thumb_im,$im,0,0,0,0,$thumb_width,$thumb_height,$info['width'],$info['height']);
if($info['type']=='gif' || $info['type']=='png')
{
$bgcolor=imagecolorallocate($thumb_im,0,255,0);
imagecolortransparent($thumb_im,$bgcolor);
}
$imagefunc='image'.($info['type']=='jpg'?'jpeg':$info['type']);
$thumbname='thumb_'.$info['name'].'.'.$info['type'];
$imagefunc($thumb_im,$info['path'].$thumbname);
imagedestroy($im);
imagedestroy($thumb_im);
return $info['path'].$thumbname;
}

function watermark($image,$pos=9,$watermarkimg='images/watermark.gif',$pct=65,$text='',$w_font=5,$w_color='#ff0000')
{
$imageinfo=$this->info($image);
$source_w=$imageinfo['width'];
$source_h=$imageinfo['height'];
$imagecreatefunc='imagecreatefrom'.($imageinfo['type']=='jpg'?'jpeg':$imageinfo['type']);
$im=$imagecreatefunc($image);
if(!empty($watermarkimg) && file_exists($watermarkimg)) //添加图片水印
{
$iswaterimage=true;
$watermarkinfo=$this->info($watermarkimg);
$width=$watermarkinfo['width'];
$height=$watermarkinfo['height'];
$watermarkcreatefunc='imagecreatefrom'.($watermarkinfo['type']=='jpg'?'jpeg':$watermarkinfo['type']);
$watermark_im=$watermarkcreatefunc($watermarkimg);
}
else //添加文字水印
{
$iswaterimage=false;
if(!empty($w_color) && strlen($w_color)==7)
{
$r=hexdec(substr($w_color,1,2));
$g=hexdec(substr($w_color,3,2));
$b=hexdec(substr($w_color,5,2));
}
$temp = imagettfbbox(ceil($w_font*2.5), 0, 'fonts/alger.ttf', $text);
$width = $temp[2] - $temp[6];
$height = $temp[3] - $temp[7];
unset($temp);
}
switch($pos)
{
case 0:
$wx = mt_rand(0,($source_w - $width));
$wy = mt_rand(0,($source_h - $height));
break;
case 1:
$wx = 5;
$wy = 5;
break;
case 2:
$wx = ($source_w - $width) / 2;
$wy = 5;
break;
case 3:
$wx = $source_w - $width-5;
$wy = 5;
break;
case 4:
$wx = 5;
$wy = ($source_h - $height) / 2;
break;
case 5:
$wx = ($source_w - $width) / 2;
$wy = ($source_h - $height) / 2;
break;
case 6:
$wx = $source_w - $width-5;
$wy = ($source_h - $height) / 2;
break;
case 7:
$wx = 5;
$wy = $source_h - $height-5;
break;
case 8:
$wx = ($source_w - $width) / 2;
$wy = $source_h - $height-5;
break;
default:
$wx = $source_w - $width-5;
$wy = $source_h - $height-5;
break;
}
if($iswaterimage)
{
if($imageinfo['type'] == 'png') {
imagecopy($im, $watermark_im, $wx, $wy, 0, 0, $width, $height);
} else {
imagecopymerge($im, $watermark_im, $wx, $wy, 0, 0, $width, $height, $pct);
}
}
else
{
imagestring($im,$w_font,$wx,$wy,$text,imagecolorallocate($im,$r,$g,$b));
}
$imagefunc='image'.($imageinfo['type']=='jpg'?'jpeg':$imageinfo['type']);
$imagefunc($im,$image);
imagedestroy($im);
return true;
}

function info($image)
{
$info=array();
$info['size']=filesize($image);
$imageinfo=getimagesize($image);
$info['width']=$imageinfo[0];
$info['height']=$imageinfo[1];
$info['width_height']=$imageinfo[3];
$info['mime']=$imageinfo['mime'];
unset($imageinfo);
$imageinfo=pathinfo($image);
$info['path']=$imageinfo['dirname'].'//m.sbmmt.com/m/';
$info['type']=strtolower($imageinfo['extension']); //图片类型，不含'.'
$info['name']=$imageinfo['filename'];
unset($imageinfo,$name);
$this->info=$info;
return $info;
}
}