php 方便水印和缩略图的图形类

    *@param string $filename 要转存的文件路径
    *@param int $zhiliang jpeg图片特有的，图像清晰度
    */
    function display($type = null,$filename = null,$zhiliang = null) {
        if($type == null) {
            $type = $this->type ? $this->type : 'jpg';
        }
        if(($type == 'jpeg' or $type == 'jpg') and $zhiliang == null) {
            $type = 'jpeg';
            $zhiliang = 100;
        }
        if($filename == null) {
            header('Content-type: image/'.$type);
        }
        $displayfunc = 'image'.$type;
        $displayfunc($this->im,$filename,$zhiliang);
        imagedestroy($this->im);
    }

    function randcolor($a,$b) {
        $a = $a>255 ? 255 : (int)$a;
        $a = $a<0 ? 0 : (int)$a;
        $b = $b>255 ? 255 : (int)$b;
        $b = $b<0 ? 0 : (int)$b;
        for($i=0;$i<3;$i++) {
            $color .= str_pad(dechex(mt_rand($a,$b)), 2, "0", STR_PAD_LEFT);
        }
        return $color;
    }
}

/*
function error($msg,$debug = false) {
    $err = new Exception($msg);
    $str = "<pre>n<span style="color:red" style="color:red">错误:</span>n".print_r($err->getTrace(),1)."n</pre>";
    if($debug == true) {
        file_put_contents(date('Y-m-d').".log",$str);
        return $str;
    }else{
        die($str);
    }
}
*/
?>

这是简单的用法实例

$img = new img('a.png');
$m = $img->im;
$im = $img->suolue(100);
$img->im = $m;
$img->suolue(300);
$img->merge($m,array('left'=>0,'top'=>0,'touming'=>60));