基于GD2图形库的PHP生成图片缩略图类代码分享

要使用PHP生成图片缩略图,要保证你的PHP服务器安装了GD2图形库 使用一个类生成图片的缩略图

1.使用方法

rush:PHP;"> $resizeimage = new resizeimage("图片源文件地址","200","100","0","缩略图地址"); //就只用上面的一句话,就能生成缩略图,其中,源文件和缩略图地址可以相同,200,100分别代表宽和高

2. 缩略图类代码

rush:PHP;"> //使用如下类就可以生成图片缩略图,function resizeimage($img,$wid,$hei,$c,$dstpath)
{
$this->srcimg = $img;
$this->resize_width = $wid;
$this->resize_height = $hei;
$this->cut = $c;
//图片的类型

$this->type = strtolower(substr(strrchr($this->srcimg,"."),1));

//初始化图象
$this->initi_img();
//目标图象地址
$this -> dst_img($dstpath);
//--
$this->width = imagesx($this->im);
$this->height = imagesy($this->im);
//<a href="https://www.jb51.cc/tag/shengcheng/" target="_blank" class="keywords">生成</a>图象
$this->newimg();
ImageDestroy ($this->im);

}
function newimg()
{
//改变后的图象的比例
$resize_ratio = ($this->resize_width)/($this->resize_height);
//实际图象的比例
$ratio = ($this->width)/($this->height);
if(($this->cut)=="1")
//裁图
{
if($ratio>=$resize_ratio)
//高度优先
{
$newimg = imagecreatetruecolor($this->resize_width,$this->resize_height);
imagecopyresampled($newimg,$this->im,$this->resize_width,$this->resize_height,(($this->height)$resize_ratio),$this->height);
ImageJpeg ($newimg,$this->dstimg);
}
if($ratio<$resize_ratio)
//宽度优先
{
$newimg = imagecreatetruecolor($this->resize_width,$this->width,(($this->width)/$resize_ratio));
ImageJpeg ($newimg,$this->dstimg);
}
}
else
//不裁图
{
if($ratio>=$resize_ratio)
{
$newimg = imagecreatetruecolor($this->resize_width,($this->resize_width)/$ratio);
imagecopyresampled($newimg,($this->resize_width)/$ratio,$this->dstimg);
}
if($ratio<$resize_ratio)
{
$newimg = imagecreatetruecolor(($this->resize_height)$ratio,($this->resize_height)*$ratio,$this->dstimg);
}
}
}
//初始化图象
function initi_img()
{
if($this->type=="jpg")
{
$this->im = imagecreatefromjpeg($this->srcimg);
}
if($this->type=="gif")
{
$this->im = imagecreatefromgif($this->srcimg);
}
if($this->type=="png")
{
$this->im = imagecreatefrompng($this->srcimg);
}
}
//图象目标地址
function dst_img($dstpath)
{
$full_length = strlen($this->srcimg);

$type_length = strlen($this->type);
$name_length = $full_length-$type_length;


$name     = substr($this->srcimg,$name_length-1);
$this->dstimg = $dstpath;

//echo $this->dstimg;
}
}
?>