共有两种等比例缩略图方法可以借鉴 一、为类文件,实例化之后即可使用 二、为自定义方法,比较轻巧
类文件
public $type;
//实际宽度
public $width;
//实际高度
public $height;
//改变后的宽度
public $resize_width;
//改变后的高度
public $resize_height;
//是否裁图
public $cut;
//源图象
public $srcimg;
//目标图象地址
public $dstimg;
//临时创建的图象
public $im;
function resizeimage($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);
//W & H
$this->width = imagesx($this->im);
$this->height = imagesy($this->im);
//生成图象
$this->newimg();
ImageDestroy ($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,
$this->resize_height
);
imagecopyresampled($newimg,
($this->resize_height)*$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 $this->dstimg;
}
}
?>
function thumbs($FileName,$SaveTo,$SetW,$SetH){
$IMGInfo= getimagesize($FileName);
if(!$IMGInfo) return false;
if($IMGInfo['mime']== "image/pjpeg" || $IMGInfo['mime']=="image/jpeg"){
$ThisPhoto= imagecreatefromjpeg($FileName);
}elseif($IMGInfo['mime']== "image/x-png" || $IMGInfo['mime']== "image/png"){
$ThisPhoto= imagecreatefrompng($FileName);
}elseif($IMGInfo['mime']== "image/gif"){
$ThisPhoto=imagecreatefromgif($FileName);
}
$width=$IMGInfo[0];
$height=$IMGInfo[1];
$scalc = max($width/$SetW,$height/$SetH);
$nw = intval($width/$scalc);
$nh = intval($height/$scalc);
echo "缩略大小:w$nw,h$nh <br /-->";
if($SetW-$nw == 1){$nw = $SetW;}
if($SetH-$nh == 1){$nh = $SetH;}
echo "+修正1像素: w$nw,h$nh
";
//补宽
if($SetW-$nw > 0){
$nh = $nh +(($nh/$nw) ($SetW-$nw));
echo "需补宽".($SetW-$nw).",陪补高".(($nh/$nw) ($SetW-$nw))."
";
$nw = $SetW;
}
//补高
if($SetH-$nh > 0){
$nw = $nw + (($nw/$nh) ($SetH-$nh));
echo "需补高".($SetH-$nh).",陪补宽". (($nw/$nh) ($SetH-$nh)) ."
";
$nh = $SetH;
}
$nw = intval($nw);
$nh = intval($nh);
echo "+修正大小:w$nw,h$nh
";
$px = ($SetW - $nw)/2;
$py = ($SetH - $nh)/2;
echo "窗口大小:w$SetW,h$SetH
";
echo "+偏移修正:x$px,y$py
";
$NewPhoto=imagecreatetruecolor($SetW,$SetH);
imagecopyresized($NewPhoto,$ThisPhoto,$px,$py,$nw,$nh,$width,$height);
ImageJpeg ($NewPhoto,$SaveTo);
return true;
}
?>