PHP图片生成缩略图

<?php
class resizeimage {
//图片类型
var $type;
//实际宽度
var $width;
//实际高度
var $height;
//改变后的宽度
var $resize_width;
//改变后的高度
var $resize_height;
//是否裁图
var $cut;
//源图象
var $srcimg;
//目标图象地址
var $dstimg;
//临时创建的图象
var $im;
function resizeimage($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 );
//--
$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, 0, 0, 0, 0, $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->resize_height );
imagecopyresampled ( $newimg, $this->im, 0, 0, 0, 0, $this->resize_width, $this->resize_height, $this->width, (($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->im, 0, 0, 0, 0, $this->resize_width, ($this->resize_width) / $ratio, $this->width, $this->height );
ImageJpeg ( $newimg, $this->dstimg );
}
if ($ratio < $resize_ratio) {
$newimg = imagecreatetruecolor ( ($this->resize_height) * $ratio, $this->resize_height );
imagecopyresampled ( $newimg, $this->im, 0, 0, 0, 0, ($this->resize_height) * $ratio, $this->resize_height, $this->width, $this->height );
ImageJpeg ( $newimg, $this->dstimg );
}
}
}
//初始化图象
function initi_img() {
if ($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, 0, $name_length - 1 );
$this->dstimg = $dstpath;
//echo$this->dstimg;
}
}
$resizeimage = new resizeimage('D:/PC_webserver/phproot/TestPhpProject/upload/12.jpg', 200, 200, false, 'D:/PC_webserver/phproot/TestPhpProject/upload/12.jpg');

?>