PHP生成圖片縮略圖

要使用PHP生成圖片縮略圖,要保證你的PHP服務器安裝了GD2圖形庫 使用一個類生成圖片的縮略圖

//使用如下類就可以生成圖片縮略圖,

<?php
class resizeimage
{
    //圖片類型
    var $type;
    //實際寬度
    var $width;
    //實際高度
    var $height;
    //改變后的寬度
    var $resize_width;
    //改變后的高度
    var $resize_height;
    //是否裁圖
    var $cut;
    //源圖象
    var $srcimg;
    //目標圖象地址
    var $dstimg;
    //臨時創建的圖象
    var $im;

    function resizeimage($img, $wid, $hei,$c,$dstpath)
    {
        $this->srcimg = $img;
        $this->resize_width = $wid;
        $this->resize_height = $hei;
        $this->cut = $c;
        //圖片的類型

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

        //初始化圖象
        $this->initi_img();
        //目標圖象地址
        $this -> dst_img($dstpath);
        //--
        $this->width = imagesx($this->im);
        $this->height = imagesy($this->im);
        //生成圖象
        $this->newimg();
        ImageDestroy ($this->im);
    }
    function newimg()
    {
        //改變后的圖象的比例
        $resize_ratio = ($this->resize_width)/($this->resize_height);
        //實際圖象的比例
        $ratio = ($this->width)/($this->height);
        if(($this->cut)=="1")
        //裁圖
        {
            if($ratio>=$resize_ratio)
            //高度優先
            {
                $newimg = imagecreatetruecolor($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)
            //寬度優先
            {
                $newimg = imagecreatetruecolor($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,$this->dstimg);
            }
        }
        else
        //不裁圖
        {
            if($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,$this->dstimg);
            }
        }
    }
    //初始化圖象
    function initi_img()
    {
        if($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);
        }
    }
    //圖象目標地址
    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;
    }
}
?>

使用方法

$resizeimage = new resizeimage("圖片源文件地址", "200", "100", "0","縮略圖地址");
//就只用上面的一句話,就能生成縮略圖,其中,源文件和縮略圖地址可以相同,200,100分別代表寬和高