標題: php的縮放圖像類使用

作者:李英江

日期: 2006-11-25 14:54:05

轉載請保留作者內容: http://www.cgsir.com

使用縮略圖有個好處就是可以減少用戶下載的時間，為此要在上傳圖片時生成一張比原圖小的圖片，一般的ＰＨＰ空間都支持ＧＤ圖形庫，我的網站上ＧＤ版本是2.0.28，你可以自己寫圖像生成程序，php手冊有現成的例子，應該不難，但為了更快完成這功能，試用網上下載的一個縮放圖像類，感覺也蠻方便的。

注意：確認你的php支持GD庫，你可以通過使用 <?php phpinfo(); ?>查看你的GD版本,以下我的網站GD版本

如果你的PHP沒有這些內容，那么說明你的php還不支持這個庫，我針對windows 和linux分別作說明。

Windows:

找到你的php.ini的配置文件，打開GD動態鏈接庫就可以了。也就是說找到“；extension=php_gd2.dll”把分號去掉，重起apache就可以了。

Linux:

# tar -zxf gd-2.0.33.tar.gz

# cd gd-2.0.33

# ./configure --prefix=/usr/local/gd2 --with-jpeg=/usr/local/jpeg6/ --with-png --with-zlib --with-freetype=/usr/local/freetype/

# make; make install

使用縮放圖像類：

1.　包含類 include_once('image_class.php');?? // 用于生成縮略圖類

2.　生成縮略圖 120*90? 0為不載圖　$small_img = new resizeimage($image_full_dir, 120, 90, 0);　($image_full_dir圖像存儲路徑)

以下是完整圖像類image_class.php 源碼：

/***************************************/

/*功? 能：利用PHP的GD庫生成高質量的縮略圖*/

/*運行環境:PHP5.01/GD2*/

/*類說明：可以選擇是/否裁圖。

如果裁圖則生成的圖的尺寸與您輸入的一樣。

原則：盡可能多保持原圖完整

如果不裁圖，則按照原圖比例生成新圖

原則：根據比例以輸入的長或者寬為基準*/

/*參 數：$img:源圖片地址

$wid:新圖的寬度

$hei:新圖的高度

$c:是否裁圖，1為是，0為否*/

/***************************************/

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????建的圖象

var $im;

function resizeimage($img, $wid, $hei,$c)??? {??????? $this->srcimg = $img;??????? $this->resize_width = $wid;??????? $this->resize_height = $hei;??????? $this->cut = $c;??????? //圖片的類型??????? $this->type = substr(strrchr($this->srcimg,"."),1);??????? //初始化圖象??????? $this->initi_img();??????? //目標圖象地址??????? $this -> dst_img();??????? //--??????? $this->width = imagesx($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,$this->dstimg);??????????? }??????????? if($ratioresize_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,$this->dstimg);??????????? }??????????? if($ratioresize_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()??? {??????? $full_length? = strlen($this->srcimg);??????? $type_length? = strlen($this->type);??????? $name_length? = $full_length-$type_length;??????? $name???????? = substr($this->srcimg,0,$name_length-1);??????? $this->dstimg = $name."s.".$this->type;??? }}?>