PHP生成圖片縮略圖_PHP教程

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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,類的源碼見下文


調用此類的方法:
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


//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;
}
}
?>

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