生成縮略圖是當我們要上傳圖片時如果圖片較大我們需要生成一張指定大小的小圖以在列表頁面顯示，這樣可節省資源也是現在常用的做法，下面我來分享一個php生成縮略圖類，支持自定義高和寬。還支持按高和寬截圖 代碼如下 復制代碼
class resizeimage
{
//圖片類型
var $type;
//實際寬度
var $width;
//實際高度
var $height;
//改變後的寬度
var $resize_width;
//改變後的高度
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()
{
//改變後的圖象的比例
$resize_ratio = ($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;
}
}
$resizeimage = new resizeimage("11.jpg", "200", "150", "1","17.jpg");
?>
實例二
代碼如下 復制代碼<?php
/**
* 生成縮略圖
* @author [email protected]
* @param string 源圖絕對完整地址{帶文件名及後綴名}
* @param string 目標圖絕對完整地址{帶文件名及後綴名}
* @param int 縮略圖寬{0:此時目標高度不能為0，目標寬度為源圖寬*(目標高度/源圖高)}
* @param int 縮略圖高{0:此時目標寬度不能為0，目標高度為源圖高*(目標寬度/源圖寬)}
* @param int 是否裁切{寬,高必須非0}
* @param int/float 縮放{0:不縮放, 0<this<1:縮放到相應比例(此時寬高限制和裁切均失效)}
* @return boolean
*/
function img2thumb($src_img, $dst_img, $width = 75, $height = 75, $cut = 0, $proportion = 0)
{
if(!is_file($src_img))
{
return false;
}
$ot = fileext($dst_img);
$otfunc = 'image' . ($ot == 'jpg' ? 'jpeg' : $ot);
$srcinfo = getimagesize($src_img);
$src_w = $srcinfo[0];
$src_h = $srcinfo[1];
$type = strtolower(substr(image_type_to_extension($srcinfo[2]), 1));
$createfun = 'imagecreatefrom' . ($type == 'jpg' ? 'jpeg' : $type);
$dst_h = $height;
$dst_w = $width;
$x = $y = 0;
/**
* 縮略圖不超過源圖尺寸（前提是寬或高只有一個）
*/
if(($width> $src_w && $height> $src_h) || ($height> $src_h && $width == 0) || ($width> $src_w && $height == 0))
{
$proportion = 1;
}
if($width> $src_w)
{
$dst_w = $width = $src_w;
}
if($height> $src_h)
{
$dst_h = $height = $src_h;
}
if(!$width && !$height && !$proportion)
{
return false;
}
if(!$proportion)
{
if($cut == 0)
{
if($dst_w && $dst_h)
{
if($dst_w/$src_w> $dst_h/$src_h)
{
$dst_w = $src_w * ($dst_h / $src_h);
$x = 0 - ($dst_w - $width) / 2;
}
else
{
$dst_h = $src_h * ($dst_w / $src_w);
$y = 0 - ($dst_h - $height) / 2;
}
}
else if($dst_w xor $dst_h)
{
if($dst_w && !$dst_h) //有寬無高
{
$propor = $dst_w / $src_w;
$height = $dst_h = $src_h * $propor;
}
else if(!$dst_w && $dst_h) //有高無寬
{
$propor = $dst_h / $src_h;
$width = $dst_w = $src_w * $propor;
}
}
}
else
{
if(!$dst_h) //裁剪時無高
{
$height = $dst_h = $dst_w;
}
if(!$dst_w) //裁剪時無寬
{
$width = $dst_w = $dst_h;
}
$propor = min(max($dst_w / $src_w, $dst_h / $src_h), 1);
$dst_w = (int)round($src_w * $propor);
$dst_h = (int)round($src_h * $propor);
$x = ($width - $dst_w) / 2;
$y = ($height - $dst_h) / 2;
}
}
else
{
$proportion = min($proportion, 1);
$height = $dst_h = $src_h * $proportion;
$width = $dst_w = $src_w * $proportion;
}
$src = $createfun($src_img);
$dst = imagecreatetruecolor($width ? $width : $dst_w, $height ? $height : $dst_h);
$white = imagecolorallocate($dst, 255, 255, 255);
imagefill($dst, 0, 0, $white);
if(function_exists('imagecopyresampled'))
{
imagecopyresampled($dst, $src, $x, $y, 0, 0, $dst_w, $dst_h, $src_w, $src_h);
}
else
{
imagecopyresized($dst, $src, $x, $y, 0, 0, $dst_w, $dst_h, $src_w, $src_h);
}
$otfunc($dst, $dst_img);
imagedestroy($dst);
imagedestroy($src);
return true;
}
使用方法
代碼如下 復制代碼$src_img = "./ROSI_050_002.JPG";
$dst_img = "./ROSI_050_002_thumb.jpg";
$stat = img2thumb($src_img, $dst_img, $width = 200, $height = 300, $cut = 0, $proportion = 0);
if($stat){
echo 'Resize Image Success!<br />';
echo '<img src="'.$dst_img.'" />';
}else{
echo 'Resize Image Fail!';
}
