php生成缩略图类_PHP教程

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("11.jpg", "200", "150", "1","17.jpg");
?>

/**
* 生成缩略图
* @author yangzhiguo0903@163.com
* @param string 源图绝对完整地址{带文件名及后缀名}
* @param string 目标图绝对完整地址{带文件名及后缀名}
* @param int 缩略图宽{0:此时目标高度不能为0，目标宽度为源图宽*(目标高度/源图高)}
* @param int 缩略图高{0:此时目标宽度不能为0，目标高度为源图高*(目标宽度/源图宽)}
* @param int 是否裁切{宽,高必须非0}
* @param int/float 缩放{0:不缩放, 0 * @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;

/**
* 缩略图不超过源图尺寸（前提是宽或高只有一个）
*/
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) //有宽无高
{
$propor = $dst_w / $src_w;
$height = $dst_h = $src_h * $propor;
}
else if(!$dst_w && $dst_h) //有高无宽
{
$propor = $dst_h / $src_h;
$width = $dst_w = $src_w * $propor;
}
}
}
else
{
if(!$dst_h) //裁剪时无高
{
$height = $dst_h = $dst_w;
}
if(!$dst_w) //裁剪时无宽
{
$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;
}

$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!
';
echo '';
}else{
echo 'Resize Image Fail!';
}