$new_img_size = array();
$new_img_size['width'] = $max_width;
$new_img_size['height'] = $max_height;

$img_func = ''; //函数名称
$img_handle = ''; //图片句柄
$thum_handle = ''; //略图图片句柄

switch($img_extension)
{
case 'jpg':
$img_handle = imagecreatefromjpeg($img_name);
$img_func = 'imagejpeg';
break;
case 'jpeg':
$img_handle = imagecreatefromjpeg($img_name);
$img_func = 'imagejpeg';
break;
case 'png':
$img_handle = imagecreatefrompng($img_name);
imagesavealpha($img_handle,true);
$img_func = 'imagepng';
break;
case 'gif':
$img_handle = imagecreatefromgif($img_name);
$img_func = 'imagegif';
break;
default:
$img_handle = imagecreatefromjpeg($img_name);
$img_func = 'imagejpeg';
break;
}

$quality = 100;//图片质量
if($img_func == 'imagepng')
{
$quality = 9;
}

$thum_handle = imagecreatetruecolor($new_img_size['height'],$new_img_size['width']);
imagealphablending($thum_handle,false);//这里很重要,意思是不合并颜色,直接用$img图像颜色替换,包括透明色;
imagesavealpha($thum_handle,true);//这里很重要,意思是不要丢了$thumb图像的透明色;

if(function_exists('imagecopyresampled'))
{
imagecopyresampled($thum_handle,$img_handle,$new_img_size['height'],$new_img_size['width'],$img_height,$img_width);
}
else
{
imagecopyresized($thum_handle,$img_width);
}

call_user_func_array($img_func,array($thum_handle,$path.'/'.$new_name,$quality));
imagedestroy($thum_handle);//清除句柄
imagedestroy($img_handle);//清除句柄
}

$IconArray = array
(
"IOS8" => array
(
array("width" => 180,"height"=> 180,"path"=>"ios8","name"=>"Icon-180.png"),array("width" => 120,"height"=> 120,"name"=>"Icon-120.png"),array("width" => 152,"height"=> 152,"name"=>"Icon-152.png"),array("width" => 76,"height"=> 76,"name"=>"Icon-76.png"),array("width" => 144,"height"=> 144,"name"=>"Icon-144.png"),array("width" => 72,"height"=> 72,"name"=>"Icon-72.png"),array("width" => 114,"height"=> 114,"name"=>"Icon-114.png"),array("width" => 57,"height"=> 57,"name"=>"Icon-57.png"),array("width" => 100,"height"=> 100,"name"=>"Icon-100.png"),array("width" => 50,"height"=> 50,"name"=>"Icon-50.png"),array("width" => 80,"height"=> 80,"name"=>"Icon-80.png"),array("width" => 40,"height"=> 40,"name"=>"Icon-40.png"),array("width" => 58,"height"=> 58,"name"=>"Icon-58.png"),array("width" => 29,"height"=> 29,"name"=>"Icon-29.png"),),"IOS" => array
(
array("width" => 180,"path"=>"ios","name"=>"Icon-60@3x.png"),"name"=>"Icon-60@2x.png"),"name"=>"Icon-76@2x.png"),"name"=>"Icon-72@2x.png"),"name"=>"Icon-57@2x.png"),"name"=>"Icon-50@2x.png"),"name"=>"Icon-40@2x.png"),"name"=>"Icon-29@2x.png"),"ANDROID" => array
(
array("width" => 144,"height" => 144,"path" => "android/drawable","name"=>"icon.png"),"path" => "android/drawable-xhdpi","height" => 72,"path" => "android/drawable-hdpi",array("width" => 48,"height" => 48,"path" => "android/drawable-mdpi",array("width" => 32,"height" => 32,"path" => "android/drawable-ldpi","name"=>"icon.png")
)
);

foreach ($IconArray["IOS8"] as $key => $IconType)
{
thumb("icon.png",$IconType['width'],$IconType['height'],$IconType['path'],$IconType['name']);
}

foreach ($IconArray["IOS"] as $key => $IconType)
{
thumb("icon.png",$IconType['name']);
}

foreach ($IconArray["ANDROID"] as $key => $IconType)
{
thumb("icon.png",$IconType['name']);
}

?>