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function resizePng($im, $dst_width, $dst_height) {
    $width = imagesx($im);
    $height = imagesy($im);

    $newImg = imagecreatetruecolor($dst_width, $dst_height);

    imagealphablending($newImg, false);
    imagesavealpha($newImg, true);
    $transparent = imagecolorallocatealpha($newImg, 255, 255, 255, 127);
    imagefilledrectangle($newImg, 0, 0, $width, $height, $transparent);
    imagecopyresampled($newImg, $im, 0, 0, 0, 0, $dst_width, $dst_height, $width, $height);

    return $newImg;
}

list($imgWidth, $imgHeight, $image_type) = getimagesize($file);

function getImage($file, $image_type)
{
	$image;

	if($image_type == IMAGETYPE_JPEG) {
		$image = imagecreatefromjpeg($file);
	} else if($image_type == IMAGETYPE_GIF) {
		$image = imagecreatefromgif($file);
	} else if($image_type == IMAGETYPE_PNG) {
		$image = imagecreatefrompng($file);
	} else {
		$image = imagecreatefromjpeg($file);
	}

	return $image;
}

function saveImageJPEG($image, $file)
{
	imagejpeg($image,$file);
	imagedestroy($image); 
}

function saveImagePNG($image, $file)
{
	//header("Content-type: image/png");    
	imagepng($image,$file);
	imagedestroy($image); 
}

function resizeImage($file)
{
	list($imgWidth, $imgHeight, $image_type) = getimagesize($file);

	$image = getImage($file, $image_type);
	$resizedWidth = $imgWidth;
	$resizedHeight = $imgHeight;

	$proportion = $imgWidth > $imgHeight ? $imgWidth / $imgHeight : $imgHeight / $imgWidth;

	if($proportion >= 1)
	{
		if ($imgWidth > 1000) {
			$resizedWidth = 1000;
			$resizedHeight = ($resizedWidth * $imgHeight) / $imgWidth;
		}
		if ($resizedHeight > 800) {
			$oldHeight = $resizedHeight;
			$resizedHeight = 800;
			$resizedWidth = ($resizedHeight * $resizedWidth) / $oldHeight;
		}
	}
	else
	{
		if ($imgHeight > 1000) {
			$resizedHeight = 1000;
			$resizedWidth = ($resizedHeight * $imgWidth) / $imgHeight;
		}
		if ($resizedWidth > 800) {
			$oldWidth = $resizedWidth;
			$resizedWidth = 800;
			$resizedHeight = ($resizedWidth * $resizedHeight) / $oldWidth;
		}
	}
	
	//solve png issues
	/*imagealphablending($image, false);
	imagesavealpha($image, true);
	$transparent = imagecolorallocatealpha($image, 0, 0, 0, 127);
	imagefilledrectangle($image, 0, 0, $imgWidth, $imgHeight, $transparent);*/
	
/*	imagesavealpha($image, true);

    $trans_colour = imagecolorallocatealpha($image, 0, 0, 0, 127);
    imagefill($image, 0, 0, $trans_colour);        */


	$resizedImage = imagecreatetruecolor($resizedWidth, $resizedHeight);
    ///////////////
    imagealphablending($resizedImage, false);
    imagesavealpha($resizedImage, true);
    $transparent = imagecolorallocatealpha($resizedImage, 255, 255, 255, 127);
    imagefilledrectangle($resizedImage, 0, 0, $width, $height, $transparent);
    ///////////////
	imagecopyresampled($resizedImage, $image, 0, 0, 0, 0, $resizedWidth, $resizedHeight, $imgWidth, $imgHeight);

	if ( $image_type == IMAGETYPE_JPEG) saveImageJPEG($resizedImage, $file);
	if ( $image_type == IMAGETYPE_PNG) saveImagePNG($resizedImage, $file);	
}