php gettype fix - php

Question

Following function I created is to store data in a database with the correct type.
I have several questions:
It makes sense to me to turn empty strings in to NULL. Are there consequences I am not considering?
What is a good max_length value for sqlite3 text. I know blob and text length constrains are the same, but are there any other considerations like displaying the data in a shell, etc.
Is there a simple way to check if data is an image, and what type, since mime is not available at this stage?
Does something stick out that I am missing?
public static function getType($value, $max_length = 50){
$type = gettype($value);
if($type == 'NULL'
|| $type == 'boolean'
|| $type == 'integer'
|| $type == 'double'
|| $type == 'object'
|| $type == 'resource'
|| $type == 'array'
)
return array('type'=>$type,'value'=>$value);
if($type == 'string' && empty($value))
return array('type'=>'NULL','value'=>$value);
if($type == 'string' && strlen($value) > $max_length)
return array('type'=>'blob','value'=>$value);
if($type == 'string' && substr($value, 0,1) === '0')
return array('type'=>'string','value'=>$value);
if($type == 'string' && is_numeric($value)){
$int = (int) $value;
$float = (float) $value;
if($int == $value){
$value = $int;
$type = 'integer';
}elseif($float == $value){
$value = $float;
$type = 'double';
}
}elseif($type == 'string'){
return array('type'=>$type,'value'=>$value);
}else{
$type = 'blob';
}
return array('type'=>$type,'value'=>$value);
}