<?php
	 //normal post type 
	 add_image_size('blog-left-thumb',150,87,false);
	 add_image_size('blog-widget-thumb',67,39,false);	
	 add_image_size('page-image',1170,800,false);

//code for normal post types
add_filter( 'intermediate_image_sizes', 'beautispa_size');
function beautispa_size($sizes){
    $type = get_post_type($_REQUEST['post_id']);
	
    foreach($sizes as $key => $value){
        if($type=='post'  && $value != 'blog-left-thumb' && $value != 'blog-widget-thumb'  ){
            unset($sizes[$key]);
        }
		else if($type=='page'  &&  $value != 'page-image'){
            unset($sizes[$key]);
        }	
    }
    return $sizes;
}
?>