Add Thumbnail Sizes

add_thbnail_sizes.php

/* FEATURED THUMBNAILS */

if ( function_exists( 'add_theme_support' ) ) { // Added in 2.9
  add_theme_support( 'post-thumbnails' );
}
add_image_size('small-thumbnail', 80, 80, true);



/* ===============================================
  --------- Custom Thumbnail sizes --------------
================================================== */

//set up thumbs
function thumb_setup() {
	add_theme_support('post-thumbnails');
	
	#add custome height ( name , width , height , crop )
	add_image_size('grid-thumb', 100, 100, true);
	
	
	$custom_sizes = array(
		'grid-thumb' => 'Grid Thumb'
	);
	///return array_merge($sizes, $custom_sizes);
}

/* Custom MEDIA SIZES*/
add_action('after_setup_theme', 'thumb_setup');