function rename_post_formats($translation, $text, $context, $domain) {
$names = array(
'Gallery' => 'Katalogas'
);
if ($context == 'Post format') {
$translation = str_replace(array_keys($names), array_values($names), $text);
}
return $translation;
}
add_filter('gettext_with_context', 'rename_post_formats', 10, 4);