og filter

i have not tested and am not sure if you are using the right hooks but the GD bit is wrong, it should be

$og_image = geodir_get_images( $post->ID, 'thumbnail' );

The $og_image will be an array for images, i’m not sure how the filter accepts them but to echo them for example you would do

if(!empty($og_image)){
    foreach($og_image as $img){
        echo $img;
    }
}

Stiofan