Plugin: Relative URL to images in another folder accessed inside a JS file

Question

For this purpose you can use wp_localize_cript() function, like this:

function localize_my_script() {
    $image_url = plugins_url( 'resources/images/myimage.png', __FILE__ );
    $localizations = array( 'imageURL' => $image_url );

    wp_localize_script( 'my-script-handle', 'localizedVars', $localizations );
}
add_action( 'wp_enqueue_scripts', 'localize_my_script' );

That is assuming that you have properly enqueued your script with my-script-handle handle as an example.