[Plugin: Get The Image] how to apply filter on image output

I’m using Get The Image on many WP Themes. I need to change src url on image tag the plugin outputs.
I don’t want to change themes or use an hack on the plugin. I prefer to create a new plugin.

Into the plugin on line 161 there is:

/* Allow plugins/theme to override the final output. */
$image = apply_filters( 'get_the_image', $image );

I wasn’t able to hook it and override the output.

Can anyone helps me to change this plugin output?

Thank you