Dear Ros-Users, I am thinking of writing a background subtraction filter for my incoming laser data through hokoyo_node. Here are my problems. 1) After going through the examples of laser_filters, I thought I can use scan_to_scan_filter_chain node to run "background_subtraction_filter-which is the one I am writing, inside it. However, it gave an error msg saying According to the loaded plugin descriptions the class LaserBackgroundSubtractionFilter with base class type filters::FilterBase does not exist. Is there a way to run a user's filter inside scan_to_scan_filter_chain node? 2) On the other hand, once you write your own filter according to the "Implementing a simple filter" tutorial how do you run it - what node should it be associated with ? Thank you in advance Peshala New Email addresses available on Yahoo! Get the Email name you've always wanted on the new @ymail and @rocketmail. Hurry before someone else does! http://mail.promotions.yahoo.com/newdomains/aa/