I'm happy to see Nokia Imaging SDK now allow us to implement custom filters. It's so great, we don't need to do anything to use our custom filters. But how we can implement custom filters and how to use it, it's not clear. As far as I see the only documentation about that is in Real-time Filter Demo page. Real-time Filter Demo.

In Real-time Filter Demo, it shows a sample filter implemantation and there isn't any other information about implementing custom filters. Moreover, I want to know that;
  • how custom filters works
  • difference from predefined ones
  • performance
  • how to pass in/out parameters

Also It's really hard for me to find this sample, I'm searching it almost a week It'll be nice to see documentation about it under Nokia Imaging SDK library page.