According to an aspect of the invention, a system for providing immersive surveillance a site has a plurality of cameras each producing a respective raw video of a respective portion of the site. A processing component receives the raw video from the cameras and generates processed video from it. A visualization engine is coupled to the processing system, and receives the processed video therefrom. The visualization engine renders real-time images corresponding to a view of the site in which at least a portion of the processed video is overlaid onto a rendering of an image based on a computer model of the site. The visualization engine displays the images in real time to a viewer. The processing component comprises first and second filter modules. The second filter module processes video received as output from the first filter module. A controller component controls all transmission of data and video between the first and second filter modules.