1. A system for semi-automated feature extraction, comprising: an image analysis server computer comprising program code stored in a memory and adapted to process raster images to determine image and pixel information and provide the images and derived information to other components of the system; a feature extraction server computer comprising program code stored in a memory and adapted to identify image features based at least in part on derived information for a raster image, and to provide the image and identified features to other components of the system; a mosaic imaging server computer comprising program code stored in a memory and adapted to receive a plurality of raster images and assemble the images to form mosaics and provide the mosaics to other components of the system; and a rendering engine computer comprising program code stored in a memory and adapted to receive a plurality of data from other components of the system and create visual representations of the data for review by a human user.