1. A computer-implemented method for extracting pixel-level micro-features from image data captured by a video camera, the method comprising: receiving the image data; identifying a foreground patch that depicts a foreground object; processing the foreground patch to compute a plurality of micro-feature values based on at least one pixel-level characteristic of the foreground patch, wherein the micro-feature value is computed independent of training data that defines a plurality of object types; generating a micro-feature vector that includes the plurality of micro-feature values; and classifying the foreground object as depicting an object type as based on the micro-feature vector.