From Categories to Individuals in Real Time — A Unified Boosting Approach

A method for online, real-time learning of individual-object detectors is presented. Starting with a pre-trained boosted category detector, an individual-object detector is trained with near-zero computational cost. The individual detector is obtained by using the same feature cascade as the category detector along with elementary manipulations of the thresholds of the weak classifiers. This is ideal for on-line operation on a video stream or for interactive learning. Applications addressed by this technique are reidentifica-tion and individual tracking. Experiments on four challeng-ing pedestrian and face datasets indicate that it is indeed possible to learn identity classifiers in real-time; besides being faster-trained, our classifier has better detection rates than previous methods on two of the datasets. 1