
ZIP: Scalable Crowd Counting via Zero-Inflated Poisson Modeling
When more than 95% of local crowd-map blocks are empty, is squared-error regression still the right statistical model?
ZIP predicts two quantities per block: a structural-zero probability for background, body parts, and other non-head-centre regions, and a Poisson rate for candidate head-centre regions. Integer count bins stabilize rate prediction, while the joint likelihood learns the distinction between structural zeros and sampling zeros directly from point annotations.