ShoeRinsics: Shoeprint Prediction for Forensics with Intrinsic Decomposition

Shoe tread impressions are one of the most common types of evidence left at crime scenes. However, the utility of such evidence is limited by the lack of databases of footwear impression patterns that cover the huge and growing number of distinct shoe models. We propose to address this gap by leveraging shoe tread photographs collected by online retailers. The core challenge is to predict the impression pattern from the shoe photograph since ground-truth impressions or 3D shapes of tread patterns are not available. We develop a model that performs intrinsic image decomposition (predicting depth, normal, albedo, and lighting) from a single tread photo. Our approach, which we term ShoeRinsics, combines domain adaptation and re-rendering losses in order to leverage a mix of fully supervised synthetic data and unsupervised retail image data. To validate model performance, we also collected a set of paired shoe-sole images and corresponding prints, and define a benchmarking protocol to quantify the accuracy of predicted impressions. On this benchmark, ShoeRinsics outperforms existing methods for depth prediction and synthetic-to-real domain adaptation.