A 65 fps Full-HD Hardware Implementation of HOG, HOF, MBHx, and MBHy for Real-Time Action Recognition

In this paper, we propose a compact hardware architecture which can support HOG, HOF, MBHx and MBHy feature extraction in real-time. To achieve low-cost hardware, we first design a hardware-oriented algorithm. In addition to simplification of complicated numeric computation, we also modify the computation of the gradient at boundary to reduce on-chip buffers. The architecture is highly parallel in order to fully reuse input data and to achieve high throughput. Other features of our architecture include a four-bank memory composed of four SRAMs, a 2-cycle weighted binning, and a 2-port memory for histogram collection. The final specification can support HOG, HOF, MBHx, and MBHy feature extraction with a throughput of 65 fps in full-HD videos operating at 215 MHz, consuming only 57.6 kB on-chip memory and a gate count of 411k.