Publication Details
Unconstrained License Plate Detection in Hardware
Musil Petr, Ing., Ph.D. (DCGM)
Zemčík Pavel, prof. Dr. Ing., dr. h. c. (DCGM)
ALPR, Soft Cascade, Decision Trees, WaldBoost
In this paper, we propose an FPGA implementation of license plate detection (LPD)
in images captured by arbitrarily placed cameras, vehicle-mounted cameras, or
even handheld cameras. In such images, the license plates can appear in a wide
variety of positions and angles. Thus we cannot rely on a-priori known geometric
properties of the license plates as many contemporary applications do. Unlike the
existing solutions targeted for DSP, FPGA or similar low power devices, we do not
make any assumptions about license plate size and orientation in the image. We
use multiple sliding window detectors based on simple image features, each tuned
to a specific range of projections. On a dataset captured by a camera mounted on
a vehicle, we show that detection rate is 98 % (and 98.7 % when combined with
video tracking). We demonstrate that our FPGA implementation can process
1280×1024 pixel image at over 40 FPS with a minimum width of detected license
plates approximately 100 pixels. The FPGA block is fully functional and it is
intended to be used in a smart camera to parking control in residential zones.
@inproceedings{BUT175774,
author="Roman {Juránek} and Petr {Musil} and Pavel {Zemčík}",
title="Unconstrained License Plate Detection in Hardware",
booktitle="Proceedings of the 7th International Conference on Vehicle Technology and Intelligent Transport Systems - VEHITS",
year="2021",
pages="13--21",
publisher="SciTePress - Science and Technology Publications",
address="Praha",
doi="10.5220/0010174000130021",
isbn="978-989-758-513-5"
}