Comparison of real-time DSP-based edge detection techniques for license plate detection

In this paper, edge detection techniques and their performance are compared when applied in license plate detection using an embedded digital signal processor. License plate detection remains to be the crucial part of a vehicle's license plate recognition process. The edge detection algorithms compared in this work are those reported capable of delivering real-time performance. These are Canny-Deriche-FGL, Haar and Daubechies-4 wavelet transform and the classic Sobel. These particular algorithms are chosen and compared due to their good performance on digital signal processors. The comparison is drawn in terms of speed and detection success of a license plate. The results show Haar wavelet-based edge detector performs better on a DSP with LP detection speed of 7.32 ms and 98.6% success using 45,032 UK images containing license plates at 768×288 resolutions.

[1]  John F. Canny,et al.  A Computational Approach to Edge Detection , 1986, IEEE Transactions on Pattern Analysis and Machine Intelligence.

[2]  Horst Bischof,et al.  TRICam - An Embedded Platform for Remote Traffic Surveillance , 2006, 2006 Conference on Computer Vision and Pattern Recognition Workshop (CVPRW'06).

[3]  P. Laguna,et al.  Signal Processing , 2002, Yearbook of Medical Informatics.

[4]  Sek M. Chai,et al.  FPGA implementation of a license plate recognition SoC using automatically generated streaming accelerators , 2006, Proceedings 20th IEEE International Parallel & Distributed Processing Symposium.

[5]  Muhammad Sarfraz,et al.  Saudi Arabian license plate recognition system , 2003, 2003 International Conference on Geometric Modeling and Graphics, 2003. Proceedings.

[6]  Hideharu Amano,et al.  Implementation and Evaluation of a High Speed License Plate Recognition System on an FPGA , 2007, 7th IEEE International Conference on Computer and Information Technology (CIT 2007).

[7]  AnagnostopoulosC. N.E.,et al.  License Plate Recognition From Still Images and Video Sequences , 2008 .

[8]  Hui Wang,et al.  The Optimization of H.264 Encoder Based On TI TMS320DM642 , 2007, Future Generation Communication and Networking (FGCN 2007).

[9]  Horst Bischof,et al.  Real-Time License Plate Recognition on an Embedded DSP-Platform , 2007, 2007 IEEE Conference on Computer Vision and Pattern Recognition.

[10]  Ioannis Anagnostopoulos,et al.  License Plate Recognition From Still Images and Video Sequences: A Survey , 2008, IEEE Transactions on Intelligent Transportation Systems.

[11]  Patrick Garda,et al.  Real time execution of optimal edge detectors on RISC and DSP processors , 1998, Proceedings of the 1998 IEEE International Conference on Acoustics, Speech and Signal Processing, ICASSP '98 (Cat. No.98CH36181).

[12]  S. Mallat.  A wavelet tour of signal processing , 1998 .

[13]  Rachid Deriche,et al.  Fast algorithms for low-level vision , 1988, [1988 Proceedings] 9th International Conference on Pattern Recognition.

[14]  Federico Garcia Lorca.  Filtres récursifs temps réel pour la détection de contours : optimisations algorithmiques et architecturales , 1996 .

[15]  Ching-Tang Hsieh,et al.  Multiple license plate detection for complex background , 2005, 19th International Conference on Advanced Information Networking and Applications (AINA'05) Volume 1 (AINA papers).

[16]  Ikhlas Abdel-Qader,et al.  Edge detection: wavelets versus conventional methods on DSP processors , 2005 .