# Vision-Based Traffic Sign Detection and Recognition Systems: Current Trends and Challenges
## 5 Current Issues and Challenges  
TSDR is the essential part of the ADAS. It is mainly designed to operate in a real-time environment for enhancing driver safety through the fast acquisition and interpretation of traffic signs. However, there are a number of external non-technical challenges that may face this system in the real environment degrading its performance significantly. Among the many issues that needed to be addressed while developing a TSDR system are the following issues outlined in Figure 13. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Ref**} & \multirow{2}{*}{**Method**} & \multirow{2}{*}{**Detection Feature**} & \multirow{2}{*}{**Advantages**} & **True** & **False** & **No. of** & **Overall** & **Time** & **Dataset** \\  & & & & **Positive** & **Rate** & **Positive Rate** & **Images** & **Accuracy** & **Time** & **Dataset** \\ \hline
[138] & SIFT matching & N/A & \
\begin{tabular}{c} Effective in recognizing \\ low light and \\ damaged signs \\ \end{tabular} & N/A & N/A & 60 & N/A & N/A &
\begin{tabular}{c} Own \\ created \\ \end{tabular} \\ \hline
[34] & \begin{tabular}{c} Fringe-adjusted joint \\ Transform Correlation \\ \end{tabular} & \begin{tabular}{c} Color Feature \\ Extraction using \\ Gabor Filter \\ \end{tabular} & \
\begin{tabular}{c} Excellent discrimination \\ ability between object \\ and non-object \\ \end{tabular} & 783 & 217 & 587 & N/A & N/A &
\begin{tabular}{c} Own \\ created \\ \end{tabular} \\ \hline
[139] & \begin{tabular}{c} Principal Component \\ Analysis \\ \end{tabular} & \
\begin{tabular}{c} HSV, CIECAM97 \\ and PCA \\ \end{tabular} & High accuracy rate & N/A & N/A & N/A & 99.2\% & 2.5 s &
\begin{tabular}{c} Own \\ created \\ \end{tabular} \\ \hline
[140] & \begin{tabular}{c} Improved Fast Radial \\ Symmetry and Pictogram \\ Distribution Histogram \\ based SVM \\ \end{tabular} & \
\begin{tabular}{c} RGB to Lab color \\ space then IFRS \\ detection \\ \end{tabular} & High accuracy rate & N/A & N/A & 300 & 96.93\% & N/A &
\begin{tabular}{c} Own \\ created \\ \end{tabular} \\ \hline
[144] & \begin{tabular}{c} Infrastructures of vehicles \\ \end{tabular} & N/A & \begin{tabular}{c} Eliminating possibility \\ of false positive rate \\ because of ID coding \\ \end{tabular} & N/A & N/A & \
\begin{tabular}{c} Video \\ data \\ \end{tabular} & N/A & N/A &
\begin{tabular}{c} Own \\ created \\ \end{tabular} \\ \hline
[145] & \begin{tabular}{c} FCM and Content Based \\ Image Recorder \\ \end{tabular} & \begin{tabular}{c} Fuzzy c means \\ (FCM) \\ \end{tabular} & \begin{tabular}{c} Effective in real \\ time application \\ \end{tabular} & N/A & N/A & \
\begin{tabular}{c} Video \\ data \\ \end{tabular} & \textless{}80\% & N/A &
\begin{tabular}{c} Own \\ created \\ \end{tabular} \\ \hline
[141] & \begin{tabular}{c} Template matching and \\ 3D reconstruction \\ algorithm \\ \end{tabular} & N/A & \begin{tabular}{c} Very effective in \\ recognizing damaged or \\ occulted road signs \\ \end{tabular} & \
\begin{tabular}{c} In 3D, 6 out \\ of 54 out \\ of 63 s \\ of 63 s \\ were missing \\ \end{tabular} & 4800 & N/A & N/A &
\begin{tabular}{c} Own \\ created \\ \end{tabular} \\ \hline
[142] & \begin{tabular}{c} Low Rank Matrix \\ Recovery (LRMR) \\ \end{tabular} & N/A & \
\begin{tabular}{c} Fast computation and \\ parallel execution \\ \end{tabular} & N/A & N/A & 40,000 & 97.51\% & \textgreater{}0.2 &
\begin{tabular}{c} CISRB \\ \end{tabular} \\ \hline
[143] & \begin{tabular}{c} Karhunen-Loeve \\ Transform and MLP \\ \end{tabular} & \begin{tabular}{c} Oriented \\ gradient maps \\ \end{tabular} & \begin{tabular}{c} Invariant in illumination \\ an different \\ lighting condition \\ \end{tabular} & N/A & N/A & 12,600 & 95.9\% & \
\begin{tabular}{c} 0.0054 \\ s/image \\ \end{tabular} &
\begin{tabular}{c} CISRB \\ \end{tabular} \\ \hline
[35] & Self-Organizing Map & N/A & Fast and accurate & N/A & N/A & N/A & \textless{}99\% & N/A &
\begin{tabular}{c} Own \\ created \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table}