1 Introduction  
2 Chart Classification Techniques  
2.1 Traditional ML Approaches  
2.2 CNN-based Deep Learning Approaches  
2.3 Transformer-based Deep Learning Approaches  
3 Chart Classification Datasets  
4 Deep Learning Models for Comparative Analysis  
5 Experimental Protocol  
6 Future Directions  
6.1 Lack of Standard Benchmark Datasets  
6.2 Lack of Robust Models  
6.3 Inclusion of Noise  
7 Conclusion