Authors:
            
                    Dong-jin Lee
                    
                        
                                1
                            
                    
                     and
                
                    Ho-sub Yoon
                    
                        
                                2
                            
                    
                    
                
        
        
            Affiliations:
            
                    
                        
                                1
                            
                    
                    University of Science and Technology, Korea, Republic of
                
                    ; 
                
                    
                        
                                2
                            
                    
                    Electronics and Telecommunications Research Institute, Korea, Republic of
                
        
        
        
        
        
             Keyword(s):
            Sign Recognition, Character Recognition, Hybrid HMM/SVM, Feature Extraction, Natural Scene Images.
        
        
            
                Related
                    Ontology
                    Subjects/Areas/Topics:
                
                        Artificial Intelligence
                    ; 
                        Biomedical Engineering
                    ; 
                        Biomedical Signal Processing
                    ; 
                        Data Manipulation
                    ; 
                        Health Engineering and Technology Applications
                    ; 
                        Human-Computer Interaction
                    ; 
                        Methodologies and Methods
                    ; 
                        Neurocomputing
                    ; 
                        Neurotechnology, Electronics and Informatics
                    ; 
                        Pattern Recognition
                    ; 
                        Physiological Computing Systems
                    ; 
                        Sensor Networks
                    ; 
                        Soft Computing
                    
            
        
        
            
                Abstract: 
                In this paper, we propose a sign classification system to recognize exit number and arrow signs in natural scene images. The purpose of the sign classification system is to provide assistance to a visually-handicapped person in subway stations. For automatically extracting sign candidate regions, we use Adaboost algorithm, however, our detector not only extracts sign regions, but also non-sign (noise) regions in natural scene images. Thus, we suggest a verification technique to discriminate sign regions from non-sign regions. In addition, we suggest a novel feature extraction algorithm cooperated with Hidden Markov Model. To evaluate the system, we tested a total of 20,177 sign candidate regions including the number of 8,414 non-sign regions on the captured images under several real environments in Daejeon in South Korea. We achieved an exit number and arrow sign recognition rate of each 99.5% and 99.8% and a false positive rate (FPR) of 0.3% to discriminate between sign regions and 
                non-sign regions.
                (More)