“…Most of these studies extract specific features and then use machine learning algorithms to classify the SL images. Many different SL have been used in these studies, namely American 3 – 11 , Amharic SL 12 , Arabic SL 13 – 17 , British SL 18 , 19 , Chinese SL 20 , 21 , German SL 22 , 23 , Indian SL 24 , Mexican SL 25 , Pakistani SL 26 – 31 , Persian SL 32 , and more in combination such as American and German SL 33 , American and Thai SL 34 and American and Indian SL 35 .…”