Feature extraction for Covid-19

Hello,

i am working on Dataset covid-19, i have to spilt dataset into : (1) Train (2) Test and apply Matlab code to extract features by given folders [Train, Test].

i have 2 folders (1)Train and test --> both contain two more folders [Covid, Non-Covid]

but when i run it take only one folder either train or test. As i mentioned below code:

my Code only taken one folder

img_dir = image/dataset % directory for dataset images

dataSet = Train

i need a code that take two folders (1)Train (2) Test -->on Run and classify then seprately.