How do extract GLRLM features from a single .jpg image

Operating system: Windows
Slicer version:
Expected behavior:
Actual behavior:
I am a learner and want to generate Gray Level Run Length Matrix features for a .jpg image. I am reading an image via opencv but could not understand about ‘mask’ input. Thus, can anybody help me by providing any sample code in python which can extract features using PyRadiomics.