alpha channel separately rotate=0, # rotate (int, multiple of 90) xref=0, # re-use existing image oc=0, # control visibility via OCG / OCMD keep_proportion=True, # keep aspect ratio overlay=True, # source PDF clip=None, # only display this area (rect-like) rotate=0, # rotate (float, any value) oc=0, # control visibility via OCG / OCMD keep_proportion=True, # keep aspect ratio overlay=True, # configuration of a PDF’s Optional Content, OCGs can be organized in higher level groupings, called OC Configurations. Each configuration being a collection of OCGs, together with each OCG’s desired initial