Question: In the Basic Image Coding Scheme for rectangular raster images in a USIM application, how are unused bits in the byte representation of an image's raster points handled?
Option 1: Unused bits are set to 0 to minimize storage space.
Option 2: Unused bits shall be set to 1 as per the coding specification.
Option 3: Unused bits are reserved for future color support and left unset.
Option 4: The handling of unused bits is dependent on the image's resolution.
Explanation: According to the Basic Image Coding Scheme, to maintain consistency and clarity in the representation of raster images within the constraints of a USIM application, unused bits in the byte sequence are specifically required to be set to 1. This ensures that any unused portions of the byte do not introduce ambiguity or variability in image interpretation.