--- basn0g01 - black & white
--- basn0g02 - 2 bit (4 level) grayscale
--- basn0g04 - 4 bit (16 level) grayscale
--- basn0g08 - 8 bit (256 level) grayscale
--- basn0g16 - 16 bit (64k level) grayscale
--- basn2c08 - 3x8 bits rgb color
--- basn2c16 - 3x16 bits rgb color
--- basn3p01 - 1 bit (2 color) paletted
--- basn3p02 - 2 bit (4 color) paletted
--- basn3p04 - 4 bit (16 color) paletted
--- basn3p08 - 8 bit (256 color) paletted
--- basn4a08 - 8 bit grayscale + 8 bit alpha-channel
--- basn4a16 - 16 bit grayscale + 16 bit alpha-channel
--- basn6a08 - 3x8 bits rgb color + 8 bit alpha-channel
--- basn6a16 - 3x16 bits rgb color + 16 bit alpha-channel