jp2_palette::get_signed

Returns true if the indicated lookup table has a signed representation. Otherwise, returns false. Note that Palette LUT outputs are always converted to signed representations anyway, for consistency with Kakadu's general principle of using signed representations for all internal data processing operations.

For this reason, there are not many applications which should need to know whether the representation is signed or unsigned, except when writing the de-palettized samples to a file which is capable of representing either signed or unsigned quantites.

lut_idx [int]