decode one 64-entry block--

get some unsigned bits

returns 1 if "a*b + add" has no negative terms/factors and doesn't overflow

returns 1 if the product of two ints fits in a signed short, 0 on overflow.

set up the kernels

read 16bit value and convert to 24bit RGB

check if a utf8 string contains a prefix which is the utf16 string; if so return length of matching utf8 string

! @param[in] j JSON value to serialize @pre j.type() == value_t::object */

! @param[in] j JSON value to serialize */

! @param[in] j JSON value to serialize */

Helper function to apply inverse gamma correction