US Patent 9817866 Lossless compression of client read data

A read is aligned to a reference data set. It is determined whether the read includes any identifier distinction, the determination being performed using the alignment. If so, positional data corresponding to the identifier distinction(s) are defined. Compressed read data is stored in association with a read identifier of the read. The compressed read data includes alignment information (e.g., a start and/or stop position of the alignment). When the read includes an identifier distinction, the compressed read data further includes the positional data and deviation data characterizing the distinction.