A method for compressing information includes accessing a read of genomic sequencing data, aligning the read to a reference, generating alignment data based on alignment of the read, obtaining a set of contexts based on the alignment data, and compressing quality values corresponding to the alignment data based on the set of contexts. The alignment data may provide an indication of errors in the genomic sequencing data, and each of the quality values may provide an indication of a probability of error at one or more bases in the genomic sequencing data.