. 2023 Feb 10;13:2401. doi: 10.1038/s41598-022-25280-5

Table 2.

Summary of estimated complexities in quantum face recognition algorithm.

Method	Output	Complexity	References
QPCA	Eigenfaces	$log N$	⁹
QICA & HHL	Face components	$log N$	²⁷
HHL	Matrix inversion	$log N$	²⁷
Our method	Determinant calculation	$N log N$	CW
Our method	Trace calculation	$log N$	CW
Log-det divergence	Face matching	$N log N$	CW
Our method (General)	Face recognition	$N log N$	CW