new metrics?

[paulmueller]

• spectral: normalized dct shannon entropy
• spectral: generalized bayesian Entropy (e=6, e=4)
• differential: Tenengrad

[paulmueller]

also:
Trujillo, Carlos; Garcia-Sucerquia, Jorge
Cooperative execution of auto-focusing metrics in digital lensless holographic microscopy for internal-structured samples
https://doi.org/10.1364/AO.56.005877