Source of UQI

TITLE:UQI (Universal Quality Index)
[[ImageQualityAssessment]] > [[UQI]] > [[SSIM]]

Wang–Bovik Index

* SSIM [#y676e357]

- https://www.cns.nyu.edu/pub/eero/wang03-reprint.pdf
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The “universal quality index” (UQI) defined in [6] and [7] corresponds to the special case that C_1=C_2=0 , which produces unstable results when either (μ_x^2+μ_y^2) or (σ_x^2+σ_y^2) is very close to zero.