Detective quantum efficiency
= Detective quantum efficiency
{title2=$\operatorname{DQE}(q)=\operatorname{SNR}_{\mathrm{out}}^2(q)/\operatorname{SNR}_{\mathrm{in}}^2(q)$}
<detective quantum efficiency> is the ratio of output to input squared <signal-to-noise ratio> for a specified measurement convention, often evaluated by <spatial frequency>. It describes information preservation by a detector rather than just its pixel size.