1. A computer implemented method of deriving a high resolution image from a plurality of low resolution images, comprising the steps of: initializing one of more alignment parameters to one or more likely values; determining the marginal likelihood of the low resolution images using the one or more alignment parameters, in which the marginal likelihood is a function ƒ of the alignment parameters where: 
 ƒ=−1g |P|+μ T Pμ, and P is the precision of the posterior distribution and μ is the mean of the distribution modeled for the high resolution image; adjusting the alignment parameters so as to optimize the marginal likelihood determination; and determining the high resolution image using the adjusted alignment parameters.