Modeling real-valued data
For images of digits it is possible to represent
intermediate intensities as if they were probabilities by
using “mean-field” logistic units.
We can treat intermediate values as the probability
that the pixel is inked.
This will not work for real images.
In a real image, the intensity of a pixel is almost
always almost exactly the average of the neighboring
Mean-field logistic units cannot represent precise
intermediate values.