Signed Pixels : advantages
Signed pixels seem at first to be counter-intuitive but they have numerous advantages.
nA value of 0 or mid
grey can be viewed as the ‘most likely’ value that a pixel takes on in the absence of other
information.
nIf you do arithmetic on images, in particular subtract
one image from another, then negative
values of pixels naturally arise.
nSigned pixels allow straightforward implementation of
contrast adjustments. For instance multiplying
an image by 0.5 halves the contrast in the
image.