Bill:
My best guess is the greyscale depth of the image. Because it's digital as
opposed to analogue, the boundaries between the shades are discrete rather
than continuous. Think of it as posterization wherein one makes a number of
contrast negatives at different densities that when combined produce an
illusion of continuous tone. I think you are looking at 8 bit depth. You
will see a similar effect in ATSC television continuous tone. It cant be
corrected without significant loss of information. In "busy" images, the
problem is a lot less obvious. For continuous tone grey scale digital
imagry, one needs to have at least 16 bit depth, and preferably 24 bit.
the image is actually a 24 bit image .. but only 219 unique colors are used.
File: - !cid_EB7D97DF-6B94-4DB7-B011-FCDAC19217BC@xxxxxxxxxxx
Software - Adobe Photoshop CS5.1 Macintosh
DateTime - 2015-07-07T00:30:52-20:00
My guess? the file has been converted to a low bit depth setting, then
converted to a greyscale (or desaurated.. or it was of a greyscale image to
start with) , then saved again as a 24 bit per chanel colour image..
corrective? rescan/reshoot ..
salvation technique? apply a horrendous amount of gaussian blur then resave
as a teeny 112x155 image!
k
