Path: utzoo!utgpu!watmath!clyde!att!pacbell!ames!xanth!ukma!uflorida!mailrus!purdue!decwrl!labrea!polya!djones From: djones@polya.Stanford.EDU (David Jones) Newsgroups: comp.graphics Subject: Re: ShowScan quality image bit rate Message-ID: <6652@polya.Stanford.EDU> Date: 5 Feb 89 00:42:01 GMT References: <18071@glacier.STANFORD.EDU> Reply-To: djones@polya.Stanford.EDU (David Jones) Organization: Stanford University Lines: 29 In article <18071@glacier.STANFORD.EDU> jbn@glacier.UUCP (John B. Nagle) writes: > > Consider 6000 x 8000 pixels x 60frames/sec x 24 bits/pixel; >the data rate is about 70 gigabits/sec, ... > > John Nagle Someone else commented that at some point you'd exceed the limits of human perception. Sorry if this is redundant, but here are some numbers worth thinking about. 2 eyes x 1,000,000 optic nerve fibres x 200 spikes/sec peak firing rate = 0.4 gigabits/sec These figures are approximate, but it's the right order of magnitude. Of course, the optic nerves are not carrying "pixels", but more sophisticated "bits" of visual information. (This estimate ignores noise, so the true information rate is lower.) Since a great deal is in fact known about how visual information is encoded (at early stages at least), images stored as 24 bits/pixel can be compressed by quite a bit with no perceptible loss in image quality (provided of course that you know precisely how the image will be viewed). It looks like there's room to better Mr Nagle's pixel representation by 3 orders of magnitude. David G. Jones djones@polya.stanford.edu