From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <775b8d190604271302y2d7262bdo233acc444c0f75dd@mail.gmail.com> Date: Fri, 28 Apr 2006 06:02:21 +1000 From: "Bruce Ellis" To: "Fans of the OS Plan 9 from Bell Labs" <9fans@cse.psu.edu> Subject: Re: [9fans] PNG and APE (cntd) In-Reply-To: <6e35c0620604271226o17e6cccdm63a0794e550a39b4@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline References: <6ac270891b09f4b5e1ea25ce1ab1adc5@terzarima.net> <6e35c0620604271226o17e6cccdm63a0794e550a39b4@mail.gmail.com> Topicbox-Message-UUID: 489f8d7e-ead1-11e9-9d60-3106f5b1d025 Yes, 12 bit was added to postscript for x-rays. brucee On 4/28/06, Jack Johnson wrote: > On 4/27/06, Charles Forsyth wrote: > > > And, BTW, PNG allows 16-bit per colour, a 48-bit depth per pixel. > > > Thanks to libpng, my "npng" can render these as 24-bit images. > > > > ``the human ear can't hear as high as that / still, it ought to please = any passing bat'' > > I used to do some image fiddling a long time ago (image prep -> TGA > for television), and came across some info regarding medical x-ray > photographs being stored in a 12-bit grayscale format. It's likely > that so fine a variation is either above or right on the edge of human > perception (given current working environments), but one > counterargument is that maybe it's not a human looking at the data. > > Plus, I think 12 bits per color would be right around the limit of > film, something like a 4000:1 contrast ratio, so depending on the > scanner you'd likely be pushing the limits of the original medium > anyway, "lossless" transfer from analog to digital, whether or not > you're in a good position to make use of the data. > > Archaeologists have the same problem all the time, looking at data > gathered by previous scientists and realizing the original gatherers > didn't save enough information for the current questions, so now they > tend to swing the opposite direction and record all the minutiae so > that years later someone can glean new information from an old dig. > > One day, you may be a bat. > > -Jack >