Resolution, Pixel color depth,

Jim Lindner (mailto:VIDIPAXJIM@DELPHI.COM)
Sat, 20 Aug 1994 21:34:39 -0400

Message-Id: <mailto:199408210136.UAA19485@library.wustl.edu>
Date:         Sat, 20 Aug 1994 21:34:39 -0400
From: Jim Lindner <mailto:VIDIPAXJIM@DELPHI.COM>
Subject:      Resolution, Pixel color depth,
To: Multiple recipients of list IMAGELIB <mailto:IMAGELIB@ARIZVM1.BITNET>

I strongly agree with Ray Lauzzana about questioning resolutions under
1024x1536 as being good enough for accurate representation.  An extremely
important element to consider is the color bit depth for each pixel, and the
associated lack of true representation at typical bit depths even with
reasonably high resolution.  Too little color information can cause many
artifacts including banding and aliasing in several ways, and perhaps most
importantly a compression of gamma and an inaccurate representation of the
image.  We are currently working on a project that is scanning a 35mm cine
format frame at approximately 3k x 4k pixels at 12 bits each of Red, Green, and
Blue.  Needless to say, we are generating quite a bit of data per frame.  Our
experience indicates that resolution and color depths at less than this level
reduce the quality of the digitized frame relative to the image holding
capacity modern film.  I would like to point out, however, that older films did
not the ability to spatially resolve with this level of detail.

Another comment about archival stability........ the archival stability of magnetic media is extremely poor when compared to film (and most anything else). It is probable that the item you are scanning will last FAR longer than the magnetic media you are storing the digitized image on. I will be happy to email interested list members some articles on this subject, or post them if there is sufficient interest.

Jim Lindner VidiPax VidiPax is a company specializing in videotape and magnetic media restoration. Our toll free help line is: 800-653-8434 PLEASE DO NOT RESPOND TO THE "REPLY" INTERNET ADDRESS ABOVE.

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