Message-Id: <mailto:199407012119.QAA10172@library.wustl.edu> Date: Fri, 1 Jul 1994 17:04:22 EDT From: Robert Rosenberg <mailto:rarosenb@GANDALF.RUTGERS.EDU> Subject: Re: Job description for scanning technician To: Multiple recipients of list IMAGELIB <mailto:IMAGELIB@ARIZVM1.BITNET>
We are in the throes of about-to-convert to digital format. Edison's stuff comes in all formats, on all sorts of paper. I will say, contra the received wisdom that 300dpi is necessary, that bit depth is much more important than resolution, and that 150dpi with 6 or 8-bit grayscale is infinitely preferable to 300dpi black and white (one-bit). Not only is it easier to see, but the detail lost in 1-bit images and the horrific problem of setting a threshold (what is black and what is white) makes 1-bit scans unacceptable.Is that too subtle? I think that anyone working with materials that are not typed or printed must have some gray. Even 4-bit (16 shades of gray) is good enough for most documents.
As for the physical problems of scanning, our experience this winter with the Kontron high-resolution digital camera (as part of a group of 5 test sites) was quite remarkable. The camera can scan in full 24-bit color, if necessary, or in 8-bit gray, and its maximum resolution is about 3000 x 2000, which is usually overkill on a document. The images we obtained of artifacts were spectacular.
Bob Rosenberg Thomas A. Edison Papers Rutgers University New Brunswick, NJ 08903 mailto:rarosenb@gandalf.rutgers.edu