Which scanners REALLY provide 36 bit output? HP?

From: Bob Washburne (rcwash@concentric.net)
Date: Thu Dec 07 2000 - 19:26:24 PST

  • Next message: Mitsuru Okaniwa: "The scan mode of the preview and the scan"

    First, let me appologise if this is an old topic. I am new to the list
    and did not see a way to search the archives.

    Second, let me apologise if this sounds like a rant. I've just about
    had it with certain scanner vendors. But a little background might help
    to show what I am looking for.

    I wish to do archival work - scanning old documents and pictures to
    preserve them. So I need accuracy, not just pretty pictures. I'm sure
    the immage enhansement software thirty years from now will do magic, but
    only if it has raw data to work with. Enhansing interpolated data is
    meaningless (that's how you put eyeballs in the face on mars).

    So, all I am looking for is a flat-bed scanner with the following specs:
    -) 1200 dpi optical resolution minimum. Both axis.
    -) 30 bits per pixel minimum output to the computer. 36 bit color/12
    bit greyscale preferred.
    -) Software to actually scan at those resolutions.

    First I bought an Epson which claimed to have these specs. But once I
    plugged it in I found that it would only output 24 bit color to the
    computer. The 36 bit data was only used internally to the scanner. So
    after much fustration, I returned it.

    Next, I investigated the HP 5370C. It claimed to do 42 bpp. But just
    to be sure, I called HP tech support. Twice. Each time I was assured
    that the scanner would actually send 36 bit pixels back to the
    computer. So I bought one.

    After much playing around with the setup I went to scan my first image
    under Windows 95. And found that the included software would only
    output 24 bit color/8 bit greyscale. ARRRRGGGHHHH!!!

    So I researched the SANE site to see if it supportted the HP 5370C. The
    answer was not encourageing. It needs the USB driver which is not in
    the kernel distribution yet and the avision backend which needs to be
    patched to accept an HP scanner. And noone seems to have made that work

    I called HP tech support back and they seemed surprised that I could
    even choose between greyscale and color. They kept asking how I knew
    that I was getting 24 bpp. Aparently, the software is supposed to do
    everything for you and you aren't supposed to be able to control it. So
    I asked them to at least confirm that the scanner was able to output 36
    bpp, even if the supplied software didn't support it. We could look for
    third-party software once that was established. After several minutes
    on hold I was told that they would have to get back to me. Sigh.

    So, can anybody out there identify a scanner which can *REALLY* output
    36 bpp? If I scan an immage which is 2"x2" at 1200 dpi will I actually
    get a file over 8.6 MB in size? And I'll be able to achieve that with
    xSANE or even the software which came with the scanner?

    The store where I purchased the HP 5370C also sells the 6300C. This
    appears to be better supported (supports SCL under the HP backend and I
    have a SCSI I/F for it). But is it pulling the same marketing crap of
    claiming 36 bpp while only delivering 24? I only mention HP because I
    can get them locally. If there is a better scanner out there I wouldn't
    mind getting it mail order.

    Thanks very much for your help.

    Bob Washburne

    Source code, list archive, and docs: http://www.mostang.com/sane/
    To unsubscribe: echo unsubscribe sane-devel | mail majordomo@mostang.com

    This archive was generated by hypermail 2b29 : Thu Dec 07 2000 - 19:36:05 PST