Re: Agfa StudioScan IIsi [long]

From: Matto Marjanovic (maddog@mir.com)
Date: Mon May 21 2001 - 07:11:58 PDT

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    Try this: uncomment both "norealcal" and "noprecal", and then send me the
     resulting debug log, of a color scan.
    (Make sure you get a little sleep first! :)

    The two are misnomers (which I intend to change this week), so here is a bit
     of explanation:

     o By default, the scanner firmware performs some little automatic calibration
        at the start of every scan. This takes a few seconds.
     o There is an inquiry bit which indicates whether or not this calibration
        can be disabled.
     o The Scanmaker E6, and maybe others, has an additional calibration feature
        which has its own SCSI command. This I call "real calibration", because
        it actually involves the backend performing calculations on data returned
        by the scanner.

     and

     o The backend tries to be clever, by only allowing the calibration once per
        session (which shaves time off of all your scans).

    So, the (purposely flawed) logic is as follows:

     o If calibration can be disabled and not (norealcal),
        use the 'real calibration' routine.
     o Else, if calibration can be disabled and not (noprecal),
        use a clever trick which does a microscan once with default calibration,
        and then disables it for the rest of the session.
     o Else, do not use 'real calibration', and don't disable default calibration.

    Actually, in v0.12.1 of the backend, I quickly changed the behavior to
     act like "norealcal | noprecal" for everything but the E6, just because
     of the volume of complaints. (I originally wanted to see which scanners
     used the 'realcal', so I made it the default and waited for the bug reports
     to come in. That was a mistake.)

    -matt m.

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