# Re: MFS-12000SP survey [was: Re: Mustec 1200SP Firmware 1.02 Color

becka@sunserver1.rz.uni-duesseldorf.de
Wed, 13 Aug 1997 13:17:52 +0200 (MET DST)

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O.K. - now for the experiences when using --disable-ld-fix at ./configure time:

> - What version of SANE are you using?
0.62

> - How was SANE configured? Did you use the --disable-ld-fix option?
Yes. No other special options.

> - What SCSI adapter are you using?
NCR53c400 as last time. And the scanner is a MFS12000 with 1.00 FW.

> - Does grayscale scanning work fine at various resolutions and without
> dropped lines (e.g., try to scan a diagonal line to detect dropped
> lines). If not, does it work for certain resolutions or do other
> settings (such as "force backtracking") affect the result?
No. No scanning at all works. The scanner locks after its three "calibration
moves" it makes at startup. The PC will still work, but the scanner process
will be left open and needs to be killed with -KILL.

After setting back to the normal mode, I have checked the seldomly used
modes and found the following :

- Color Lineart and Color Halftone have wrong colors. Brightness seems all
right, but color is wrong by far. Maybe the assignment of the color-planes
is wrong.(Don't waste too much time on that - who needs it ?)
- Halftone mode works fine, if a 0 pattern size is set. If you set a pattern,
it doesn't work right.
- The pattern vector does seem to have incorrect length constraints.
You can only set up to pattern-size values. pattern-size^2 should be the
correct limit.
- Pattern setting itself seems to work right except for the far too small
size.

The halftoning mechanism works as follows :

The image is scanned in grayscale-mode internally, but for each dot the
scanner has an individual threshold to decide it is black or white. This
threshold is in the halftoning matrix.

Say we have a matrix of 1 3 and an all gray picture of value 3.5, we get
2 4
* * in the output. The downloaded matrix is repeated like a tile-pattern.
* -

Ask if I haven't made myself clear. The default matrix ain't bad, but rolling
your own might be nice for some applications.

CU,Andy

    --
    Andreas Beck              |  Email :  <becka@sunserver1.rz.uni-duesseldorf.de>
    ========  GGI - The Right Thing To Do : http://synergy.foo.net/~ggi/  ========

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     Next message: Christophe Zwecker: "Re: libc prob with 0.62 solved, now gimp"
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     In reply to: David Mosberger-Tang: "MFS-12000SP survey [was: Re: Mustec 1200SP Firmware 1.02 Color Problem]"

     Next in thread: David Mosberger-Tang: "Re: MFS-12000SP survey [was: Re: Mustec 1200SP Firmware 1.02 Color"
     Reply: David Mosberger-Tang: "Re: MFS-12000SP survey [was: Re: Mustec 1200SP Firmware 1.02 Color"