Re: Mustek 1200SP: Missing Lines
Mon, 3 Nov 1997 11:27:08 +0100 (MET)

> - what happens at different resoultions ? I only see the effect at medium
> resolutions of about 70-150 dpi. Higher resolutions are probably too slow moving
> or the effect it not visible enough and at lower ones, I ususally have no
> or only few boundaries.

I just re-checked. They are there even for 300dpi, but usually only 1-2 lines
are duplicated. The duplication is not exeact, as one can easily check by
using some image manipulation tools that allows for custom filters.

I tried a horizontal simple edge-detect (-1*last_line+1*current_line ) and
it shows black stripes at the buffer boundaries. However they are not exactly
black, but contain brightness values of up to about 6.

This leads to the conclusion, that it is not a problem with SANE buffering or
the like, as this would probably result in perfect duplication.

However the overall geometry of the image is _not_ distorted as far as I can
tell. It just looks like you took the correct picture, selected a line and
copied it over the one below.

So it doesn't sound like a mechanical problem either, leaving open as the
most probable cause some timing related issue.

Maybe we should try dropping a few sleep()s in at various places and see if
it changes anything ...


Andreas Beck              |  Email :  <>
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