[sane-devel] Re: [ANN] Plustek Backend update V0.45-1

Gene Heskett gene_heskett@iolinc.net
Sat, 11 Jan 2003 16:08:35 -0500

On Saturday 11 January 2003 10:05, Jaeger, Gerhard wrote:
Announcing a 45-1 release.

I unpacked it over the old 45 in sane-backends-1.0.9, did a make 
clean && make && make install, which apparently went well.

Fireing up xsane from the icon, I had it do a preview, which ran as 
far as the end of the forward travel of the carriage, at which time 
it cleared Olivers logo from the preview window, and the whole 
thing went away about 1 second later.  The carriage went back home 
as it should have, but the lamp was left on.

Running it from a shell, it did the same thing, and reported a 
"segfault" to the shell window as it exited.

The epson iscan-1.40 derived backend still works ok though.

I'm going to do another make clean and get rid of the config.cache 
etc stuffs and try it again, as I've re-arranged the order in 
ld.so.conf a bit since that configure was done.

Humm, that might have done something, in 2 restarts it hasn't 
crashed yet.

However, the returned image seems to be quite dark in the 600 dpi 
mode, with the raw histogram only occupying about the left hand 25% 
of that window.  Also, all the britness and contrast sliders for 
both overall and rgb are pegged at the right border of the slider, 
and labeled 100 at that point.  The initial image doesn't look that 
bad in the preview window, but 1/2 second later when the autoadjust 
kicks in, the image drops to be dark enough to be obvious.  It can 
only be rescued by the options window britness slider being set for 
about +4 and a new scan done.

Also, the white line artifact is (hooray!) gone when at 600 dpi.  
However, at 300dpi, its back and the output is too dark as before.
Then at 1200 dpi, the inverse appears to be true, I'm on the third 
scan right now with the britness slider in the option window now at 
-15 and its still quite a bit too bright.  Not making too much 
progress, I'm trying -30 now.  Still too bright in the whites, but 
the darker colors are now all black, but the histograms haven't 
changed.  Now the contrast is set for -30 also, but its still too 
bright and contrasty. Final settings for a decent scan are 
brightness=0 and contrast = -65.  So thats a bit off.

I also tried a 2400dpi scan (can we say slow?) at those settings and 
it looked pretty close to the 1200 dpi result except its beginnng 
to look like it was jpegged a wee bit too much.  Is this mode by 
interpolation?  Even the white line artifact is fuzzy.

Then at 150dpi, the inverse is true, the usable setting is +7 and 
+50.  Ditto for the 75dpi setting.

I don't recall this change dpi, change everything else as being this 
obvious before, and ISTR the main control windows sliders all were 
centered at 100.0 prior to this.  The motor you'll be glad to hear 
is running very quietly, only noticable at 150 and 300 dpi.

This is odd indeed, I went back to do one more check at 600dpi, and 
had to virtually zero those sliders to get a decent scan again.  I 
think I've got ghosts or something...  Should this not be 

Cheers, Gene
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