[sane-devel] Plans for an updated avision backend (HP7400+HP5300+Minolta Scan Dual II+???)

[Jose Paulo Moitinho de Almeida]

On Wednesday 14 November 2001 14:05, Martin Jelínek wrote:

> Martin Jelínek, Wed Nov 14, 2001 at 02:58:
> > I attach a attach.c source with parsed output at debug level 3, raw bytes
> > moved to debug level 5.
> >
> > mates
> >

It looks great! I will try it tonight.

Now for the resolutions:

Your "Maximum Scanning width" (81/82) is 9*256+248 = 2552
2552/300= 8.5 (in) *25.4 = 216 mm (Question at the end)

Your "Maximum Scanning height" (83/84) is 16*256+104 = 4200 
4200/300= 14 (in) *25.4 = 355.6 mm


Using this formula for my scanner I get:

My "Maximum Scanning width" (81/82) is 10*256+128 = 2668
2668/300= 8.96 (in) *25.4 = 227.6 mm (Not bad for a film scanner)

My "Maximum Scanning height" (83/84) is 15*256+192 = 4032
4032/300= 13.44 (in) *25.4 = 341.4 mm


If instead of dividing by 300 I divide by the optical resolution (multiply 
the result by a factor of 300/2820) I get: width=24.6 mm height=36.3 mm. 
These are the dimensions of a "normal" 35mm image.

Anyway it seems that the only scanner that needs this correction is the film 
scanner.

Regards

Ze Paulo




Question: 
The driver reports X-Range: 203.199997mm. My "computations" give 216 mm. What 
is wrong??? Is it SANE_FIX / SANE_UNFIX?