[sane-devel] genesys backend

Jens Luedicke jens.luedicke at gmail.com
Thu Aug 18 04:57:33 UTC 2005

On 8/15/05, Pierre Willenbrock <pierre at pirsoft.dnsalias.org> wrote:
> Hi
> The canon lide 35 is now scanning in color at any resolution. No
> calibration yet. I'd like the calibration code to use a more generic
> interface to the scanning logic before. But that will have to wait.
> This time i want to propose a new mechanism for generating slope tables
> in the genesys backend, which i implemented for my work.
> In my opinion it is sufficient to describe one slope for each step type.
> This slope is truncated as soon as the exposure time is reached. This
> leads to a variable step count, which can be used to shorten the
> acceleration/deceleration considerably.
> I used slopes derived from a start step time(vstart), a final step
> time(vend), a power(g) and a step count(steps):
> p[i] = (i/(steps-1))^g
> t[i] = vstart*(1-p[i])+vend*p[i]
> For i in 0..(steps-1).
> Pros:
> + less Constants
> + a means for calculating exposure time(which is limited by maximum
> motor speed and number of pixels processed per line)
> Cons:
> - variable step count
> - may be not applicable to all supported scanners
> - breaks the current code
> I attached the code i am using.

Could you create a patch for use with current CVS?

I tried to apply your code, but some things don't work out for me and
I'm not a developer and not familiar with the API + changes.


Jens Luedicke
web: http://perldude.de/

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