Le 2024-05-11 17:16, Alexander Pevzner a écrit :
The eSCL and WSD devices provide their capabilities, so I don't see
how an "IPP Scan" overlay would be better (the implementation why
not).
I prefer the PIXMA or EPSONSCAN2 backends, which expose many more
properties than eSCL or WSD.
Let me try to explain these things a little bit.
Thanks Alexander, that makes it clearer!
2. The daemon may initialize early, so when user application wants to
scan, everything is ready (currently, if there are many backends
enabled, initialization may take seconds).
From my point of view, a scanner configuration module is missing, so as
not to waste time on initialization.
Initialization should just be a readout of configured devices.
The choice is between SANE's native protocol (used by saned and
sane-net backend) and standard-compliant scanning protocol (here we
have eSCL, WSD, TWAIN Direct and IPP-scan).
Once a configuration exists, sane-net is operational.
So it is not actually correct to say that eSCL is limited in comparison
to the PIXMA protocol.
Cannon implementation of eSCL may be limited (and this is Canon's
decision to promote their proprietary protocol by limiting their
implementation of the standard eSCL), but these limitations are not
part of the eSCL specification by itself, and other hardware exposes
all its functionality to both proprietary protocol and to eSCL.
You're right, the problem isn't the protocol but the manufacturers,
because this isn't unique to Canon.
Thierry
