[sane-devel] Adding a Reflecta RPS 10M to pieusb

[Thomas Wilshaw]

Hi,

Just to follow up with this I’m happy to say I’ve managed to get the
Reflecta RPS 10M working (aka the Pacific Image PrimeFilm XAs) working with
SANE. It was quite straight forward in the end, I followed the suggestions
in this thread (
https://sane-devel.alioth.debian.narkive.com/F0oktUpc/reflecta-digidia-5000-not-found)
and managed to extract the vendor ID, device ID and model number and add
them to pieusb.conf. I’ve not done particularly extensive tests yet but the
things seem to be working okay. If anybody else is interested this is what
I added to the pieusb.conf:

usb 0x05e3 0x0144 0x0048 0x00

I don’t know if anyone wants to add that to the code base and add the
printer to the supported printers page.

I do however have a few questions about exactly what some of the settings
do and wondered if anyone here could help. I’ve read the man pages for them
but it still not clear.

1. If I generate a RGBI image, what format is best to access that? I saved
it as  tiff but that of course only has 3 channels and messed u things up
quite a bit.
2. --threshold, I’m guessing that sets exactly what amount of transmission
is mapped to the maximum value (255 in 8bit), the default is 50% which
seems very low to me. Have I got that correct and why is the default 50%?
3. –calibration, what exactly is this and which options affect it?
4. –correct-infrared, what precisely is this doing and how is it doing it?
I guess it’s a fairly standard IR dust removal process but more specifics
would be nice
5. –gain-adjust, is this the curve that is applied to the scan and will
setting this to 1.0 mean no curve is applied and the image will be linearly
encoded? Is this done in the scanner or just applied to whatever the
scanner hands off to SANE?
6. –crop, the options here are “inside” and “outside”, what does it mean to
crop outside?
7. –save-ccdmask, is this a mask of dead pixels that can be used to median
filter them out after the scan (and does this happen regardless)?
8. –light, I assume this is the brightness of the lamp in the scanner? What
units is it working in and what are the min/max values?
9. – double-times, I assume this doubles the exposure times of each channel
allowing one to quickly bracket scans? With a setting of 1 being one
doubling?
10. Finally, the gain and offset options, does the gain multiply each pixel
value by 0-63 and offset add 0-255 to each pixel? These seem rather
arbitrary limits, especially if one is scanning in 16bit, or have I missed
the point?

Apologies if I’ve totally misunderstood anything or missed some
documentation somewhere that explains all this. I've briefly looked at
various parts of the source code but I'm still finding it quite
overwhelming. Also if there's a better place to have this sort of
discussion please do let me know.

Thanks very much.
Tom



On Sat, 26 Jun 2021 at 13:26, Thomas Wilshaw <thomaswilshaw at gmail.com>
wrote:

> Apologies for the delay in replying.
>
> I should probably have mentioned this before but I'm compiling and running
> SANE on Windows with Cygwin, I don't know how much that changes things. I
> have successfully used SANE with this setup with an Epson printer so I know
> it can work.
>
> > Where do you got these numbers from ?
>
> They were reported by sane-find-scanner as:
>
> found USB scanner (vendor=0x05e3, product=0x0144) at libusb:001:009
>
> The vendor code matches the other Reflecta scanners that pieusb supports
> which is why I thought to use that backend. I'll have a go at catching the
> traffic though with scanners default driver, what sort of things would you
> be looking out for?
>
> Thanks,
> Tom
>
> On Sun, 13 Jun 2021 at 18:50, Klaus Kämpf <kkaempf at suse.de> wrote:
>
>> On 12.06.21 20:15, Thomas Wilshaw wrote:
>> > Hi,
>> >
>> > I'm trying to hook up my Reflecta RPS 10M film scanner to sane and I
>> > wondere if anyone had any suggestions? I've compiled sane with just
>> > pieusb support and I get the following when I run sane-find-scanner:
>>
>> Looks like you don't have access rights to USB devices.
>> Please check the internet for documentation about gaining this access.
>> It highly depends on the Linux distribution you're using.
>>
>> >
>> > I added the followiing line to pieusb.conf:
>> > usbm 0x05e3 0x0144 0x37 0x00
>>
>> Where do you got these numbers from ?
>>
>> >
>> > (model number is made up, I don't know if that's important)
>>
>> Yes, the model number is important (at least within pieusb).
>>
>>
>> Please start with running the scanner with a known driver (possibly
>> under Windows) and try to capture the USB traffic. Then I can tell you
>> if pieusb is the right driver for your scanner or not.
>>
>>
>> Klaus
>>
>
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