Java Jive wrote:
On 07/03/2019 21:52, Roger Mills wrote:

Does it need to be bluetooth?

Perhaps not. I'll explain my need and see what others suggest.

There is in my wider family's safekeeping, but which rightfully belongs
to me, a very beautiful antique book, which because of an unforeseen
horrendous problem I've decided must be sold to fund my house
renovations, but, beforehand, I'd like to photograph the hand-painted
pictures that it contains. I had considered scanning it, but it's too
big, so some of the images would need to be scanned piecemeal, and I'm
worried that the book might not survive such rough handling as to be
perched on a scanner.

So I've decided to try and photograph it using my tablet. I'll
construct some sort of frame to hold the tablet securely a suitable
height over the book, and try and find a suitable source of
illumination. The need therefore is a way of controlling the tablet's
camera from a PC, either via WiFi, Bluetooth, or USB cable.

After managing late last night to pair the tablet with one of my W7
laptops, I tried some software called Camera Remote PC Sync (on the PC)
and Camera Remote (on the tablet). This pair of apps are supposed to be
able to connect either via Bluetooth or WiFi, but if the PC side tries
to connect to the tablet side via WiFi, the tablet app bombs, so it has
to be Bluetooth. I could do the job with this software, but it would
require a great deal of time and patience, because it's clunky in the
extreme - the PC window is too big for the height of my laptop's
screen even though that is fairly standard dimensions for a laptop
screen; some of the dialogs have black text on a black background; you
can only download one picture at a time, not mark a whole lot of them
and download them all at once, and each time you do a download, the
software begins by defaulting to the User's folder on the C: drive, thus
necessitating a wearisome navigation back to the D: drive to save it
where I actually want to save it; etc; etc!

So if anyone here can suggest suitable software to allow a PC to control
an Android tablet's camera relatively painlessly, I'd be very grateful
to know.

You can rent a book scanner. This scanner "snapscan SV600" is no
longer in production. It takes 3 seconds per page. And software is
there for curvature correction.

https://fujitsuscannerstore.com/rentsv600-aenbd/

Advert for one.

https://www.amazon.com/Fujitsu-Scann.../dp/B00FPW9946

Since the field of view is limited and text at the bottom of the page
may be "blurry" according to one review, you may need to rotate the
book and take images of the pages a second time.

*******

It's either that, or operate the tablet directly while
it is in your scan frame.

I find it's just about impossible to photo stuff with
a webcam, unless the webcam is firmly held via a tripod
or the like. I did documentation photos for a project,
with the webcam screwed to a tripod.

If you take two photos and absolutely nothing moves, you
can use Photoshop (A+B)/2 to average out sensor noise. That's
what I did for my webcam shots. Even though the scene was
well lit, the webcam still had a lot of noise. Averaging
just two photos together, gives some improvement. Averaging
sixteen photos, doesn't actually seem to do much more than
two photos averaged together.

I have a $150 Point and Shoot digital camera now, which is
miles better than a $100 webcam. The only problem with that
is, the autofocus gets confused by "complex" scenes
with a dark left half and a bright white right half. You
can't convince the camera to focus on the material in
the center of field. I suppose disabling the autofocus
would be one solution. But in terms of recognizing
"typical" applications of the camera, it's pretty good.
It's just not a replacement for a "lab microscope".

*******

Based on my experience with doing stuff like this, I find
you need "immediate feedback" of what is going on. Trying
to operate remotely is "a step too far". If you stand over
the equipment, you get to visually review that the book
is properly placed, that the page hasn't moved, while you
operate the device. If the tablet has a camera on the
side opposite the LCD panel, that would be ideal. If you
need more storage space for the photos (until download),
you can always plug in an SD or a USB flash stick.

Paul