scan-manager -- python app for controlling tethered cameras

[og200]

OK, a new Windows build, 0.4.5, is up. It has a fix to stop the app freezing when capturing on some DSLRs using the libgphoto2 backend. I'm going to rework the libgphoto2 interface soon so it is more stable (there's little documentation for libgphoto2 so there has been a lot of guesswork).

I've also added some dlls to the installer that are needed to run on a clean Windows XP install.

[tkr]

OG, just got my A480 in the mail today - was unable to get gphoto2 to take a picture, even with CHDK loaded on it. However I was able to use a program called ptpcamgui to send LUA scripts to the camera and have it take photographs. I believe I read somewhere on this forum, that one can use gphoto2 with a --chdk option. I'll try that and report back.

[og200]

Let me know how you get on with gphoto2 + CHDK. If that doesn't work and ptpcamgui does it's always possible to write a new backend for CHDK and that would be worth doing as it opens up a lot of cameras.

The best option for doing this seems to me to use existing code (ptpcam or the newer chdkptp) compiled as a dll and call it from Python. There's a DLL around for ptpcam and even some very basic Python code that calls some of its functions here (piggyPTP).

[og200]

OG, just got my A480 in the mail today - was unable to get gphoto2 to take a picture

Just to be sure -- did you install a libusb-win32 filter driver for the A480 before you tried gphoto?

[tkr]

OG,
Yes I did load the USB driver prior to trying gphoto2.

The only app that I have had any luck with is ptpcamgui. I was able to control my camera and get it to take photographs, could also download them.
CHDKptp was supposed to have much better performance etc, but I was unable to get it to take a pic (although it did recognize my camera)
TKR

[og200]

CHDKptp was supposed to have much better performance etc, but I was unable to get it to take a pic (although it did recognize my camera)

Well, it seems chdkptp is being actively developed, which is good, and it might be fixed soon. But, it's also changing fast, which isn't so good for building a wrapper.

In short, ptpcam may have to do for now. I'll look into what would be needed for a ptpcam backend. The code doesn't look complex although I'm a bit confused about what seem to be different versions of ptpcam.dll.

E.g. here and here, though ptpcam.exe seems to do the same thing in each case.

[Fab52]

Hi,

Og, is working hard to solved the DSLR freezing after the first frame capture.

Congrat. OG. you fix that problem, I'am able to take capture with Scanmanager using my Nikon D90.

I will do more testing on SM using my D90 later on.



Cheers!!!

Fab

[og200]

Here are the next steps I've been thinking about:

• More work on camera support. CHDK is the main target for this. I've looked at ptpcamgui and I don't like it. It works by opening a pipe to a command line application (ptpcam.exe) and passing it text commands, which is a bit primitive. It also seems very slow with my A640s. I'm going to try putting together a PTP wrapper in Python+pyusb and that will talk directly to CHDK-enabled cameras. If that fails I may use ptpcam.dll. Either way I'd really like a CHDK backend.
• Add a grid and think about a more sensible UI for cropping and calibration -- I think I may want to take these operations offline anyway (i.e. set them up as you shoot but do the actual image processing automatically after shooting). It might be that BookScanWizard already does everything we need here; perhaps some sort of integration is in order. I'll look into that once the Wiki is back and I can figure out how BSW works.
• Documentation! Esp. on installing libusb-win32 drivers.
• Some testing on Linux.

[Gerard]

this is what i've used for chdk camera control,
a small warning when you start with chdk

• there are a lot of race condition
• memory on this cameras is small, scripts fail often due to memory shortage

chdkptp is an newer client to chdk ptp cams, what i've read it should be faster than ptpcamgui

[og200]

this is what i've used for chdk camera control

Wow! Thanks Gerard -- this is amazing. It looks like it incorporates a lot of hard-won experience.

I'll have a play with my camera tonight and see if I can get some basic remote control running over CHDK. I hope to do something with direct access to PTP over USB or using Python's ctypes to talk to ptpcam.dll/chdkptp, but if all else fails I may have to go down the ptpcam.exe-over-a-pipe route.