Digital Cameras, Linux, and BSD

Using Your Digital Camera

There are several sections to this page, jump to what you need:
Attaching the camera or phone Mass storage, MTP, or PTP? Using MTP Using PTP How to Recover Deleted Images

Attach the camera to the USB port, verify that it's seen

The kernel should detect the USB device.

On Linux, lsusb should display a line showing the device.

On BSD, use usbdevs.

With either command, add the -v option for verbose output and many more details.

Linux% lsusb
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 003: ID 05e3:0761 Genesys Logic, Inc. Genesys Mass Storage Device
Bus 003 Device 004: ID 04ca:707f Lite-On Technology Corp. USB Storage
Bus 003 Device 002: ID 05e3:0608 Genesys Logic, Inc. Hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 0bda:b00b Realtek Semiconductor Corp. Bluetooth Radio 
Bus 001 Device 015: ID 22b8:2e82 Motorola PCS moto z4
Bus 001 Device 002: ID 093a:2510 Pixart Imaging, Inc. Optical Mouse
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

BSD% usbdevs
addr 1: EHCI root hub, Intel
 addr 2: 802.11 n WLAN, Ralink
addr 1: EHCI root hub, Intel
 addr 2: USB PTP Camera, Fuji Photo Film
addr 1: UHCI root hub, Intel
addr 1: UHCI root hub, Intel
addr 1: UHCI root hub, Intel
addr 1: UHCI root hub, Intel
addr 1: UHCI root hub, Intel
addr 1: UHCI root hub, Intel

usbview may provide a detailed graphical user interface for examining USB devices.

Fuji FinePix digital camera with USB cable.

Mass storage, MTP, or PTP?

There are three entirely different methods of data storage on digital cameras:

USB Mass Storage Device
Picture Transfer Protocol or PTP
Media Transfer Protocol or MTP

If your camera behaves as a mass storage device, it will appear as a SCSI disk. Mount it with something like the following:

% mount /dev/sda1 /media/camera

The device will be something like /dev/sd0i on BSD.

How can you tell what the device name is? It will probably be the first partition of some SCSI/SATA device, but how do you get the specific name? If you can't just guess, on Linux you could ask for your partition tables as root:

# fdisk -l

You could also see what the kernel has recently noticed:

% dmesg | grep 'sd[a-z]'

How can you allow an ordinary user to mount removeable file systems? Specify this in /etc/fstab:

% grep media /etc/fstab
/dev/sda1  /media/camera  auto  user  0  0

However, it seems that most newer cameras do not support USB mass storage. You will need to use some user-space tools.

Using MTP

The desktop environment on my Mint laptop uses MTP with some GTK tools and daemons. While it works fine with USB disks and flash drives, it does not work with a camera. I get a pop-up with this error message:

Unable to open a folder for moto z4
No such interface "org.gtk.vfs.Mount" on object at path /org/gtk/vfs/mount/1

I see these processes running:

$ ps axuww | egrep 'PID|gvfs'
USER         PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
cromwell   21249  0.0  0.1 239708  7588 ?        Ssl  01:09   0:00 /usr/libexec/gvfsd
cromwell   21254  0.0  0.1 378336  6484 ?        Sl   01:09   0:00 /usr/libexec/gvfsd-fuse /run/user/1000/gvfs -f -o big_writes
cromwell   28501  0.0  0.1 388012  9404 ?        Ssl  08:49   0:00 /usr/libexec/gvfs-udisks2-volume-monitor
cromwell   28507  0.0  0.1 316716  8804 ?        Ssl  08:49   0:00 /usr/libexec/gvfs-afc-volume-monitor
cromwell   28512  0.0  0.1 238104  6236 ?        Ssl  08:49   0:00 /usr/libexec/gvfs-gphoto2-volume-monitor
cromwell   28516  0.0  0.0 235872  5996 ?        Ssl  08:49   0:00 /usr/libexec/gvfs-goa-volume-monitor
cromwell   28520  0.0  0.1 236312  6808 ?        Ssl  08:49   0:00 /usr/libexec/gvfs-mtp-volume-monitor
cromwell   28524  0.0  0.1 313800  7936 ?        Sl   08:49   0:00 /usr/libexec/gvfsd-trash --spawner :1.192 /org/gtk/gvfs/exec_spaw/1
cromwell   28541  0.0  0.1 387940  8580 ?        Sl   08:49   0:00 /usr/libexec/gvfsd-network --spawner :1.192 /org/gtk/gvfs/exec_spaw/2
cromwell   28558  0.0  0.3 524540 23352 ?        Sl   08:49   0:00 /usr/libexec/gvfsd-smb-browse --spawner :1.192 /org/gtk/gvfs/exec_spaw/3
cromwell   28566  0.0  0.1 314980  8212 ?        Sl   08:49   0:00 /usr/libexec/gvfsd-dnssd --spawner :1.192 /org/gtk/gvfs/exec_spaw/4
cromwell   29450  0.0  0.1 162796  6788 ?        Ssl  08:56   0:00 /usr/libexec/gvfsd-metadata
cromwell   31197  0.3  1.5 676336 92964 ?        Sl   09:44   0:03 nemo /run/user/1000/gvfs/mtp:host=motorola_moto_z4_ZY226VKDSH
cromwell   31233  0.0  0.1 470468  9252 ?        Sl   09:44   0:00 /usr/libexec/gvfsd-mtp --spawner :1.192 /org/gtk/gvfs/exec_spaw/7

Kill those processes:

$ pkill gvfs

go-mtpfs

Unplug the phone, and plug it back in.

Do what's needed to enable file transfer. On my Motorola "moto z4", that's:

Swipe down to see notifications.
Tap "Android System: Charging this device via USB"
Tap "Tap for more options"
Tap "File Transfer"

Now go-mtpfs and gphoto2 and related tools will work.

go-mtpfs uses FUSE, a user-space file system. You create a mount point, and then mount the device there. By default it runs in the foreground, so start it in the background to use the same terminal to interact with the file system.

$ mkdir /tmp/phone
$ go-mtpfs /tmp/phone &
$ df -hT /tmp/phone
Filesystem          Type                      Size  Used Avail Use% Mounted on
Locked(fs.rootNode) fuse.Locked(fs.rootNode)  169G   22G  148G  13% /tmp/phone

Now let's browse the result. The mounted file system contains what actually is two file systems: that of the phone itself, plus the one on the Micro SD memory card. My memory card has a file system label of ANDROID, and so change that for your card.

$ ls -F /tmp/phone
ANDROID/  Internal shared storage/
$ ls -F /tmp/phone/Internal\ shared\ storage
Alarms/   DCIM/      Movies/  Notifications/  Podcasts/
Android/  Download/  Music/   Pictures/       Ringtones/
cromwell@aphrodite:~$ ls -F /tmp/phone4/ANDROID/
$ ls -F /tmp/phone/ANDROID
Android/  Download/  Movies/  Pictures/  alarms/  notifications/
DCIM/     LOST.DIR/  Music/   Podcasts/  media/   ringtones/

My pictures are now in:
/tmp/phone/ANDROID/DCIM/Camera/
I can change to that directory, list what's there, view them, and then copy or move them to the computer.

gphoto2

The gphoto2 tool is more suited for scripting.

To download all the pictures from the command line, simply use:

% cd /path/to/desired/storage/area
% gphoto2 -P

See the gphoto2 manual page for far more.

Using PTP

The Konqueror browser part of the KDE desktop, understands PTP. Just bring up a Konqueror browser and change the location to camera:/

That should let you browse the camera's storage. The URL ends up being something like this:

camera://USB%20PTP%20Class%20Camera@[usb:004,006]/store_10000001/DCIM/101_FUJI

Of course, that 004,006, indicating USB bus #4 and device #6, will depend on where you attach your camera. See the lsusb output above for how you can figure out in advance what this will be.

However, Konqueror will give give you icons to click on:
USB PTP Class Camera, then
store_10000001, then
DCIM, then
101_FUJI (or however your camera identifies itself).

How to Recover Deleted Images

recoverjpeg is a very nice tool. Get it from rfc1149.net or from free(code).

If your camera works as a USB mass storage device, you can simply find its device name (it will appear as if it were a SCSI or SATA disk, use fdisk -l to figure out its name). Then you can image the camera's memory into a file, and extract images from there:

$ cd
$ dd if=/dev/sdb of=camera-image bs=1M
$ recoverjpeg camera-image

Or you could simply recover the JPEG image files directly, there is no real need to save an image of the camera's memory:

$ cd
$ recoverjpeg /dev/sdb

If, on the other hand, your camera uses the Picture Transfer Protocol, or PTP, then as far as I know you will have to put the memory card into a reader so it appears as a USB mass storage device. I don't think there's a way of using the PTP interface to directly access or copy the memory. See the gphoto2 manual page for far more, maybe there's a way to image or directly access the memory.