The Kodak DC290 Camera and Linux

(In contrast to what this image might suggest, the Kodak DC290 is not mouse-controlled)

The Kodak DC290 camera is quite well supported on Linux. However, finding all the tools is a bit difficult. I created this page to collect some links and information. Some of it is specific to the DC290, some will work with other Kodak cameras, and some information might be useful for other cameras, too.

I don't think I'm a real expert on this, but I have a working setup, so the information will be useful for someone who is trying to get it up and running. It will probably be incomplete, since I tend to forget what I did to get things going as soon as they start working without playing around with the config files...

Basic USB-setup

I found about everything I needed to know on David Brownell's page (unfortunately, this page no longer exists). I use it with a Redhat 7 and a SuSE 6.2 system, which was updated to SuSE 7.3 recently.

Redhat 7

This comes with USB installed and configured. The core modules will be loaded at system boot, so you have to load the dc2xx module only. This can be done by hand with /sbin/modprobe dc2xx (as root). You can also make it happen automatically by adding the following line to /etc/modules.conf:

    above usb-uhci dc2xx

SuSE 6.2

This doesn't have USB support, so I applied the USB backport. Unfortunately, the kernel is not exactly the version the patch expects, but I figured out how to apply the missing pieces by hand. Since this is a laptop that is rebooted quite often, I don't want to start the USB system in the boot scripts. Instead, I added some bits to /etc/conf.modules. At the very beginning, it needs

    keep
    path[usb]=/lib/modules/2.2.10/usb

to find the USB modules. At the end of the alias char-major... part, I added

    alias char-major-180      usb-uhci
    above usb-uhci dc2xx

This will load the USB modules if the camera-device is accessed. Well, the first time I start the software, it complains that it can't open the device, but it works when I try a second time. There's probably a better solution.

A bug in the dc2xx module

With the USB backport, my computers couldn't talk to the camera if I disconnected and reconnected it. I had to reload the dc2xx and/or the usb-uhci modules using rmmod and modprobe to make it find the camera again. Dothory Cao Nguyen send me the tip to edit the source code of the dc2xx module and change a few lines in the function camera_release(). It should look like this:

static int camera_release (struct inode *inode, struct file *file)
{
	struct camera_state *camera;

	camera = (struct camera_state *) file->private_data;
	if (camera->buf) {
	       kfree(camera->buf);
	       camera->buf = NULL;
	}
...

You then have to compile and install the modules (or at least the dc2xx module).

SuSE 7.3

After upgrading my 6.2 system, I plugged in my DC290 and tried to talk to it. I had to load the modules by hand, but then it worked immediately. To load the modules automatically, I added the following to /etc/modules.conf:

    alias char-major-180	usb-uhci
    above usb-uhci dc2xx

With the new kernel, even the Infrared-connection to the camera works (if the computer has an IrDA port, of course). To start it, I entered (as root)

    irattach /dev/ttyS1 -s

This tells the system that the second serial port is connected to the IrDA port. Then, irdadump showed that there is a Kodak DC290. To talk to the camera, I used "ks -d /dev/ircomm0" (ks is part of the Open Digita Services, see below). I tried to download some pictures, which worked, but at an incredibly low speed.

Talking to the camera

So, if the USB system is running, you need some software to talk to the camera and transfer pictures. I tried gPhoto, but the DC290 is supported in the CVS version only. I managed to get and compile it, but it crashed immediately when I tried to start it, so I decided not to use it.

The easiest way is to use this python script (at least if python is already installed). However, this is not really user-friendly and not very versatile.

A better approach are the Open Digita Services. The version on their download page is able to download thumbnails and full images, and can do some less useful things like switching the camera off. The version in CVS (which is also available to everyone) seems to be able to do more, but it doesn't compile out of the box.

The python-script usually creates larger files than ks, but they are identical to the end of the shorter file. I think this is caused by some padding the camera does during the transfer. This should probably not be written to the file, but the python-script does it anyway.

Looking at the pictures

The easiest way to look at pictures on Linux is xv, of course. However, it is simply too old to know about the new EXIF-data that is hidden in the pictures created by digital cameras. Furthermore, the DC290 can record short audio clips which are embedded in the image file. Some utilities to extract these informations:

jhead is a simple program to display the EXIF-data in the file. It can also re-insert the data after applying some command to it. It even can remove the thumbnail embedded in the image, but I don't know why one should worry about the space wasted by a 10 KByte thumbnail in a 300000 KByte image.
The Exif-Tools are useful to extract the audio-clip from the images. They should be able to dsplay all kinds of data about the structure of the JPG-file, but I couldn't compile all of them.
The EXIF utilities became available recently as binary for Redhat 6.2. The author considers them beta, he plans to make the source code available once they are finished.
JExif uses Java, so it should run on Linux, but I don't have the right JDK version, so I don't know if it works.
Finally, if you want to invent a better wheel, you can get the description of the Exif file format. (Thanks to Bill Marr for the new URL of this page).

Image processing

There are zillions of programs out there to manipulate images, but you should be aware that you will lose details and add more artifacts every time you save it in JPEG format. However, it is possible to perform simple operations like rotation and some special cases of cropping without uncompressing and recompressing the image. Some information about this can be found on "Guido's Tech' Corner" He also wrote a patch to properly preserve the Exif data in JPEG images.

Rainer Köhler