Digital camera enthusiasts will probably give you suspicious looks when you explain them the joys of the free software world. Digital photography is typically a minefield of proprietary file formats, proprietary communication protocols and proprietary imaging software. However, the gPhoto2 project promises to give supportive arguments to those fighting the prejudice that digital photography and free software do not mix.
gPhoto2 is a collection of various software packages, which give you access to the images on your camera. More than 800 models are currently supported, and the list is growing steadily with every release. To get there, the developers had not only to implement some crude protocols like PTP or MTP, but often also proprietary extensions, which had to be painstakingly documented by reverse engineering. gPhoto2 does not support cameras acting as USB mass storage devices since these are nothing but external hard drives containing your images.
Browsing images using
For users, gPhoto2 offers several different ways to communicate with a camera. The most intuitive one is gtkam, a GUI program allowing to do various simple tasks. It shows the cameras connected to your computer and lets you browse through thumbnails of the images stored on a camera. From there, you can transfer the images to your hard disk. Exif information is available as well.
If gtkam does not satisfy your needs, there is still the command-line interface. It offers all the features gtkam has, and is necessary for more advanced stuff like remotely controlling your camera to take pictures.
A rather unorthodox way to access the images on your camera is to mount the camera as a file system. This is done by using gphotofs, which installs a FUSE mount point on your system. At the moment, however, it only supports downloading of images.
The heart of gPhoto2 is a library proving the core functions, which allows other programs to quickly incorporate it. Applications relying on gPhoto2 include gThumb, GPC and kamera, the latter enabling you to use Konqueror to access you camera via a camera:/ URL.
gPhoto2 is an essential tool for working with digital cameras. It aims to provide an easy-to-use interface to a camera, and it does exactly that. However, besides downloading images there is hardly anything you can do with it, which is a bit disappointing given the potential the project has.