Using Still Cameras with Fedora Core Linux

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Most still cameras used in connection with Fedora fall into one of two categories: webcams (small, low-resolution cameras connected to the computer's interface) or handheld digital cameras that record image data on disks or memory cards for downloading and viewing on a PC. Fedora supports both types. Other types of cameras, such as surveillance cameras that connect directly to a network via wire or wireless connections, need no special support (other than a network connection and viewing software) to be used with a Linux computer.

Fedora supports hundreds of different digital cameras, from early parallel-port (CPiA chipset-based) cameras to today's newer USB-based cameras. You can even use Intel's QX3 USB microscope with Fedora. If you prefer a standalone network-based webcam, explore the capabilities of Linux-based cameras from Axis (at http://www.axis.com/products/video/camera/productguide.htm). The following sections describe some of the more commonly used still camera hardware and software supported by Fedora.

Webcams

Webcams are typically small, low-resolution cameras connected to your computer via a parallel port or USB port. The camera can act in two modes: streaming (for a series of images of a moving object) and grabbing (for a single still image) . The most common uses for webcams include videoconferencing and web voyeurism. The latter is not as lurid as it might sound, although some webcam sites are notorious for their pornographic content. Webcams can be used to send almost-live images to an online correspondent; many people include screen grabs of themselves at their computer workstations just because they can.

Coffee Pot Cam

One of the more interesting uses of a webcam was the legendary "Internet coffee pot" cam (started in 1991, but turned off on August 22, 2001 a day that will live in infamy). A webcam was trained on a coffee maker, and the sysadmin could see whether fresh coffee was available without leaving his cubicle. Some webcams take grabs of intersections in various cities. You will likely find some similar worthwhile use for your webcam.


You can use any of the video applications that can access a video4linux device to view webcam or still camera images in Fedora. You also can use GnomeMeeting (discussed in Chapter 8, "On the Internet: Surfing the Web, Writing Email, and Reading the News") as a viewer for your webcam.

Not all webcams are supported in Linux and the drivers are based on the chipset used, rather than the model or manufacturer. Some of the files in /usr/src/linux-2.6/Documentation/usb contain information about USB webcams and drivers supported by Fedora Core Linux, including:

  • ibmcam.txt

  • ov511.txt

  • phillips.txt

  • se401.txt

  • stv0608.txt

Documentation on parallel port cameras, including the CQ cam (Cqcam.txt) and CPiA camera (README.cpia), is found in /usr/src/linux-2.6/Documentation/video4linux/ if you have installed the kernel documentation on your computer.

TIP

Unfortunately, most of the documentation provided for webcams is abysmal, and it is difficult to associate the webcam you just purchased with a related driver. If you are interested in a particular USB webcam, but are not sure whether it is supported by Linux, browse to http://www.qbik.ch/usb/devices/showdevcat.php?id=9.


Handheld Digital Cameras

Handheld cameras have been a hit with consumers since they were introduced, especially digital cameras. You can capture your photographs to a disk or memory card, view and print photos on your computer screen, and store and edit the images on a CD. Unfortunately, the instant gratification afforded by digital cameras is often overcome with frustration when users try to link those devices to a Linux workstation. Most software provided by digital camera manufacturers is designed for use with Microsoft's operating systems.

Fedora does provide some useful camera applications, but you must use them with a supported device. Most USB cameras, when connected to a computer as SCSI storage devices, are detected during the initial Fedora Core Linux or after reboot. To see whether your camera is detected when connected, look at the output of

 # cat /proc/bus/usb/devices 

or

 # lsusb 

Your camera will likely be detected as /dev/sda1, the first SCSI data device.

Fedora also includes the GNOME gtkam digital camera support client, listed as Digital Camera Tool in the Graphics menu selection. When you first launch gtkam by clicking on the menu icon, you are asked to select the type of camera and connection port it uses. The Select Camera drop-down menu demonstrates that an extensive list of digital cameras is supported.

After saving your configuration, you can download selected images from your camera or download an index of thumbnail views. You can retrieve images in batches from your camera by clicking on individual thumbnail images. The images will then be displayed in individual windows, which you can access in full view by choosing them from gtkam's main window with your mouse.

The GIMP graphics program, included with Fedora Core Linux, also can import images from cameras. You can use The GIMP's extensive options to edit images by adjusting the contrast, brightness, and color. You also can use The GIMP to edit out content and alter images with special effects.

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    Red Hat Fedora 4 Unleashed
    Red Hat Fedora 4 Unleashed
    ISBN: 0672327929
    EAN: 2147483647
    Year: 2006
    Pages: 361

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