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Unregistered
July 25, 2003, 18:57:20
Hi.

The question I want to ask is, what is the difference between cameras that use frame grabbers (be it PCI or ISA grabbers), USB and Firewire?
How do USB and Firewire cameras work if they don't have a frame grabber?
Does windows software handles the frame grabbers task?
DOes the software IC Imaging Control handles the task for these types of cameras.?

Johannes Vogel
July 28, 2003, 12:57:13
Hello,

USB and FireWire cameras do not need a frame grabber because they have a built-in interface for a serial bus: the FireWire resp. USB bus. On all modern PC system there is a USB interface. FireWire interfaces are part of a growing number of systems. If a PC is not equipped with a FireWire controller, add-on hardware is availabel for a low price. The hardware is one side, software and drivers the other.
First of all, FireWire and USB are buses (like the PCI bus on a PC mainboard). The driver for the bus hardware is part of the operating system. Therefore, you do not have to install a driver if you add a FireWire controller to your system.
For every camera on the bus, you need a device driver. These drivers are provided by the camera manufacturer. The good news is, that these drivers can be accessed in a way that is defined by the operating system (DirectShow).
Drivers for frame grabbers are proprietary and therefore the way of accessing a frame grabber driver is proprietary. This means, a program that was written for frame grabber x will not work with frame grabber y. On the other hand, a program that was written for a camera x that provides a DirectShow compliant driver (FireWire, USB) is potentially able to work with camera y, as long as camera y provides a DirectShow compliant driver. The drawback is the complexity of the programming interface of DirectShow. IC Imagaging Control encapsulates DirectShow by hiding the complexity and maintaining the flexibility and hardware independency. In other words, IC Imaging Control makes DirectShow easy to use from a programmers point of view.

More inforamtion about hardware independent image aquisition can be found here:
http://www.1394imaging.com/resources/articles/hw_indep_image_acq/
http://www.1394imaging.com/resources/articles/fw_mothan_digvidlnk/


Best regards
Johannes
IC Support