Q+A CENTER

Frame grabbers are generally the proper choice for high-end applications that require significant image processing, says Euresys' Damhaut. The emergence of very-high-resolution cameras is driving the demand for high-bandwidth image transfer and processing, particularly in line-scan applications.

"This demand can only be satisfied by frame grabber-based systems, even frame grabber cards providing on-board processing.," he says. "Also, for applications requiring several cameras, possibly with different characteristics, the combination of one or several frame grabbers in a computer is the solution offering the highest degree of flexibility at the lowest price. Finally, the use of a standard computer platform for image processing provides complete freedom regarding the choice of image-processing software tools."

And, finally, there's cost. "We make several camera and frame grabber combinations that sell for a list price of $1,100 and, in volume, for half that," says Epix's Peterson. "The smart camera has a higher fixed cost due to packing the required processor, memory and support hardware in a small package. Something has to give. The processing capability has to be balanced with the power consumption and dissipation of the package. This balancing act does not have to be performed with a frame grabber in a desktop system."

The main factor, agrees Damhaut, is the performance/price ratio—with a caveat. "Depending on the application, the performance/price ratio may not be the most important criteria. One example: If the task is to read a data matrix code on a package somewhere on a production line, a smart camera will surely be the easiest way to go. It offers a fast and easy-to-integrate solution. However, if the job is to read the same code, but you are designing a manufacturing or inspection machine that will be produced and sold in quantity, you will find that the most cost-effective solution is to use a camera with a frame grabber plugged into the control PC of the machine."

Matrox's Crawford sees cameras with higher data rates, 3D and multi-spectral images becoming more common and pushing buses and processors further along. Frame grabbers, he says, will remain the primary tool for handling the ever-increasing data rates and processing requirements.