Firewire Untethered: High-Quality Images for Notebook Computers

摘要

Until recently, no solution existed for acquiring high-quality color images in real-time with a regular notebook computer, even though a high-quality color image acquisition system for notebook computers would open the doors for a wide array of portable applications. In particular, such a combination would be ideal for mobile robots that use high-resolution color vision, which is part of our area of research. While a large selection of frame grabbers is available for PCI desktop systems, only a few have been available for PCMCIA notebook systems. Unfortunately, most PCMCIA frame grabbers accept video only in the NTSC format, which allocates much more bandwidth to luminance than color. Consequently, the NTSC signal is adequate for gray-scale image processing, but its color content is too noisy for any reasonable color image processing. In particular, the NTSC encoding allocates very little bandwidth to the blue channel, which is more delicate than the red and green channels to begin with. The source of the problem is that most CCD sensors are least sensitive in the blue spectrum. This problem is further exacerbated indoors, where the illumination is often yellow and contains little power in the blue spectrum. As a consequence, the already noisy blue signal from the CCD sensor is further weakened by NTSC, resulting in a very poor signal-to-noise ratio.