Fluoroscopic performance tests with a portable computer/frame grabber

This paper measures Wiener spectra of TV-viewed fluoroscopic systems using a portable computer/frame grabber, as part of the development of routine quantitative fluoroscopic imaging tests. A portable computer/frame grabber was used to capture a fluoroscopic image from the TV signal. To avoid digitization noise using an 8-bit digitizer, a low-noise video amplifier was used to spread image noise offer more quantization levels. One-dimensional Wiener spectra were calculated from captured images using synthesized slits both parallel and perpendicular to the TV raster lines. To eliminate structure noise, Wiener spectra were calculated from images formed by subtracting frames