Abstract
In recent years, there has been a growing demand for optimal X-ray photography of elderly persons without producing physical pain or mental stress. The author therefore presents a new technique for creating pseudo image contrast by computer to prevent repeated taking of X-ray photographs, and an experimental formula to estimate photographic density by fluorescence intensity and the real-time wave form of X-ray tube voltage. It was found that the pseudo image contrast of an acrylic phantom estimated by this technique matched well with the photographic density of the actual X-ray photograph.