Scatter correction in digital radiography using interpolated local sampling of aperture signals

A scatter correction scheme for radiographic images which is based on two-dimensional interpolation of local scatter measurements is described. Local scatter measurements are obtained using an aperture array. The effect of the scheme on physical imaging performance is evaluated by examining the broad-area contrast, edge sharpness, square wave response function and signal-to-noise ratio of images from a digital fluoroscopy system. It is found that the scheme generates substantial improvement in broad-area contrast and densitometric linearity, has no direct effect on sharpness and limiting spatial resolution, and considerably reduces the signal-to-noise ratio. This latter result is the sole deleterious feature of the correction scheme.