Spatial Warping Experiments With A Precision CRT Display
Donald C. Wells, Leo Paffrath, H. Mery, John Cover · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1977
We have recently assembled a precision CRT display system which uses 16-bit digital-to-analog converters to control its x and y deflections. We have used this hardware to perform spatial warping experiments with digital images in which the desired locations of the pixels are computed according to the warp functions. For moderately distorted images, the cosmetic defects in imagery produced by this process may be acceptable in some of our applications. We show that the polynomials describing the warping functions can be efficiently evaluated by finite difference tables. We discuss the design of microprogrammed controllers, which can calculate the warped coordinates at the same rate that the CRT beam exposes the film by using difference tables.