Analysis of subpixel target location accuracy using Fourier-transform-based models

The simulation of the performance of subpixel algorithms under known conditions is a valuable tool. For instance, the optimum size for a target can be determined as well as the influence of varying the threshold level or target size. Previous work looked at the effects of quantization and additive noise on the location of target images. More recently, work by Shortis et al, 1994 has tested more algorithms and looked at other effects such as those caused by saturation and DC offset. In this paper the electronic noise present in imagery from typical CCD cameras is both measured and used within a simulation of the subpixel location performance of the centroid and squared centroid method. The effect on target lcoation of uneven background characteristics are also analyzed. To achieve this the physical characteristics are modeled by using the Fourier transform of both background and target models and combining them in the frequency domain. By performing the inverse Fourier transform the resulting target image is used to locate the target. The simulation methodology will be explained and tests performed so that a better understanding of the factors that contribute to subpixel errors can be gained.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.