We have revealed that there exists an upper bound of the sampling interval of the scanning parameter in the Hough Transform by the analysis of the general lines which have 2-dimensional parameters. We have also derived and proposed the method for finding the upper bound.
We have derived the upper bounds of the sampling intervals for two famous parameterizations (a-b and -) which are often used for line detection. The sampling interval for a-b parameterization agrees with the one proposed by Svalbe. The condition for the sampling interval in - parameterization also agrees with the condition which Van Veen et al. showed. We have made it clear that these conditions proposed previously also guarantee the precision of the Hough Transform.