Television standards converters

Claim 1

A television standards converter comprising: an input store for receiving an input digital television signal of one standard and deriving therefrom arrays of sixteen lines, each array consisting of four successive lines from each of four successive fields of said input television signal; a weighting coefficient store for storing sets of sixteen weighting coefficients, respective said sets corresponding to positions both spatial and temporal of respective lines of an output digital television signal relative to said sixteen lines of said input television signal; two interpolation filters each for deriving line-by-line said output television signal by multiplying corresponding sample values from each of said sixteen lines of said input television signal by a respective weighting coefficient in a said set of weighting coefficients and summing the resulting products to form an interpolated sample value; an output store for receiving and storing said derived lines of said output television signal and from which said output television signal is read; and a multi-line store connected between the output of one of said interpolation filters and said output store and used to store the additional lines derived when said output television signal has more lines per field than said input television signal.