METHOD OF AND APPARATUS FOR ENABLING DIFFERENT PARTS OF AN INPUT TELEVISION SIGNAL TO BE MADE AVAILABLE SIMULTANEOUSLY,AND TELEVISION STANDARDS CONVERTER INCORPORATING SAID APPARATUS

摘要

A method of and apparatus for simultaneously enabling different parts of an input television signal to be made available is used as a television standards converter. Successive lines of an input television signal are cyclically written into n (eg 4) sucessive random access store sections, using in each cycle the same addresses for the different sections. The write addresses are incremented for sucessive cycles. The sections are read from using for each section addresses which are related to each other and to the write addresses so as to access a desired set of up to n sucessive lines. These lines are combined by weighted addition to provide an interpolated output line. The read addresses are derived by counting the desired output lines during each field and multiplying the count by the line conversion ratio. The integral part of the resultant controls the read addresses and the non-integral part controls the weighted addition. A total storage of two fields is used, each divided into sections. Standards conversion to either higher or lower lines rates is possible with improved quality.