Digital Frame Memory for Still Picture Television Receivers — PASS Encoding System and Application

A new form of television broadcasting is proposed. It consists of the transmission of a series of color still pictures accompanied by their individual sound complements. To this effect, the still picture receiver must incorporate a frame memory for the storage and repeated readout of a given program picture until a new picture signal is received. Single-chip 64K-bit CCD memories are now commercially available (among other memory devices) and may provide for a quite economical frame memory of small size, well suited for the purpose. Phase Alternating Sub-Nyquist Sampling (PASS) is used for the digital recording of NTSC video signals. This reduces the bit rate and the amount of memory required. The principles of PASS encoding are explained. Three types of interpolation filters, needed for the suppression of aliasing, have been investigated. A two-dimensional analysis of PASS encoding is discussed in the paper. Three PASS encoding methods are described in detail: (1) field alternation; (2) one-line alternation; and (3) two-line alternation. An outline of the practical design of an experimental digital frame memory for a still picture television receiver is given. With this design, actual picture signals appeared good. Vectorscope color bar displays before and after processing by the frame memory showed good coincidence.

Print ISSN

0036-1682

Published

1980-04

Content type

Original Research

DOI

10.5594/J00506