RP 221:2008 : Specifications for Extraction of 4 × 3 Areas from Digital 16 × 9 Images for Television Systems
The Society of Motion Picture and Television Engineers eBooks · 2008
This practice describes how to extract 4 × 3 aspect ratio images from the center of a 16 × 9 aspect ratio television picture from a digital source. This practice is intended primarily for non-scripted or live television productions where it is impractical to use pan and scan techniques to track the areas of interest in the picture. Protecting the 16 × 9 picture for a 4 × 3 extraction is a prerequisite for parts of the picture where action occurs to be preserved in the 4 × 3 cropped picture.