technoguy

Expansion or shrinking of a picture uniformly both horizontally and vertically, possibly cropping the sides and/or top and bottom, or the control on a TV set or projector or DVD player or scaler for performing said function. We refer to the spacing out or scrunching in of scan lines on a CRT as optical zoom. Electronic zoom, on an LCD or other fixed pixel display or keeping the scan lines on a CRT in the same places, requires scaling (upconversion, downconversion).