Improved-definition television (IDTV) or enhanced-quality television transmitters and receivers exceed the performance requirements of the NTSC standard, while remaining within the general parameters of NTSC emissions standards.

IDTV improvements may be made at the television

Television

Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...

 transmitter or receiver. Improvements include enhancements in encoding, digital

Digital

A digital system is a data technology that uses discrete values. By contrast, non-digital systems use a continuous range of values to represent information...

 filtering, scan

Scan

Scan may refer to:Acronyms:*Schedules for Clinical Assessment in Neuropsychiatry , a psychiatric diagnostic tool developed by WHO*Shared Check Authorization Network , a database of bad check writers and collection agency for bad checks...

 interpolation, interlaced line scanning, and ghost cancellation.

IDTV improvements must allow the TV signal to be transmitted and received in the standard 4:3 aspect ratio

Aspect ratio (image)

The aspect ratio of an image is the ratio of the width of the image to its height, expressed as two numbers separated by a colon. That is, for an x:y aspect ratio, no matter how big or small the image is, if the width is divided into x units of equal length and the height is measured using this...

.