Deinterlacing
1. Deinterlacing is the process of converting interlaced video, such as common analog television signals or 1080i format HDTV signals, into a non-interlaced form.
Interlaced video frame consists of two sub-fields taken in sequence, each sequentially scanned at odd then even lines of the image sensor; analog television employed this technique because it allowed for less transmission bandwidth and further eliminated the perceived flicker that a similar frame rate would give using progressive scan.
Source: Wikipedia