Deinterlacing refers to the technique which demands the display to buffer one or more fields and recombine them into full frames. Theoretically, this technique sound as simple as capturing one field and combining it with the next field to be received and then producing a single frame. However, deinterlacing is far more form simple in actual application. Generally speaking, the originally recorded signal was produced as a series of fields. What’s more, any motion of the objects during the short period between the fields will be encoded into the display. As a result, even the slightest differences between the two field due to the motion of the objects may lead to a “combing” effect in the combination process of a single frame. Therefore, deinterlacing is a very demanding technique requiring people to be careful and patient.
Actually, there are a variety of methods for people to choose from in terms of deinterlacing video. In addition, each method will cause different problems or artifacts of its own. On the other hand, some methods are much cleaner in artifacts than other methods.
Most deinterlacing techniques can be divided into three different groups which use their own exact techniques. The first group is called field combination deinterlacers. The name comes from the fact that they are able to take the even and odd fields and combine them into frame displayed later. The second group is called field extension deinterlacers for each field is extended to the entire screen in order to make a frame. The third group is called motion compensation which uses a combination of both.
Modern deinterlacing systems are able to buffer several fields and use techniques like edge detection in order to locate the motion between the fields. Therefore, this is adopted by people to interpolate the missing lines from the original field and reducing the combining effect.