Friday, January 23, 2015

Brief Introduction of Deinterlacing

Deinterlacing refers to the technique of converting interlaced video. For example, when you are converting the common analog television signals or 1080i format signal into a non-interlaced form, you are performing the process of deinterlacing by your own. Generally speaking, interlaced video can be directly displayed on ALiS plasma panels and the old CRTs. However, modern computer video displays and TV sets are mostly based on LCD technology, the majority of which adopt progressive scanning. Therefore, interlaced video can not be directly displayed on such modern computer video displays and TV sets. Under this circumstance, the technique of deinterlacing is of great necessity and value in our daily life. The process of deinterlacing plays a vital role for people to display interlaced video on a progressive scan display.

As a matter of fact, interlaced video is made up of two sub-fields which are taken in sequence. Generally speaking, each of the two sub-fields is sequentially scanned at odd and even lines of the image sensor separately. This technique is adopted by the analog television because less transmission bandwidth is allowed for and the perceived flicker can be eliminated to a greater degree. Displays based on CRT were able to correctly display interlaced video because of its complete analog nature. On the other hand, all of the modern displays are designed to be digital in nature because the display consists of discrete pixels. As a result, the two fields need to be combined into a single frame, which will lead to a variety of visual defects. The technique of deinterlacing should try to avoid such conditions as much as possible.

People have been dedicated to improving the technique of deinterlacing for decades. What’s more, complex processing algorithms have been adopted as well. Unfortunately, it is rather difficult to achieve consistent results. However, we should have confidence in technologists and the more and more developed science and technology. The technique of deinterlacing will be improved step by step.