Interlace is part of television standards since the very start of TV-broadcast. The advent of new display principles that cannot handle interlaced video, the wish to up-scale standard definition video for display on large high-definition screens and the introduction of video in traditionally non-interlaced multimedia PCs ask for advanced de-interlacing techniques.
Various de-interlacing techniques can be categorized into non-motion compensated methods and motion compensated methods. The former includes linear techniques such as spatial filtering, temporal filtering, vertical-temporal filtering and non-linear techniques like motion adaptive filtering, edge-dependent interpolation, implicitly adapting methods and hybrid methods. The latter category includes temporal backward projection, time-recursive de-interlacing, adaptive-recursive de-interlacing, generalized sampling theorem de-interlacing method and hybrid method. An objective comparison based on Mean Square Error (MSE) and Motion Trajectory Inconsistency (MTI) metric has been given on above listed methods. In this paper, we describe a subjective assessment in which a number of de-interlacing techniques will be ranked by a group of viewers (typically twenty persons). The experiment was set-up according to the recommendations of the ITU. Combined with the objective scores presented in the earlier publications, we then have a thorough analysis of each selected de-interlacing algorithms. This improves the relevance and reliability of our knowledge concerning the performance of these de-interlacing algorithms.