The film and broadcast industry have been massively using the Chroma Key technique, also known as Blue Screen Matting. This technique deeply transformed the entertainment industry, allowing impossible scenes become reality. The evolution of this technique allowed that complex productions could have better control and lower costs. However, this technique needs a sequence of preparation stages, which require high budgets and precise planning. Furthermore, continuity errors usually cause serious post-production problems. Currently, the entertainment industry is searching for other matting techniques that work on any kind of background. The use of these techniques is still restricted to academic works and softwares of still image manipulation. The present work has the goal of making an analysis of the current chroma key processes and aims to propose a matting technique over any type of background in High Definition images. Two methods of calculating alpha values are presented: a local method based on clusters and a local one based on electric potential.