Signal transformation system and method for providing picture-in-picture in high definition television receivers

摘要

The present invention relates to a novel method and system for providing high definition television receivers with a picture-in-picture (PIP) feature through the use of a reduced number of transform coefficients. The system comprises first decoding unit for decoding a main picture signal, second decoding unit for decoding a picture-in-picture signal by using a reduced number of transform coefficients including a d.c. coefficient, and position control means for providing a composite image composed of the main picture and the picture-in-picture on the screen. Interpolation of pixel data is performed by applying appropriate weight factors on neighboring pixel data based on the spatial relationship between the pixels and the heads generated by reduced motion vectors.