| 摘要 |
The bandwidth reduction of a video signal is attained by processing with a two-component model, the first being a very economical but recognizable cartoon or line drawing which is derived from the grey-level image by valley detection 210. The second component is generated by using the cartoon as a sampling template to sample the grey-level image, so that samples, for example two, of the original image are taken at the cartoon lines. A (or several) further sample is taken mid-way between the valleys and the original image is reconstructed using two dimensional second order (quadratic) interpolation between the sampled points. To generate the most suitable line drawing the grey level image is thresholded, the discontinuous lines generated by valley detection are filled in, i.e. made continuous and this image is subjected to boundary extraction, 230 which produces a continuous line drawing with lines of one pel width. Streaks produced in the final, interpolated image may be removed by allowing distinction between valleys and edges and then applying conditional adaptive filtering to the interpolated image. <IMAGE> |
