| 摘要 |
There is provided a method and apparatus for scene change detection for use with bit-rate control of a video compression system. The method and apparatus may be used for scene change detection in intra-coded and/or inter-coded pictures. The method comprises the steps of: compressing each picture in a video signal in turn; determining complexity data from the compressed signal for each picture after partial compression of the picture; determining from the complexity data whether a scene change may have taken place; and adjusting the compression step and allocated compressed bit number for pictures after a scene change detection in dependence on the result of the determination. For an intra-coded picture, the complexity data is a monotonically increasing function of a quantisation parameter and a compressed bit number used in the compression step for the partial compression from which the complexity data is determined. For an inter-coded picture, the complexity data is determined from a combination of a) the change of temporal prediction difference in relation to the average prediction difference of previous inter-coded pictures, b) the intra-coded macroblock number in the current inter-coded picture in relation to the average intra-coded macroblock number in previous inter-coded pictures, and c) the intra-coded macroblock number in the current inter-coded picture in relation to the total encoded macroblock number in the current inter-coded picture. |
