摘要 |
In an image transmitting system such that an image frame is divided into plural blocks and video signals are transformed block by block in accordance with an orthogonal transform method before coding and transmission of the transform coefficients, transform coefficients are coded, only when differences in transform coefficient between the preceding frame and the current frame are significant, to reduce the coding speed and therefore the video signal transmission speed. In addition, transform coefficients are weighted under consideration of human visual characteristics (the weighting is increased with decreasing order of transform coefficient). Further, when only differences in transform coefficient are coded and transmitted, it is possible to further reduce the transmission speed.
|