| 摘要 |
<p>The invention relates to an adaptive method for coding and decoding a series of images by transformation, the coding comprising: dividing each image into image element frames, each frame being represented by a frame of luminance values, a frame of blue color difference values, and a frame of red color difference values; applying a bi-dimensional cosine transformation to each frame of values in order to obtain a frame of transformation coefficients; transmitting for each frame of values, either the value of the coefficients of transformation of the frame, or the value difference of these transformation coefficients, with respect to the value of the transformation coefficients of the homologous frame in the preceding image; multiplying the transformation coefficients and the differences of transformation coefficients, before the transmission, by a weighting coefficient favouring the low spatial frequencies and by a quantification coefficient, theses two coefficients being variable as a function of the filling of the buffer memory wherein are simultaneously stored coded data corresponding to the luminance values, to the blue color difference values and to the red color difference values. Application to the reduction of flow rate for the transmission of a series of television images.</p> |
