| 摘要 |
The invention concerns a method of compressing and transmitting digital data, in particular images, at a constant bit rate, the method comprising the following steps: splitting input data into blocks of data, applying an orthogonal or bi-orthogonal transform ( 12 ) to each block, quantizing ( 14 ) the coefficients obtained by applying the transform, entropically coding ( 20 ) the quantized coefficients, temporarily saving the data resulting from coding in a buffer memory ( 18 ), removing a particular number of bits from the memory for each block of digital data, and adjusting the quantizing step by applying a control function ( 50 ) to obtain, after coding, a number of bits close to the number of bits removed from the memory for each block of data. The control function ( 50 ) takes account of the data bit rate measured for at least the preceding block. |
