| 摘要 |
Methods and Apparatus for coding and decoding digital monochrome or colour television signals are described. Apparatus for coding comprises means (18, 19, 20, 22 and 25) for predicting the values of digital signals representing the luminance (and for colour, chrominance components) of picture elements from the previous element or the corresponding element in the previous frame according to whether motion is detected or not by a motion detector (24 and 45). Coding is carried out by a subtraction circuit (12) which subtracts the prediction from the actual value to provide an error signal and quantizer means (13 to 16) which quantizes the error signal preferably using a different quantizer for each form of prediction. Decoding apparatus comprises prediction means providing prediction signals dependent on the previous element, or the corresponding element in the previous frame and an addition circuit for adding the output of the prediction means to the encoded signal. <IMAGE> |
