Inside-frame prediction, decoding and coding method and device

The embodiment of the invention discloses an infraframe predicting method, comprising the step that a coding terminal determines the predictive value of a pixel to be predicted in current coding block according to the predictive values of the predicted pixels in current coding block. The embodiment of the invention also discloses an infraframe predictive coding method, in an expanded prediction mode, and the coding terminal determines the predictive value of a pixel to be predicted in current coding block according to the predictive values of the predicted pixels. Furthermore, the embodiment of the invention discloses an infraframe predictive decoding method, in an expanded prediction mode, a decoding terminal determines the predictive value of a pixel to be predicted in current decoding block according to the predictive values of the predicted pixels in current decoding block, and decodes current coding block. In addition, the embodiment of the invention discloses the coding terminal and the decoding terminal. By using the methods and devices provided by the embodiment of the invention, the rate-distortion performance of infraframe predictive coding can be improved.