The invention discloses intra frame image prediction coding and decoding methods, a video coder and a video decoder, wherein the intra frame image prediction coding method comprises the following steps: selecting part of pixels in a current prediction unit for predicting so as to obtain the predicted pixels of the selected pixels; acquiring the residual signals of the predicted pixels; sequentially performing transformation, quantization, entropy coding, inverse quantization and inverse transformation to the residual signals; reconstructing the processed signals to obtain the reconstructed pixels; and taking the reconstructed pixels as reference pixels of the current prediction unit and performing intra frame image prediction coding. Through the adoption of the intra frame image prediction coding and decoding methods, the video coder and the video decoder, the accuracy of the prediction for an intra frame image is improved, so that the efficiency of the coding and decoding for the intra frame image is improved; and since the intra frame image prediction coding and decoding methods, the video coder and the video decoder do not break the structure of a convention video prediction coding and decoding unit, the intra frame image prediction coding and decoding methods, the video coder and the video decoder are in favor of hardware implementation. The intra frame image prediction coding and decoding methods, the video coder and the video decoder can be applied in the prediction mode of a conventional intra frame image and improves the accuracy of the prediction for the conventional intra frame image, and can also be applied in the prediction of a boundary image prediction unit when the intra frame image is coded.