1. A moving image coding device that permits generation of an intra prediction value that is based on an intra prediction direction, comprising: a prediction error statistic evaluation unit configured to express, as a parameter, a statistic of a prediction error that is based on the intra prediction direction, and approximate the parameter of the statistic in accordance with a distance from a reference pixel located along the intra prediction direction to a pixel to be processed; a prediction value feature amount calculation unit configured to calculate, for a pixel near the pixel to be processed, a feature amount of a prediction value that is based on the intra prediction direction; and a prediction value calculation unit configured to estimate a prediction error corresponding to the distance from the reference pixel located along the intra prediction direction to the pixel to be processed using the parameter of the statistic approximated by the prediction error statistic evaluation unit, reflect the prediction error in the prediction value that is based on the intra prediction direction using the feature amount calculated by the prediction value feature amount calculation unit, and generate a new prediction value.