The image encoding device includes: signal-to-signal predicting means 8 for separating an intra-signal prediction residual signal obtained by performing difference processing between an input image signal and an intra-signal prediction signal into a reference signal and a signal to be predicted and calculating signal-to-signal prediction information used for performing signal-to-signal prediction on each pixel of the signal to be predicted corresponding to each pixel of the reference signal; and signal-to-signal compensating means 9 for obtaining a signal-to-signal prediction signal of the region to be encoded from a decoded intra-signal prediction residual signal and the signal-to-signal prediction information from the signal-to-signal predicting means, wherein each pixel of the signal to be predicted is encoded by performing orthogonal conversion, quantization, and encoding on the signal-to-signal prediction residual signal obtained by performing the difference processing between the intra-signal prediction residual signal and the signal-to-signal prediction signal.