The present invention relates to an encoding apparatus, an encoding method, an encoding program, a decoding apparatus, a decoding method and a decoding program for adaptively controlling an encoding bit rate. Coefficient data obtained using wavelet transform is quantized, and segmented into bit planes. The coefficient data is entropy encoded from the bit plane of the MSB in a direction from an upper bit position to a lower bit position. Entropy encoding is stopped at a bit position where an amount of code has reached a target amount. On the bit plane, the coefficient data is entropy encoded from a lower frequency region to a higher frequency region. Data greatly affecting subjective image quality of a decoded image is selectively output while the amount of code is easily controlled.