Image encoding/image decoding method and image encoding/image decoding apparatus

An image decoding apparatus comprising:

• a decoder to decode an input image signal to generate a decoded image signal including prediction mode information;
• a generator to generate a predictive image signal by changing the number of reference pixels for use in prediction and a procedure for prediction pixel generation according to a selected prediction mode based on the prediction mode information of the decoded image signal and a distance between an encoded reference pixel and a prediction pixel, and performing intra prediction for extrapolating or interpolating the decoded image signal in units of pixel;
• a generator to generate a prediction error signal based on the decoded image signal;
• and
• a generator generating a reconstructed image by adding the predictive image signal and the prediction error signal.

A computer-readable medium storing a program for decoding an encoded image, the program comprising:

• means for instructing a computer to decode an input image signal to generate a decoded image signal including prediction mode information;
• means for instructing the computer to change the number of reference pixels for use in prediction and a procedure for prediction pixel generation according to a selected prediction mode based on the prediction mode information of the decoded image signal and a distance between an reference pixel and a prediction pixel;
• means for instructing the computer to generate a predictive image signal by intra-picture prediction for extrapolating or interpolating the decoded image signal in units of pixel;
• means for instructing the computer to generate a prediction error signal based on the decoded image signal;
• and
• means for instructing the computer to generate a reconstructed image by adding the predictive image signal and the prediction error signal.