To provide a predictive coding apparatus, a predictive coding method, and a storage medium thereof, which are highly efficient for multi-level image data.
Predictive coding to predict coding pixels by using neighboring pixels comprises prediction converting means for performing prediction by using the pixel value and the weighting factor of neighboring pixels, a weighting factor updating means for updating the weighting factor by the size relation between a pixel value and a predicted value, and a scan converting means for converting the scan sequence of image data. Since the prediction by the prediction converting means and the weighting factor by the weighting factor updating means are performed in the scan sequence converted by the scan converting means, a weighting factor used in prediction can be updated not into raster scan sequence but into data sequence in which two-dimensional correlation of an image is strong. Thus, prediction suitable for an image can be performed appropriately, and a highly efficient predictive coding apparatus is obtained.
KAMATA SEIICHIRO
Tomoyasu Sakaguchi
Hiroki Naito