Patent Document ID: 20100080479
Application ID: 12568099
Patent Flag: 0

Claim One:
1. An image data compression apparatus compressing image data by one-dimensional subband coding, the image data compression apparatus comprising: a filter coefficient calculation unit configured to perform a filter process to separate a predetermined plurality of pixels extracted in accordance with the one-dimensional subband coding into a low-frequency component and a high-frequency component, and to calculate coefficient values of respective filter coefficients of the separated low-frequency component and the high-frequency component; a plurality of prediction units configured to perform different predictions respectively for the coefficient values of the respective filter coefficients calculated by the filter coefficient calculation unit; a predicted coefficient value calculation unit configured to calculate predicted coefficient values to be used for posterior predictions by calculating each of the predicted coefficient values from at least one of predicted values having been predicted by a corresponding one of the plurality of prediction units and from corresponding at least one of the coefficient values of the respective filter coefficients that the filter coefficient calculation unit has calculated; a memory unit configured to hold the predicted coefficient values calculated by the predicted coefficient value calculation unit; and a compression coding unit configured to calculate a difference between each of the predicted values having been predicted by each of the plurality of prediction units and corresponding each of the coefficient values of the respective filter coefficients that the filter coefficient calculation unit has calculated, and to perform coding after quantizing the difference, or to perform coding on the basis of the difference.