PICTURE DATA DECODING DEVICE

摘要

PURPOSE:To display lots of reduced patterns in less arithmetic quantity and time by extracting only a DC component of a data and multiplying a prescribed value from a ROM coefficient with an extracted data and interpolating the data. CONSTITUTION:A data is divided into a quantization matrix and a picture data by a division circuit 2 and the picture data subjected to fixed length processing is subjected to inverse quantization by an inverse quantizing device 4 by using a DC component 20 of a quantization matrix in a sent data. Then the data of the DC component subjected to inverse quantization is inversely converted. An address data is converted by using a coefficient ROM 5 and the converted data is interpolated according to the reduction rate of the displayed pattern and a required magnification depending on a picture element number M of one side of a data block subjected to orthogonal conversion. Thus, since only the data DC component is decoded, lots of reduced patterns are displayed in less calculation quantity and time.