ENLARGING/REDUCING METHOD FOR PHOTOGRAPHIC PICTURE

摘要

PURPOSE:To perform a fast picture processing with a comparatively simple circuit constitution and also to reduce the deterioration of picture quality such as the moire, etc., by performing the direct picture enlargement/reduction processing based on the received photographic picture data to obtain the magnification ratio and the number of thinned picture elements. CONSTITUTION:The parameters of both input and output sizes of a photographic picture are inputted to an arithmetic circuit 21 and a ratio N between the output and input sizes is obtained. The clock f1 of a prescribed frequency is outputted by a timing generating circuit 27 and sent to a 1st line emory 24 after undergoing the (f[N]+1) multiple through a frequency multiplying circuit 26. A picture train correcting circuit 22 outputs the thinning rate of the signals stored in the memory 24 and randomizes the timing via a randomizing circuit 23. Then the picture signals are thinned by a gate circuit 28 when they are moved to a 2nd line memory 25 from the memory 24. The picture signals of the memory 25 are outputted at a fixed rate by the read timing f3 produced by the circuit 27.