VIDEO REDUCING/ENLARGING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide video matched to the aspect ratio of the screen of a display device by reducing/enlarging entire video into any arbitrary size. SOLUTION: A video signal is written in a memory 103 by a write clock from an input terminal 118. A clock generating circuit 119 supplies a read clock having about 4/3-fold frequency of the write clock to the memory 103. A vertical enlargement control circuit 110 reads the video signal out of the memory 103 in a line cycle corresponding to an enlargement scale. In the similar cycle, the write of a one-line memory 105 is stopped and the line delay output of the output signal of the memory 103 is provided. According to a control signal from the vertical enlargement control circuit 110, a vertical interpolating circuit 106 prepares a scan line signal through interpolating operation. A horizontal direction is similarly controlled by a horizontal enlargement control circuit 113.