Digital video signal transmitting apparatus

Claim 1

A digital video signal transmitting apparatus comprising: picture element data forming means for obtaining picture element data by subjecting an analog video signal to a digital pulse modulation; transmitting picture element data producing means for successively producing for every one field period, picture element data which are located at different picture element positions in a picture for each one field period and amount to 1/4 the number of picture element data amounting to one field, among the picture element data which are successively obtained from said picture element data forming means in each one field period among first, second, third, and fourth field periods; transmitting means for transmitting through a transmission path a digital video signal in which the transmitting picture element data from said transmitting picture element data producing means are time-sequentially multiplexed; a memory circuit into which said digital video signal obtained through said transmission path is written; comparator means supplied with each of the picture element data making up said digital video signal as an input picture element data and supplied with one of said reproduced picture element data located at the same picture element position as said input picture element data, for comparing values of said input picture element data and said one of said reproduced picture element data so as to detect a difference therebetween and for producing a detection signal indicative of said difference; control circuit means for controlling a write-in to said memory circuit responsive to said detection signal from said comparator means, said control circuit means causing write-in of said input picture element data at the same write-in address in said memory circuit as said one of said reproduced picture element data when said detection signal indicates said difference to be essentially zero, and said control circuit means causing write-in of said input picture element data at the same write-in address as said one of said reproduced picture element data and at write-in addresses of the reproduced picture element data which are located in a vicinity of the picture element position of said input picture element data in the picture and amount to a number depending on said difference when said detection signal indicates said difference to be not essentially zero; reproduced picture element data forming means for obtaining reproduced picture element data corresponding to one frame which are to be reproduced, by successively reading out the picture element data which amount to one field and were written into said memory circuit in said first through fourth field periods; and reproduced analog video signal forming means for forming a reproduced analog video signal from the reproduced picture element data obtained from said reproduced picture element data forming means.