Abstract: The invention provides a video data interpolation apparatus which can readily produce a number of data sets by interpolation. The apparatus comprises some pairs of buffer memories and an interpolation circuit, the two buffer memories of each pair alternately temporarily storing data sets regarding an image, the data sets being given successively. The currently incoming data is written bit by bit to one buffer memory of first pair and also to one buffer memory of second pair. In step with this writing operation, the immediately previous data set is read from the other memory of the second pair. Then, data sets are interpolated between the data set read from the other memory of the second pair and the currently incoming data set, based on these two data sets. The data sets obtained by interpolation are written to one buffer memory of third pair and also to each one buffer memory of subsequent pair or pairs.