It is intended to restore moving-picture data whose pixels have been thinned rapidly with a small-capacity memory and with prevention of image deterioration. There is provided a moving picture converting apparatus for reconstructing an original moving picture from compressed moving-picture data, which includes an input unit to receive compressed moving-picture data including a thinned image consisting of invalid pixels and valid pixels and a forward motion vector incident to the thinned image, an intra-frame interpolator for interpolating the invalid pixels in a present frame to be restored on the basis of the valid pixels of the thinned image in the present frame to produce a padded image, and a frame rendering unit to produce a rendered image by making preceding-frame rendering to restore pixels of the padded image on the basis of valid pixels in a preceding frame and subsequent-frame rendering to restore pixels of the padded image on the basis of valid pixels in a subsequent frame, the frame rendering unit making the preceding-frame rendering to restore a pixel at an end point of tracing in the padded image on the basis of valid pixels detected in the process of tracing, started at a pixel in the preceding frame, in a sequence from the preceding frame to the present frame according to the forward motion vector, and the subsequent-frame rendering to restore a pixel at the start point of the tracing in the padded image on the basis of valid pixels detected in the process of tracing, started at an invalid pixel of the padded image in the present frame, in a sequence from the present frame to the subsequent frame according to the forward motion vector.