1. A moving picture converting apparatus for restoring a string of thinned images resulted from thinning pixels of a string of original images, comprising: an input unit to receive the string of thinned images; an initial motion vector detector to detect a new string of motion vector images on the basis of the string of thinned images; a reconstructing unit to reconstruct, each time the new string of motion vector images is detected, a string of restored images on the basis of a previous string of restored images and a previous string of motion vector images; a motion vector detector to detect, each time the string of restored images is reconstructed, the new string of motion vector images based on the string of restored images and the previous string of motion vector images; and a process terminating unit to terminate a reconstructing process by the reconstructing unit and a motion vector detecting process by the motion vector detector and output a restored image, which has been restored, of the string of restored images obtained at the time of terminating the reconstruction process.