The present invention discloses a missing pixels interpolating method and an apparatus using the method. The method forms a second image from a first image by interpolating a plurality of pixels constituting the first image with a plurality of first pseudo-pixels in such a way that they neighbor to the pixels diagonally and with a plurality of second pseudo-pixels in such a way that they neighbor to the pixels vertically and horizontally. The method comprises the first process of computing values of the first pseudo-pixels using a first monotonous increasing non-linear function, and the second process of computing values of the second pseudo-pixels using a second monotonous increasing non-linear function. The primary derived functions of the first and second monotonous increasing non-linear functions are upwards convex, the domains of definition of input values thereof are consistent with the respective ranges of mapping values, and only one input value other than the limits in each domain of definition is equal to its mapping value. The only one input value and the mapping value are the central neighborhood values of the domain of definition and the range, respectively.