In an apparatus for processing holographic data reproduced from a holographic medium, a data arranging unit arranges input data in a form of M1×M2 data pixels on a page basis to thereby generate arranged data. Then, a holographic data detector outputs a page image including a detected data image, each data pixel of the arranged data corresponding to P1×P2 image pixels of the detected data image. Thereafter, a resized pixel detector finds a resized vertical length V and a resized horizontal length H of the detected data image. Finally, a sampling unit extracts image pixels at different intervals depending on whether the horizontal length and/or the vertical length of the detected data image is increased or decreased.