An apparatus and method for spatially predicting image data, an apparatus and method for encoding image data, an apparatus and method for compensating for spatial prediction of image data, and an apparatus and method for decoding image data. The spatial prediction apparatus of image data includes: a spatial prediction unit performing a spatial prediction of pixel values of a current block using pixel values of blocks adjacent to an upper row of the current block. A pipeline process is possible when the spatial prediction is performed, thereby performing real time encoding and decoding.