A decoder decodes encoded binary image data on each block in order to recover a target block of the binary image. The image decoder includes motion compensated blocking which obtains a reference block from a reference binary image by applying motion compensation using motion information. A selector selects a statistical model from among a plurality of statistical models, based on states of pixels surrounding a reference pixel in the reference block, in which the reference pixel also corresponds to a target pixel in the target block. An arithmetic decoder recovers the target block by decoding the encoded data using the selected statistical model. In one embodiment, the pixels surrounding the reference pixel in the reference block are pixels positioned within one pixel distance from the reference pixel.