Patent ID: 8861879

Claim:
An image encoding method comprising: if a current block of an image is an initial block of a current slice of the image, determining whether a virtual block, in which pixel values are equal to a predetermined value, is identical to the current block; and encoding the current block in a first mode from among a plurality of modes, based on a result of the determining, wherein the first mode is a skip mode for encoding information representing that the current block is encoded in the skip mode instead of encoding pixel values of the current block, when the current block is identical to the virtual block, wherein the plurality of modes comprises: the first mode; a second mode for encoding the current block based on discrete cosine transformation (DCT); and a third mode for encoding the current block based on a plurality of bit planes of pixel values, wherein the encoding the current block in the first mode based on the determining comprises encoding the current block in the second mode or the third mode if the current block is not the initial block of the current slice or if the virtual block is not identical to the current block according to the determining, wherein each of the current block and the virtual block is an N×N block, and N is greater than or equal to two, and wherein each of the current block and the virtual block is smaller than the image.