Patent ID: 8315304

Claim:
A method, in a computing device comprising a processor having computing device-executable instructions, of encoding transform coefficients, the method comprising: reading, by the processor, transform coefficients in a current block according to a predetermined scan order, determining whether a first transform coefficient having an absolute value greater than a predetermined threshold value N exists in the transform coefficients in the current block, and generating first flag information indicating whether the first transform coefficient exists; encoding information of the first transform coefficient; encoding information of a second transform coefficient that indicates remaining transform coefficients existing in the current block, except for the first transform coefficient; and adding the first flag information, the encoded information of the first transform coefficient, and the encoded information of the second transform coefficient to a bitstream, wherein the predetermined threshold value N is a positive number greater than 2, and wherein the encoding of the information of the first transform coefficient comprises: generating a first significant map indicating a position of the first transform coefficient if the first transform coefficient exists; generating a second flag indicating whether the first transform coefficient is a last of the first transform coefficients existing in the current block according to the predetermined scan order; and encoding magnitude information of the first transform coefficient, and wherein the encoding of the information of the second transform coefficient comprises: generating a second significant map indicating a position of a non-zero significant coefficient from among remaining transform coefficients; and generating a third flag indicating whether the second transform coefficient corresponding to the non-zero significant coefficient is a last of the second transform coefficient.