Patent ID: 8325820

Claim:
A decoding method for decoding received input image compression information, the method, comprising: generating a context model corresponding to a frame/field flag indicating whether an encoding processing at a macroblock level is field-based or frame-based; generating a context model corresponding to a syntax element for carrying out the frame-based or the field-based encoding of a current macroblock based on motion vector information of macroblocks neighboring the current macroblock, wherein when the current macroblock is subjected to the field-based encoding and a neighboring macroblock is subjected to frame-based encoding, the motion vector information corresponding to the neighboring macroblock is calculated by dividing the vertical component of the motion vector information corresponding to the neighboring macroblock to obtain the equivalent for field-based encoding and is applied to the context model corresponding to the motion vector information of the current macroblock; and decoding the input image compression information using the context model corresponding to the syntax element for carrying out the frame-based or the field-based encoding.