Patent ID: 7962542

Claim:
A non-transitory computer readable medium storing a computer program which when executed by at least one processor of a computing device performs a two-dimensional inverse discrete cosine transform (“IDCT”) to produce image data from a block of dequantized image data arranged in rows and columns, the computer program comprising sets of instructions for: determining a row performance offset from the dequantized image data by identifying a highest column number in the rows of dequantized image data at which a last non-zero element is found and specifying the highest column number as the row performance offset; performing a column-wise IDCT upon the dequantized image data to produce a column-wise IDCT result data; and performing a row-wise IDCT upon the column-wise IDCT result data by performing a set of arithmetic operations for each element on every row up to the highest column number specified by the row performance offset, said set of operations including one or more operations for any zero element.