Fixed-point IDCT without multiplications based on B.G. Lee's algorithm

An improved approach to compute the inverse discrete cosine transform (IDCT) for image and video coding applications for mobile devices is proposed based on B.G. Lee algorithm. We replace the multiplication operators in original B.G. Lee's algorithm with addition and shift operators to realize the fix-point computation. Due to the absence of the multiplication operators, this modified algorithm takes less time to complete the computation than the traditional B.G. Lee's.