Analysis of Integer Transform In MPEG-4 Video Standard

In this paper, Integer cosine transform (ICT) is introduced in MPEG-4 instead of Discrete cosine transform (DCT. Integer cosine transform (ICT) is adopted by H.264/AVC for its bit-exact implementation and significant complexity reduction. As adoption of the newly standardized H.264 becomes increasingly more widespread, efforts must be made to transcode video from earlier standards, such as MPEG-4, to the H.264 format. The block sizes of most appropriate are 8 or 16 for the transform coding of the image data. Therefore, implementation of the order 8 and 16 DCTs has fast computing time and costeffectiveness for realization of a transform coding. However, the components of the basis vectors of the DCT exist irrational numbers then cannot be reduced to integers by simple scaling. Therefore, it is hard to implement and using floating point arithmetic is complex and expensive, so integer cosine transforms (ICTs) are proposed to implement the DCT by using simple integer arithmetic. By investigating the structure of the transform kernels, two efficient schemes are introduced to convert an 8 x 8 DCT block into its corresponding four 4 x 4 integer cosine transform blocks. This technique can be used to improve the result of MPEG-4 video compression standard.