A Pattern-based Assembled DCT (PADCT) scheme is proposed as a general framework to fully utilize texture structure
property in images in a more feasible and flexible manner. Different patterns can be designed or extracted according to
texture structures such as directionality and distribution patterns. Pixels in the block are divided into sub-partitions,
followed by assembling pixels in each sub-partitions together into a compact and efficient form for the succeeding
separated one dimensional transform operations, suitable DC prediction and entropy coding schemes are also introduced.
PADCT has the advantages of advanced compact energy concentration, efficient usage of memory, fewer categories of
one dimensional transform, and adaptability for hardware optimization. Experimental results show that the bitrate
reduction over the 2-D DCT is up to 35%. It also outperforms significantly than previous typical directional transform
schemes in comparison with PSNR or subjective quality.