Integer time-domain pre- and post-filters for low-complexity extension of JPEG standard

Time-domain lapped transform (TDLT) is a family of lapped transforms (LTs) which reduce blocking artifacts occurred by the DCT algorithm. Also, we can directly apply it to the existing JPEG framework because it is constructed by the DCT with time-domain pre- and post-filters. It obviously has higher complexity than an ordinary DCT. We present an integer approximated TDLT (IntTDLT) which can be easily implemented with only adders/shifters, i.e., no floating-point multipliers, and fewer step processing, while preserving the characteristics such as allowing the use of symmetric extension and structural one degree of regularity (1-regularity). As a result, it performs good coding, especially at a low bitrate, in spite of the low-complexity.