Lossless Image and Intra-Frame Compression With Integer-to-Integer DST

Abstract

Video coding standards are primarily designed for efficient lossy compression, but it is also desirable to support efficient lossless compression within video coding standards using small modifications to the lossy coding architecture. A simple approach is to skip transform and quantization, and simply entropy code the prediction residual. However, this approach is inefficient at compression. A more efficient and popular approach is to skip transform and quantization but also process the residual block with DPCM, along the horizontal or vertical direction, prior to entropy coding. This paper explores an alternative approach based on processing the residual block with integer-tointeger (i2i) transforms. I2i transforms can map integer pixels to integer transform coefficients without increasing the dynamic range and can be used for lossless compression. We focus on lossless intra coding and develop novel i2i approximations of the odd type-3 DST (ODST-3). Experimental results with the HEVC reference software show that the developed i2i approximations of the ODST-3 improve lossless intra-frame compression efficiency with respect to HEVC version 2, which uses the popular DPCM method, by an average 2.7% without a significant effect on computational complexity.

An Overview of Systolic Arrays for Forward and Inverse Discrete Sine Transforms and Their Exploitation in View of an Improved Approach

“…The DCT is also used in wireless communications [7][8][9], digital watermarking [10,11], and analysis of hyperspectral data [12,13]. The DST has additional important applications such as Lossless Image and Intra-Frame Compression [14], image interpolation [15], video steganography [16], and graph filtering [17]. There are some other applications as in [18][19][20], where both the DCT and DST are necessary.…”

Reversible Integer-to-Integer Wavelet Filter Design for Lossless Image Compression

“…Lossless compression is also very often used in routine applications. Therefore, lossless compression has always been an important and hot research topic [1]- [6], even if it is not a new research area. In terms of compression efficiency, currently, JPEG2000 lossless mode [7] and JPEG-LS [8] are the stateof-the-art lossless image compression algorithms, and overall JPEG-LS has, perhaps, a slightly higher compression efficiency than JPEG2000 lossless mode.…”

A New Integer-to-Integer Transform

“…The Weyl transform which has binary valued inner elements is described in [13]. Integer-to-integer approximations of DST are still an active research area, as can be seen in [14]. In comparison to most integer-tointeger transforms, the MRT is distinguished by the utmost simplicity of its kernel.…”