Abstract
An efficient two-layer coding method using the histogram packing technique with the backward compatibility to the legacy JPEG is proposed in this paper. The JPEG XT, which is the international standard to compress HDR images, adopts two-layer coding scheme for backward compatibility to the legacy JPEG. However, this two-layer coding structure does not give better lossless performance than the other existing methods for HDR image compression with single-layer structure. Moreover, the lossless compression of the JPEG XT has a problem on determination of the coding parameters; The lossless performance is affected by the input images and/or the parameter values. That is, finding appropriate combination of the values is necessary to achieve good lossless performance. It is firstly pointed out that the histogram packing technique considering the histogram sparseness of HDR images is able to improve the performance of lossless compression. Then, a novel two-layer coding with the histogram packing technique and an additional lossless encoder is proposed. The experimental results demonstrate that not only the proposed method has a better lossless compression performance than that of the JPEG XT, but also there is no need to determine image-dependent parameter values for good compression performance without losing the backward compatibility to the well known legacy JPEG standard.
Abstract (translated)
本文提出了一种使用直方图打包技术的高效双层编码方法，该方法具有与传统JPEG的向后兼容性。 JPEG XT是压缩HDR图像的国际标准，采用双层编码方案向后兼容传统JPEG。然而，与具有单层结构的HDR图像压缩的其他现有方法相比，这种双层编码结构不能提供更好的无损性能。此外，JPEG XT的无损压缩在确定编码参数方面存在问题;无损性能受输入图像和/或参数值的影响。也就是说，找到值的适当组合对于实现良好的无损性能是必要的。首先指出考虑HDR图像直方图稀疏性的直方图打包技术能够提高无损压缩的性能。然后，提出了一种采用直方图打包技术和附加无损编码器的新型双层编码。实验结果表明，不仅所提出的方法具有比JPEG XT更好的无损压缩性能，而且不需要确定与图像相关的参数值以获得良好的压缩性能，同时不会失去与众所周知的传统的向后兼容性。 JPEG标准。
URL
https://arxiv.org/abs/1808.00956
