Two-Layer Lossless HDR Coding Using Histogram Packing Technique with Backward Compatibility to JPEG

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.

Performance Evaluation of Two-layer lossless HDR Coding using Histogram Packing Technique under Various Tone-mapping Operators

“…From the Fig Figure 3 shows boxplots of total bitrates calculated using the same 105 HDR images. We chose R = 0 or 4, rR = 0 and q = 80 or 90 for JPEG XT, and we chose only q = 80 or 90 for the HP one, where R, rR and q are the number of bits used for the refinement scan, the number of bits used for the residual refinement scan, and the quantization parameter in the base layer, respectively [10]. From Fig.3, HP coder outperformed JPEG XT under all TMOs.…”

“…The JPEG XT is a two-layer coding method and is backward compatible with the legacy JPEG standard [6], and some extended coding methods have been studied [7], [8]. Our research group proposed a novel two layer lossless HDR coding method using a histogram packing technique, which has the backward compatibility to JPEG, referred to as HP coder [9], [10]. The packing technique allows us to improve the performance of lossless compression for HDR images when images have the histogram sparseness [11], [12].…”

Hierarchical lossless color image coding method using cellular neural networks based predictors

“…Specifically, 256 bits are required for an 8-bit depth image and 512 bits for a 9-bit depth image. Because of the large amount of additional information in such an implementation method, [19] reduces the additional information by performing DPCM (differential pulse-code modulation) [20].…”