Luma-aware multi-model rate-control for HDR content in HEVC

Watermarking of HDR Images in the Spatial Domain With HVS-Imperceptibility

“…Hence, these watermarks can be easily identified without the need for private keys or any additional information about the embedding process. We evaluate the proposed HDR-IW method for the embedding of binary watermarks in terms of embedding payload, imperceptibility (qualitatively and quantitatively), robustness to tone-mapping operations (TMOs), which are widely used to display HDR images on SDR screens, lossy compression [5]- [7] and other common signal processing operations. To the best of our knowledge, there are no other watermarking methods for HDR images that also embed information in the spatial domain in an imperceptible manner.…”

Graph-Based Rate Control in Pathology Imaging With Lossless Region of Interest Coding

“…The work in [19] proposes a framework for RoI coding that uses a preprocessing step to replace non-RoI areas by known pixels, thus relying on the R-D optimization process to optimally encode the data. The work in [20] presents a region-based RC method aimed at improving the objective quality of highdynamic range sequences. A similar idea is presented in [21] for intra-predicted frames.…”

Rate Control for Hevc Intra-Coding Based on Piecewise Linear Approximations

“…This R-λ-based RC algorithm has been shown to provide a better performance than the one based on a quadratic model [3]. Other proposals for RC in HEVC include an algorithm based on textured and non-textured rate models [4], methods that allow compressing different regions of a frame using distinct R-λ models [5,6], and an algorithm that allows for lossless region-of-interest coding with lossy coding of the remaining regions [7].…”

“…To this end, this R-λ based RC algorithm includes a mechanism to adaptively update the parameters that approximate λ during the encoding process, starting from a set of parameters that are obtained by using training data. Although this adaptation mechanism avoids computing the value of λ for each sequence a priori, a poor adaptation to the true RD characteristics of the sequence may result in inaccurately attaining the target bit rate [6][7]. This issue may be very severe for intra-coded sequences, i.e., the all intra (AI) profile in HEVC [8], as this RC algorithm poorly adapts the model's parameters for Iframes [6,7].…”

“…Although this adaptation mechanism avoids computing the value of λ for each sequence a priori, a poor adaptation to the true RD characteristics of the sequence may result in inaccurately attaining the target bit rate [6][7]. This issue may be very severe for intra-coded sequences, i.e., the all intra (AI) profile in HEVC [8], as this RC algorithm poorly adapts the model's parameters for Iframes [6,7]. Although recent proposals aim to optimally allocate a target bit rate by exploiting intrinsic characteristics of the encoding method, such as the dependencies among frames induced by motion compensation [9], little work has been done for I-frames.…”