The drastic visual improvements introduced by High Dynamic Range (HDR) technologies open new markets for a wide range of industries. Among them, a significant opportunity is offered to owners of legacy Standard Dynamic Range (SDR) content that can be converted to the new standard to take advantage of the enhanced capabilities of the HDR displays. Similarly, since SDR broadcasting infrastructure will continue to be around for the time being, such conversion process is becoming an obvious necessity. To this end, different approaches have tried to efficiently convert SDR images and videos to HDR format, a procedure well known as inverse Tone Mapping. In this paper, we propose a novel high visual quality video inverse Tone Mapping Operator (iTMO) that addresses the inadequacies of the state-of-the-art methods, resulting in high visual quality HDR videos that match the capabilities of the HDR technology. Our approach is based on human visual perception and employs a segmentation method according to the Human Visual System (HVS) sensitivity to brightness changes in different regions of the frame and constructs the mapping curve using the brightness distribution information of these regions. Our iTMO uses a hybrid approach to achieve an optimal balance between the overall contrast and brightness of the output HDR frame by maximizing a weighted sum of contrast and brightness difference between input SDR and generated HDR frame. The proposed iTMO works equally well for all levels of brightness, eliminating any visual artifacts by dynamically maintaining changes at non-perceivable levels. Subjective and objective evaluations validated the superior visual performance of our proposed iTMO over state-of-the-art methods.

中文翻译：

---

基于感知的逆音映射运算符，用于高动态范围视频应用

高动态范围（HDR）技术带来的显着视觉改进为众多行业打开了新的市场。其中，为传统标准动态范围（SDR）内容的所有者提供了巨大的机会，这些内容可以转换为新标准以利用HDR显示器的增强功能。同样，由于SDR广播基础结构暂时仍将存在，因此这种转换过程变得很明显。为此，不同的方法试图将SDR图像和视频有效地转换为HDR格式，这是众所周知的反色调映射过程。在本文中，我们提出了一种新颖的高视觉质量的视频逆色调映射算子（iTMO），该算子解决了最新方法的不足之处，产生与HDR技术功能相匹配的高品质HDR视频。我们的方法基于人的视觉感知，并根据人的视觉系统（HVS）对帧不同区域中亮度变化的敏感性采用了分割方法，并使用这些区域的亮度分布信息构造了映射曲线。我们的iTMO使用混合方法，通过最大化输入SDR和生成的HDR帧之间的对比度和亮度差的加权总和，在输出HDR帧的整体对比度和亮度之间实现最佳平衡。提议的iTMO在所有亮度级别上均能很好地发挥作用，通过动态地将变化保持在不可感知的水平上，从而消除了任何视觉伪影。