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Book ChapterDOI

Dual Modulation for LED-Backlit HDR Displays

01 Jan 2016-pp 371-388
TL;DR: This chapter outlines a new dual modulation algorithm for the rendering of HDR content and discusses practical lessons that can be helpful toward therender of more accurate and visually appealing HDR content.
Abstract: High dynamic range (HDR) and wide color gamut video processing have started to receive significant research attention in recent years, especially in relation to content generation and processing. However, displaying such content is still a challenge, and efforts are required to make their deployment possible at consumer levels. While the emergence of locally backlit displays has helped to achieve higher contrast in the display of traditional low dynamic range videos, their use for displaying HDR videos is nontrivial. This chapter, therefore, aims to first identify a few challenges in this area. It then outlines a new dual modulation algorithm for the rendering of HDR content. It also discusses practical lessons that can be helpful toward the rendering of more accurate and visually appealing HDR content.
Citations
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Journal ArticleDOI
TL;DR: A subjective experiment attempting to determine users’ preference with respect to these two types of content in two different viewing scenarios—with and without the HDR reference shows that the absence of the reference can significantly influence the subjects' preferences for the natural images, while no significant impact has been found in the case of the synthetic images.
Abstract: The popularity of high dynamic range (HDR) imaging has grown in both academic and private research sectors. Since the native visualization of HDR content still has its limitations, the importance of dynamic range compression (i.e., tone-mapping) is very high. This paper evaluates observers’ preference of experience in context of image tone-mapping. Given the different nature of natural and computer-generated content, the way observers perceive the quality of tone-mapped images can be fundamentally different. In this paper, we describe a subjective experiment attempting to determine users’ preference with respect to these two types of content in two different viewing scenarios—with and without the HDR reference. The results show that the absence of the reference can significantly influence the subjects’ preferences for the natural images, while no significant impact has been found in the case of the synthetic images. Moreover, we introduce a benchmarking framework and compare the performance of selected objective metrics. The resulting dataset and framework are made publicly available to provide a common test bed and methodology for evaluating metrics in the considered scenario.

22 citations

Journal ArticleDOI
TL;DR: In this paper, a great interest in doping of different types of nanoparticles (NPs) in the opto-electronic display devices including liquid crystal displays and polymer dispersed LCs is discussed.
Abstract: There is a great interest in doping of different types of nanoparticles (NPs) in the opto-electronic display devices including liquid crystal displays and polymer dispersed LCs. Doping of NPs into ...

22 citations

Proceedings ArticleDOI
11 Jul 2016
TL;DR: This work presents an iterative scaling approach to estimate dual modulated signals to drive the back LED panel and the front LCD screen, which is able to reproduce accurately luminance values stored in HDR files and describes a temporal smoothing mechanism to compute backlight illumination.
Abstract: In this paper, we consider the problem of accurately reproducing high dynamic range (HDR) images and video on HDR displays. Differently from conventional image reproduction devices, HDR displays require dual modulated signals to drive the back LED panel and the front LCD screen. In this work, we present an iterative scaling approach to estimate these two signals, which is able to reproduce accurately luminance values stored in HDR files. To avoid temporal artifacts due to frame-by-frame processing, we also describe a temporal smoothing mechanism to compute backlight illumination. Our results demonstrate higher accuracy than simpler approaches such as built-in display rendering. Furthermore, the proposed method offers the possibility to estimate precisely the luminance emitted by the display.

6 citations


Cites background from "Dual Modulation for LED-Backlit HDR..."

  • ...Given an HDR picture, the problem of estimating the corresponding LED/LCD panel values is known as dual modulation [2]....

    [...]

Journal ArticleDOI
TL;DR: In this paper , a deep learning based local dimming method is proposed for rendering HDR images on dual-panel HDR displays, which uses a convolutional neural network (CNN) to directly predict backlight values, using as input the HDR image that is to be displayed.
Abstract: High dynamic range (HDR) displays with dual-panels are one type of displays that can provide HDR content. These are composed of a white backlight panel and a colour LCD panel. Local dimming algorithms are used to control the backlight panel in order to reproduce content with high dynamic range and contrast at a high fidelity. However, existing local dimming algorithms usually process low dynamic range (LDR) images, which are not suitable for processing HDR images. In addition, these methods use hand-crafted features to estimate the backlight values, which may not be suitable for many kind of images. In this work, a novel deep learning based local dimming method is proposed for rendering HDR images on dual-panel HDR displays. The method uses a Convolutional Neural Network (CNN) to directly predict backlight values, using as input the HDR image that is to be displayed. The model is designed and trained via a controllable power parameter that allows a user to trade off between power and quality. The proposed method is evaluated against seven other methods on a test set of 105 HDR images, using a variety of quantitative quality metrics. Results demonstrate improved display quality and better power consumption when using the proposed method compared to the best alternatives.

1 citations

Journal ArticleDOI
TL;DR: A novel deep learning based local dimming method that uses a Convolutional Neural Network to directly predict backlight values, using as input the HDR image that is to be displayed on dual-panel HDR displays is proposed.
Abstract: High dynamic range (HDR) displays with dual-panels are one type of displays that can provide HDR content. These are composed of a white backlight panel and a colour LCD panel. Local dimming algorithms are used to control the backlight panel in order to reproduce content with high dynamic range and contrast at a high fidelity. However, existing local dimming algorithms usually process low dynamic range (LDR) images, which are not suitable for processing HDR images. In addition, these methods use hand-crafted features to estimate the backlight values, which may not be suitable for many kind of images. In this work, a novel deep learning based local dimming method is proposed for rendering HDR images on dual-panel HDR displays. The method uses a Convolutional Neural Network (CNN) to directly predict backlight values, using as input the HDR image that is to be displayed. The model is designed and trained via a controllable power parameter that allows a user to trade off between power and quality. The proposed method is evaluated against seven other methods on a test set of 105 HDR images, using a variety of quantitative quality metrics. Results demonstrate improved display quality and better power consumption when using the proposed method compared to the best alternatives.

1 citations

References
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Journal ArticleDOI
01 Aug 2004
TL;DR: This paper discusses the design of two different display systems that are capable of displaying images with a dynamic range much more similar to that encountered in the real world.
Abstract: The dynamic range of many real-world environments exceeds the capabilities of current display technology by several orders of magnitude. In this paper we discuss the design of two different display systems that are capable of displaying images with a dynamic range much more similar to that encountered in the real world. The first display system is based on a combination of an LCD panel and a DLP projector, and can be built from off-the-shelf components. While this design is feasible in a lab setting, the second display system, which relies on a custom-built LED panel instead of the projector, is more suitable for usual office workspaces and commercial applications. We describe the design of both systems as well as the software issues that arise. We also discuss the advantages and disadvantages of the two designs and potential applications for both systems.

629 citations

Book
01 Jan 1996
TL;DR: Video Monitor Adjustments: Black Level and Picture Gamma Component Video Colour Coding Composite NTSC and PAL Colour.
Abstract: Video Monitor Adjustments: Black Level and Picture Gamma Component Video Colour Coding Composite NTSC and PAL Colour. Appendices: Gamma Correction on the Apple Macintosh Reducing Eyestrain.

461 citations

Journal ArticleDOI
01 May 2003
TL;DR: This paper provides a description of the technology as well as findings from a supporting psychological study that establishes that correction for the low resolution display through compensation in the high resolution display yields an image which does not differ perceptibly from that of a purely high resolution HDR display.
Abstract: We have developed an emissive high dynamic range (HDR) display that is capable of displaying a luminance range of 10,000cd/m2 to 0.1cd/m2 while maintaining all features found in conventional LCD displays such as resolution, refresh rate and image quality. We achieve that dynamic range by combining two display systems — a high resolution transmissive LCD and a low resolution, monochrome display composed of high brightness light emitting diodes (LED). This paper provides a description of the technology as well as findings from a supporting psychological study that establishes that correction for the low resolution display through compensation in the high resolution display yields an image which does not differ perceptibly from that of a purely high resolution HDR display.

204 citations

Journal ArticleDOI
TL;DR: In this article, the inverse of a mapping function (IMF) method proposed as a dynamic gamma mapping curve for the backlight module, has been demonstrated to further improve in HDR image quality.
Abstract: A high dynamic range liquid crystal display (HDR-LCD) can enhance the contrast ratio of images by utilizing locally controlled dynamic backlight. We studied the HDR-LCD as a dual-panel display: a backlight module and a liquid crystal (LC) cell. As the gamma of the LC signal, the backlight module was also endowed with a gamma function to control the contrast ratio of HDR images. The inverse of a mapping function (IMF) method proposed as a dynamic gamma mapping curve for the backlight module, has been demonstrated to further improve in HDR image quality. By implementing the IMF method on a HDR-LCD TV with 88 backlight zones, the image contrast ratio can reach while maintaining high brightness, clear image detail, and an average power reduction of 30%.

116 citations

Journal ArticleDOI
TL;DR: The paper presents an adaptive dimming technique to reduce backlight power consumption and enhance image contrast for global backlight applications and shows the performance and usefulness of the proposed technique on a 2.2-inch mobile phone liquid crystal display made by thin-film-transistor (TFT) technology.
Abstract: The paper presents an adaptive dimming technique to reduce backlight power consumption and enhance image contrast for global backlight applications. The proposed adaptive dimming technique consists of two new algorithms: backlight dimming algorithm and contrast enhancement algorithm. The backlight-dimming algorithm obtains appropriate 0% to 50% backlight power reduction depending on characteristics of the image data. The contrast enhancement algorithm not only reduces the adverse effect of backlight power saving, but also improves 20.75% enhancement of image contrast ratio on the average. Numerous simulation results are used for illustration of the effectiveness and merits of the proposed adaptive dimming technique. Experimental results are conducted to show the performance and usefulness of the proposed technique on a 2.2-inch mobile phone liquid crystal display (LCD) made by thin-film-transistor (TFT) technology.

112 citations