Luminance Range Research Articles

Reconstructing High Dynamic Range Image from a Single Low Dynamic Range Image Using Histogram Learning

High dynamic range imaging is an important field in computer vision. Compared with general low dynamic range (LDR) images, high dynamic range (HDR) images represent a larger luminance range, making the images closer to the real scene. In this paper, we propose an approach for HDR image reconstruction from a single LDR image based on histogram learning. First, the dynamic range of an LDR image is expanded to an extended dynamic range (EDR) image. Then, histogram learning is established to predict the intensity distribution of an HDR image of the EDR image. Next, we use histogram matching to reallocate pixel intensities. The final HDR image is generated through regional adjustment using reinforcement learning. By decomposing low-frequency and high-frequency information, the proposed network can predict the lost high-frequency details while expanding the intensity ranges. We conduct the experiments based on HDR-Real and HDR-EYE datasets. The quantitative and qualitative evaluations have demonstrated the effectiveness of the proposed approach compared to the previous methods.

Optimizing Bipolar Reset Waveform to Improve Grayscale Stability in Active Matrix Electrowetting Displays.

The electrowetting display (EWD) device is a new type of electrowetting-on-dielectric (EWOD) equipment that can achieve a paper-like display effect under the control of an electric field. In this microfluidic system, the stability of grayscale can be affected by various factors, such as the physicochemical properties of the materials, the device structure, and electric field distribution. To improve the grayscale stability of active matrix electrowetting displays (AM-EWDs), the impact of different polarities of driving voltage on oil backflow was investigated in this study. Based on the driving principles of AM-EWD, an optimized inter-frame bipolar reset driving waveform was designed to overcome oil backflow. The proposed driving waveform maintained the stability of the oil state by periodically and rapidly releasing trapped charges in the dielectric layer through a reverse driving voltage. Additionally, the effect of feed-through voltage on pixel driving voltage was eliminated by compensating for the driving voltage on a common electrode. Finally, the performance of the designed driving waveform was evaluated with a 6-inch AM-EWD driving platform. Compared to the conventional unipolar reset driving waveform, the backflow speed decreased by 2.70 a.u./s. The standard deviation of the display luminance was also reduced by 11.24 a.u. Experimental results indicated that both the oil backflow speed and the fluctuation range of luminance were effectively suppressed by the proposed driving waveform.

Ultralow Roll-off Thermally Activated Delayed Fluorescent Light-Emitting Diodes Based on Furo[2,3-b]quinoxaline Emitters.

Herein, a Y-type compound (67dMeOTPA-FQ) and a T-type compound (58dMeOTPA-FQ) based on furo[2,3-b]quinoxaline were synthesized. The theory calculation shows the S1 and T1 of both compounds own a charge-transfer feature while their T2 states have a local excitation feature. The calculated kRISC(T2-S1) is one to 2 orders of magnitude larger than kRISC(T1-S1). Thus, the nonadiabatic spin-vibronic mechanism involved in the T2 state is suggested to be responsible for the thermally activated delayed fluorescence (TADF) feature. Meanwhile, when 2-methyl-9,10-bis(naphthalen-2-yl)anthracene is selected as host, the maximum luminance of the device based on 67dMeOTPA-FQ is up to 104215 cd·m-2, and the external quantum efficiency (EQE) keeps in the 8.2-8.0% range with the luminance changed from 55.0 cd·m-2 to 90000 cd·m-2, only 2.4% efficiency roll-off. As for 58dMeOTPA-FQ, a slightly lower EQE of 7.1-6.7% with the luminance range of 1-40000 cd·m-2 was achieved for orange-red emission. Both the reverse intersystem crossing (RISC) and triplet-triplet annihilation mechanisms are supposed to concurrently contribute to the utilization of triplet excitons and suppress the notorious efficiency roll-off observed in TADF-based devices.

High‐Efficiency Hybrid White Organic Light‐Emitting Diodes with Extremely Low Efficiency Roll‐Off and Superior Color Stability Enabled by an Emitting System with Imidazole‐Biphenyl Derivatives

AbstractHybride white organic light‐emitting diodes (WOLEDs) have experienced great success as a prospective technology for the new generation lighting source. Nevertheless, WOLEDs exhibiting excellent effciency and good color stability at high operation brightness are still rare. Herein, a simple but efficient blue molecule, pyrenoimidazole‐biphenyl (PPyIM), which exhibits promising external quantum efficiency (EQE) of 7.6% and 7.2% at the luminescence of 1000 −and 5000 cd m−2 in nondoped blue OLED, is first developed. And then, phenanthroimidazole‐biphenyl (PPIM) with analogous molecular skeleton of PPyIM is chosen as the host of phosphorescent dye PO‐01, and the resulting doped device achieves excellent EQE of 26.5% at the high luminescence of 5000 cd m−2. Furthermore, adopting PPyIM as nondoped blue emissive layer, the two‐color hybrid WOLED exhibites stable warm white emission with CIE coordinates of (0.454, 0.439), color rendering index (CRI) of 45, and correlated color temperature (CCT) of 2996 K. The maximum EQE reaches 23.5%, and the EQE still maintains 21.2% even at the luminance of 5000 cd m−2. Notably, this device exhibits exceptionally stable warm white emission, the CIE coordinates variation is only (0.004, 0.003) in the wide luminance range from 400 to 10000 cd m−2, representing the best outcome for hybrid WOLEDs to date.

The Position Index of Overhead LED Sources Under Different Spectral Power Distributions and Background Luminances

ABSTRACT The position index was developed by Luckiesh and Guth in 1949 and is widely used in discomfort glare models to account for the position of the glare source when predicting the presence and magnitude of visual discomfort. The applicability of this index to modern LED sources has not been evaluated; however, it is of concern due to potentially higher luminance levels of LEDs compared to the sources used by Luckiesh and Guth. Furthermore, the position index of overhead sources beyond 60° above the line of sight has not been quantified. An experiment was conducted using a hemispherical apparatus with LED sources. The position of the light source, background luminance, the spectral power distribution, and anchor (starting luminance level before adjustment) were varied and two procedures were used to determine the position index of these sources. Data from 29 participants indicate that overhead sources located 60° or 80° above the line of sight were detectable and their position index can be quantified. The position index values were found to be higher than those reported in previous studies, suggesting that anchor bias and the small luminance range in previous studies likely influenced their position index values. No differences were found in position index values by spectral power distribution, background luminance, participant age group, or eyeglass wearing. The position index values reported in this study account for range and anchor bias, providing a better estimate that should be incorporated into discomfort glare models.

Optimizing Ag films towards efficient flexible quantum-dot light-emitting diodes

Metal film electrodes are frequently adopted in flexible quantum-dot light-emitting diodes (FQLEDs) to form microcavity structures, which accelerate the recombination of excitons and thereby enhancing the efficiency of devices, especially under high driving current density. However, metal films prepared by thermal evaporation grow according to the Volmer-Weber nucleation mechanism, thereby resulting in the formation of numerous metal islands on the target substrate. The serious leakage current and light scattering (hence weakened microcavity effect) caused by these islands lead to inefficient FQLEDs. Here we fabricated a highly uniform and smooth Ag-based flexible electrode by utilizing an ultrathin polyethyleneimine as the nucleation-inducing seed layer. A smooth surface with a root-mean-square of approximately 3.7 nm and an ultralow sheet resistance of 3.65 Ω sq−1 have been obtained for the Ag film with a thickness of only 16 nm. Thus, a high-efficiency FQLED is achieved with the maximum external quantum efficiency up to 25.6 %. Furthermore, this device exhibits ultralow efficiency roll-off, characterized by the external quantum efficiency of over 20 % across an extremely wide luminance range, from 300 to 160,000 cd m−2, meeting all display and lighting requirements.

All-fluorescent white organic light-emitting diodes employing a deep-blue HLCT material simultaneously as emitter and host achieving excellent electroluminescence performance with efficiency roll-off

Simultaneously achieving high efficiency and small efficiency roll-off remains a huge challenge for white organic light-emitting diodes (OLEDs), which greatly restricts their industrial application in the lighting field. Recently developed hybridized local and charge transfer (HLCT) materials have a “hot exciton” channel, which can maximize the utilization rate of excitons and suppress efficiency roll-off via rapid reverse intersystem crossing (RISC) from high-lying triplet state (Tn, n ≥ 2) to singlet state (S1). In this work, employing blue HLCT material pCzAnN as the sensitizing host, by precise concentration management, the traditional fluorescent C545T- and DCJTB-based green and orange-red OLEDs are first fabricated, which achieve the maximum external quantum efficiency (EQE) exceeding the theoretical limit of 5 %, reaching 8.51 % and 6.64 %, respectively. On this basis, by strategic device structure design, all-fluorescent two- and three-color white OLEDs are demonstrated having pCzAnN simultaneously as blue emitter and sensitizing host of C545T and DCJTB. The resulting two- and three-color white devices obtain maximum EQE beyond 5 %. What's more, all three-color white devices exhibit extremely small efficiency roll-off, where the efficiency drops are less than 1 % at a practical luminance of 1000 cd/m2, which is comparable to the best works reported in the literatures. At the same time, the optimized three-color white device realizes ideal white emission, in which the electroluminescence (EL) spectra contain three almost equal intensity emission wavebands accompanied by a high color rendering index of 87. Stable EL spectra under a wide luminance range (3863 ∼ 27710 cd/m2) indicate a huge potential application. We believe this work can provide new idea for developing high-efficiency and low roll-off white OLEDs in the future.

Multi‐exposure embeddings for graph learning: Towards high dynamic range image saliency prediction

AbstractIdentifying saliency in high dynamic range (HDR) images is a fundamentally important issue in HDR imaging, and plays critical roles towards comprehensive scene understanding. Most of existing studies leverage hand‐crafted features for HDR image saliency prediction, lacking the capabilities of fully exploiting the characteristics of HDR image (i.e. wider luminance range and richer colour gamut). Here, systematical studies are carried out on HDR image saliency prediction by proposing a new framework to single out the contributions from multi‐exposure images. Specifically, inspired by the mechanism of HDR imaging, the method first utilizes graph neural networks to model the relations among multi‐exposure images and the tone‐mapped image obtained from an HDR image, enabling more discriminative saliency‐related feature representations. Subsequently, the saliency features driven by global semantic knowledge are aggregated from the tone‐mapped image through enhancing global context‐aware semantic information. Finally, a fusion module is designed to integrate saliency‐oriented feature representations originated from multi‐exposure images and the tone‐mapped image, producing the saliency maps of HDR images. Moreover, a new challenging HDR eye fixation database (HDR‐EYEFix) is created, expecting to further contribute the research on HDR image saliency prediction. Experiment results show that the method obtains superior performance compared to the state‐of‐the‐art methods.

Speckle Noise Removal from Biomedical MRI Images and Classification by Multi-Support Vector Machine

INTRODUCTION: Image Processing (IP) methods play a vital role in medical images for diagnosing and predicting illness, as well as monitoring the patient's progress. The IP methods are utilized in many applications for example in the field of medicine. OBJECTIVES: The images that are obtained by the MRI magnetic Resonance imaging and x rays are analyzed with the help of image processing. METHODS: This application is very costly to the patient. Because of the several non-idealities in the image process, medical images are frequently tainted by impulsive, multiplicative, and addictive noise. RESULTS: By replacing some of the original image's pixels with new ones that have luminance values which are less than the allowed dynamic luminance range, noise frequently affects medical images. CONCLUSION: In this research work, the Speckle type noises are eliminated with the help of Mean Filter (MF) and classify the images using Multi-SVM classifier. The entire system developed using python programming.

A record-high EQE of 7.65%@3300 cd m-2 achieved in non-doped near-ultraviolet OLEDs based on novel D'-D-A type bipolar fluorophores upon molecular configuration engineering.

Developing a high-performance near-ultraviolet (NUV) material and its simple non-doped device with a small efficiency roll-off and good color purity is a promising but challenging task. Here, we proposed a novel donor'-donor-acceptor (D'-D-A) type molecular strategy to largely solve the intrinsic contradictions among wide-bandgap NUV emission, fluorescence efficiency, carrier injection and transport. An efficient NUV fluorophore, 3,6-mPPICNC3, exhibiting a hybridized local and charge-transfer state, is achieved through precise molecular configuration engineering, realizing similar hole and electron mobilities at both low and high electric fields. Moreover, the planarized intramolecular charge transfer excited state and steric hindrance effect endow 3,6-mPPICNC3 with a considerable luminous efficiency and good color purity in the aggregation state. Consequently, the non-doped device emitting stable NUV light with Commission Internationale de l'Eclairage (CIE) coordinates of (0.160, 0.032) and a narrow full width at half maximum of 44 nm exhibits a state-of-the-art external quantum efficiency (EQE) of 7.67% and negligible efficiency roll-off over a luminance range from 0 to 3300 cd m-2. This is a record-high efficiency among all the reported non-doped NUV devices. Amazingly, an EQE of 7.85% and CIE coordinates of (0.161, 0.025) are achieved in the doped device. This demonstrates that the D'-D-A-type molecular structure has great potential for developing high-performance organic light-emitting materials and their optoelectronic applications.

Contrast Sensitivity of ON and OFF Human Retinal Pathways in Myopia.

The human visual cortex processes light and dark stimuli with ON and OFF pathways that are differently modulated by luminance contrast. We have previously demonstrated that ON cortical pathways have higher contrast sensitivity than OFF cortical pathways and the difference increases with luminance range (defined as the maximum minus minimum luminance in the scene). Here, we demonstrate that these ON-OFF cortical differences are already present in the human retina and that retinal responses measured with electroretinography are more affected by reductions in luminance range than cortical responses measured with electroencephalography. Moreover, we show that ON-OFF pathway differences measured with electroretinography become more pronounced in myopia, a visual disorder that elongates the eye and blurs vision at far distance. We find that, as the eye axial length increases across subjects, ON retinal pathways become less responsive, slower in response latency, less sensitive, and less effective and slower at driving pupil constriction. Based on these results, we conclude that myopia is associated with a deficit in ON pathway function that decreases the ability of the retina to process low contrast and regulate retinal illuminance in bright environments.

Poster Session: Evidence for preserved conscious orientation discrimination in perimetrically-blind fields early after V1-damage.

Cortically-blind (CB) patients with stroke damage to the primary visual cortex (V1) lose conscious vision but many exhibit blindsight - the ability to unconsciously detect or discriminate moving or flickering targets inside their blind-fields. However, the prevalence of conscious visual abilities in CB is less clear. Having developed a new method to assess vision inside perimetrically-defined blind fields, we found that >50% of subacute CB patients (<6 months post-stroke) can consciously discriminate global motion inside their blind field. Here, we asked if they can also discriminate orientation of static targets, which do not typically elicit blindsight. In 10 subacute patients, we mapped their intact and blind hemifields using static, non-flickering, 1cpd Gabors across a wide range of luminance contrasts. Blind-field locations were labeled "preserved" if performance was >72.5% correct. Considering overall performance, only 1 participant had preserved static orientation perception in the blind-field. However, this increased to 4 participants when only considering performance at high contrasts (>50%), all of whom reported awareness of stimuli. Thus, early after V1 damage, conscious percepts for oriented, high-contrast, static targets can remain inside CB fields, similar in incidence to global motion discriminations. We are now testing additional patients to assess if these abilities persist into the chronic period and to detail their underlying neural substrates.

Light Environment Evaluation of the Architecturalized Immer-sive New Media Public Art Installation from the Audiences’ Visual Safety Perspective

How to balance the artistry and comfort of the light environment in an architecturalized immersive new media public art installation (AINMPAI) to ensure the safety of the audiences’ visual safety has become a new issue. The lack of corresponding lighting design standards makes this issue more challenging. This paper explores the appropriate luminance range of the irregularly curved LED screens of the AINMPAI with high-luminance natural light as the background. The influence of the audience behavior mode on the brightness threshold of the LED screens in the AINMPAI under the background of Internet communication is discussed. Through software simulation and field measurement, the effectiveness of the design measures based on the local characteristics of the work is verified. The overall average luminance, the regional luminance, the partial luminance, and the corresponding luminance contrast of the inner screen surface were measured at every 10° change in the solar altitude angle during daytime. The nighttime light environment parameters and the temperature of the device throughout the day were also measured. A total of 487 visitors were interviewed for subjective evaluation of the comfort of the light and thermal environments. The results show that: (1) the overall average luminance cannot wholly describe the actual luminance of the critical parts of the special-shaped curved screen in the device and that two indicators, the regional luminance and the partial average luminance, need to be added; (2) the maximum brightness limit of LED screens in the daytime can be 1000 cd/m2 but at night it should be controlled within 200 cd/m2; (3) natural light is the main factor that causes the high average brightness and low contrast of the daytime device screen; (4) the recommended indicators for such artistic installations should balance the absolute values of average brightness, artistic effect, and transmission priority. This study can provide foundational data and a methodological reference for establishing AINMPAI light environment design guidelines or recommended standards based on audiences’ visual safety.

Observation of image quality for HDR micro LED display

This paper compared a high-dynamic range (HDR) micro-light-emitting diode (Micro LED) display with an LCD (Liquid Crystal Display) with a relatively low luminance range to determine the relationship between HDR and its factors and the effect of quality factors on the final image quality evaluation. The experimental subjects were general consumers, who evaluated images displayed on a Micro LED 4 K (110 in.) and an LCD 8 K (85 in.). The image-quality characteristics of the Micro LED reinforced texture analysis of the surface and clear image quality especially for the microscopic image group. Vividness perceptions have shown to affect all items, indicating that the increase in vividness due to the color gamut extension of Micro LED has a significant impact on the analytical evaluation of the details of an image. This study revealed that HDR is an important factor for image contrast that is comparable to the high resolution of the 8 K display. Among the currently commercialized displays, the Micro LED has the widest HDR, and clear, high-quality images are expected using this new display.

Ultrastable and High-Efficiency Deep Red QLEDs through Giant Continuously Graded Colloidal Quantum Dots with Shell Engineering.

Quantum dot (QD) based light-emitting diodes (QLEDs) hold great promise for next-generation lighting and displays. In order to reach a wide color gamut, deep red QLEDs emitting at wavelengths beyond 630 nm are highly desirable but have rarely been reported. Here, we synthesized deep red emitting ZnCdSe/ZnSeS QDs (diameter ∼16 nm) with a continuous gradient bialloyed core-shell structure. These QDs exhibit high quantum yield, excellent stability, and a reduced hole injection barrier. The QLEDs based on ZnCdSe/ZnSeS QDs have an external quantum efficiency above 20% in the luminance range of 200-90000 cd m-2 and a record T95 operation lifetime (time for the luminance to decrease to 95% of its initial value) of more than 20000 h at a luminance of 1000 cd m-2. Furthermore, the ZnCdSe/ZnSeS QLEDs have outstanding shelf stability (>100 days) and cycle stability (>10 cycles). The reported QLEDs with excellent stability and durability can accelerate the pace of QLED applications.

Phosphorescent ultrathin emitting layers sensitized by TADF interfacial exciplex enables simple and efficient monochrome/white organic light-emitting diodes

In this work, we proposed a novel scheme enabling simple and efficient monochrome/white organic light-emitting diodes (OLEDs) by simultaneously combining thermally activated delayed fluorescence (TADF) interfacial exciplex and phosphorescent ultrathin emitting layers (Ph-UEMLs). Specifically, monochrome/white OLEDs were structured by directly inserting single or complementary Ph-UEMLs into the interface of TADF interfacial exciplex (m-bis(N-carbazolyl)-benzene (mCP)/2,4,6-tris[3-(diphenylphosphinyl)phenyl]-1,3,5-triazine (PO-T2T)) using simple doping-free technology. Consequently, all monochrome (blue, green, orange and red) OLEDs exhibit a low turn-on voltage of 2.4–2.5 V and realize ultra-high device performance with maximum external quantum efficiency (EQE) exceeding 20%. Therein, the Bis[2-(4,6-difluorophenyl)pyridinato-C2,N](picolinato)iridium(III) (FIrpic)-based blue OLED achieves the forward-viewing EQE reaching 30.21%, which is among highest values ​reported in literatures. Moreover, the fabricated two-, three- and four-colors white OLEDs also obtain the same excellent performance with a low turn-on voltage of 2.5 V and high EQEs of 23.47, 22.70 and 23.88% (corresponding to 78.80, 76.70 and 70.89 lm/W). All white devices also exhibit extremely high color stability at a practical luminance range from about 5000 to 12000 cd/m2, indicating a huge potential application. It is demonstrated that Ph-UEMLs sensitized by TADF interfacial exciplex ensures a complete exciton utilization by multi-channels energy transfer from TADF interfacial exciplex to Ph-UEMLs, which is responsible for the main reason for achieving high device performance. We believe our proposed scheme paves a new path for developing ultra-simple and high-performance monochrome/white OLEDs.

Novel Multiple Resonance Type TADF Emitter as Blue Component for Highly Efficient Blue‐Hazard‐Free White Organic Light‐Emitting Diodes

AbstractRealizing blue‐hazard‐free emission is an important goal for white organic light‐emitting diodes (OLEDs) toward healthy lighting applications. However, conventional blue organic emitters with broad emission spectra would generally cover the high‐energy emission region and thus cannot meet the demand. Here a blue multiple resonance type thermally activated delayed fluorescence (TADF) emitter DPMX‐CzDABNA is newly designed. The DPMX‐CzDABNA‐based OLEDs can realize blue narrowband emission peaked at 484 nm with a full width at half maximum of 29 nm, and external quantum efficiencies (EQEs) around 26%, which allows DPMX‐CzDABNA to precisely avoid the high‐energy photon contribution and thus be a promising blue component to construct high‐performance white OLEDs with human‐eye‐friendly emission spectra. Using DPMX‐CzDABNA and a reported TADF emitter BPPZ‐DPXZ, respectively, as blue and orange components in white OLEDs, the single‐emitting‐layer devices approach white emission with outstanding EQE up to 35.8%; the double‐emitting‐layer OLEDs achieve blue‐hazard‐free white emissions with a maximum EQE of 26.5% and very stable Commission Internationale de l'Eclairage coordinates of ≈(0.38,0.43) over a wide luminance range from 100 to 10 000 cd m−2. It is expected that this strategy can pave a new way for developing highly efficient all‐TADF white OLEDs without blue‐hazard emission.

Deviations from constancy in contrast matching over a wide range of luminances

Deviations from constancy in contrast matching over a wide range of luminances

Color Appearance Characterization of Highlight Stimuli in HDR Scenes Across a Wide Range of Diffuse White Luminance

Various uniform color spaces and color appearance models were mainly developed for characterizing stimuli under a low dynamic range condition. Real scenes in daily life, however, are commonly high dynamic range (HDR), containing highlights with luminance beyond the diffuse white, whose color appearance characterization was never investigated in the past. This study was carefully designed to investigate the color appearance characterization of highlights in HDR scenes, covering extremely wide ranges of diffuse white luminance (up to 11000 cd/m&lt;sup&gt;2&lt;/sup&gt;), stimulus luminance (up to 49000 cd/m&lt;sup&gt;2&lt;/sup&gt;), stimulus chromaticities (reach Rec. 2020 gamut), and scene luminance contrast (up to 72045). The observers viewed two stimuli, including one highlight and one dark stimulus, in a viewing booth, and were asked to adjust the color appearance of another stimulus, so that the color differences between the adjusted stimulus to each of the other two stimuli appeared the same. The results clearly showed that none of the existing models, including the one (i.e., IC&lt;sub&gt;t&lt;/sub&gt;C&lt;sub&gt;p&lt;/sub&gt;) that was recently designed for HDR scenes, has a good performance. The models using a power function to characterize the non-linear compressive responses of the human visual system (i.e., CIELAB and IPT) had a slightly better performance. The findings provided some guidance for performing tone mapping and chroma/saturation adjustments, and clearly suggest the necessity to carry out further work to develop a better model for HDR scenes.

Luminance, Brightness, and Lightness Metrics for HDR

High dynamic range (HDR) technology enables a much wider range of luminances &#x2013; both relative and absolute &#x2013; than standard dynamic range (SDR). HDR extends black to lower levels, and white to higher levels, than SDR. HDR enables higher absolute luminance at the display to be used to portray specular highlights and direct light sources, a capability that was not available in SDR. In addition, HDR programming is mastered with wider color gamut, usually DCI P3, wider than the BT.1886 (&#x201C;BT.709&#x201D;) gamut of SDR. The capabilities of HDR strain the usual SDR methods of specifying color range. New methods are needed. A proposal has been made to use CIE LAB to quantify HDR gamut. We argue that CIE L* is only appropriate for applications having contrast range not exceeding 100:1, so CIELAB is not appropriate for HDR. In practice, L* cannot accurately represent lightness that significantly exceeds diffuse white &#x2013; that is, L* cannot reasonably represent specular reflections and direct light sources. In brief: L* is inappropriate for HDR. We suggest using metrics based upon ST 2084/BT.2100 PQ and its associated color encoding, IC&lt;sub&gt;T&lt;/sub&gt;C&lt;sub&gt;P&lt;/sub&gt;.