Mark D. Fairchild's research while affiliated with Rochester Institute of Technology and other places

Publications (224)

Article
Increasing the purity of a visual stimulus increases its brightness, even if the stimulus luminance is held constant. This perceptual phenomenon is known as the Helmholtz–Kohlrausch (H–K) Effect. This paper reviews published experimental data and models of the effect. Using past experimental data, we derive a modification of the CIECAM02 and CAM16...
Article
Full-text available
Observer metamerism refers to a situation in which some observers with normal color vision will see two colors as identical while others will see them mismatch. In recent years, some issues with metameric failure have been exacerbated by displays with more saturated primaries and narrower emission spectra. Classic trichromatic colorimetry is incapa...
Conference Paper
Full-text available
The Luther condition has been a guideline for colorimetric camera design. However, the standard observer only represents an average observer without considering the inter-observer variability. Thus, there is still potential observer-camera metamerism between a camera colorimetric to the standard observer and an actual observer that has different CM...
Article
Full-text available
A larger display color gamut volume (CGV) is expected to produce higher perceived brightness and colorfulness of the images displayed. However, display control algorithms such as gamut mapping and color conversion need to be carefully controlled to fully take advantage of the higher luminance and more saturated display primaries. Using RGBW display...
Article
Metrics that predict the perceptual brightness of displayed imagery are vitally important, especially as wide color gamut, high dynamic range displays become more widespread. We implemented a color appearance modeling pipeline derived from the iCAM image color appearance framework and CAM76 color appearance model that allows for the accurate predic...
Article
In the CIECAM02 and CAM16 color appearance models, brightness is computed as a nonlinear function of lightness. This paper traces the history of that nonlinearity to its roots in the Hunt color appearance model. A new, more robust, linear relationship between lightness and brightness is proposed. This new formula also prompts the reevaluation of th...
Article
This article presents a color chart explicitly designed for the visual color assessment of wines as a part of more comprehensive hedonistic or analytical tasting systems. The chart is based on visual, colorimetric, and in situ evaluations of existent wine color and the techniques for its assessment in wine sensory evaluation. The system is specifie...
Article
A web application (Virtual Colour Atlas) has been developed that implements seven of the leading color order systems: Colorcurve, Coloroid, DIN 6164, Munsell, OSA‐UCS, NCS, and Swiss Colour Atlas 2541, three color spaces: CIE xyY, CIELAB, and CIELUV, and three colour ranges: BS:5252, RAL 840‐HR, and RAL 841‐GL—allowing the user to view any of the c...
Article
Brilliance and zero grayness (denoted as G0) and are two terms coined by Ralph Evans. Nayatani, Heckaman and Fairchild have done series of work to incorporate them into comprehensive color appearance models. In this work, those concepts were reexamined to scale lightness/brightness across the chromaticity diagram. Specifically, observers, mostly wi...
Article
Color inconstancy refers to significant changes in the perceived color of an object across two or more different lighting conditions, such as daylight and incandescent light. This research focusses on defining the threshold of color inconstancy between generated D65 and A illumination through a psychophysical experiment. Although modern color appea...
Article
The human visual system is capable of adapting across a very wide dynamic range of luminance levels; values up to 14 log units have been reported. However, when the bright and dark areas of a scene are presented simultaneously to an observer, the bright stimulus produces significant glare in the visual system and prevents full adaptation to the dar...
Article
In this article, a dual seven‐primary lighting system is constructed for color research and education. The system offers sufficient spectral variability to approximate the spectral power distribution of a variety of standard illuminants. More importantly, the constructed multiprimary lighting system was verified to have crucial advantages over conv...
Article
Although the world has been high dynamic range (HDR) all along, commercial HDR displays’ burgeoning availability provides new and interesting challenges for colorimetry and perceptual modeling. The biggest challenge stems from the way that large luminance changes spatial and temporal scales often compressed relative to the natural world. This resul...
Conference Paper
Full-text available
White lighting and neutral-appearing objects are essential in numerous color applications. In particular, setting or tuning a reference white point is a key procedure in both camera and display applications. Various studies on observer metamerism pointed out that noticeable color disagreements between observers mainly appear in neutral colors. Thus...
Conference Paper
Full-text available
One of the essential mechanisms employed by the human visual system when interpreting the natural world is that of trichromatic integration of physical scene spectra by cone photoreceptors. By extension of this, different scene spectra can result in the same color sensation in an observer, a phenomenon known as metamerism. This allows imaging syste...
Article
In this paper, two psychophysical experiments were conducted to explore the effect of peak luminance on the perceptual color gamut volume. The two experiments were designed with two different image data rendering methods: clipping the peak luminance and scaling the image luminance to display's peak luminance capability. The perceptual color gamut v...
Article
Full-text available
A new color space, IGPGTG, was developed. IGPGTG uses the same structure as IPT, an established hue-uniform color space utilized in gamut mapping applications. While IPT was fit to visual data on the perceived hue, IGPGTG was optimized based on evidence linking the peak wavelength of Gaussian-shaped light spectra to their perceived hues. The perfor...
Article
Image quality measures are becoming increasingly important in the field of computer graphics. For example, there is currently a major focus on generating photorealistic images in real time by combining path tracing with denoising, for which such quality assessment is integral. We present FLIP, which is a difference evaluator with a particular focus...
Article
Full-text available
In this work, we address the problem of spectral reflectance recovery from both CIEXYZ and RGB values by means of a machine learning approach within the fuzzy logic framework, which constitutes the first application of fuzzy logic in these tasks. We train a fuzzy logic inference system using the Macbeth ColorChecker DC and we test its performance w...
Article
Image edge detection based on low‐level feature is usually performed on gray‐scale images. Some methods have been developed for edge detection on colour images based on low‐level feature, but they are not consistent with human colour perception. This research provides a new algorithm for edge detection based on the “HyAB” large‐colour‐difference fo...
Article
There are claims that multi‐chromatic displays can achieve a wider color gamut by the use of additional highly saturated secondary color channels. However, there are other claims that these displays lose lightness and/or color saturation at brighter levels. These apparently divergent views have led to some controversy in the display industry and at...
Article
A new color space, I G P G T G, was developed. I G P G T G uses the same structure as IPT, an established hue-uniform color space utilized in gamut mapping applications. While IPT was fit to visual data on the perceived hue, I G P G T G was optimized based on evidence linking the peak wavelength of Gaussian-shaped light spectra to their perceived h...
Article
A method is proposed to generate categorical colour observer functions (individual colour matching functions) for any field size based on the CIE 2006 system of physiological observer functions. The method combines proposed categorical observer techniques of Sarkar et al with a physiologically‐based individual observer model of Asano et al and a cl...
Article
Small, supra‐threshold color differences are typically described with Euclidean distance metrics, or dimension‐weighted Euclidean metrics, in color appearance spaces such as CIELAB. This research examines the perception and modeling of very large color differences in the order of 10 CIELAB units or larger, with an aim of describing the salience of...
Article
In September 2017, the first author suffered a rhegmatogenous retinal detachment. This experience included a series of remarkable, sometimes unsettling visual phenomena, which included visible differences in the color vision between her two eyes during the recovery from retinal detachment, as a cataract developed, and following cataract surgery. He...
Article
Different whiteboard image degradations highly reduce the legibility of pen-stroke content as well as the overall quality of the images. Consequently, different researchers addressed the problem through different image enhancement techniques. Most of the state-of-the-art approaches applied common image processing techniques such as background foreg...
Article
Diffuse white is an important concept in all color appearance models. However, there is a lack of research directly about the perceived diffuse white in HDR images. Three experiments were conducted to explore the perceptual estimation of diffuse white in real HDR images when presented on displays. The first experiment showed that the perceptual est...
Article
Electronic displays are used in every modern day medical clinic. They are used to view images that are needed to diagnose, treat, and follow-up on patients with a variety of conditions. The type of electronic display used varies from department to department. Currently, a type of displays called medical grade displays are used to evaluate and diagn...
Article
It is said that multi‐chromatic displays can achieve wider color gamut by using saturated color channels, while there are also claims that these displays lose brightness and/or color saturation for higher luminance colorful images. This topic has created some controversy in the display industry and at standards‐setting organizations. This research...
Conference Paper
Nine selected high dynamic range (HDR) images were visually evaluated through a paired-comparison method in regard of colorfulness and details (proxies for perceived color gamut volume). HDR images are clipped into different peak luminance while keeping the same diffuse white setting. Psychophysical experimental results indicated an overall linear...
Conference Paper
Triangular gamut area plots on chromaticity diagrams (e.g., CIE xy or CIE u′v′) have long been used in attempts to describe and compare the range of colors that can be produced on displays. This has been done despite the long-established recognition that three-dimensional color gamut volumes in color appearance spaces (e.g. CIELAB or CIECAM02) more...
Article
This note examines the different concepts of encoding hue perception based on four unique hues (like NCS) or five principal hues (like Munsell). Various sources of psychophysical and neurophysiological information on hue perception are reviewed in this context and the essential conclusion that is reached suggests there are two types of hue percepti...
Article
Munsell crayons were discontinued in 1944 but the concept of the Munsell color wheel is still a part of the Crayola Crayon Company to this day. We performed a set of measurements using an original set of Munsell crayons to see if they still hold their specification and how they compare to the entire available spectrum of the Crayola crayon family....
Article
Relating instrumentally measured to visually perceived colour-differences is one of the challenges of advanced colorimetry. Lately, the use of color difference formulas is becoming more important in the computer vision field as it is a key tool in advancing towards perceptual image processing and understanding. In the last decades, the study of con...
Article
Display gamuts usually render complex shapes in a uniform color space, requiring observers to change views to comprehend a 3D plot. We propose a 2D representation of a display color gamut, named “gamut rings,” where the area within an arbitrary luminance and hue angle range corresponds to gamut volume.
Article
In this work, a methodology is introduced to use ordinary digital RGB cameras for the purpose of spectral and colorimetric color reproduction. First, it is attempted to recover the spectral reflectance from RGB camera response using different approaches, among which, it is shown that weighted nonlinear regression as performed better than other appr...
Article
The precision of corresponding colors data is critical to improve chromatic adaptation models. This research aims to obtain high precision and individually resolved corresponding colors data, as well as to look into the reversibility of chromatic adaptation. The experiment included 2 phases. The illumination changes were simply reverses of one anot...
Article
The colour rendition characteristics of light sources are quantified with measures based on CIE standard observers, which are reasonable representations of population averages. However, even among people with normal colour vision, the natural range of variation in colour sensitivity means any individual may see something different than the standard...
Article
There have been numerous methods for accessing the reflectance spectra; some methods enable one to obtain the spectra directly, such as using a spectrophotometer, hyper-spectral camera, and so forth. Even though the accuracy by which the spectra are obtained can be very high, the high price of these methods could pose an obstacle. On the other hand...
Article
Television and cinema displays are both trending toward greater ranges and saturation of reproduced colors, which are made possible by near-monochromatic illumination technologies. Through current broadcast and digital cinema standards work, system designs employing laser light sources, narrowband light-emitting diodes, quantum dots, and others are...
Data
Matlab codes. Matlab codes to simulate color matches as well as codes for individual colorimetric observer model. The codes allow to simulate three different color matching datasets demonstrated in the manuscript. Codes for an individual colorimetric observer model are included as well. (ZIP)
Article
Full-text available
This study proposes a vision model for individual colorimetric observers. The proposed model can be beneficial in many color-critical applications such as color grading and soft proofing to assess ranges of color matches instead of a single average match. We extended the CIE 2006 physiological observer by adding eight additional physiological param...
Article
Human color vision differs from person to person, not only when color deficiencies occur but also within color-normal populations. Investigating individual variability in normal color vision is beneficial both for clinical purposes and for quantifying observer metamerism. Researchers have used color matches such as Rayleigh matches, Moreland matche...
Article
Full-text available
We performed objective spectroradiometric measurements on an LCD image of the recently famous Tumblr dress which is typically perceived by people as blue/black or white/gold. The average ± standard deviation of the CIELAB coordinates was as follows: For a set of 33 points in the areas considered as blue/white, L* = 46 ± 6, C*ab = 33 ± 6, and hab =...
Article
In a color matching experiment, the colors of two stimuli might match perfectly to one observer. However, to another, those same two stimuli might not match depending on the spectral characteristics of the two stimuli and each of the observers' visual responses. This phenomenon, that any two observers perceive color matches differently, is termed o...
Article
The perception of color in nature is a complex multidimensional phenomenon. The vast range and high dimensionality of the light stimulus in a natural scene is reduced in range and dimension by the human visual system. The color experience is reduced to the appearance attributes of brightness, lightness, colorfulness, chroma, saturation, and hue fro...
Poster
Full-text available
Variation in color reproduction for retinal fundus photography represents a significant gap in the standardization of color for fundus cameras. This research aims to identify these color inconsistencies and reconcile them by proposing a color model standard.
Article
Wide color gamut media are emerging in the market, and this trend has been accelerated by ITU recommendation, Rec.2020 in 2012. Wide color gamut media possess spectrally narrow primaries, which would potentially increase the degree of observer metamerism. In this study, it was investigated if observer metamerism could be a serious issue under pract...
Article
The electronic display industry has begun a migration towards higher color gamut devices driven by LED, OLED, quantum dot and laser technologies capable of generating near monochromatic color stimuli in the traditional red, green, blue three-channel paradigm. The use of highly selective spectral stimuli, however, poses a risk to the consistency of...
Article
The perceptual gloss space defined in Pellacini et al. [9] could be used for quality control applications to bring similar benefits as seen in color with the use of CIELAB. However, a distance metric to relate all the dimensions in the space does not exist, and the space was only validated with the materials used to define the space. The current sp...
Article
A perceptually uniform gloss space was defined in Pellacini et al. [2000] as a reparameterization of the Ward BRDF model. Two dimensions, distinctness-of-image gloss and contrast gloss, were found to be enough to describe gloss perception, and the CIELAB lightness function was added to represent the diffuse component.
Conference Paper
A color matching experiment was designed and carried out to estimate human observers’ color matching functions (CMFs). 61 color-normal observers participated in the experiment. Their results were traced back to physiological factors using a mathematical vision model. The experiment time was 15 minutes, which is much faster than previous research ai...
Article
The effects of design decisions in the development of systems that generate images for human consumption, such as cameras and displays, are often evaluated using real-world images. However, human observers can react differently to complex pictorial stimuli over the course of a lengthy experiment. This study was conducted to develop understanding of...
Conference Paper
In this paper, we present a novel approach of tone mapping as gamut mapping in a high-dynamic-range (HDR) color space. High- and low-dynamic-range (LDR) images as well as device gamut boundaries can simultaneously be represented within such a color space. This enables a unified transformation of the HDR image into the gamut of an output device (in...
Article
Full-text available
Color variation in retinal fundus photography represents a significant gap in the standardization of color for fundus cameras. Fundus cameras are used in the context of ophthalmology as a method of documenting a patient’s retina to monitor pathology over time. This form of ophthalmic imaging is also used in clinical trial research and, increasingly...
Conference Paper
In general, it can be stated that unfortunately in most countries the number of students interested in traditional scientific disciplines (e.g. physics, chemistry, biology, mathematics, etc.) for his/her future professional careers has considerably decreased during the past years. It is likely that among the reasons of this trend we can find that m...
Chapter
The strong technological push for reliable device-independent color imaging over the last two decades has stressed the scientific capabilities in the area of color appearance modeling since the various images are typically viewed in a wide variety of viewing conditions. While it has been recognized for some time that a color appearance model is nec...
Article
Widely varying estimates of the number of discernible object colors have been made by using various methods over the past 100 years. To clarify the source of the discrepancies in the previous, inconsistent estimates, the number of discernible object colors is estimated over a wide range of color temperatures and illuminance levels using several chr...
Article
No two observers perceive color the same. To one observer, the colors of two objects might match perfectly; yet to another, those same two objects might not match depending on the spectral characteristics of the colors of the two objects, their illuminant, and each of the observer's spectral eye response. Here we create a large, representative grou...
Article
There exist individual differences in color matching functions and the use of a single standard observer as a representative of a whole population often limits the accuracy of color reproduction, especially for narrowband stimuli. We conducted a paired comparison experiment for 58 color-normal people involving color difference judgments using four...
Conference Paper
Full-text available
Using a metric feature space for pattern recognition, data mining, and machine learning greatly simplifies the mathematics because distances are preserved under rotation and translation in feature space. A metric space also provides a “ruler”, or absolute measure of how different two feature vectors are. In the computer vision community color can e...
Article
A study is currently underway that is aimed at increasing understanding of the optimal design of pictorial stimuli in perceptual experiments. Evaluating the impact of image complexity on visual attention is of particular interest. Since this work centers on pictorial scenes, a variety of such scenes must be selected as stimuli. The experiments plan...
Article
— A technique was developed and tested for generating CRT pictorial image reproductions that match the color appearance of print originals. Five observers, experienced in using Adobe Photoshop™ to adjust images, matched two scenes using a memory-matching technique. Observers were able to produce accurate matches when originals and reproductions wer...
Article
A methodology for achieving brighter, more colorful colors and deeper, darker colors based on Evans' zero gray (G0) [described in The Perception of Color] and his concept of brilliance as a percept in color vision was demonstrated and tested psychometrically in media produced under current digital video and digital cinema standards—basically the sR...
Article
Traditional color spaces have been widely used in a variety of applications including digital color imaging, color image quality, and color management. These spaces, however, were designed for the domain of color stimuli typically encountered with reflecting objects and image displays of such objects. This means the domain of stimuli with luminance...
Article
Teeth in a patient's mouth in a dental office, or in the natural environment, represent very complex stimuli for the human color vision system. Predicting their perceived color is a daunting task at best. Colorimetry is designed mainly for the evaluation of uniform, flat, opaque, materials of fairly large size viewed on a medium-grey background und...
Article
In digital image reproduction, it is often desirable to compute image difference of reproductions and the original images. The traditional CIE color difference formula, designed for simple color patches in controlled viewing conditions, is not adequate for computing image difference for spatially complex image stimuli. Zhang and Wandell [Proceeding...
Article
This article describes a new perceived whiteness index, C/V index, which focuses on the brightness-enhancement effect of color components included in the spectral reflectance factor distribution of approximate white objects or in the spectral power distribution of illuminations. The index is developed on the basis of a color vision model. The perce...
Article
Current HDR display technology approaches the dynamic-range capabilities of the fully adapted human visual system. As such, this technology has potential for performing as a surrogate for real-world scenes in the perceptual evaluation of high-dynamic-range (HDR) image-reproduction algorithms that aim to map HDR scenes to the limited dynamic ranges...
Conference Paper
The purpose of this research was to design and complete psychophysical experiments for scaling lightness and lightness differences for achromatic percepts above and below the lightness of diffuse white (L*= 100). Below diffuse white experiments were conducted under reference conditions recommended by CIE for color difference research. Overall a ran...
Article
Different gamut expansion algorithms were applied to sRGB images and evaluated using paired comparison on image preference. Two performed better regardless test scenes. Image preference was highly correlated to lightness contrast, and there is a preferable range in the degree of chroma enhancement.
Article
The overarching goal of this research was to compare different rendering solutions in order to understand why some yield better results specifically when applied to rendering synthetic objects into real photographs. A psychophysical experiment was conducted in which the composite images were judged for accuracy against the original photograph. In a...
Article
Full-text available
— The effect of varying the color gamut of an extended-gamut LCD on color appearance and preference was measured psychometrically in two experiments at each of two separate laboratories over a representative set of 10 images each. The first experiment measured the effect of color gamut on appearance, and the effect on the appearance attribute color...
Article
Color imaging technologies with higher dynamic range, wider color gamut, and greater bit depth require new and/or different ways of thinking about color. In particular, color appearance issues become more important. This paper discusses some recent research on the application of color and image appearance modeling to high-dynamic-range and wide-col...
Article
We measured image preference using paired comparison when varying the color gamut and maximum luminance of the display to investigate the effect of color gamut volume on image preference. There is a trade-off relationship between the area of color gamut and luminance on image preference.
Article
This paper describes a proof-of-concept implementation that uses a high dynamic range CMOS video camera to integrate daylight harvesting and occupancy sensing functionalities. It has been demonstrated that the proposed concept not only circumvents several drawbacks of conventional lighting control sensors, but also offers functionalities that are n...
Article
Full-text available
Hyperspectral image data can provide very fine spectral resolution with more than 200 bands, yet presents challenges for visualization techniques for displaying such rich information on a tristimulus monitor. This study developed a visualization technique by taking advantage of both the consistent natural appearance of a true color image and the fe...
Article
Can images from professional digital SLR cameras be made equivalent in color using simple colorimetric characterization? Two cameras were characterized, these characterizations were implemented on a variety of images, and the results were evaluated both colorimetrically and psychophysically. A Nikon D2x and a Canon 5D were used. The colorimetric an...
Article
The spectrum locus of a CIE chromaticity diagram defines the boundary within which all physically realizable color stimuli must fall. While that is a physical and mathematical reality that cannot be violated, it is possible to create colors that appear as if they were produced by physically impossible stimuli. This can be accomplished through caref...
Article
The goal of color and contrast enhancement in general is to provide a more appealing image or video by adjusting the amount of saturation and lightness to achieve more vivid or realistic colors and to increase the visibility of details that may be obscured by deficient global and local lightness. We implemented and compared the performance of vario...