Gary Meyer's publications have appeared in conference proceedings, journals, and books related to computer graphics, color science, and coating technologies. His students have also written Bachelor's, Master's and PhD theses at both the University of Oregon and the University of Minnesota.
Creating Metallic Color Sequences for an Architectural Wall
Citation
Seth Berrier, Gary Meyer, and Clement Shimizu. Creating Metallic Color Sequences for an Architectural Wall. ACADIA 2008: Proceedings of the 28th Annual Conference of the Association for Computer Aided Design in Architecture, 308-313, 2008.
Abstract
A metallic paint scheme for an architectural wall is created using computer aided color
appearance design techniques. New computer graphic hardware that allows real-time
rendering of complex reflectance functions is employed to produce photo-realistic images
of the metallic paint applied to the surface of the wall. An interpolation scheme is
developed that permits one and two dimensional metallic shade sequences to be
determined between individual bricks in a single row of the wall and between the
complete rows of bricks that compose the wall. Paint formulation software, originally
developed for auto refinish applications, is used to determine the paint mixtures
necessary to realize the metallic colors in the design. A prototype of the wall is
constructed and exhibited in a museum gallery.
Citation
Jonathan Konieczny and Gary Meyer. Material and Color Design Using Projectors. CGIV 2006: Third European Conference on Colour in Graphics, Imaging, and Vision, 438-442, 2006
Abstract
A novel front projection system is introduced for the pur
pose of material and color design. The system explores tech
niques for simulation of color on real objects lit by projectors.
Choice of size, shape, and color of the target projection object
is considered. Ambient lighting conditions are controlled, and
a second projector is used as the light source. This permits the
target projection object to be “cut out” from the light source,
allowing for a realistically lit scene without “washing out” the
simulated color. The surrounding environment is captured using
high dynamic range environment maps in order to realistically
simulate glossy materials. Metallic colors are emphasized, but
the principles and conclusions also extend to the simulation of
other materials.
Citation
Gary W. Meyer. Computer Aided Color Appearance Design. CGIP 2000: Proceedings of the First International Conference on Color in Graphics and Image Processing, 195-200, 2000.
Abstract
Recent developments in the eld o f computer graph-ics wil l p rovidecolor scientistswith anew set of de-sign tools. Real-timeshading wil lmakeit possible
to interactively evaluate surfaces that exhibit com-plexvariationin the directionandcolorofre
ected
light. New software simulation techniques will facili-tate the prediction of these important surfacere
ec-tion p roperties. Togetherthese tools for synthesizing
and e valuating color appearance d e ne a new method-ologycal led computer aided color appearance design.
This paper reviews the important computer graphics
advances in real-timeshading and surfacere
ection
modeling that have made this novel approach to color
appearance design possible.
The Wall of Inspiration: A Computer Aided Color Selection System
Citation
Seth Berrier, Clement Shimizu, Patrick Chong, Dnardo Colucci, and Gary Meyer. The Wall of Inspiration: A Computer Aided Color Selection System, CGIV 2008: Fourth European Conference on Colour in Graphics, Imaging, and Vision, 132-137, 2008
Abstract
Computer graphics hardware and software is used to create
a new set of tools for selecting a household paint color. Impor-tant surface reflection effects, such as gloss and pearlescence,
are rendered in real time using pixel shading hardware. Unlike
traditional paint chips, this feature permits colors to be evaluated
on three dimensional shapes and in different surface finishes. A
novel set of color navigation tools is provided to allow the user
to visualize the color collection supplied by the manufacturer, to
select subsets of the collection for consideration, and to match or
modify an existing color sample. This interface is easier to use
and less expensive to produce than the fan deck found in most
paint stores. The pictures produced by the software are displayed
on a four panel video wall. The large size of the wall allows the
user to evaluate the appearance of the color at a scale similar to
its final dimension once it has been applied to a surface.
Citation
Gary W. Meyer and Chad A. Robertson. A Data Flow Approach to Color Gamut Visualization. Fifth Color Imaging Conference: Color Science, Systems, and Applications, 209-214, 1997
Abstract
Software has been developed to help engineers visualize the
gamuts of color hardcopy devices. Software modules have
been written so that color gamuts and color space
transformations can be explored using a scientific
visualization program. Tools have been created that allow
the user to accentuate the differences between gamuts and to
interact with the displayed data. The data flow architecture
of the program makes it easy to add more color gamuts and
to investigate additional color transformations.
Citation
Clement Shimizu, Gary W. Meyer, and Joseph P. Wingard. Interactive Goniochromatic Color Design. Eleventh Color Imaging Conference, 16-22, 2003
Abstract
An interactive program has been developed to assist in
the design of new goniochromatic colors. The program
gives the user a unique set of controls over a second order
polynomial that defines these color families at a sequence of
aspecular reflection angles. One approach, based on
traditional metallic colors, allows the user to adjust the
average hue, saturation, and brightness of all of the colors
interpolated by the polynomial. Another method,
appropriate for the newer effect colors, permits the designer
to establish face and flop colors to be reached at either end
of the interpolation. In a final technique, variations
produced by adjusting model parameters can be evaluated
and selected.
Citation
Clement Shimizu and Gary Meyer. Color Styling Tools, Eighteenth Color Imaging Conference, 272-279, 2010
Abstract
Creative tools are proposed that allow color stylists to take
advantage of their training in the art and design fields. A sim-ple reflection model is employed that has the minimum number of
free parameters required to design solid and metallic color fin-ishes from conceptualization to fabrication. The parameters cor-respond to color specification terms familiar to designers such as
face color, flop color, travel, and gloss. We demonstrate how the
reflection model can also be used to develop effective interfaces
for color stylists. We create a virtual mood board that allows di-rect selection of the reflection model parameters from pictures. We
also develop an image based BRDF tweaker for adjusting color
appearance directly on a 3D object.
A 3D Interface for Selecting Household Paint Colors
Citation
Seth Berrier and Gary Meyer. A 3D Interface for Selecting Household Paint Colors, Nineteenth Color Imaging Conference, 2011
Abstract
Commercially available tools for searching collections of
paint colors are critically examined and a new computer interface
for selecting household paint colors is proposed. The new system
is organized according to a perceptual color space and uses mod-eless, constrained, in-place, 3D interaction. Two user studies are
performed to evaluate this system and the results are discussed.
These studies demonstrate that, with enough training, our system
is faster and at least as accurate as current color search tools.
The results suggest that the tool could be beneficial to properly
trained design professionals. Users also report a favorable im-pression of our system over the current tools.
A BRDF Database Employing the Beard-Maxwell Reflection Model
Citation
Harold B. Westlund and Gary W. Meyer. A BRDF Database Employing the Beard-Maxwell Reflection Model. Proceedings of Graphics/Vision Interface ’02, 189-200, 2002
Abstract
TheBeard-Maxwellreflection modelis presentedas
anewlocal reflection modelfor usein realistic image
synthesis. Themodelis important becausethere is a
publicdomaindatabaseofsurfacereflection parameters,
the NonconventionalExploitationFactors DataSystem
(NEFDS), that utilizes a modifiedform ofthe Beard-Maxwellmodel.Additionalsurfacereflectionparameters
for the databasecanbedeterminedbecauseameasure-mentprotocol, using existingradiometric instruments,
hasbeenspecified. TheBeard-Maxwellmodelis also
ofhistoricalsignificancebecauseit predatesmanycom-putergraphicsreflection modelsandbecauseit includes
severalfeatures that areincorporated into existinglocal
reflection models.TheNEFDSis describedandaspe-cialshaderis developedforusewithNEFDS.Theshader
makesuseofthe aliasmethodfor determiningrandom
variates from discreteprobabilitydistributions. Realis-tic imagesaresynthesizedfromtheexistingdatabaseand
fromsamplesthat werecharacterizedusingthemeasure-mentprotocol.
Citation
Lijun Qu and Gary Meyer, Perceptually Driven Interactive Geometry Remeshing, I3D 2006: Symposium on Interactive 3D Graphics and Games, 199-206, 2006
Abstract
Visual patterns on the surface of an object, such as two dimen-sional texture, are taken into consideration as part of the geome-try remeshing process. Given a parameterized mesh and a texture
map, the visual perceptual properties of the texture are first com-puted using a visual discrimination metric. This precomputation is
then used to guide the distribution of samples to the surface mesh.
The system automatically distributes few samples to texture areas
with strong visual masking properties and more samples to texture
areas with weaker visual masking properties. In addition, due to
contrast considerations, brighter areas receive fewer samples than
do darker surface features. Because of the properties of the human
visual system, especially visual masking, the artifacts in the ren-dered mesh are invisible to the human observer. For a fixed number
of polygons, this approach also improves the quality of the rendered
mesh since the distribution of the samples is guided by the princi-ples of visual perception. The utility of the system is demonstrated
by showing that it can also account for other observable patterns
on the surface, besides two dimensional texture, such as those pro-duced by bump mapping, lighting variations, surface reflectance,
and interreflections.
Citation
Jonathan Konieczny, John Heckman, Gary Meyer, Mark Manyen, Marty Rabens, and Clement Shimizu. Automotive Spray Paint Simulation, ISVC 2008: 4th International Symposium on Visual Computing, 998-1007, 2008
Abstract
A system is introduced for the simulation of spray painting.
Head mounted display goggles are combined with a tracking system to
allow users to paint a virtual surface with a spray gun. Ray tracing is
used to simulate droplets landing on the surface of the object, allowing
arbitrary shapes and spray gun patterns to be used. This system is com-bined with previous research on spray gun characteristics to provide a
realistic simulation of the spray paint including the effects of viscosity,
air pressure, and paint pressure. The simulation provides two different
output modes: a non-photorealistic display that gives a visual represen-tation of how much paint has landed on the surface, and a photorealistic
simulation of how the paint would actually look on the object once it has
dried. Useful feedback values such as overspray are given. Experiments
were performed to validate the system.
Airbrush Simulation for Artwork and Computer Modeling
Citation
Jonathan Konieczny, and Gary Meyer. Airbrush Simulation for Artwork and Computer Modeling, NPAR 2009: 7th International Symposium on Non-Photorealistic Animation and Rendering, 61-69, 2009
Abstract
A computerized airbrush system with a full three dimensional air-brush interface is presented. The position and orientation of an
electronic airbrush tool is tracked in space, and, when the trigger
is pulled, paint is sprayed onto two and three dimensional objects
displayed on a computer monitor. The experimentally derived paint
spray model used for the airbrush takes into account factors such
as air to paint ratio, viscosity, and distance of the airbrush from the
work. Paint mixing between colors applied to the surface is mod-eled using Kubelka-Munk theory. Computerized stencils, including
semi-permeable stencils, can be manually positioned by the artist
or projected onto the object’s surface. Two and three dimensional
examples of traditional airbrush artwork, produced using the sys-tem, are presented. The system can also be used as a modeling tool
to decorate three dimensional objects.
Citation
Lijun Qu and Gary Meyer. Faceting Artifact Analysis for Computer Graphics, Pacific Graphics, 419-422, 2007
Abstract
The faceting signal, defined in this paper as the difference signal between a rendering of the original geometric
modeland a simplified version of the geometric model, is
responsible for the faceting a rtifacts commonly observed in
the renderings of coarse geometric models. In this paper,
we analyze the source of the faceting signal and develop a
perceptual metric for the visibility of the faceting signal.
Perceptually Guided Rendering of Textured Point-based Models
Citation
Lijun Qu, Xiaoru Yuan, Minh Nguyen, Gary Meyer, Baoquan Chen, and Jered Windsheimer. Perceptually Guided Rendering of Textured Point-based Models. PBG 2006: Symposium on Point-Based Graphics, 95-102, 2006
Abstract
In this paper, we present a textured point-based rendering scheme that takes into account the masking properties of
the human visual system. In our system high quality textures are mapped to point-based models. Given one texture,
an importance map is first computed using the visual masking tool included in the JPEG2000 standard. This
importance map indicates the masking potential of the texture. During runtime, point-based models are simplified
and rendered based on this computed importance. In our point simplification method, called Simplification by
Random Numbers (SRN), each point in the model is pre-assigned a random value. During rendering, the pre-
assigned value is compared with the preferred local point density (derived from importance) to determine whether
this point will be rendered. Our method can achieve coherent simplification for point models.
A First Step Towards Photorealistic Rendering of Coated Surfaces and Computer Based Standards of Appearance
Citation
Fern Y. Hunt, Egon Marx, Gary W. Meyer, Theodore Vorburger, Peter A. Walker and Harold B. Westlund. A First Step Towards Photorealistic Rendering of Coated Surfaces and Computer Based Standards of Appearance. Service Life Prediction Methodology and Metrologies, Jonathan W. Martin and David R. Bauer, Editors, American Chemical Society Symposium Series, No. 805, Oxford University Press, 437-451, 2001
Abstract
In an effort to understand the physical basis for coating and surface appearance we are
combining the results of optical and surface topographical measurements, mathematical
modeling and computer graphic rendering. We seek to explore the feasibility of using
computer graphic images to visualize the color and gloss of surfaces using measured data
and models so that rendering becomes a tool to identify important parameters in the material
formulation process that contribute to appearance. Here we report on a study of gloss
variation in a series of samples with controlled roughness. The work makes use of the
sample preparation, characterization and measurement described in [3]. Modeling based on
that data was used to produce computer graphic images of the samples. We also briefly
describe work on the rendering of data from some early measurements of colored metallic
paint.
Citation
Jonathan Konieczny, Clement Shimizu, Gary Meyer, and D’nardo Colucci. A Handheld Flexible Display System. Proceedings of IEEE Visualization 2005, 591-597, 2005
Abstract
A new close range virtual reality system is introduced that allows
intuitive and immersive user interaction with computer generated
objects. A projector with a special spherical lens is combined with
a flexible, tracked rear projection screen that users hold in their
hands. Unlike normal projectors, the spherical lens allows for a
180 degree field of view and nearly infinite depth of focus. This
allows the user to move the screen around the environment and use
it as a virtual “slice” to examine the interior of 3D volumes. This
provides a concrete correspondence between the virtual representa-tion of the 3D volume and how that volume would actually appear
if its real counterpart was sliced open. The screen can also be used
as a “magic window” to view the mesh of the volume from different
angles prior to taking cross sections of it. Real time rendering of the
desired 3D volume or mesh is accomplished using current graphics
hardware. Additional applications of the system are also discussed.
A Computer Graphic System for Rendering Gonio-Apparent Colors
Citation
Gary W. Meyer, Harold B. Westlund, Peter A. Walker, and Joseph P. Wingard. A Computer Graphic System for Rendering Gonio-Apparent Colors. in 9th Congress of the International Colour Association, Proc. SPIE 4421, 922-925, 2002.
Abstract
A computer graphic system has been developed that allows a color scientist to evaluate the appearance of gonio-apparent
colors. Reflection modeling software is used to define a BRDF from existing computer graphic reflection models and
standard appearance measurements for gloss and metallic travel. A visualization program allows the user to examine the
BRDF that results from reflection modeling. Real-time software and hardware can be employed to adjust the BRDF and
display a surface with the specified reflection properties. A high quality rendering system is available to make individual
pictures that incorporate complex lighting and reflection effects.
Citation
Gary Meyer, Clement Shimizu, Alan Eggly, David Fischer, Jim King, and Allan Rodriguez. Computer Aided Design of Automotive Finishes. Proceedings of 10th Congress of the International Colour Association, 685-688, 2005
Abstract
The principles of computer aided design were applied to the creation of new automotive
finishes. A computer graphic program was written that allows the user to interactively adj ust the
surface reflection properties of an automotive paint and visualize the appearance of that paint on a
three dimensional surface. The program gives a designer intuitive controls over a second order
polynomial that defines the color of the paint at a series of aspecular angles. An automotive stylist
was permitted to use the program and design three new automotive paints that had never been
manufactured. Formulations for the designed paints were determined by inputting the desired
aspecular measurements into an automotive refinish system. The new paints were mixed and sprayed
on metal panels. Comparisons between the actual and simulated finishes were j udged to be adequate
by those involved in the experiment.
Citation
Clement Shimizu and Gary W. Meyer. Predicting and Fixing Geometric Color Mismatches, Proceedings of 11th Congress of the International Colour Association, 2009.
Abstract
Color mismatches that result from geometric misalignment are studied. Differences in color can result
when adjacent parts of an object are coated with the same paint but are not aligned to create a
continuous geometric surface. The color difference that results due to shading can be accentuated by
the use of metallic and pearlescent paints with goniochromatic properties. A metric is developed for
determining when the color difference is large enough for the misalignment to become apparent. A
technique is also presented for selecting a paint that matches the adjacent part and creates the illusion
of geometric continuity even though the two parts are misaligned.
A Computer Graphics System for Examining Paint Color Collections
Citation
Seth Berrier, Gary Meyer, and Clement Shimizu. A Computer Graphics System for Examining Paint Color Collections, Proceedings of 11th Congress of the International Colour Association, 2009
Abstract
A computer graphic program for organizing and displaying the colors in a paint collection is
presented. A virtual representation for the traditional color card fan deck is described. This
interactive program provides a lightness, chroma and hue interface for selecting a color from the
collection. Software for visualizing a paint color on a three dimensional surface is also discussed.
This tool allows the user to evaluate the sheen of a solid paint color and the travel of a metallic or
pearlescent paint color
Citation
Gary Meyer and Clement Shimizu. Computational Automotive Color Appearance. Eurographics Workshop on Computational Aesthetics in Graphics, Visualization, and Imaging, 217-221, 2005.
Abstract
A computer graphic system has been developed that permits the interactive design of new automotive finishes.
The software makes use of a reflection model for car paint that is based on industry standards for measuring the
appearance characteristics of the paint. These measurements include gloss for the clearcoat and three aspecular
measurements for the metallic basecoat. The program interface provides a means for altering the reflectance
properties of the paint and for visualizing the effect of those changes on the color appearance of the car. The
desired aspecular measurements for the new paint can be input to a paint formulation system so that the paint can
be manufactured. A test of the system shows good correspondence between the designed and the fabricated paint.
Computer Aided Color Appearance Design using Environment Map Based Lighting
Citation
Clement Shimizu and Gary Meyer. Computer Aided Color Appearance Design using Environment Map Based Lighting. Eurographics Workshop on Computational Aesthetics in Graphics, Visualization, and Imaging, 223-230, 2005.
Abstract
A BRDF approximation is developed that is suitable for interactive color appearance design in direct lighting
provided by environment maps. The BRDFs are approximated as a linea r combination of cosine lobes with a fixed
set of specular exponents. A nonlinear optimization routine is used to fit the cosine lobes to BRDFs appropriate
for a specific color appearance design application: automotive paint. Modifi cation and rendering of the BRDF is
made possible by linearly combining prefiltered environment maps for each cosine lobe in real time.
Citation
Bei Li, Gary W. Meyer, and R. Victor Klassen. A Comparison of Two Image Quality Models. Human Vision and Electronic Imaging III, Bernice E. Rogowitz and Thrasyvoulos N. Pappas, Editors, Proc. SPIE 3299, 98-109, 1998
Abstract
In recent years a numb er of dierent vision mo dels have b een prop osed to assist in the evaluation of image quality
However there have b een few attempts to indep endently evaluate these mo dels and to make comparisons b etween
them In this pap er we rst summarize the work that has b een done in image quality mo deling We then select two
of the leading image quality mo dels the Daly Visible Dierences Predictor and the Sarno Visual Discrimination
Mo del for further study We b egin by describing our implementation which was done from the published pap ers
of each of the mo dels We next discuss the similarities and the dierences b etween the two mo dels The pap er ends
with a summary of the imp ortant advantages of each approach The comparison of these two mo dels is presented in
the context of our research interests which are image quality evaluation for b oth computer imaging and computer
graphics tasks The pap er includes illustrations drawn from these two areas
A Visual Difference Metric for Realistic Image Synthesis
Citation
Mark R. Bolin and Gary W. Meyer. A Visual Difference Metric for Realistic Image Synthesis. Human Vision and Electronic Imaging IV, Bernice E. Rogowitz and Thrasyvoulos N. Pappas, Editors, Proc. SPIE 3644, 106-120, 1999
Abstract
An accurate and e±cient model of human perception has been developed to control the placement of samples in a
realistic image synthesis algorithm. Previous sampling techniques have sought to spread the error equally across the
image plane. However, this approach neglects the fact that the renderings are intended to be displayed for a human
observer. The human visual system has a varying sensitivity to error that is based upon the viewing context. This
means that equivalent optical discrepancies can be very obvious in one situation and imperceptible in another. It is
ultimately the perceptibility of this error that governs image quality and should be used as the basis of a sampling
algorithm.
This paper focuses on a simpli¯ed version of the Lubin Visual Discrimination Metric (VDM) that was developed
for insertion into an image synthesis algorithm. The simpli¯ed VDM makes use of a Haar wavelet basis for the
cortical transform and a less severe spatial pooling operation. The model was extended for color including the
e®ects of chromatic aberration. Comparisons are made between the execution time and visual di®erence map for the
original Lubin and simpli¯ed visual di®erence metrics. Results from the realistic image synthesis algorithm are also
presented.
Implementation of a Visual Difference Metric Using Commodity Graphics Hardware
Citation
Jered E. Windsheimer and Gary W. Meyer. Implementation of a Visual Difference Metric Using Commodity Graphics Hardware. Human Vision and Electronic Imaging IX, Bernice E. Rogowitz and Thrasyvoulos N. Pappas, Editors, Proc. SPIE 5292, 150-161, 2004.
Abstract
Recent improvements in Graphics Processing Units (GPUs) make it possible to execute complex image-processing
tasks on commodity video cards. The vertex and pixel pipelines of modern GPUs are reprogrammable using
high-level programming languages to accomplish almost any task a CPU can perform. Additionally, GPUs are
designed to execute vector and matrix operations at high speeds with high parallelism. GPUs now support full
floating-point precision in each color channel, allowing techniques that require such precision to be more easily
supported than in the past. This paper reviews the development of a complete implementation of the Sarnoff
Visual Discrimination Model (VDM) that executes almost exclusively upon the GPU. This implementation takes
advantage of several properties of modern GPUs to improve the running time by an order of magnitude compared
to the CPU implementations. An interactive version of the VDM allows the user to explore, in near real time,
the significance of various pictorial artifacts.
Citation
Jonathan Konieczny, Gary Meyer, Clement Shimizu, John Heckman, Mark Manyen, and Marty Rabens. VR Spray Painting for Training and Design. VRST 2008: 15th ACM Symposium on Virtual Reality Software and Technology, 293-294, 2008
Abstract
A system is introduced for the simulation of spray painting. Head
mounted display goggles are combined with a tracking system to al-
low users to paint a virtual surface with a spray gun. Ray tracing is
used to simulate droplets landing on the surface of the object, allow-
ing arbitrary shapes and spray gun patterns to be used. This system
is combined with previous research on spray gun characteristics to
provide a realistic simulation of the spray paint including the effects
of viscosity, air pressure, and paint pressure. The simulation pro-
vides two different output modes: a non-photorealistic display that
gives a visual representation of how much paint has landed on the
surface, and a photorealistic simulation of how the paint would ac-
tually look on the object once it dried. Useful feedback values such
as overspray are given. Experiments were performed to validate the
system.
Color Defective Vision and Computer Graphics Displays
Citation
Gary W. Meyer and Donald P. Greenberg. Color Defective Vision and Computer Graphics Displays. IEEE Computer Graphics and Applications, 8:28-40, 1988.
Abstract
The fundamental spectral sensitivity functions of the
human visual system define a color space that can help
in designing better color user interfaces. In particular,
this color space makes it possible to accommodate
individuals with color-deficient vision. To screen poten-
tial users of computer graphics systems, traditional
color vision tests, such as the Farnsworth-Munsell
100-hue test, can be implemented using a digitally con-
trolled color television monitor, and these tests can be
extended in ways that improve the specificity of their
diagnoses. To assist in the design of computer graphics
displays, a picture of the world as seen by color-
deficient observers can be synthesized, and guidelines
can be given for the selection of colors to be presented
to color-deficient observers.
Computer Rendering and Visual Detection of Orange Peel
Citation
Jonathan Konieczny and Gary W. Meyer. Computer Rendering and Visual Detection of Orange Peel. to appear in Journal of Coatings Technology and Research.
Abstract
The computer graphic simulation of a com-mon spray painting artifact, called orange peel, is
discussed. Orange peel distorts surface reflections and
is commonplace in product design applications. The
orange peel measurements from a standard industrial
instrument are used to construct a height field, and this
surface is rendered using traditional normal mapping
techniques. Comparisons are made between real pan-els with orange peel and simulations of those panels. A
simple visual model for detecting the presence of
orange peel is also presented and evaluated. User
testing of the model confirms that orange peel is more
visible on dark paint colors than on light paint colors.
The latter outcome suggests that to minimize applica-tion time, but still keep orange peel below visual
threshold, paint application systems should be de-signed to take paint color into account.
Citation
Gary W. Meyer and Donald P. Greenberg. Perceptual Color Spaces for Computer Graphics. Proceedings of SIGGRAPH’80, 254-261, 1980.
Abstract
Perceptually uniform color spaces can be a useful tool for solving computer graphics color selection prob-
lems. However, before they can be used effectively some basic principles of tristimulus colorimetry must be
understood and the color reproduction device on which they are to be used must be properly adjusted. The
Munsell Book of Color and the Optical Society of America (OSA) Uniform Color Scale are two uniform color
spaces which provide a useful way of organizing the colors of a digitally controlled color television moni-
tor. The perceptual uniformity of these color spaces can be used to select color scales to encode the vari-
ations of parameters such as temperature or stress.
Citation
Jay S. Gondek, Gary W. Meyer, and Jonathan G. Newman. Wavelength Dependent Reflectance Functions. Proceedings of SIGGRAPH’94, 213-220, 1994.
Abstract
A wavelength based bidirectional reflectance function is developed
for use in realistic image synthesis. A geodesic sphere is employed
to represent the BRDF, and a novel data structure is used to store
this description and to recall it for rendering purposes. A virtual
goniospectrophotometer is implemented by using a Monte Carlo
ray tracer to cast rays into a surface. An optics model that incorpo-rates phase is used in the ray tracer to simulate interference effects.
An adaptive subdivision technique is applied to elaborate the data
structure from rays scattered into the hemisphere above the surface.
The wavelength based BRDF and virtual goniospectrophotometer
are utilized to analyze and make pictures of thin films, idealized
pigmented materials, and pearlescent paints.
Applying Appearance Standards to Light Reflection Models
Citation
Harold B. Westlund and Gary W. Meyer. Applying Appearance Standards to Light Reflection Models. Proceedings of SIGGRAPH’01, 501-510, 2001
Abstract
Appearance standards for gloss, haze, and goniochromatic color are
applied to computer graphic reflection models. Correspondences
are derived between both the gloss and haze standards and the
specular exponent of the Phong model, the surface roughness of
the Ward model, and the surface roughness of the Cook-Torrance
model. Metallic and pearlescent colors are rendered using three
aspecular measurements defined in a proposed standard for go-niochromatic color. The reflection models for gloss and goniochro-matic color are combined to synthesize pictures of clear coated au-tomotive paint. Advantages of using appearance standards to select
reflection model parameters include the small number of required
measurements and the inexpensive commercially available instru-ments necessary to acquire the data. The use of a standard appear-ance scale also provides a more intuitive way of selecting the reflec-tion model parameters and a reflection model independent method
of specifying appearance.
An Experimental Evaluation of Computer Graphics Imagery
Citation
Gary W. Meyer, Holly E. Rushmeier, Michael F. Cohen, Donald P. Greenberg, and Kenneth E. Torrance. An Experimental Evaluation of Computer Graphics Imagery. ACM Transactions on Graphics, 5:30-50, 1986
Abstract
Accurate simulation of light propagation within an environment and perceptually based imaging
techniques are necessary for the creation of realistic images. A physical experiment that verifies the
simulation of reflected light intensities for diffuse environments was conducted. Measurements of
radiant energy flux densities are compared with predictions using the radiosity method for those
physical environments. By using color science procedures the results of the light model simulation
are then transformed to produce a color television image. The final image compares favorably with
the original physical model. The experiment indicates that, when the physical model and the
simulation were viewed through a view camera, subjects could not distinguish between them. The
results and comparison of both test procedures are presented within this paper.
Modeling Pigmented Materials for Realistic Image Synthesis
Citation
Chet S. Haase and Gary W. Meyer. Modeling Pigmented Materials for Realistic Image Synthesis. ACM Transactions on Graphics, 11:305-335, 1992
Abstract
This article discusses and applies the Kuhelka Munk theory of pigment mixing to computer
graphics in order to facilitate improved image synthesis. The theories of additive and subtractive
color m]xing arc discussed and are shown to be insufficient for pigmented materials. The
Kubclka Munk theory of pigment mixing is developed and the relevant equations arc derived.
pigmer]t mixing experiments are performed and the results are displayed on cokw tekm’ision
monitors. A paint program that uscs Kubelka Munk theory to mix real pigments is presented.
Theories of color matching with pigments are extended to determine rcflectances for use in
realistic image synthesis.
Visual Cues and Pictorial Limitations in Photorealistic Images
Citation
Chet S. Haase and Gary W. Meyer. Modeling Pigmented Materials for Realistic Image Synthesis. ACM Transactions on Graphics, 11:305-335, 1992
Abstract
The limitations of two-dimensional pic-
tures as representations for reality are dis-
cussed. A review is made of the perceptual
cues necessary to convey a sense of real-
ism. These cues include, but are not limited
to, binocular disparity, field of view, ac-
commodation, vergence, and chromatic
adaptation. Examples are given of how the
physical characteristics of two-dimension-
al pictures limit the use of these cues in
computer-graphic images. Techniques de-
veloped by artists and photographers to
overcome some of these limitations are
discussed.
Shadow Mapping and Visual Masking in Level
of Detail Systems
Abstract
This paper examines the effects of real-time lighting and shadows on the
perception of low detail three-dimensional models. It does so through the
creation of a simulated slide projector that can be used to study the masking
effect of textures in a level of detail system. Surface textures have long been
known to have an effect on a viewer’s perception of model detail, but since
surface textures are generally static, they are of little use in dynamic LOD
systems. This paper looks at how a dynamically changing projected texture,
in the form of a simulated slide projector with realistic real-time shadow
generation, affects model detail perception. The results of this experiment
show that light and shadow falling on a model can have a dramatic effect on
the perceived quality of models, which could allow such factors to be taken
into account when developing a sophisticated level of detail system.
An Analysis and Comparison of Two
Visual Discrimination Models
Abstract
Visual models are often used to analyze the performance of image processing
systems
Two of the leading models are the Daly and the Sarno model whichhave
been designed to predict the visibility of luminance di erences between static input
images
They accomplish this by attempting to reproduce the functional responses
of every physiological mechanism in the visual pathway of the brain
These two models are based on the same set of psychophysical facts about
human vision
Therefore they have a similar basic architecture and some similar
mechanistic features
However the Daly and the Sarno models take totally di er
ent approaches to modeling visual perception the frequency domain approachand
the spatial domain approach respectively
A comparison of these two models is made based on a detailed description of
v
their structures and on detection test results
Similarities and di erences of both
models are discussed along with their strengths and weaknesses
Abstract
Software has been developed to help engineers visualize the gamuts of color
hardcopy devices. Software modules have been written so that color gamuts and color
space transformations can be explored using a scientific visualization program. Tools
have been created that allow the user to accentuate the differences between gamuts and to
interact with the displayed data. The data flow architecture of the program makes it easy
to add more color gamuts and to investigate additional color transformations.
A Visualization System for Bidirectional
Reflectance Distribution Functions
Abstract
Electromagnetic radiation is scattered by the interfaces it encounters. This
scattering can be mathematically described using the Bidirectional Reflectance Distribution
Function (BRDF). BRDFs are studied in many fields, and the diverse
BRDF literature was surveyed with the goal of developing a software library of
BRDF representation schemes. The Oregon BRDF Library was subsequently employed
in the construction of a visualization tool that is useful for both research and
education. This tool, known as BRDFvis, was built using Advanced Visual Systems
Inc. Express. BRDFvis permits interactive viewing of the scatter predicted
by the models present in the Oregon BRDF Library as well as reflectance distributions
stored in a database of measured samples. The Nonconventional Exploitation
Factors (NEF) database and the Oregon BRDF Library models were then used to
generate images.
Abstract
Industry standard methods for measuring appearance are applied to realistic image
synthesis. Two appearance attributes, gloss and haze, are known to be determined by
the shape of the specular reflection lobe. Standards which specify the measurement of
these two geometric appearance attributes are used to select BRDF model parameters
for a number of computer graphics reflection models. The bi-directional reflectance
distribution function (BRDF) of metallic and pearlescent paints can be characterized
with only a few industry standard specular measurements. Using these measurements,
a new computer graphics BRDF model is developed.
An Inexpensive Method of Setting the Monitor White Point
Abstract
Calibrating a color television monitor in terms of the CIE XYZ color notation system
has assumed an increasingly important role in computer graphics. This adjustment has
been shown to be useful in applications as diverse as two-dimensional page layout for
the graphics arts and three-dimensional realistic image synthesis for commercial animation.
Part of the calibration process involves setting the individual brightness and contrast
controls for the three monitor guns so that a white color with known chromaticity
coordinates is produced whenever R = G = B (Meyer, 1990). Typically, this is thought
to require an expensive color measurement device, such as a colorimeter or a color comparator.
The Importance of Gun Balancing in Monitor Calibration
Abstract
The transformation from the RGB primaries of a television monitor to the CIE XYZ color
notation system is usually formulated as a three by three matrix applied to a one by
three vector. In the general case, however, this is not true because the black point
of the monitor gamut is displaced from the origin of CIE XYZ space. An affine
transformation is necessary to accommodate this translation of the monitor gamut, and
this affine transformation can be reformulated as a four by three matrix times a one
by four vector. Balancing the monitor guns so that they maintain the same luminance
ratio over their entire dynamic range can minimize the error assuming a three by three
transform when a four by three matrix is actually called for. This procedure also
leads to improved calibration for applications where the front panel brightness
and contrast controls will be adjusted.
Color Spatial Acuity Control of a Screen Subdivision Image Synthesis Algorithm
Abstract
The limited color spatial acuity of the human visual system is exploited to develop a
more efficient algorithm for realistic image synthesis. A screen subdivision ray tracer
is modified to control the amount of chromatic and achromatic detail present at the
edges is an environment. An opponents color space (previously used to select wavelengths
for synthetic image generation) is used to define the chromatic and achromatic channels
present in the image. Computational savings achieved by the algorithm are discussed.
A perceptual evaluation shows that image quality is not seriously degraded by the use
of technique.
Newton's Colors : Simulating Interference Phenomena in Realistic Image Synthesis
Abstract
The laws of physics that govern thin film interference are reviewed and the colors
in nature that are produced by this mechanism are simulated. An efficient technique
for adjusting out of gamut colors is developed and is applied to the problem of
synthesizing the highly saturated interference colors. Common examples of thin film
interference are reproduced, including the iridescent colors created by multiple film layers.
Abstract
A database for storing and searching spectral curves is presented. The database gives
the user of a synthetic imaging system a means to select spectral reflectance, emittance,
transmittance, and absorptance curves for use in the realistic image synthesis process.
This provides an alternative to the usual synthesis process. This provides an alternative
to the usual RGB and HSV interfaces that are typically used for image color selection and
specification. The design of the database, the method of adding curves to it, and the
techniques available for searching it are discussed.
Wavelength Selection for Synthetic Image Generation
Abstract
The efficient synthesis of color in computer graphics is dependent on modeling the
correct number and spacing of wavelengths across the visible spectrum. It has
recently been shown that the opponent representation of the fundamental spectral
sensitivity functions is optimal from the point of view of statistical communication
theory. This result is used in this paper to guide the selection of wavelengths for
synthetic image generation. Gaussian quadrature with the opponent fundamentals as
weighting functions is used to choose the wavelengths. This approach is shown to be
superior to using Gaussian quadrature with the fundamental spectral sensitivity
functions or the CIE XYZ matching functions. The technique is evaluated by using
color difference calculations and by comparisons between a real scene and a computer
generated picture of that scene.
Color Education and Color Synthesis in Computer Graphics
Abstract
The important role that color science plays in computer-graphics image synthesis is discussed.
Simulated scenes of environments with diffuse and specular reflections as well as light
scattering are used as examples to demonstrate how tristimulus colorimetry and color- naming
systems are used in computer graphics. These examples also illustrate the need for
color-science literacy in the field of computer graphics. Color-science educational software
that has been developed to meet this need and that utlizes both vector-graphic and raster
graphic devices is also described.
Reproducing and Synthesizing Colour in Computer Graphics
Abstract
The use of color display devices in computer graphics is explored. First, some
principles of color science are reviewed are reviewed. Next, RGB and NTSC monitors,
the two most common color reproduction media used in computer graphics, are discussed.
Finally, some of the color synthesis problems encountered in reproducing color
collections, doing proper anti- aliasing, and making synthetic images are addressed.
