CIC 24

9:00 – 10:00 AM
THURSDAY KEYNOTE AND IS&T AWARDS

A Relational Approach to Color, Peter Morovic, HP Inc. (Spain)
It is well established in the study of color vision that the perception and interpretation of color is fundamentally relational – stimuli are interpreted in relation to their spatio-temporal environment at many levels of the visual experience. From the way the retina encodes color signals to color opponency, all the way to effects such as simultaneous contrast, or the crispening effect etc., there are many examples of experiments in vision science that demonstrate these principles. In this keynote we take this intuition further and show how thinking about color in relational terms allows for new insights in how we address color imaging problems. For example, metamerism and the definition of metamer sets can exploit relationships among wavelengths, surfaces and how we perceive them by way of Maxwell’s color top principle – any set of known reflectances directly implies the existence of all their combinations. Thinking about color in these relational terms then also led to the discovery of the HANS imaging paradigm, where exercising control over relative proportions of the simples constituent states of an imaging system (for example Neugebauer Primaries in print) over a local neighbourhood results in a vastly greater choice of possible patterns and leads to unprecedented levels of control. We show how applying these principles results in new theoretical results, such as metameric patterns even for 3-ink CMY printing systems that until now were taught as not having any redundancy, as well as practical applications such as finding more ink-efficient alternatives for the same colors, and extends to a wide range of applications including emissive display design and 3D print.

14:00 – 15:00 PM
KEYNOTE (moved from Friday)
SPONSORED BY GOOGLE

Google Street View: Unique Challenges of Collecting Imagery at Global Scale, Luc Vincent and Rom Clement, Google Inc. (USA)

Computer vision, geospatial imagery,  big data, machine learning, large scale systems, image processing and analysis,  and of course color all come together in  the creation and deployment of Google’s   360° Street View. In this keynote, the engineering and technical challenges with particular emphasis on those related to color are discussed.

COLOR and Imaging WORSHOPS

W1: Camera Color Characterization

8:00 – 12:00
Chair: Sabine Süsstrunk, EPFL (Switzerland)

This workshop covers the process of camera characterization in theory and practice. Background and demonstrations are provided on all important aspects. Many camera manufacturers utilize traditional test chart based color characterization methods because of reluctance to change running systems or incomplete appreciation of the benefits of modern characterization techniques. This workshop identifies known issues in traditional approaches and demonstrates potential solutions using current technology including multispectral LED light sources, in situ measurements of spectral radiances of natural objects, and modern color transform methods including multidimensional color look up tables. This workshop provides all the information needed to implement advanced color correction in cameras and software. Speakers for this workshop are:

• The need for camera characterization and calibration and the impact of color correction on general image quality (Kevin Matherson, Microsoft Corporation)•  Target based versus spectral camera characterization (Eric Walowit, consultant)
• Target based versus in situ spectral training data (Dietmar Wueller, Image Engineering GmbH & Co. KG)
• Multidimensional color lookup tables (Michael Vrhel, Artifex Software, Inc.)
• Live demonstration of spectral camera characterization, camera transform generation, and matching from capture to display (in cooperation with all speakers)

W2:The Life of a Color (sponsored by ISCC)

8:30 – 12:00
Chairs: David R. Wyble, Avian Rochester, LLC and John Conant, Aerodyne Research, Inc. (USA)

Within the context of the CIC technical program, “color” has a more limited scope, and does not typically include creative and production aspects. This workshop is designed to help expose attendees to those and other facets of color, all described as how a color is processed through various disciplines. This exposure can help technologists “connect the dots” by learning first hand how color and imaging research is applied.

This workshop will serve as the technical content for the 2016 Annual Meeting for the Inter-Society Color Council (ISCC), but the content is appropriate for all conference attendees. The workshop will be followed by the ISCC Annual Business Meeting Lunch (additional fee). Four presentations begin with the creative design process and work through color communication, production, and finally perception.

The Design of a Color (Leslie Harrington, CAUS)

How a brand color is originally selected? What are the associated strategic decisions to align the color with a product/brand’s 
attributes? How are colors properly placed, both geographically and in the right 
customer segments?

The Management of a Color (Max Derhak, Onyx Graphics)

Traditional color management has used only CIEXYZ colorimetry. New systems account for a complete color process: from light sources onto objects, and captured through color matching, including perceptual aspects of color.

The Manufacturing of a Color (Ann Laidlaw, ACL Color Consulting LLC)

The path of a color is described from the 
creative process through development, approval, and manufacturing. The use of robust standards and consistent procedures is 
crucial to managing accurate color with 
on-time deliveries, especially when products are fabricated from multiple materials.

The Perception of a Color (Mark Fairchild, RIT)

Follow a photon from the sun, to an object, into the human eye. Those photons are traced to their ultimate fate in a cone photoreceptor. Finally, aspects of neuroscience are used to explore how the photons result in color 
appearance.

W3: Color Science for 3D Printing: From Mondrian to Miró

9:00 AM – 12:00 PM
Chairs: Peter Morovic and Ján Morovic, HP Inc. (Spain)

This workshop looks at the state-of-the-art of color science in 3D, as well as presents the upcoming challenges of 3D printing in color. While there is a rich and well established body of work in the Mondrian world (2D) that allows us to predict, model, and measure the colors of surfaces, their appearance in a given environment, the perceptual differences between surfaces under a variety of conditions, perform reliable psychophysic and psycho-visual experiments etc., a Miró world (3D) has additional complexity and additional degrees of freedom that need to be considered for a thorough understanding of how we perceive colors of objects that have different shapes, depths, textures, and surface finishes—and that vary significantly with illumination geometry etc. A straight-forward application of 2D methods often fails to deliver since, after all, these were derived for a flat world where many of these effects can be 
discounted.

The field of color science in 3D is still relatively young and is a treasure trove of open problems that require rigorous work and creative solutions. This workshop is both an overview of the state-of-the-art, as well as an invitation for the community to tackle them.

Color 3D Printing and its Challenges (Ján Morovic and Peter Morovic, HP Inc.)

Even though 3D color printing technologies build up objects layer-by-layer, and these layers are two-dimensional, it would be a mistake to think of 3D simply as stacked 2D printing. From color formation, where local material combinations in an object are the basis, via metrology challenges following from complex surface geometry and phenomena like translucency, to the intricacies even of having reliable psychophysical methods for the evaluation of color appearance, color in 3D is anything but a simple extension of its 2D counterpart. These, and other, aspects of 3D printing pose challenges for delivering predictable and consistent color properties and call for new scientific and engineering work. At the same time, there is existing knowledge in adjacent fields that can accelerate the process of understanding and controlling color in 3D printing, which we would like to facilitate in this workshop.

Color Measurements for 3D Printing (Philipp Urban, Fraunhofer Institute for Computer Graphics Research IGD)

I start the talk by showing that measurements made by spectrophotometers used in the graphic arts industry are systematically biased towards lower reflectance for many resin materials used in multimaterial 3D printing. Then, I present a gonio-imager particularly dedicated to sample the Bidirectional Reflectance Distribution Functions (BRDF) of such materials or material compositions arranged in a color-characterization chart. The setup comprises an almost colorimetric RGB camera and a spectrally tunable light source allowing it to perform bidirectional reflectance measurements or to act as a bidirectional colorimeter. At the end of the talk, I introduce a modular, fully-automatic color 3D scanning pipeline developed at our institute. It is capable of capturing bidirectional color information in addition to shape by combining photogrammetry and structured light scanning.

Material Appearance Measurement: The Road to Reality (Marc Ellens, X-Rite, Inc.)

Material appearance is more than color; it isolates the characteristics of the material that an observer uses to identify, categorize, and ultimately use the material for its intended purpose. The wide range of materials has 
often posed a challenge for virtualization as many characteristics of material representation need to be hand-crafted. Measured material appearance provides a direct construction of these appearance characteristics, shortening product lifecycles, and delivering more physically accurate and realistic visualizations. We address such questions as: what is material appearance? what characteristics of geometry contribute to the appearance?  how can it be captured with today’s and tomorrow’s technology? what methods we can use to communicate this appearance? and, what are the challenges as we move forward?

Overview of Color Image Reproduction for 3D Printing Using CIE Colorimetry (Kaida Xiao, University of Liverpool)

With dramatically developed 3D color printing technique, the accurate color management and reproduction for 3D printed objects becomes more and more important, although it is still a huge challenge for color and imaging science. Conventional color image reproduction techniques based on CIE Colorimetry have been developed for more than 20 years and perform very well in transforming color images from one digital media to another under various viewing conditions. However, CIE standard observer and psychophysical data for color appearance modelling and color difference evaluation were all obtained for flat color samples. It is not straightforward or accurate to apply conventional color image reproduction technique for 3D printed objects. Moreover, it is greatly difficult to evaluate color reproduction for 3D printed objects objectively using current technology. In this presentation, a brief summary of color reproduction for 3D printed objects is given. The limitation of CIE colorimetry for color reproduction of 3D printed object is given special interest. A method to develop new technique to fulfill color reproduction of 3D printed object is discussed.

Tangible Imaging Systems: Bringing Virtual Surfaces into the Real World (James A. Ferwerda, RIT)

Surfaces are everywhere, and it’s through the interaction of light with surfaces, that we visually perceive the properties of the world. We often create images of surfaces to document their visual properties, and it’s clear that images can serve quite well as visual representations of surfaces. However, the visual information we get from an image of a surface is not the same that provided by the surface itself. In particular, we get a lot of information about surface properties by interacting with surfaces, either through direct manipulation, or through observation from different viewpoints, and conventional images don’t support either of these behaviors. For this reason we have been working to develop tangible imaging systems, that harness the power of digital modeling, computer graphics, and sensor technologies to produce new kinds of images that look and behave much more like the surfaces they represent.

In this talk, I describe our efforts to develop a tangible imaging system we call ImpastoR that supports the photometrically-accurate and visually-realistic simulation of surfaces with complex color, gloss, and textural properties in real-world lighting environments, and allows users to interact with and manipulate these virtual surfaces as naturally as if they were real ones. I discuss the potential uses of tangible imaging systems in a range of scientific, cultural, and commercial applications.

Color Assessment of Teeth and Skin Using Digital Imaging (Stephen Westland, University of Leeds)

Quantification of the colorimetric and color appearance properties of teeth and skin in vivo present serious technical challenges. Unlike many man-made materials (including many plastics, textiles, and painted surfaces) teeth and skin are three-dimensional structures that present a surface that is often not flat. In addition, the features to be measured may be small relative to the apertures of many commercially available spectrophotometers and difficult to access with bulky equipment. Color assessment using digital images potentially provides an alternative route to conventional color measurement but in practice presents several different technical challenges. This presentation explores the difficulties in using digital cameras to assess color and color appearance of teeth and skin. Several practical case studies are presented to demonstrate ways in which digital imaging can be used in this context.