, Northwestern University
, Cornell University
Pages: pp. 20-21
Abstract—The goal of computer graphics isn't to control light, but to control our perception of it. Light is merely a carrier of the information we gather by perception.
Computer graphics puts ideas into our heads. In a peculiar way, it lets us see inside our computers by showing us pictures made from the data it holds. If the pictures are well made, we can grasp important ideas and information at a glance. It's this easy transfer from machine to mind that makes computer graphics important and appealing.
Computer graphics helps us make pictures of any sort, from graphs, plots, and charts to line drawings and watercolors to photography to physically accurate modeling, rendering, and animation. Each type can vividly convey ideas in well-made pictures.
But what, exactly, constitutes a well-made picture, and how might a computer make it better? What arrangement of display outputs is most likely to transfer useful information from the computer into our heads accurately and effectively? Given the wide and growing range of picture types and displays we have available, no single best answer exists, and as researchers, we're not yet satisfied with what we have. Most current work in computer graphics stops at the frame buffer, but this is only the first stage of the machine-to-mind transfer we want to achieve.
This special issue on applied perception directs your attention to the other half of computer graphics—the part of the machine-to-mind information transfer that begins as light reaches your eye and ends at the edge of conscious understanding. Perception informs every aspect of computer graphics, including our ability to see important trends in plots and graphs, the entire field of color science, and all forms of visual quality metrics for modeling, rendering, and display (see the sidebar " What is Perception?"). Perceptual effects aren't confined to abstract pictures such as plots or vector fields—even the most rigorous physically accurate pictures concern both physics and perception in equal measure. No matter how carefully we compute the displayed image, perception determines how much and how accurately we'll understand what we see.
We're pleased to present this special issue. Although we both know this area of research has grown steadily, from a trickle of papers in Siggraph, Eurographics, and IEEE conferences and journals to discussions of a separate conference at the Siggraph/Eurographics Campfire on Perceptually Adaptive Graphics (see http://isg.cs.tcd.ie/campfire/), we were still surprised to receive no less than 14 submissions for this one special issue. Based on the careful work of more than 50 reviewers, we filled the entire issue with the six highest-ranked articles and a tutorial article by co-editor Jim Ferwerda. Although we almost exceeded the magazine's page limit, we wish we had space for more.
Each of the seven articles in this issue address a different perception-related topic in computer graphics systems and applications:
Because every measurable quantity we simulate in computer graphics has a corresponding perceived amount, exploring perception offers many opportunities for exciting new research work. As these articles amply demonstrate, applying explicit computed models of perception lets us improve both the accuracy and the effectiveness of computer graphics. We look forward to many more exciting developments in this field.
Perception connects our minds to the world around us. It's the host of processes that converts all the measurable physical stimuli that our bodies receive into a conscious awareness of our surroundings. Its inputs are physical and measurable, but its outputs are purely psychological. Perception supplies us with an immediate, moment-by-moment estimate of reality, it gives us the basic notions of where we are and what's happening around us—the starting information we need to understand and interact with our environment.
Perception is much more than a simple metering of physical stimulation. It's not a passive measurement of the light, sound, pressure, or chemical vapors that impinge on our sensory organs. It's a set of processes that actively construct mental representations of the world from raw, noisy, and incomplete sensory signals.
We routinely perceive much more than we can directly sense, especially with the visual system, where we can perceive sensed light patterns as illumination, shadow, reflectance, shape, occlusion, position, movement, color, and other fundamental components of our 3D environment.
Perception and understanding are so tightly interwoven that we use their words interchangeably in casual conversations: "I see what you mean," "I don't know where to look for an answer," or "Look, this is important." It's easy to confuse what we look at (stimulus) with what we see (perception).