RPoulsonPsych221Project

Introduction

A beautifully rendered image on a computer screen or cell phone is the result of complex algorithms, careful measurements, intrinsically elegant machinery, and hard work. Designers must take into account the limitations and brilliance of the human visual system in order to produce an outcome that looks as close to the real scene as possible. Through a variety of processes, accounting for different technical limitations as well as human-related issues, a vivid replica is created for viewing delight. One of these steps is that of creating color constancy (or chromatic adaptation)-- or specifically, mimicking the human visual system’s ability to perceive the color of an object or a scene of objects as identical, not matter what the illumination on the object truly is (Gevers & Gijsenij, 2011). This feature of the human visual system is necessary to correctly identify features of objects. For example, an apple viewed under the fluorescent light of a kitchen is red, but the same apple is also red when viewed in daylight.

Specifically, my project dealt with altering the illumination of a painting, and attempting to create color constancy with a variety of methods to find the most closely depicted replica to a direct rending of the image under a preferred light source. For instance, my preferred light source was D65, or daylight, and I changed the illumination on the image to fluorescent and tried a variety of transforms to perform color balancing on the resulting image. These transformations occurred on a hyperspectral image of “Virgin, Child and St. John,” a painting by 15th century Italian artist Jacopo del Sellaio, which is currently on display at the Cantor Art Center.