I. INTRODUCTION
In an environmental control system, users always wear
some devices. That is, these devices are said to be a contact
type. However, if a user uses a contact type device for a long
time, the user must work hard to endure pain. The contactless
type device is expected to reduce a user’s pain. By the
development of a human-computer interaction system, various
contactless type devices have been proposed [1], [2]. A device
using a human eye is one of contactless type devices [2]. In a
human eye-computer interaction system, we need to understand
eye movement to detect an eye. In this paper, to detect an eye
accurately, we focus a pupil of an eye. The pupil detection and
tracking is an important step for developing a human-computer
interaction system [2]. To develop a human eye-computer
interaction system, we examine pupil detection and tracking by
image processing techniques [3], [4]. In the image processing
techniques, the illumination directly influences the image
quality in general [5]. If influence of the illumination is little,
we can obtain an image of good image quality. The subsequent
image processing techniques are expected almost to succeed.