A New Method for Determining Geometry of Planetary Images

TL;DR

This paper introduces a semi-automatic image processing method using VOISE segmentation to accurately determine the geometry of planetary images, aiding in precise disc parameter estimation for astronomical studies.

Contribution

A novel semi-automatic technique combining VOISE segmentation with algebraic fitting to improve planetary disc boundary detection in images.

Findings

Achieves disc center localization within a few tens of pixels.

Provides an objective and accurate boundary detection method.

Useful for auroral imaging and planetary studies.

Abstract

This paper presents a novel semi-automatic image processing technique to estimate accurately, and objectively, the disc parameters of a planetary body on an astronomical image. The method relies on the detection of the limb and/or the terminator of the planetary body with the VOronoi Image SEgmentation (VOISE) algorithm (Guio and Achilleos, 2009). The resulting map of the segmentation is then used to identify the visible boundary of the planetary disc. The segments comprising this boundary are then used to perform a "best" fit to an algebraic expression for the limb and/or terminator of the body. We find that we are able to locate the centre of the planetary disc with an accuracy of a few tens of one pixel. The method thus represents a useful processing stage for auroral "imaging" based studies.