On the focusing of thermal images

TL;DR

This paper introduces a new thermal image database and evaluates focus measures to automatically determine optimal focus positions, demonstrating accurate detection with low computational effort and providing an acquisition tool.

Contribution

It presents the first study on automatic focus detection for thermal images and introduces a new database and acquisition tool for this purpose.

Findings

Automatic focus detection is accurate and computationally efficient.

The database enables analysis of focus measures on thermal images.

The acquisition tool facilitates thermal image collection.

Abstract

In this paper we present a new thermographic image database suitable for the analysis of automatic focus measures. This database consists of 8 different sets of scenes, where each scene contains one image for 96 different focus positions. Using this database we evaluate the usefulness of six focus measures with the goal to determine the optimal focus position. Experimental results reveal that an accurate automatic detection of optimal focus position is possible, even with a low computational burden. We also present an acquisition tool able to help the acquisition of thermal images. To the best of our knowledge, this is the first study about automatic focus of thermal images.