Introduction to object-based landscape analysis

Abstract

Current environmental challenges often require regular and wide-area monitoring, which in theory Earth observation (EO) can provide. Commonly, these challenges do not focus on individual point targets, as represented by image pixels, but require consideration of whole landscapes and assessment of features in broader spatial contexts. Object-based approaches, which operate at the scale of real-world objects rather than pixels, offer a means of analysing EO data in a realistic context and integrating associated ancillary information to support real-world applications. The development of object-based image analysis has accelerated over the past decade and can now be considered mainstream, with commercially available software and a wide user community. For full and rigorous consideration of the implementation of object-based analysis in environmental applications, we propose an extension of the discussion to object-based ‘landscape’ analysis. This article serves as an introduction to a Special Issue on this theme, drawing on a technical meeting held in 2009 at The University of Nottingham, UK. The meeting's aim was to bring together practitioners in remote sensing, geographic information science (GIScience) and environmental science to identify best practice in the development and application of object-based landscape analysis techniques. The papers presented outline new opportunities for object-based landscape analysis, showing the expansion of object-centred classification studies beyond routine use of image data, engaging with fundamental GIScience concepts such as spatial accuracy and scale and demonstrating the wider and growing relevance for the EO, GIScience, landscape ecology and broader environmental science communities.

Keywords:

• object
• landscape
• scale
• image
• classification

Acknowledgements

This Special Issue represents the culmination of a lengthy initiative to stimulate interest, research and communication in object-based landscape analysis. The starting point, and a very significant part of the initiative, was the technical meeting held in Nottingham in 2009. Many people contributed to the meeting, not least the participants who presented and discussed their work, leading directly towards this publication. Special thanks to Meredith Williams, Karen Laughton and Roger Hore, variously involved in the Remote Sensing and Photogrammetry Society, who helped organise the meeting. Thanks too to Somnath Ghosal and Nural Islam for their general assistance throughout the event. Following the meeting, Gemma Polmear helped with the early stages of the Special Issue. We are most grateful to the many reviewers who gave their time generously, ensuring the papers are of the highest quality. Finally, thanks to Brian Lees, chief editor of the International Journal of Geographical Information Science, who provided very useful and very prompt guidance throughout the preparation of the Special Issue.