Plot extraction from aerial imagery: A precision agriculture approach

Abstract

The plant phenotyping community is adopting technological innovations in order to record phenotypic attributes more quickly and objectively. Low altitude aerial imaging is an appealing option for increasing throughput but there are still challenges in the image processing pipeline. One such challenge involves the assignment of a spatial reference to each plot entry in an experimental layout. Image-based approaches are increasingly popular since plot boundaries are often, but not always, clearly visible in low altitude imagery. In addition, workflows that make geometric assumptions about plot layout also show promise. We outline an alternative approach to generate plot boundaries to overlay with aerial imagery. The proposed method involves high-accuracy georeferencing (i.e., within a few cm) of imagery and planter activity, after which georeferencing of all plot entries is complete and only requires a few simple steps to convert logged spatial positions to polygons using open source geographic information systems (GIS) software. Compared with other approaches, the proposed method provides imagery that is precisely aligned over time and always aligns with plot boundaries, which are fixed and do not vary from image to image.