EcoIP: An open source image analysis toolkit to identify different stages of plant phenology for multiple species with pan–tilt–zoom cameras

•EcoIP is a toolkit that calculates phenological dates based on an image series.•EcoIP estimates phenological dates within 2.78 days of observed dates.•EcoIP analyzed 2 phenophases of 3 species.•Color separability and scene illumination contribute to the overall error.•EcoIP analyzes phenophases with characteristic colors different from green.

Because of the increased number of cameras employed in environmental sensing and the tremendous image output they produce, we have created a flexible, open-source software solution called EcoIP to help automatically determine different phenophases for different species from digital image sequences. Onset and ending dates are calculated through an iterative process: (1) training images are chosen and areas of interest identified, (2) separation of foreground and background is accomplished based on a naive Bayesian method, (3) a signal is created based on the separation model and (4) it is then fit to a sigmoid that contains the dates of interest. Results using different phenological events of different species indicate that estimated dates fall within a few days of the observed dates for most cases. Our experiments indicate that color separability and scene illumination are contributing factors to this error. EcoIP is implemented as an open platform that encourages anyone to execute, copy, distribute, study, change, and/or improve the application.