The GPEA, GPEureka, and Otsureka algorithms are algorithms designed to measure the growth rate of plants using overhead cameras (a color camera for the GPEA algorithm, and an infrared camera for the GPEureka and Otsureka algorithms). The Otsureka algorithm has been modified for color images, see Otsureka.py on the color branch.
Their inner workings are documented in paper.ipynb. I haven't written up the Otsureka variant yet, but it's the GPEureka algorithm with Otsu's binarization applied instead of a static value.