I'm trying to write some image processing code in python to differentiate between two types of images (we'll call them set Blue and set Amber). I have run an algorithm I wrote that results in the data graphed below for a sample from one image from each set. Although the absolute scale of the data varies, the Blue image always seems to have that characteristic steep ramp somewhere in the middle of the data.
Programmatically, what would be the best way to find such a steep, high ramp in this noisy data? I'm looking for a binary answer: is this ramp present.