lightning

On July 23, 2019, the most spectacular lightning storm that I've ever seen rolled through Spokane. I managed to capture 15 minutes' worth of video. Rather than pick out the most striking stills manually, I took the opportunity to acquaint myself with OpenCV, and wrote some code that automatically extracts frames whose brightness exceeds a given threshold. (Well, more precisely, it extracts a frame if the proportion of the frame's pixels that fall within prescribed regional and brightness bounds exceeds a given threshold.)

For the 10-second, potentially seizure-inducing result of this endeavor, check out data/flashes.mp4. ⚡

requirements

• matplotlib (but only for the show_histogram function)
• opencv-python

resources

• OpenCV: Histograms - 1 : Find, Plot, Analyze !!! : The tutorial that brought me up to speed.
• Reading and Writing Images and Video
• cv2.cvtColor: Documentation for the method that I used to convert color images to grayscale ones.