11 AM, December 29, 2011
56 degrees Fahrenheit
Traced paths of bees flying in and out of hive. Play video below with an HTML5 capable browser. Or view video track.mp4 (H.264) for Mac or Windows, or track.ogv (Theora) for Linux.
Original video taken with Sony TX7 digital camera using VGA mode (640x480). Low resolution used to speed up processing of bee flight paths. Video bees.mp4 (H.264) for Mac or Windows, or bees.ogv (Theora) for Linux. Or play image below with an HTML5 capable browser.
Average image frames of 60 seconds of video. Histogram of average image values (0-255) from Gimp. Peak around 220 is white portion of hive box. Peak around 170 is unpainted wood of hive box. Lower image intensities are from dark background. For identifying bees it worked better to compare images to a 2 second window of averaged images. This reduced false positives from wind induced noise (plants moving, camera moving) and shadows.
Variance of 60 seconds of video image frames. Brightness uses linear ramp peaking at value 4 using Gimp Curves tool. Histogram shows distribution of variance values. Bar heights are logarithmically scaled. Linear scaled heights shown at right.
Cumulative bee flights for durations from 0.5 to 60 seconds. Color coded by time, red = start, blue = end.