A toolkit for the dynamic study of air sacs in siamang and other elastic circular structures
Fig 3
Image processing to increase Hough Transform circle detection success.
Four pre-processing steps in four different frames with various backgrounds are shown to illustrate the necessity of the preprocessing steps for the Hough Transform approach to work. Only after the last pre-processing step are air sacs correctly found with the Hough Transform. All images are photos by Wim Pouw and Mounia Kehy.