detect-lines

• Image reading

• Image low pass filtering

• Emphasis on low image intensities:

• Background subtraction, horizontal stripes removal

• Obtaining one-dimensional (special case) Fourier spectra for image fragments using https://github.com/leerichardson/tree-swdft-2D

• Finding the separation line points where spectra main frequencies abruptly change

• Preliminary filtering of points using cv::partition and nanoflann library

• Using RANSAC to find the separation line using separation line points

• Using CERES solver to refine the separation line

• Using both adaptiveThreshold and binary background subtraction to generate threshold image

• Using thinning to obtain lines skeletons

• Calling erode/dilate to filter out vertical lines

• Invoking HoughLinesP to generate lines from skeletons

• Merging lines according to https://stackoverflow.com/a/51121483/10472202

• Filtering out short lines

• Cutting lines using the RANSAC/CERES separation line mentioned above

• Filtering out short lines once more

• Search for the beginnings of short stripes with "known good" SURF data

• Movement to the left and up along long lines

• Merging HoughLinesP and SURF results to obtain the final data