Table of dim parameters

Parameter Name Type Default value Description
minFlux float 0.02 for bright, all negative values are set to 0. For dim, all values below minFlux treshold are set to zero.
addFlux float 0.5 value added to all remaining pixels with values still above 0.
erodeKernel array np.ones((3,3)) Erosion kernel
dilateKernel array np.ones((9,9)) Dilation kernel
contoursMode CV2 const cv2.RETR_LIST All edges returned, see OpenCV of findContours for details.
contoursMethod CV2 const cv2.CHAIN_ APPROX_NONE All edge points returned, see OpenCV of findContours
minAreaRectMinlen int 1 Once contours have been found minimal area rectangles are fitted. Length of sides are determined. If determined. If either side is shorter than this value, in pixels, the detection is dismissed.
lwTresh int 5 ratio that longer/shorter rectangle side has to satisfy to be considered a possibly valid detection
houghMethod int 20 Min number of votes required in Hough space to be considered a valid line
nlinesInSet int 3 Hough transform returns a list of all possible lines. Only nlinesInSet top voted for lines are taken into consideration for futher checks. This is called a “set” of lines. There are 2 sets in total.
thetaTresh float 0.15 if within a single set the dispe- rsion of maximal-minimal theta is larger than thetaTresh, detection is dismissed as False. In radians
linesetTresh float 0.15 if both line sets pass thetaTresh, but their respective average thetas are larger than this, detection is dismissed. In radians.
dro int 20 if r averages of both Hough line sets are larger than dro then detection is dismissed as false.
debug bool False see above.