Comparison of two Edge Tracing Methods

  © Bureau H. Glünder 2021

  1_INITIAL RoI-MEAN
The initial mean value from a circular RoI is maintained for the following horizontally shifted positions.
   This is accomplished by vertically searching for the mean value that comes closest to the initial one.
The method is fast and tolerant against noise as well as irregular edges.
The method fails for edges of varying intensity or contrast.
 
  2_BALANCED RoI-HISTOGRAMS
For every horizontal position of a circular RoI, the histogram of its values is computed.
   The vertical positions are those, for which the individusl histogram is balanced.
The method is non-parametric and tolerant against intensity as well as contrast fluctuations.
The method fails for irregular and especially interrupted edges.
 
  EXAMPLE
Test images (8 bit):
Edge traces: