CPLopendistance

by Tim C. Lueth, SG-Lib Toolbox: SolidGeometry 5.6 - CPL/Closed Polygon Lists
Introduced first in SolidGeometry 4.3, Creation date: 2018-10-18, Last change: 2025-09-14

returns the maximal distance between neighbor points of a contour related to the contour size

Description

This function is designed for analyzing CPLofprocessedimage contoures or CPLofimage contours

See Also: CPLofprocessedimage , CPLofimage

Example Illustration

Syntax

[DP,DN]=CPLopendistance(CPL)

Input Parameter

CPL: CLosed Polygon line

Output Parameter

`DP`:		maximum distance in relation to bb of CPL
`DN`:		maximum distance between two points

Examples


[a,b]=CPLopendistance(CPLsample(8)), CPLopendistance(CPLsample(8));

Copyright 2018-2025 Tim C. Lueth. All rights reserved. The code is the property of Tim C. Lueth and may not be redistributed or modified without explicit written permission. This software may be used free of charge for academic research and teaching purposes only. Commercial use, redistribution, modification, or reverse engineering is strictly prohibited. Access to source code is restricted and granted only under specific agreements. For licensing inquiries or commercial use, please contact: Tim C. Lueth

Algorithm (Workflow)

This function, CPLopendistance, calculates the maximum distance between neighboring points of a closed polygon line (CPL) and relates it to the contour size. It is part of the SolidGeometry library and is used for analyzing contours from processed images.

Input Parameters

CPL: A closed polygon line represented as a list of points.

Output Results

DP: The maximum distance in relation to the bounding box (bb) of the CPL.
DN: The maximum distance between two neighboring points in the CPL.

Algorithm Steps

Calculate the number of line segments (nl) and their starting indices (sl) using the lengthNaN function.
Determine the number of segments n and adjust nl and sl for indexing.
Compute the ending indices el for each segment.
Initialize arrays DP, DN, and ss to store results.
For each segment i from 1 to n:

Extract the segment CPLi from CPL using sl(i) and el(i).
Calculate the size of the bounding box ss(i) using sofBB and BBofCPL.
Compute the differences DLi between consecutive points in CPLi using circshift.
Normalize the differences and find the maximum distance DN(i) using PLnorm.
Calculate DP(i) as the ratio of DN(i) to ss(i).

If no output arguments are specified, plot the CPL:

Calculate the mean of DP.
Plot segments with DP greater than the mean in blue and others in red using CPLplot and selectNaN.

Algorithm explaination created using ChatGPT on 2025-08-19 01:28. (Please note: No guarantee for the correctness of this explanation)

Last html export of this page out of FM database by TL: 2025-09-21