# MAPLE_BOUNDARY Determine the Boundary of a Maple Leaf

MAPLE_BOUNDARY, a MATLAB library which takes an image of a maple leaf and determines the pixels that form the boundary.

For a discussion of quasirandom sampling, Brian Hayes published a picture of a maple leaf and considered how its area could be estimated using a regular grid of points, random sampling, or quasirandom sampling.

For various reasons, it will be interesting to have a copy of this maple leaf image accessible. The MAPLE_BOUNDARY functions use various MATLAB procedures to turn the maple leaf image into a polygonal curve definining the boundary, following which various calculations may be made.

### Languages:

MAPLE_BOUNDARY is available in a MATLAB version.

### Related Data and Programs:

CONVEX_HULL, a MATLAB program which demonstrates the computation of the convex hull of a set of 2D points.

FLORIDA_CVT_GEO, MATLAB programs which explore the creation of a centroidal Voronoi Tessellation (CVT) of the state of Florida, based solely on geometric considerations.

FLORIDA_CVT_POP, MATLAB programs which explore the creation of a centroidal Voronoi Tessellation (CVT) of the state of Florida, based on population density.

HAND_AREA, a MATLAB program which estimates the area of a curve which outlines a person's hand.

HAND_DATA, MATLAB programs which carry out some numerical exercises based on data that came from tracing several points on a person's hand.

MAPLE_AREA, a MATLAB library which takes the list of pixels that form the boundary of the image of a maple leaf within a picture, and uses grid, Monte Carlo, and Quasi Monte Carlo sampling to estimate the area of the leaf.

MESH2D_HAND, a MATLAB program which reads in a set of 59 points which outline a human hand, and calls MESH2D, which is able to create a fine triangular mesh of the region outlined by the points.

POLYGON, a dataset directory which contains examples of polygons.

TRIANGULATE, a MATLAB program which triangulates a polygonal region.

### Reference:

• Brian Hayes,
Quasirandom Ramblings,
American Scientist,
Volume 99, Number 4, July-August 2011, pages 282-287.

### Source Code:

• maple_boundary.png, a plot of the boundary lines of the maple leaf, as determined by MATLAB.
• maple_boundary_vertex.png, a plot of the boundary vertices of the maple leaf, as determined by MATLAB.
• maple_bw.png, a version of the maple leaf image that I thought was just black and white.
• maple_snapshot.png, a snapshot of the maple leaf illustration from Brian Hayes's paper, not quite exactly aligned with the original image size.
• maple_boundary.txt, a file that lists the pixel coordinates constituting the boundary of the maple leaf image.

### Examples and Tests:

You can go up one level to the MATLAB source codes.

Last revised on 20 August 2016.