inra.ijpb.measure.region2d

Class RegionBoundaries

java.lang.Object

inra.ijpb.measure.region2d.RegionBoundaries

public class RegionBoundaries
extends Object

Utility functions for computing position of boundary points/corners of regions within binary or label images. The methods in this class are mostly used for computing convex hulls.

Author:

dlegland

See Also:

Convexity

Method Summary

Modifier and Type	Method and Description
static ArrayList<Point2D>	boundaryPixelsMiddleEdges(ij.process.ImageProcessor binaryImage) Extracts boundary points from a binary region, keeping middle points of pixel edges.
static ArrayList<Point2D>[]	boundaryPixelsMiddleEdges(ij.process.ImageProcessor labelImage, int[] labels) Extracts boundary points from the different regions.
static ArrayList<Point2D>	runLengthsCorners(ij.process.ImageProcessor image) Returns a set of points located at the corners of a binary particle.
static ArrayList<Point2D>[]	runlengthsCorners(ij.process.ImageProcessor image, int[] labels) Returns a set of points located at the corners of a binary particle.
static Map<Integer,ArrayList<Point2D>>	runLengthsCornersMap(ij.process.ImageProcessor image, int[] labels) Returns a set of points located at the corners of each region.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

runLengthsCorners

public static final ArrayList<Point2D> runLengthsCorners(ij.process.ImageProcessor image)

Returns a set of points located at the corners of a binary particle. Point coordinates are integer (ImageJ locates pixels in a [0 1]^d area).

Parameters:

image - a binary image representing the particle

Returns:

a list of points that can be used for convex hull computation

runlengthsCorners

public static final ArrayList<Point2D>[] runlengthsCorners(ij.process.ImageProcessor image,
                                                           int[] labels)

Returns a set of points located at the corners of a binary particle. Point coordinates are integer (ImageJ locates pixels in a [0 1]^d area). This methods computes the results as a Map, and converts the result into an array.

Parameters:

image - a binary image representing the particle

labels - the list of labels to process

Returns:

for each label, an array of points

See Also:

runLengthsCornersMap(ImageProcessor, int[])

runLengthsCornersMap

public static final Map<Integer,ArrayList<Point2D>> runLengthsCornersMap(ij.process.ImageProcessor image,
                                                                         int[] labels)

Returns a set of points located at the corners of each region. Point coordinates are integer (ImageJ locates pixels in a [0 1]^2 area).

Parameters:

image - a binary image representing the particle

labels - the list of labels to process

Returns:

a list of points that can be used for convex hull computation

See Also:

runlengthsCorners(ImageProcessor, int[])

boundaryPixelsMiddleEdges

public static final ArrayList<Point2D> boundaryPixelsMiddleEdges(ij.process.ImageProcessor binaryImage)

Extracts boundary points from a binary region, keeping middle points of pixel edges. This method considers middle points of pixel edges, assuming a "diamond shape" for pixels. For a single pixel (x,y), ImageJ considers equivalent area to be [x,x+1[ x [y,y+1[, and pixel center at (x+0.5, y+0.5). The boundaries extracted by this methods have following coordinates:

• (x+0.5, y): top boundary
• (x , y+0.5): left boundary
• (x+1 , y+0.5): right boundary
• (x+0.5, y+1): bottom boundary

Parameters:

binaryImage - the image processor containing the binary region

Returns:

an array of Point2D, located on the boundary of the region.

boundaryPixelsMiddleEdges

public static final ArrayList<Point2D>[] boundaryPixelsMiddleEdges(ij.process.ImageProcessor labelImage,
                                                                   int[] labels)

Extracts boundary points from the different regions. This method considers middle points of pixel edges, assuming a "diamond shape" for pixels. For a single pixel (x,y), ImageJ considers equivalent area to be [x,x+1[ x [y,y+1[, and pixel center at (x+0.5, y+0.5). The boundaries extracted by this methods have following coordinates:

• (x+0.5, y): top boundary
• (x , y+0.5): left boundary
• (x+1 , y+0.5): right boundary
• (x+0.5, y+1): bottom boundary

Parameters:

labelImage - the image processor containing the region labels

labels - the array of region labels

Returns:

an array of arrays of boundary points, one array for each label.