cc.label: Connected Component Labelling.

In wvtool: Image Tools for Automated Wood Identification

Description

A function labels the connected components in a binary image. For example, it can be used for statistical analysis of tracheids (see examples).

Usage

cc.label(x, connect=8, inv=FALSE, img.show=FALSE,text.size=0.3)

Arguments

x	A binary image (A matrix with 0 and 1)
connect	8-connectivity or 4-connectivity. Default is 8-connectivity.
inv	inverse the binary image x before labelling. Labelling the connected area with 0 when this is TRUE.
img.show	If this is TRUE, the image with labelling numbers are shown.
text.size	the size of labelling numbers used when img.show=TRUE.

Details

Labelling the connected components with pixels equal to 1 (white) in a binary image (If pixels equal to 0 (black) should be labelled, select inv=TRUE). The function returns the labelled image and the statistical data of the labelled components.

Value

a list with 2 components (a matrix and a dataframe)

image	A matrix with labels
summary	A dataframe summarizing the labelled components with 8 following variables.
summary$label	labelling numbers, area: area of each component
summary$aveX, summary$aveY	center position of each component
summary$dX, summary$dY	width and height of each component
summary$edge	If the component is on the edge of the image, this value is 1, otherwise 0.

Examples

## Not run: 
data(cryptomeria)
img <- rgb2gray(cryptomeria)
img.c <- crop(img,300,300)
img.bin <- gray2bin(img.c, auto=FALSE, th=180)
par(mfrow=c(2,2))
test <- cc.label(img.bin, connect=8, img.show=TRUE)
hist(test$summary$area,main="histogram of area")
hist(test$summary$dX,main="histogram of dX")
hist(test$summary$dY,main="histogram of dY")

## End(Not run)

Example output

wvtool documentation built on May 1, 2019, 10:27 p.m.