imfill matlab fillimage regions and holes

Syntax

BW2 = imfill(BW)

[BW2,locations] = imfill(BW)

BW2 = imfill(BW,locations)

BW2 = imfill(BW,'holes')

I2 = imfill(I)

BW2 = imfill(BW,locations,conn)

Description

BW2 = imfill(BW) displays the binary image BW onthe screen and lets you define the region to fill by selecting pointsinteractively by using the mouse. To use this interactive syntax, BW mustbe a 2-D image. Press Backspace or Delete toremove the previously selected point. A shift-click, right-click,or double-click selects a final point and starts the fill operation.Pressing Return finishes the selection withoutadding a point.

[BW2,locations] = imfill(BW) returns thelocations of points selected interactively in locations. locations isa vector of linear indices into the input image. To use this interactivesyntax, BW must be a 2-D image.

BW2 = imfill(BW,locations) performs a flood-filloperation on background pixels of the binary image BW,starting from the points specified in locations.If locations is a P-by-1 vector, it contains thelinear indices of the starting locations. If locations isa P-by-ndims(BW) matrix, eachrow contains the array indices of one of the starting locations.

BW2 = imfill(BW,'holes') fills holes inthe binary image BW. A hole is a set of backgroundpixels that cannot be reached by filling in the background from theedge of the image.

I2 = imfill(I) fills holes in the grayscaleimage I. In this syntax, a hole is defined as anarea of dark pixels surrounded by lighter pixels.

BW2 = imfill(BW,locations,conn) fills thearea defined by locations, where conn specifiesthe connectivity. conn can have any of the followingscalar values.

Value	Meaning
Two-dimensionalconnectivities
4	4-connected neighborhood
8	8-connected neighborhood
Three-dimensionalconnectivities
6	6-connected neighborhood
18	18-connected neighborhood
26	26-connected neighborhood

Connectivity can be defined in a more general way for any dimensionby using for conn a 3-by-3-by- ... -by-3 matrixof 0's and 1's. The 1-valuedelements define neighborhood locations relative to the center elementof conn. Note that conn mustbe symmetric about its center element.