Matlab boundarymask function (find the boundary of the divided area)

grammar

mask = boundarymask(L)
mask = boundarymask(BW)
mask = boundarymask(___,conn)

explain

mask = boundarymask(L)
% Calculation represents input label matrix L The mask of the area boundary .
% Output mask It's a logical image , The boundary position is true, At the non boundary position false

mask = boundarymask(BW)
% Calculate the input binary image BW Area boundary of 

mask = boundarymask（___,conn）
% Use conn Calculate the area boundary by specifying the connectivity 

Example

Create a rasterized mesh of area boundaries

% Read the image into the workspace 
I = imread('kobi.png');
figure(1)
imshow(I)

% Create a super pixel representation of the image , Returns in the form of a label matrix 
L = superpixels(I,100);

% Display images 
figure(2)
imshow(label2rgb(L))

% Find the region boundary of the label matrix 
mask = boundarymask(L);

% By using labeloverlay Function to display the boundary mask on the original image 
% The area boundary of the label matrix is displayed as 1 Pixel wide cyan line 
figure(3)
imshow(labeloverlay(I,mask,'Transparency',0))

Input parameters

L ： Label matrix
Label matrix , A two-dimensional numeric matrix or a two-dimensional logical matrix specified as a non negative number .
data type ：single | double | int8 | int16 | int32 | uint8 | uint16 | uint32 | logical

BW： Binary image
Binary image , Specify as and L Numbers or logical matrices of the same size .
data type ：ingle | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | logical

conn： Pixel connection
Pixel connectivity , Designated as 4 or 8.
4 Connect ：

8 Connect ：

data type ：single | double | int8 | int16 | int32 | uint8 | uint16 | uint32

Output parameters

mask： Grid the boundary of the region
Grid the boundary of the region , Specified as a two-dimensional logical matrix with the same size as the input image . When there is a value in the input image P The adjacent pixels of the corresponding pixels of have different characteristics from P The value of , Pixels in the mask are true .
data type ： logical