mmseline - Create a line structuring element.

Synopsis

B = mmseline( l, theta )

Input

l: Non-negative integer. Default: 3.

theta: (degrees) Default: 0.

Output

B: Structuring element.

Description

mmseline creates a structuring element B that is a line segment that has an extremity at the origin, length l and angle theta (0 degrees is east direction). If l=0, it generates the origin.

Examples

mmseshow(mmseline) ans = 0 0 1 1 1 b1 = mmseline(4,45); mmseshow(b1) ans = 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 b2 = mmseline(4,-180); mmseshow(b2) ans = 1 1 1 1 0 0 0 a=mmtext('Line'); b=mmdil(a,b1); mmshow(a); mmshow(b); (a) (b)

Equation

Algorithm

function B = mmseline_equ(l, theta)
theta = pi*theta/180;
if abs(tan(theta)) <= 1
   s = sign(cos(theta));
   x1 = 0:s:round(l * cos(theta))-s;
   x2 = round(x1 * tan(theta));
else
   s = sign(sin(theta));
   x2 = 0:s:round(l * sin(theta))-s;
   x1 = round(x2 / tan(theta));
end
%convert to center image
X1=max(abs(x1)); X2=max(abs(x2));
L1=2*X1+1; L2=2*X2+1;
Bimg=full(sparse(x2+X2+1, x1+X1+1,1, L2,L1));
B=mmimg2se(logical(uint8(Bimg)));

See Also

mmdil - Dilate an image by a structuring element.

mmfreedom - Control automatic data type conversion.

mmimg2se - Create a structuring element from a pair of images.

mmsebox - Create a box structuring element.

mmsecross - Cross structuring element.

mmsedisk - Create a disk or a semi-sphere structuring element.

mmseshow - Display a structuring element as an image.

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