mmthin - Image transformation by thinning.

Synopsis

y = mmthin( f, Iab, n, theta, DIRECTION )

Input

f: Binary image (logical uint8).

Iab: Interval. Default: Homotopic thinning interval (mmhomothin).

n: Non-negative integer. Number of iterations. Default: Infinite (-1).

theta: Degrees of rotation: 45, 90, or 180. Default: 45.

DIRECTION: String. 'CLOCKWISE' or ' ANTI-CLOCKWISE' Default: "CLOCKWISE".

Output

y: Binary image (logical uint8).

Description

mmthin creates the binary image y by performing a thinning of the binary image f. The number of iterations of the thinning is n and each iteration is performed by subtracting the points that are detect in f by hit-miss operators characterized by rotations of theta of the interval Iab. When n is infinite and the interval is mmhomothin (default conditions), mmthin gives the skeleton by thinning.

Examples

f=mmreadgray('scissors.tif'); f1=mmthin(f); mmshow(f,f1); % skeleton f2=mmthin(f1,mmendpoints,15); % prunning 15 pixels mmshow(f,f2); % prunned skeleton (f,f1) (f,f2)

Equation

Algorithm

function y = mmthin_equ( f, Iab, n, theta, DIRECTION )
  y = f;
  for i=1:n
    for alpha=0:theta:360-theta
      Iab = mminterot(Iab, alpha, DIRECTION);
      y = mmsubm(y,mmsupgen(y,Iab));
    end;
  end; 

See Also

mmcthin - Image transformation by conditional thinning.

mmendpoints - Interval to detect end-points.

mmfreedom - Control automatic data type conversion.

mmhomothin - Interval for homotopic thinning.

mmse2hmt - Create a Hit-or-Miss Template (or interval) from a pair of structuring elements.

mmthick - Image transformation by thickening.

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