mmtoggle - Image contrast enhancement or classification by the toggle operator.

Synopsis

y = mmtoggle( f, f1, f2, OPTION )

Input

f: Gray-scale (uint8 or uint16) image.

f1: Gray-scale (uint8 or uint16) image.

f2: Gray-scale (uint8 or uint16) image.

OPTION: String. 'BINARY' or 'GRAY'. Default: "GRAY".

 

Obs: f, f1, f2 must have the same data type.

Output

y: Gray-scale (uint8 or uint16) or binary image (logical uint8). binary image if option is 'BINARY' or same type as f

Description

mmtoggle creates the image y that is an enhancement or classification of the image f by the toggle operator, with parameters f1 and f2. If the OPTION is 'GRAY', it performs an enhancement and, if the OPTION is 'BINARY', it performs a binary classification. In the enhancement, a pixel takes the value of the corresponding pixel in f1 or f2, according to a minimum distance criteria from f to f1 or f to f2. In the classification, the pixels in f nearest to f1 receive the value 0 , while the ones nearest to f2 receive the value 1.

Limitation

f1 must be less or equal f and f must be less or equal f2.

Examples

Gray-scale option:

f = uint8([0 1 2 3 4 5 6]); f1 = uint8([0 0 0 0 0 0 0]); f2 = uint8([6 6 6 6 6 6 6]); mmtoggle(f,f1,f2) ans = 0 0 0 6 6 6 6

a = mmreadgray('angiogr.tif'); b = mmero(a,mmsedisk(2)); c = mmdil(a,mmsedisk(2)); d = mmtoggle(a,b,c); mmshow(a); mmshow(d); (a) (d)

Binary option:

e = mmreadgray('lenina.tif'); f = mmero(e,mmsedisk(2)); g = mmdil(e,mmsedisk(2)); h = mmtoggle(e,f,g,'BINARY'); mmshow(e); mmshow(h); (e) (h)

Equation

Gray-scale option

Binary option

Algorithm

function g = mmtoggle_equ(f,f1,f2,option)
  g=mmthreshad(mmsubm(f2,f),mmsubm(f,f1));
  if (strcmp(option,'gray'))
    t=mmgray(g);
    g=mmunion(mmintersec(mmneg(t),f1),mmintersec(t,f2));
  end

See Also

mmfreedom - Control automatic data type conversion.

mmthreshad - Threshold (adaptive).

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