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mmsubm
Subtraction of two images, with saturation.

Synopsis

function y = mmsubm ( f1 , f2 )

Input

f1 Image Unsigned gray-scale (uint8 or uint16), signed (int32) or binary image
f2 Image Unsigned gray-scale (uint8 or uint16), signed (int32) or binary image

Or constant.

Output

y Image Unsigned gray-scale (uint8 or uint16), signed (int32) or binary image

Description

mmsubm creates the image y by pixelwise subtraction of the image f2 from the image f1. When the subtraction of the values of two pixels is negative, 0 is taken as the result of the subtraction. When f1 and f2 are binary images, y represents the set subtraction of f2 from f1.

Examples

f=uint8([...

255   255    0   10   20   10    0   255   255]);

g=uint8([...

10     20   30   40   50   40   30    20    10]);

y1=mmsubm(f,g)

y1 =
  245  235    0    0    0    0    0  235  245

y2=mmsubm(f,uint8(100))

y2 =
  155  155    0    0    0    0    0  155  155

y3=mmsubm(uint8(100),f)

y3 =
    0    0  100   90   80   90  100    0    0
Gray scale image:
a = mmreadgray('boxdrill-C.tif');

b = mmreadgray('boxdrill-B.tif');

c = mmsubm(a,b);

mmshow(a); 

mmshow(b); 

mmshow(c);
a b c

Equation

Algorithm

function g = mmsubm_equ(f1,f2)
g = max(max(f1-f2,0));

See also

mmfreedom Control automatic data type conversion.
mmaddm Addition of two images, with saturation.
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