Adaptive thresholding
Thresholds an image using a moving rectangular window.
thresh(x, w=5, h=5, offset=0.01)
x |
An |
w, h |
Half width and height of the moving rectangular window. |
offset |
Thresholding offset from the averaged value. |
This function returns the binary image resulting from the comparison
between an image and its filtered version with a rectangular window.
It is equivalent of doing
{
f = matrix(1, nc=2*w+1, nr=2*h+1);
f = f/sum(f);
x > (filter2(x, f, boundary="replicate") + offset)
}
but faster. The function filter2 provides hence more
flexibility than thresh.
An Image object or an array, containing the transformed version
of x.
Oleg Sklyar, osklyar@ebi.ac.uk, 2005-2007
filter2
x = readImage(system.file('images', 'nuclei.tif', package='EBImage'))
display(x)
y = thresh(x, 10, 10, 0.05)
display(y)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.