thresh {EBImage} | R Documentation |
Thresholds an image using a moving rectangular window.
thresh(x, w=5, h=5, offset=0.01)
x |
An |
w, h |
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)+offset)}
but slightly faster. The function filter2
provides hence more
flexbility 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')) if (interactive()) display(x) y = thresh(x, 10, 10, 0.05) if (interactive()) display(y)