thresh: Adaptive thresholding

In EBImage: Image processing and analysis toolbox for R

Description

Thresholds an image using a moving rectangular window.

Usage

thresh(x, w=5, h=5, offset=0.01)

Arguments

x	An Image object or an array.
w, h	Half width and height of the moving rectangular window.
offset	Thresholding offset from the averaged value.

Details

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.

Value

An Image object or an array, containing the transformed version of x.

Author(s)

Oleg Sklyar, [e-mail], 2005-2007

See Also

filter2

Examples

  x = readImage(system.file('images', 'nuclei.tif', package='EBImage'))
  display(x)
  y = thresh(x, 10, 10, 0.05)
  display(y)

Example output

Only the first frame of the image stack is displayed.
To display all frames use 'all = TRUE'.
Only the first frame of the image stack is displayed.
To display all frames use 'all = TRUE'.

EBImage documentation built on Nov. 8, 2020, 5:41 p.m.