threshold_li {LFApp}

Li Thresholding Algorithm

Description

The function computes a background theshold of an image by using Li's iterative minimum cross entropy method.

Usage

threshold_li(image, tolerance = NULL, initial_guess = NULL, iter_callback = NULL)

Arguments

image

object of class Image from package EBImage.

tolerance

optional tolerance threshold.

initial_guess

optional initial value for the minimization.

iter_callback

optional function applied to the minimizsation criterion.

Details

For more details about the method see Li and Lee (1993) as well as Li and Tam (1998).

Value

numeric vector with the computed threshold.

Author(s)

Filip Paskali [e-mail]

References

C.H. Li and C.K. Lee (1993). Minimum cross entropy thresholding. Pattern Recognition 26 (4): 617-25. https://doi.org/10.1016/0031-3203(93)90115-D.

C.H. Li and P.K.S. Tam (1998). An iterative algorithm for minimum cross entropy thresholding. Pattern Recognition Letters 19 (8): 771-76. https://doi.org/10.1016/S0167-8655(98)00057-9.

Examples

library(EBImage)
x <- readImage(system.file("images", "sample.TIF", package="LFApp"))
threshold_li(x)